darling-xnu/bsd/vfs/vfs_cluster.c
2023-05-16 21:41:14 -07:00

7508 lines
215 KiB
C

/*
* Copyright (c) 2000-2020 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_cluster.c 8.10 (Berkeley) 3/28/95
*/
#include <sys/param.h>
#include <sys/proc_internal.h>
#include <sys/buf_internal.h>
#include <sys/mount_internal.h>
#include <sys/vnode_internal.h>
#include <sys/trace.h>
#include <kern/kalloc.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/resourcevar.h>
#include <miscfs/specfs/specdev.h>
#include <sys/uio_internal.h>
#include <libkern/libkern.h>
#include <machine/machine_routines.h>
#include <sys/ubc_internal.h>
#include <vm/vnode_pager.h>
#include <mach/mach_types.h>
#include <mach/memory_object_types.h>
#include <mach/vm_map.h>
#include <mach/upl.h>
#include <kern/task.h>
#include <kern/policy_internal.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_pageout.h>
#include <vm/vm_fault.h>
#include <sys/kdebug.h>
#include <libkern/OSAtomic.h>
#include <sys/sdt.h>
#include <stdbool.h>
#include <vfs/vfs_disk_conditioner.h>
#if 0
#undef KERNEL_DEBUG
#define KERNEL_DEBUG KERNEL_DEBUG_CONSTANT
#endif
#define CL_READ 0x01
#define CL_WRITE 0x02
#define CL_ASYNC 0x04
#define CL_COMMIT 0x08
#define CL_PAGEOUT 0x10
#define CL_AGE 0x20
#define CL_NOZERO 0x40
#define CL_PAGEIN 0x80
#define CL_DEV_MEMORY 0x100
#define CL_PRESERVE 0x200
#define CL_THROTTLE 0x400
#define CL_KEEPCACHED 0x800
#define CL_DIRECT_IO 0x1000
#define CL_PASSIVE 0x2000
#define CL_IOSTREAMING 0x4000
#define CL_CLOSE 0x8000
#define CL_ENCRYPTED 0x10000
#define CL_RAW_ENCRYPTED 0x20000
#define CL_NOCACHE 0x40000
#define MAX_VECTOR_UPL_ELEMENTS 8
#define MAX_VECTOR_UPL_SIZE (2 * MAX_UPL_SIZE_BYTES)
#define CLUSTER_IO_WAITING ((buf_t)1)
extern upl_t vector_upl_create(vm_offset_t);
extern boolean_t vector_upl_is_valid(upl_t);
extern boolean_t vector_upl_set_subupl(upl_t, upl_t, u_int32_t);
extern void vector_upl_set_pagelist(upl_t);
extern void vector_upl_set_iostate(upl_t, upl_t, vm_offset_t, u_int32_t);
struct clios {
lck_mtx_t io_mtxp;
u_int io_completed; /* amount of io that has currently completed */
u_int io_issued; /* amount of io that was successfully issued */
int io_error; /* error code of first error encountered */
int io_wanted; /* someone is sleeping waiting for a change in state */
};
struct cl_direct_read_lock {
LIST_ENTRY(cl_direct_read_lock) chain;
int32_t ref_count;
vnode_t vp;
lck_rw_t rw_lock;
};
#define CL_DIRECT_READ_LOCK_BUCKETS 61
static LIST_HEAD(cl_direct_read_locks, cl_direct_read_lock)
cl_direct_read_locks[CL_DIRECT_READ_LOCK_BUCKETS];
static LCK_GRP_DECLARE(cl_mtx_grp, "cluster I/O");
static LCK_MTX_DECLARE(cl_transaction_mtxp, &cl_mtx_grp);
static LCK_SPIN_DECLARE(cl_direct_read_spin_lock, &cl_mtx_grp);
static ZONE_DECLARE(cl_rd_zone, "cluster_read",
sizeof(struct cl_readahead), ZC_ZFREE_CLEARMEM | ZC_NOENCRYPT);
static ZONE_DECLARE(cl_wr_zone, "cluster_write",
sizeof(struct cl_writebehind), ZC_ZFREE_CLEARMEM | ZC_NOENCRYPT);
#define IO_UNKNOWN 0
#define IO_DIRECT 1
#define IO_CONTIG 2
#define IO_COPY 3
#define PUSH_DELAY 0x01
#define PUSH_ALL 0x02
#define PUSH_SYNC 0x04
static void cluster_EOT(buf_t cbp_head, buf_t cbp_tail, int zero_offset);
static void cluster_wait_IO(buf_t cbp_head, int async);
static void cluster_complete_transaction(buf_t *cbp_head, void *callback_arg, int *retval, int flags, int needwait);
static int cluster_io_type(struct uio *uio, int *io_type, u_int32_t *io_length, u_int32_t min_length);
static int cluster_io(vnode_t vp, upl_t upl, vm_offset_t upl_offset, off_t f_offset, int non_rounded_size,
int flags, buf_t real_bp, struct clios *iostate, int (*)(buf_t, void *), void *callback_arg);
static int cluster_iodone(buf_t bp, void *callback_arg);
static int cluster_ioerror(upl_t upl, int upl_offset, int abort_size, int error, int io_flags, vnode_t vp);
static int cluster_is_throttled(vnode_t vp);
static void cluster_iostate_wait(struct clios *iostate, u_int target, const char *wait_name);
static void cluster_syncup(vnode_t vp, off_t newEOF, int (*)(buf_t, void *), void *callback_arg, int flags);
static void cluster_read_upl_release(upl_t upl, int start_pg, int last_pg, int take_reference);
static int cluster_copy_ubc_data_internal(vnode_t vp, struct uio *uio, int *io_resid, int mark_dirty, int take_reference);
static int cluster_read_copy(vnode_t vp, struct uio *uio, u_int32_t io_req_size, off_t filesize, int flags,
int (*)(buf_t, void *), void *callback_arg) __attribute__((noinline));
static int cluster_read_direct(vnode_t vp, struct uio *uio, off_t filesize, int *read_type, u_int32_t *read_length,
int flags, int (*)(buf_t, void *), void *callback_arg) __attribute__((noinline));
static int cluster_read_contig(vnode_t vp, struct uio *uio, off_t filesize, int *read_type, u_int32_t *read_length,
int (*)(buf_t, void *), void *callback_arg, int flags) __attribute__((noinline));
static int cluster_write_copy(vnode_t vp, struct uio *uio, u_int32_t io_req_size, off_t oldEOF, off_t newEOF,
off_t headOff, off_t tailOff, int flags, int (*)(buf_t, void *), void *callback_arg) __attribute__((noinline));
static int cluster_write_direct(vnode_t vp, struct uio *uio, off_t oldEOF, off_t newEOF,
int *write_type, u_int32_t *write_length, int flags, int (*)(buf_t, void *), void *callback_arg) __attribute__((noinline));
static int cluster_write_contig(vnode_t vp, struct uio *uio, off_t newEOF,
int *write_type, u_int32_t *write_length, int (*)(buf_t, void *), void *callback_arg, int bflag) __attribute__((noinline));
static void cluster_update_state_internal(vnode_t vp, struct cl_extent *cl, int flags, boolean_t defer_writes, boolean_t *first_pass,
off_t write_off, int write_cnt, off_t newEOF, int (*callback)(buf_t, void *), void *callback_arg, boolean_t vm_initiated);
static int cluster_align_phys_io(vnode_t vp, struct uio *uio, addr64_t usr_paddr, u_int32_t xsize, int flags, int (*)(buf_t, void *), void *callback_arg);
static int cluster_read_prefetch(vnode_t vp, off_t f_offset, u_int size, off_t filesize, int (*callback)(buf_t, void *), void *callback_arg, int bflag);
static void cluster_read_ahead(vnode_t vp, struct cl_extent *extent, off_t filesize, struct cl_readahead *ra,
int (*callback)(buf_t, void *), void *callback_arg, int bflag);
static int cluster_push_now(vnode_t vp, struct cl_extent *, off_t EOF, int flags, int (*)(buf_t, void *), void *callback_arg, boolean_t vm_ioitiated);
static int cluster_try_push(struct cl_writebehind *, vnode_t vp, off_t EOF, int push_flag, int flags, int (*)(buf_t, void *),
void *callback_arg, int *err, boolean_t vm_initiated);
static int sparse_cluster_switch(struct cl_writebehind *, vnode_t vp, off_t EOF, int (*)(buf_t, void *), void *callback_arg, boolean_t vm_initiated);
static int sparse_cluster_push(struct cl_writebehind *, void **cmapp, vnode_t vp, off_t EOF, int push_flag,
int io_flags, int (*)(buf_t, void *), void *callback_arg, boolean_t vm_initiated);
static int sparse_cluster_add(struct cl_writebehind *, void **cmapp, vnode_t vp, struct cl_extent *, off_t EOF,
int (*)(buf_t, void *), void *callback_arg, boolean_t vm_initiated);
static kern_return_t vfs_drt_mark_pages(void **cmapp, off_t offset, u_int length, u_int *setcountp);
static kern_return_t vfs_drt_get_cluster(void **cmapp, off_t *offsetp, u_int *lengthp);
static kern_return_t vfs_drt_control(void **cmapp, int op_type);
static kern_return_t vfs_get_scmap_push_behavior_internal(void **cmapp, int *push_flag);
/*
* For throttled IO to check whether
* a block is cached by the boot cache
* and thus it can avoid delaying the IO.
*
* bootcache_contains_block is initially
* NULL. The BootCache will set it while
* the cache is active and clear it when
* the cache is jettisoned.
*
* Returns 0 if the block is not
* contained in the cache, 1 if it is
* contained.
*
* The function pointer remains valid
* after the cache has been evicted even
* if bootcache_contains_block has been
* cleared.
*
* See rdar://9974130 The new throttling mechanism breaks the boot cache for throttled IOs
*/
int (*bootcache_contains_block)(dev_t device, u_int64_t blkno) = NULL;
/*
* limit the internal I/O size so that we
* can represent it in a 32 bit int
*/
#define MAX_IO_REQUEST_SIZE (1024 * 1024 * 512)
#define MAX_IO_CONTIG_SIZE MAX_UPL_SIZE_BYTES
#define MAX_VECTS 16
/*
* The MIN_DIRECT_WRITE_SIZE governs how much I/O should be issued before we consider
* allowing the caller to bypass the buffer cache. For small I/Os (less than 16k),
* we have not historically allowed the write to bypass the UBC.
*/
#define MIN_DIRECT_WRITE_SIZE (16384)
#define WRITE_THROTTLE 6
#define WRITE_THROTTLE_SSD 2
#define WRITE_BEHIND 1
#define WRITE_BEHIND_SSD 1
#if !defined(XNU_TARGET_OS_OSX)
#define PREFETCH 1
#define PREFETCH_SSD 1
uint32_t speculative_prefetch_max = (2048 * 1024); /* maximum bytes in a specluative read-ahead */
uint32_t speculative_prefetch_max_iosize = (512 * 1024); /* maximum I/O size to use in a specluative read-ahead */
#else /* XNU_TARGET_OS_OSX */
#define PREFETCH 3
#define PREFETCH_SSD 2
uint32_t speculative_prefetch_max = (MAX_UPL_SIZE_BYTES * 3); /* maximum bytes in a specluative read-ahead */
uint32_t speculative_prefetch_max_iosize = (512 * 1024); /* maximum I/O size to use in a specluative read-ahead on SSDs*/
#endif /* ! XNU_TARGET_OS_OSX */
#define IO_SCALE(vp, base) (vp->v_mount->mnt_ioscale * (base))
#define MAX_CLUSTER_SIZE(vp) (cluster_max_io_size(vp->v_mount, CL_WRITE))
#define MAX_PREFETCH(vp, size, is_ssd) (size * IO_SCALE(vp, ((is_ssd) ? PREFETCH_SSD : PREFETCH)))
int speculative_reads_disabled = 0;
/*
* throttle the number of async writes that
* can be outstanding on a single vnode
* before we issue a synchronous write
*/
#define THROTTLE_MAXCNT 0
uint32_t throttle_max_iosize = (128 * 1024);
#define THROTTLE_MAX_IOSIZE (throttle_max_iosize)
SYSCTL_INT(_debug, OID_AUTO, lowpri_throttle_max_iosize, CTLFLAG_RW | CTLFLAG_LOCKED, &throttle_max_iosize, 0, "");
void
cluster_init(void)
{
for (int i = 0; i < CL_DIRECT_READ_LOCK_BUCKETS; ++i) {
LIST_INIT(&cl_direct_read_locks[i]);
}
}
uint32_t
cluster_max_io_size(mount_t mp, int type)
{
uint32_t max_io_size;
uint32_t segcnt;
uint32_t maxcnt;
switch (type) {
case CL_READ:
segcnt = mp->mnt_segreadcnt;
maxcnt = mp->mnt_maxreadcnt;
break;
case CL_WRITE:
segcnt = mp->mnt_segwritecnt;
maxcnt = mp->mnt_maxwritecnt;
break;
default:
segcnt = min(mp->mnt_segreadcnt, mp->mnt_segwritecnt);
maxcnt = min(mp->mnt_maxreadcnt, mp->mnt_maxwritecnt);
break;
}
if (segcnt > (MAX_UPL_SIZE_BYTES >> PAGE_SHIFT)) {
/*
* don't allow a size beyond the max UPL size we can create
*/
segcnt = MAX_UPL_SIZE_BYTES >> PAGE_SHIFT;
}
max_io_size = min((segcnt * PAGE_SIZE), maxcnt);
if (max_io_size < MAX_UPL_TRANSFER_BYTES) {
/*
* don't allow a size smaller than the old fixed limit
*/
max_io_size = MAX_UPL_TRANSFER_BYTES;
} else {
/*
* make sure the size specified is a multiple of PAGE_SIZE
*/
max_io_size &= ~PAGE_MASK;
}
return max_io_size;
}
#define CLW_ALLOCATE 0x01
#define CLW_RETURNLOCKED 0x02
#define CLW_IONOCACHE 0x04
#define CLW_IOPASSIVE 0x08
/*
* if the read ahead context doesn't yet exist,
* allocate and initialize it...
* the vnode lock serializes multiple callers
* during the actual assignment... first one
* to grab the lock wins... the other callers
* will release the now unnecessary storage
*
* once the context is present, try to grab (but don't block on)
* the lock associated with it... if someone
* else currently owns it, than the read
* will run without read-ahead. this allows
* multiple readers to run in parallel and
* since there's only 1 read ahead context,
* there's no real loss in only allowing 1
* reader to have read-ahead enabled.
*/
static struct cl_readahead *
cluster_get_rap(vnode_t vp)
{
struct ubc_info *ubc;
struct cl_readahead *rap;
ubc = vp->v_ubcinfo;
if ((rap = ubc->cl_rahead) == NULL) {
rap = zalloc_flags(cl_rd_zone, Z_WAITOK | Z_ZERO);
rap->cl_lastr = -1;
lck_mtx_init(&rap->cl_lockr, &cl_mtx_grp, LCK_ATTR_NULL);
vnode_lock(vp);
if (ubc->cl_rahead == NULL) {
ubc->cl_rahead = rap;
} else {
lck_mtx_destroy(&rap->cl_lockr, &cl_mtx_grp);
zfree(cl_rd_zone, rap);
rap = ubc->cl_rahead;
}
vnode_unlock(vp);
}
if (lck_mtx_try_lock(&rap->cl_lockr) == TRUE) {
return rap;
}
return (struct cl_readahead *)NULL;
}
/*
* if the write behind context doesn't yet exist,
* and CLW_ALLOCATE is specified, allocate and initialize it...
* the vnode lock serializes multiple callers
* during the actual assignment... first one
* to grab the lock wins... the other callers
* will release the now unnecessary storage
*
* if CLW_RETURNLOCKED is set, grab (blocking if necessary)
* the lock associated with the write behind context before
* returning
*/
static struct cl_writebehind *
cluster_get_wbp(vnode_t vp, int flags)
{
struct ubc_info *ubc;
struct cl_writebehind *wbp;
ubc = vp->v_ubcinfo;
if ((wbp = ubc->cl_wbehind) == NULL) {
if (!(flags & CLW_ALLOCATE)) {
return (struct cl_writebehind *)NULL;
}
wbp = zalloc_flags(cl_wr_zone, Z_WAITOK | Z_ZERO);
lck_mtx_init(&wbp->cl_lockw, &cl_mtx_grp, LCK_ATTR_NULL);
vnode_lock(vp);
if (ubc->cl_wbehind == NULL) {
ubc->cl_wbehind = wbp;
} else {
lck_mtx_destroy(&wbp->cl_lockw, &cl_mtx_grp);
zfree(cl_wr_zone, wbp);
wbp = ubc->cl_wbehind;
}
vnode_unlock(vp);
}
if (flags & CLW_RETURNLOCKED) {
lck_mtx_lock(&wbp->cl_lockw);
}
return wbp;
}
static void
cluster_syncup(vnode_t vp, off_t newEOF, int (*callback)(buf_t, void *), void *callback_arg, int flags)
{
struct cl_writebehind *wbp;
if ((wbp = cluster_get_wbp(vp, 0)) != NULL) {
if (wbp->cl_number) {
lck_mtx_lock(&wbp->cl_lockw);
cluster_try_push(wbp, vp, newEOF, PUSH_ALL | flags, 0, callback, callback_arg, NULL, FALSE);
lck_mtx_unlock(&wbp->cl_lockw);
}
}
}
static int
cluster_io_present_in_BC(vnode_t vp, off_t f_offset)
{
daddr64_t blkno;
size_t io_size;
int (*bootcache_check_fn)(dev_t device, u_int64_t blkno) = bootcache_contains_block;
if (bootcache_check_fn && vp->v_mount && vp->v_mount->mnt_devvp) {
if (VNOP_BLOCKMAP(vp, f_offset, PAGE_SIZE, &blkno, &io_size, NULL, VNODE_READ | VNODE_BLOCKMAP_NO_TRACK, NULL)) {
return 0;
}
if (io_size == 0) {
return 0;
}
if (bootcache_check_fn(vp->v_mount->mnt_devvp->v_rdev, blkno)) {
return 1;
}
}
return 0;
}
static int
cluster_is_throttled(vnode_t vp)
{
return throttle_io_will_be_throttled(-1, vp->v_mount);
}
static void
cluster_iostate_wait(struct clios *iostate, u_int target, const char *wait_name)
{
lck_mtx_lock(&iostate->io_mtxp);
while ((iostate->io_issued - iostate->io_completed) > target) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 95)) | DBG_FUNC_START,
iostate->io_issued, iostate->io_completed, target, 0, 0);
iostate->io_wanted = 1;
msleep((caddr_t)&iostate->io_wanted, &iostate->io_mtxp, PRIBIO + 1, wait_name, NULL);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 95)) | DBG_FUNC_END,
iostate->io_issued, iostate->io_completed, target, 0, 0);
}
lck_mtx_unlock(&iostate->io_mtxp);
}
static void
cluster_handle_associated_upl(struct clios *iostate, upl_t upl,
upl_offset_t upl_offset, upl_size_t size)
{
if (!size) {
return;
}
upl_t associated_upl = upl_associated_upl(upl);
if (!associated_upl) {
return;
}
#if 0
printf("1: %d %d\n", upl_offset, upl_offset + size);
#endif
/*
* The associated UPL is page aligned to file offsets whereas the
* UPL it's attached to has different alignment requirements. The
* upl_offset that we have refers to @upl. The code that follows
* has to deal with the first and last pages in this transaction
* which might straddle pages in the associated UPL. To keep
* track of these pages, we use the mark bits: if the mark bit is
* set, we know another transaction has completed its part of that
* page and so we can unlock that page here.
*
* The following illustrates what we have to deal with:
*
* MEM u <------------ 1 PAGE ------------> e
* +-------------+----------------------+-----------------
* | |######################|#################
* +-------------+----------------------+-----------------
* FILE | <--- a ---> o <------------ 1 PAGE ------------>
*
* So here we show a write to offset @o. The data that is to be
* written is in a buffer that is not page aligned; it has offset
* @a in the page. The upl that carries the data starts in memory
* at @u. The associated upl starts in the file at offset @o. A
* transaction will always end on a page boundary (like @e above)
* except for the very last transaction in the group. We cannot
* unlock the page at @o in the associated upl until both the
* transaction ending at @e and the following transaction (that
* starts at @e) has completed.
*/
/*
* We record whether or not the two UPLs are aligned as the mark
* bit in the first page of @upl.
*/
upl_page_info_t *pl = UPL_GET_INTERNAL_PAGE_LIST(upl);
bool is_unaligned = upl_page_get_mark(pl, 0);
if (is_unaligned) {
upl_page_info_t *assoc_pl = UPL_GET_INTERNAL_PAGE_LIST(associated_upl);
upl_offset_t upl_end = upl_offset + size;
assert(upl_end >= PAGE_SIZE);
upl_size_t assoc_upl_size = upl_get_size(associated_upl);
/*
* In the very first transaction in the group, upl_offset will
* not be page aligned, but after that it will be and in that
* case we want the preceding page in the associated UPL hence
* the minus one.
*/
assert(upl_offset);
if (upl_offset) {
upl_offset = trunc_page_32(upl_offset - 1);
}
lck_mtx_lock_spin(&iostate->io_mtxp);
// Look at the first page...
if (upl_offset
&& !upl_page_get_mark(assoc_pl, upl_offset >> PAGE_SHIFT)) {
/*
* The first page isn't marked so let another transaction
* completion handle it.
*/
upl_page_set_mark(assoc_pl, upl_offset >> PAGE_SHIFT, true);
upl_offset += PAGE_SIZE;
}
// And now the last page...
/*
* This needs to be > rather than >= because if it's equal, it
* means there's another transaction that is sharing the last
* page.
*/
if (upl_end > assoc_upl_size) {
upl_end = assoc_upl_size;
} else {
upl_end = trunc_page_32(upl_end);
const int last_pg = (upl_end >> PAGE_SHIFT) - 1;
if (!upl_page_get_mark(assoc_pl, last_pg)) {
/*
* The last page isn't marked so mark the page and let another
* transaction completion handle it.
*/
upl_page_set_mark(assoc_pl, last_pg, true);
upl_end -= PAGE_SIZE;
}
}
lck_mtx_unlock(&iostate->io_mtxp);
#if 0
printf("2: %d %d\n", upl_offset, upl_end);
#endif
if (upl_end <= upl_offset) {
return;
}
size = upl_end - upl_offset;
} else {
assert(!(upl_offset & PAGE_MASK));
assert(!(size & PAGE_MASK));
}
boolean_t empty;
/*
* We can unlock these pages now and as this is for a
* direct/uncached write, we want to dump the pages too.
*/
kern_return_t kr = upl_abort_range(associated_upl, upl_offset, size,
UPL_ABORT_DUMP_PAGES, &empty);
assert(!kr);
if (!kr && empty) {
upl_set_associated_upl(upl, NULL);
upl_deallocate(associated_upl);
}
}
static int
cluster_ioerror(upl_t upl, int upl_offset, int abort_size, int error, int io_flags, vnode_t vp)
{
int upl_abort_code = 0;
int page_in = 0;
int page_out = 0;
if ((io_flags & (B_PHYS | B_CACHE)) == (B_PHYS | B_CACHE)) {
/*
* direct write of any flavor, or a direct read that wasn't aligned
*/
ubc_upl_commit_range(upl, upl_offset, abort_size, UPL_COMMIT_FREE_ON_EMPTY);
} else {
if (io_flags & B_PAGEIO) {
if (io_flags & B_READ) {
page_in = 1;
} else {
page_out = 1;
}
}
if (io_flags & B_CACHE) {
/*
* leave pages in the cache unchanged on error
*/
upl_abort_code = UPL_ABORT_FREE_ON_EMPTY;
} else if (((io_flags & B_READ) == 0) && ((error != ENXIO) || vnode_isswap(vp))) {
/*
* transient error on pageout/write path... leave pages unchanged
*/
upl_abort_code = UPL_ABORT_FREE_ON_EMPTY;
} else if (page_in) {
upl_abort_code = UPL_ABORT_FREE_ON_EMPTY | UPL_ABORT_ERROR;
} else {
upl_abort_code = UPL_ABORT_FREE_ON_EMPTY | UPL_ABORT_DUMP_PAGES;
}
ubc_upl_abort_range(upl, upl_offset, abort_size, upl_abort_code);
}
return upl_abort_code;
}
static int
cluster_iodone(buf_t bp, void *callback_arg)
{
int b_flags;
int error;
int total_size;
int total_resid;
int upl_offset;
int zero_offset;
int pg_offset = 0;
int commit_size = 0;
int upl_flags = 0;
int transaction_size = 0;
upl_t upl;
buf_t cbp;
buf_t cbp_head;
buf_t cbp_next;
buf_t real_bp;
vnode_t vp;
struct clios *iostate;
boolean_t transaction_complete = FALSE;
__IGNORE_WCASTALIGN(cbp_head = (buf_t)(bp->b_trans_head));
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 20)) | DBG_FUNC_START,
cbp_head, bp->b_lblkno, bp->b_bcount, bp->b_flags, 0);
if (cbp_head->b_trans_next || !(cbp_head->b_flags & B_EOT)) {
lck_mtx_lock_spin(&cl_transaction_mtxp);
bp->b_flags |= B_TDONE;
for (cbp = cbp_head; cbp; cbp = cbp->b_trans_next) {
/*
* all I/O requests that are part of this transaction
* have to complete before we can process it
*/
if (!(cbp->b_flags & B_TDONE)) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 20)) | DBG_FUNC_END,
cbp_head, cbp, cbp->b_bcount, cbp->b_flags, 0);
lck_mtx_unlock(&cl_transaction_mtxp);
return 0;
}
if (cbp->b_trans_next == CLUSTER_IO_WAITING) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 20)) | DBG_FUNC_END,
cbp_head, cbp, cbp->b_bcount, cbp->b_flags, 0);
lck_mtx_unlock(&cl_transaction_mtxp);
wakeup(cbp);
return 0;
}
if (cbp->b_flags & B_EOT) {
transaction_complete = TRUE;
}
}
lck_mtx_unlock(&cl_transaction_mtxp);
if (transaction_complete == FALSE) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 20)) | DBG_FUNC_END,
cbp_head, 0, 0, 0, 0);
return 0;
}
}
error = 0;
total_size = 0;
total_resid = 0;
cbp = cbp_head;
vp = cbp->b_vp;
upl_offset = cbp->b_uploffset;
upl = cbp->b_upl;
b_flags = cbp->b_flags;
real_bp = cbp->b_real_bp;
zero_offset = cbp->b_validend;
iostate = (struct clios *)cbp->b_iostate;
if (real_bp) {
real_bp->b_dev = cbp->b_dev;
}
while (cbp) {
if ((cbp->b_flags & B_ERROR) && error == 0) {
error = cbp->b_error;
}
total_resid += cbp->b_resid;
total_size += cbp->b_bcount;
cbp_next = cbp->b_trans_next;
if (cbp_next == NULL) {
/*
* compute the overall size of the transaction
* in case we created one that has 'holes' in it
* 'total_size' represents the amount of I/O we
* did, not the span of the transaction w/r to the UPL
*/
transaction_size = cbp->b_uploffset + cbp->b_bcount - upl_offset;
}
if (cbp != cbp_head) {
free_io_buf(cbp);
}
cbp = cbp_next;
}
if (ISSET(b_flags, B_COMMIT_UPL)) {
cluster_handle_associated_upl(iostate,
cbp_head->b_upl,
upl_offset,
transaction_size);
}
if (error == 0 && total_resid) {
error = EIO;
}
if (error == 0) {
int (*cliodone_func)(buf_t, void *) = (int (*)(buf_t, void *))(cbp_head->b_cliodone);
if (cliodone_func != NULL) {
cbp_head->b_bcount = transaction_size;
error = (*cliodone_func)(cbp_head, callback_arg);
}
}
if (zero_offset) {
cluster_zero(upl, zero_offset, PAGE_SIZE - (zero_offset & PAGE_MASK), real_bp);
}
free_io_buf(cbp_head);
if (iostate) {
int need_wakeup = 0;
/*
* someone has issued multiple I/Os asynchrounsly
* and is waiting for them to complete (streaming)
*/
lck_mtx_lock_spin(&iostate->io_mtxp);
if (error && iostate->io_error == 0) {
iostate->io_error = error;
}
iostate->io_completed += total_size;
if (iostate->io_wanted) {
/*
* someone is waiting for the state of
* this io stream to change
*/
iostate->io_wanted = 0;
need_wakeup = 1;
}
lck_mtx_unlock(&iostate->io_mtxp);
if (need_wakeup) {
wakeup((caddr_t)&iostate->io_wanted);
}
}
if (b_flags & B_COMMIT_UPL) {
pg_offset = upl_offset & PAGE_MASK;
commit_size = (pg_offset + transaction_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
if (error) {
upl_set_iodone_error(upl, error);
upl_flags = cluster_ioerror(upl, upl_offset - pg_offset, commit_size, error, b_flags, vp);
} else {
upl_flags = UPL_COMMIT_FREE_ON_EMPTY;
if ((b_flags & B_PHYS) && (b_flags & B_READ)) {
upl_flags |= UPL_COMMIT_SET_DIRTY;
}
if (b_flags & B_AGE) {
upl_flags |= UPL_COMMIT_INACTIVATE;
}
ubc_upl_commit_range(upl, upl_offset - pg_offset, commit_size, upl_flags);
}
}
if (real_bp) {
if (error) {
real_bp->b_flags |= B_ERROR;
real_bp->b_error = error;
}
real_bp->b_resid = total_resid;
buf_biodone(real_bp);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 20)) | DBG_FUNC_END,
upl, upl_offset - pg_offset, commit_size, (error << 24) | upl_flags, 0);
return error;
}
uint32_t
cluster_throttle_io_limit(vnode_t vp, uint32_t *limit)
{
if (cluster_is_throttled(vp)) {
*limit = THROTTLE_MAX_IOSIZE;
return 1;
}
return 0;
}
void
cluster_zero(upl_t upl, upl_offset_t upl_offset, int size, buf_t bp)
{
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 23)) | DBG_FUNC_START,
upl_offset, size, bp, 0, 0);
if (bp == NULL || bp->b_datap == 0) {
upl_page_info_t *pl;
addr64_t zero_addr;
pl = ubc_upl_pageinfo(upl);
if (upl_device_page(pl) == TRUE) {
zero_addr = ((addr64_t)upl_phys_page(pl, 0) << PAGE_SHIFT) + upl_offset;
bzero_phys_nc(zero_addr, size);
} else {
while (size) {
int page_offset;
int page_index;
int zero_cnt;
page_index = upl_offset / PAGE_SIZE;
page_offset = upl_offset & PAGE_MASK;
zero_addr = ((addr64_t)upl_phys_page(pl, page_index) << PAGE_SHIFT) + page_offset;
zero_cnt = min(PAGE_SIZE - page_offset, size);
bzero_phys(zero_addr, zero_cnt);
size -= zero_cnt;
upl_offset += zero_cnt;
}
}
} else {
bzero((caddr_t)((vm_offset_t)bp->b_datap + upl_offset), size);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 23)) | DBG_FUNC_END,
upl_offset, size, 0, 0, 0);
}
static void
cluster_EOT(buf_t cbp_head, buf_t cbp_tail, int zero_offset)
{
cbp_head->b_validend = zero_offset;
cbp_tail->b_flags |= B_EOT;
}
static void
cluster_wait_IO(buf_t cbp_head, int async)
{
buf_t cbp;
if (async) {
/*
* Async callback completion will not normally generate a
* wakeup upon I/O completion. To get woken up, we set
* b_trans_next (which is safe for us to modify) on the last
* buffer to CLUSTER_IO_WAITING so that cluster_iodone knows
* to wake us up when all buffers as part of this transaction
* are completed. This is done under the umbrella of
* cl_transaction_mtxp which is also taken in cluster_iodone.
*/
bool done = true;
buf_t last = NULL;
lck_mtx_lock_spin(&cl_transaction_mtxp);
for (cbp = cbp_head; cbp; last = cbp, cbp = cbp->b_trans_next) {
if (!ISSET(cbp->b_flags, B_TDONE)) {
done = false;
}
}
if (!done) {
last->b_trans_next = CLUSTER_IO_WAITING;
DTRACE_IO1(wait__start, buf_t, last);
do {
msleep(last, &cl_transaction_mtxp, PSPIN | (PRIBIO + 1), "cluster_wait_IO", NULL);
/*
* We should only have been woken up if all the
* buffers are completed, but just in case...
*/
done = true;
for (cbp = cbp_head; cbp != CLUSTER_IO_WAITING; cbp = cbp->b_trans_next) {
if (!ISSET(cbp->b_flags, B_TDONE)) {
done = false;
break;
}
}
} while (!done);
DTRACE_IO1(wait__done, buf_t, last);
last->b_trans_next = NULL;
}
lck_mtx_unlock(&cl_transaction_mtxp);
} else { // !async
for (cbp = cbp_head; cbp; cbp = cbp->b_trans_next) {
buf_biowait(cbp);
}
}
}
static void
cluster_complete_transaction(buf_t *cbp_head, void *callback_arg, int *retval, int flags, int needwait)
{
buf_t cbp;
int error;
boolean_t isswapout = FALSE;
/*
* cluster_complete_transaction will
* only be called if we've issued a complete chain in synchronous mode
* or, we've already done a cluster_wait_IO on an incomplete chain
*/
if (needwait) {
for (cbp = *cbp_head; cbp; cbp = cbp->b_trans_next) {
buf_biowait(cbp);
}
}
/*
* we've already waited on all of the I/Os in this transaction,
* so mark all of the buf_t's in this transaction as B_TDONE
* so that cluster_iodone sees the transaction as completed
*/
for (cbp = *cbp_head; cbp; cbp = cbp->b_trans_next) {
cbp->b_flags |= B_TDONE;
}
cbp = *cbp_head;
if ((flags & (CL_ASYNC | CL_PAGEOUT)) == CL_PAGEOUT && vnode_isswap(cbp->b_vp)) {
isswapout = TRUE;
}
error = cluster_iodone(cbp, callback_arg);
if (!(flags & CL_ASYNC) && error && *retval == 0) {
if (((flags & (CL_PAGEOUT | CL_KEEPCACHED)) != CL_PAGEOUT) || (error != ENXIO)) {
*retval = error;
} else if (isswapout == TRUE) {
*retval = error;
}
}
*cbp_head = (buf_t)NULL;
}
static int
cluster_io(vnode_t vp, upl_t upl, vm_offset_t upl_offset, off_t f_offset, int non_rounded_size,
int flags, buf_t real_bp, struct clios *iostate, int (*callback)(buf_t, void *), void *callback_arg)
{
buf_t cbp;
u_int size;
u_int io_size;
int io_flags;
int bmap_flags;
int error = 0;
int retval = 0;
buf_t cbp_head = NULL;
buf_t cbp_tail = NULL;
int trans_count = 0;
int max_trans_count;
u_int pg_count;
int pg_offset;
u_int max_iosize;
u_int max_vectors;
int priv;
int zero_offset = 0;
int async_throttle = 0;
mount_t mp;
vm_offset_t upl_end_offset;
boolean_t need_EOT = FALSE;
/*
* we currently don't support buffers larger than a page
*/
if (real_bp && non_rounded_size > PAGE_SIZE) {
panic("%s(): Called with real buffer of size %d bytes which "
"is greater than the maximum allowed size of "
"%d bytes (the system PAGE_SIZE).\n",
__FUNCTION__, non_rounded_size, PAGE_SIZE);
}
mp = vp->v_mount;
/*
* we don't want to do any funny rounding of the size for IO requests
* coming through the DIRECT or CONTIGUOUS paths... those pages don't
* belong to us... we can't extend (nor do we need to) the I/O to fill
* out a page
*/
if (mp->mnt_devblocksize > 1 && !(flags & (CL_DEV_MEMORY | CL_DIRECT_IO))) {
/*
* round the requested size up so that this I/O ends on a
* page boundary in case this is a 'write'... if the filesystem
* has blocks allocated to back the page beyond the EOF, we want to
* make sure to write out the zero's that are sitting beyond the EOF
* so that in case the filesystem doesn't explicitly zero this area
* if a hole is created via a lseek/write beyond the current EOF,
* it will return zeros when it's read back from the disk. If the
* physical allocation doesn't extend for the whole page, we'll
* only write/read from the disk up to the end of this allocation
* via the extent info returned from the VNOP_BLOCKMAP call.
*/
pg_offset = upl_offset & PAGE_MASK;
size = (((non_rounded_size + pg_offset) + (PAGE_SIZE - 1)) & ~PAGE_MASK) - pg_offset;
} else {
/*
* anyone advertising a blocksize of 1 byte probably
* can't deal with us rounding up the request size
* AFP is one such filesystem/device
*/
size = non_rounded_size;
}
upl_end_offset = upl_offset + size;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 22)) | DBG_FUNC_START, (int)f_offset, size, upl_offset, flags, 0);
/*
* Set the maximum transaction size to the maximum desired number of
* buffers.
*/
max_trans_count = 8;
if (flags & CL_DEV_MEMORY) {
max_trans_count = 16;
}
if (flags & CL_READ) {
io_flags = B_READ;
bmap_flags = VNODE_READ;
max_iosize = mp->mnt_maxreadcnt;
max_vectors = mp->mnt_segreadcnt;
} else {
io_flags = B_WRITE;
bmap_flags = VNODE_WRITE;
max_iosize = mp->mnt_maxwritecnt;
max_vectors = mp->mnt_segwritecnt;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 22)) | DBG_FUNC_NONE, max_iosize, max_vectors, mp->mnt_devblocksize, 0, 0);
/*
* make sure the maximum iosize is a
* multiple of the page size
*/
max_iosize &= ~PAGE_MASK;
/*
* Ensure the maximum iosize is sensible.
*/
if (!max_iosize) {
max_iosize = PAGE_SIZE;
}
if (flags & CL_THROTTLE) {
if (!(flags & CL_PAGEOUT) && cluster_is_throttled(vp)) {
if (max_iosize > THROTTLE_MAX_IOSIZE) {
max_iosize = THROTTLE_MAX_IOSIZE;
}
async_throttle = THROTTLE_MAXCNT;
} else {
if ((flags & CL_DEV_MEMORY)) {
async_throttle = IO_SCALE(vp, VNODE_ASYNC_THROTTLE);
} else {
u_int max_cluster;
u_int max_cluster_size;
u_int scale;
if (vp->v_mount->mnt_minsaturationbytecount) {
max_cluster_size = vp->v_mount->mnt_minsaturationbytecount;
scale = 1;
} else {
max_cluster_size = MAX_CLUSTER_SIZE(vp);
if (disk_conditioner_mount_is_ssd(vp->v_mount)) {
scale = WRITE_THROTTLE_SSD;
} else {
scale = WRITE_THROTTLE;
}
}
if (max_iosize > max_cluster_size) {
max_cluster = max_cluster_size;
} else {
max_cluster = max_iosize;
}
if (size < max_cluster) {
max_cluster = size;
}
if (flags & CL_CLOSE) {
scale += MAX_CLUSTERS;
}
async_throttle = min(IO_SCALE(vp, VNODE_ASYNC_THROTTLE), ((scale * max_cluster_size) / max_cluster) - 1);
}
}
}
if (flags & CL_AGE) {
io_flags |= B_AGE;
}
if (flags & (CL_PAGEIN | CL_PAGEOUT)) {
io_flags |= B_PAGEIO;
}
if (flags & (CL_IOSTREAMING)) {
io_flags |= B_IOSTREAMING;
}
if (flags & CL_COMMIT) {
io_flags |= B_COMMIT_UPL;
}
if (flags & CL_DIRECT_IO) {
io_flags |= B_PHYS;
}
if (flags & (CL_PRESERVE | CL_KEEPCACHED)) {
io_flags |= B_CACHE;
}
if (flags & CL_PASSIVE) {
io_flags |= B_PASSIVE;
}
if (flags & CL_ENCRYPTED) {
io_flags |= B_ENCRYPTED_IO;
}
if (vp->v_flag & VSYSTEM) {
io_flags |= B_META;
}
if ((flags & CL_READ) && ((upl_offset + non_rounded_size) & PAGE_MASK) && (!(flags & CL_NOZERO))) {
/*
* then we are going to end up
* with a page that we can't complete (the file size wasn't a multiple
* of PAGE_SIZE and we're trying to read to the end of the file
* so we'll go ahead and zero out the portion of the page we can't
* read in from the file
*/
zero_offset = (int)(upl_offset + non_rounded_size);
} else if (!ISSET(flags, CL_READ) && ISSET(flags, CL_DIRECT_IO)) {
assert(ISSET(flags, CL_COMMIT));
// For a direct/uncached write, we need to lock pages...
upl_t cached_upl;
/*
* Create a UPL to lock the pages in the cache whilst the
* write is in progress.
*/
ubc_create_upl_kernel(vp, f_offset, non_rounded_size, &cached_upl,
NULL, UPL_SET_LITE, VM_KERN_MEMORY_FILE);
/*
* Attach this UPL to the other UPL so that we can find it
* later.
*/
upl_set_associated_upl(upl, cached_upl);
if (upl_offset & PAGE_MASK) {
/*
* The two UPLs are not aligned, so mark the first page in
* @upl so that cluster_handle_associated_upl can handle
* it accordingly.
*/
upl_page_info_t *pl = UPL_GET_INTERNAL_PAGE_LIST(upl);
upl_page_set_mark(pl, 0, true);
}
}
while (size) {
daddr64_t blkno;
daddr64_t lblkno;
u_int io_size_wanted;
size_t io_size_tmp;
if (size > max_iosize) {
io_size = max_iosize;
} else {
io_size = size;
}
io_size_wanted = io_size;
io_size_tmp = (size_t)io_size;
if ((error = VNOP_BLOCKMAP(vp, f_offset, io_size, &blkno, &io_size_tmp, NULL, bmap_flags, NULL))) {
break;
}
if (io_size_tmp > io_size_wanted) {
io_size = io_size_wanted;
} else {
io_size = (u_int)io_size_tmp;
}
if (real_bp && (real_bp->b_blkno == real_bp->b_lblkno)) {
real_bp->b_blkno = blkno;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 24)) | DBG_FUNC_NONE,
(int)f_offset, (int)(blkno >> 32), (int)blkno, io_size, 0);
if (io_size == 0) {
/*
* vnop_blockmap didn't return an error... however, it did
* return an extent size of 0 which means we can't
* make forward progress on this I/O... a hole in the
* file would be returned as a blkno of -1 with a non-zero io_size
* a real extent is returned with a blkno != -1 and a non-zero io_size
*/
error = EINVAL;
break;
}
if (!(flags & CL_READ) && blkno == -1) {
off_t e_offset;
int pageout_flags;
if (upl_get_internal_vectorupl(upl)) {
panic("Vector UPLs should not take this code-path\n");
}
/*
* we're writing into a 'hole'
*/
if (flags & CL_PAGEOUT) {
/*
* if we got here via cluster_pageout
* then just error the request and return
* the 'hole' should already have been covered
*/
error = EINVAL;
break;
}
/*
* we can get here if the cluster code happens to
* pick up a page that was dirtied via mmap vs
* a 'write' and the page targets a 'hole'...
* i.e. the writes to the cluster were sparse
* and the file was being written for the first time
*
* we can also get here if the filesystem supports
* 'holes' that are less than PAGE_SIZE.... because
* we can't know if the range in the page that covers
* the 'hole' has been dirtied via an mmap or not,
* we have to assume the worst and try to push the
* entire page to storage.
*
* Try paging out the page individually before
* giving up entirely and dumping it (the pageout
* path will insure that the zero extent accounting
* has been taken care of before we get back into cluster_io)
*
* go direct to vnode_pageout so that we don't have to
* unbusy the page from the UPL... we used to do this
* so that we could call ubc_msync, but that results
* in a potential deadlock if someone else races us to acquire
* that page and wins and in addition needs one of the pages
* we're continuing to hold in the UPL
*/
pageout_flags = UPL_MSYNC | UPL_VNODE_PAGER | UPL_NESTED_PAGEOUT;
if (!(flags & CL_ASYNC)) {
pageout_flags |= UPL_IOSYNC;
}
if (!(flags & CL_COMMIT)) {
pageout_flags |= UPL_NOCOMMIT;
}
if (cbp_head) {
buf_t prev_cbp;
uint32_t bytes_in_last_page;
/*
* first we have to wait for the the current outstanding I/Os
* to complete... EOT hasn't been set yet on this transaction
* so the pages won't be released
*/
cluster_wait_IO(cbp_head, (flags & CL_ASYNC));
bytes_in_last_page = cbp_head->b_uploffset & PAGE_MASK;
for (cbp = cbp_head; cbp; cbp = cbp->b_trans_next) {
bytes_in_last_page += cbp->b_bcount;
}
bytes_in_last_page &= PAGE_MASK;
while (bytes_in_last_page) {
/*
* we've got a transcation that
* includes the page we're about to push out through vnode_pageout...
* find the bp's in the list which intersect this page and either
* remove them entirely from the transaction (there could be multiple bp's), or
* round it's iosize down to the page boundary (there can only be one)...
*
* find the last bp in the list and act on it
*/
for (prev_cbp = cbp = cbp_head; cbp->b_trans_next; cbp = cbp->b_trans_next) {
prev_cbp = cbp;
}
if (bytes_in_last_page >= cbp->b_bcount) {
/*
* this buf no longer has any I/O associated with it
*/
bytes_in_last_page -= cbp->b_bcount;
cbp->b_bcount = 0;
free_io_buf(cbp);
if (cbp == cbp_head) {
assert(bytes_in_last_page == 0);
/*
* the buf we just freed was the only buf in
* this transaction... so there's no I/O to do
*/
cbp_head = NULL;
cbp_tail = NULL;
} else {
/*
* remove the buf we just freed from
* the transaction list
*/
prev_cbp->b_trans_next = NULL;
cbp_tail = prev_cbp;
}
} else {
/*
* this is the last bp that has I/O
* intersecting the page of interest
* only some of the I/O is in the intersection
* so clip the size but keep it in the transaction list
*/
cbp->b_bcount -= bytes_in_last_page;
cbp_tail = cbp;
bytes_in_last_page = 0;
}
}
if (cbp_head) {
/*
* there was more to the current transaction
* than just the page we are pushing out via vnode_pageout...
* mark it as finished and complete it... we've already
* waited for the I/Os to complete above in the call to cluster_wait_IO
*/
cluster_EOT(cbp_head, cbp_tail, 0);
cluster_complete_transaction(&cbp_head, callback_arg, &retval, flags, 0);
trans_count = 0;
}
}
if (vnode_pageout(vp, upl, (upl_offset_t)trunc_page(upl_offset), trunc_page_64(f_offset), PAGE_SIZE, pageout_flags, NULL) != PAGER_SUCCESS) {
error = EINVAL;
}
e_offset = round_page_64(f_offset + 1);
io_size = (u_int)(e_offset - f_offset);
f_offset += io_size;
upl_offset += io_size;
if (size >= io_size) {
size -= io_size;
} else {
size = 0;
}
/*
* keep track of how much of the original request
* that we've actually completed... non_rounded_size
* may go negative due to us rounding the request
* to a page size multiple (i.e. size > non_rounded_size)
*/
non_rounded_size -= io_size;
if (non_rounded_size <= 0) {
/*
* we've transferred all of the data in the original
* request, but we were unable to complete the tail
* of the last page because the file didn't have
* an allocation to back that portion... this is ok.
*/
size = 0;
}
if (error) {
if (size == 0) {
flags &= ~CL_COMMIT;
}
break;
}
continue;
}
lblkno = (daddr64_t)(f_offset / 0x1000);
/*
* we have now figured out how much I/O we can do - this is in 'io_size'
* pg_offset is the starting point in the first page for the I/O
* pg_count is the number of full and partial pages that 'io_size' encompasses
*/
pg_offset = upl_offset & PAGE_MASK;
if (flags & CL_DEV_MEMORY) {
/*
* treat physical requests as one 'giant' page
*/
pg_count = 1;
} else {
pg_count = (io_size + pg_offset + (PAGE_SIZE - 1)) / PAGE_SIZE;
}
if ((flags & CL_READ) && blkno == -1) {
vm_offset_t commit_offset;
int bytes_to_zero;
int complete_transaction_now = 0;
/*
* if we're reading and blkno == -1, then we've got a
* 'hole' in the file that we need to deal with by zeroing
* out the affected area in the upl
*/
if (io_size >= (u_int)non_rounded_size) {
/*
* if this upl contains the EOF and it is not a multiple of PAGE_SIZE
* than 'zero_offset' will be non-zero
* if the 'hole' returned by vnop_blockmap extends all the way to the eof
* (indicated by the io_size finishing off the I/O request for this UPL)
* than we're not going to issue an I/O for the
* last page in this upl... we need to zero both the hole and the tail
* of the page beyond the EOF, since the delayed zero-fill won't kick in
*/
bytes_to_zero = non_rounded_size;
if (!(flags & CL_NOZERO)) {
bytes_to_zero = (int)((((upl_offset + io_size) + (PAGE_SIZE - 1)) & ~PAGE_MASK) - upl_offset);
}
zero_offset = 0;
} else {
bytes_to_zero = io_size;
}
pg_count = 0;
cluster_zero(upl, (upl_offset_t)upl_offset, bytes_to_zero, real_bp);
if (cbp_head) {
int pg_resid;
/*
* if there is a current I/O chain pending
* then the first page of the group we just zero'd
* will be handled by the I/O completion if the zero
* fill started in the middle of the page
*/
commit_offset = (upl_offset + (PAGE_SIZE - 1)) & ~PAGE_MASK;
pg_resid = (int)(commit_offset - upl_offset);
if (bytes_to_zero >= pg_resid) {
/*
* the last page of the current I/O
* has been completed...
* compute the number of fully zero'd
* pages that are beyond it
* plus the last page if its partial
* and we have no more I/O to issue...
* otherwise a partial page is left
* to begin the next I/O
*/
if ((int)io_size >= non_rounded_size) {
pg_count = (bytes_to_zero - pg_resid + (PAGE_SIZE - 1)) / PAGE_SIZE;
} else {
pg_count = (bytes_to_zero - pg_resid) / PAGE_SIZE;
}
complete_transaction_now = 1;
}
} else {
/*
* no pending I/O to deal with
* so, commit all of the fully zero'd pages
* plus the last page if its partial
* and we have no more I/O to issue...
* otherwise a partial page is left
* to begin the next I/O
*/
if ((int)io_size >= non_rounded_size) {
pg_count = (pg_offset + bytes_to_zero + (PAGE_SIZE - 1)) / PAGE_SIZE;
} else {
pg_count = (pg_offset + bytes_to_zero) / PAGE_SIZE;
}
commit_offset = upl_offset & ~PAGE_MASK;
}
// Associated UPL is currently only used in the direct write path
assert(!upl_associated_upl(upl));
if ((flags & CL_COMMIT) && pg_count) {
ubc_upl_commit_range(upl, (upl_offset_t)commit_offset,
pg_count * PAGE_SIZE,
UPL_COMMIT_CLEAR_DIRTY | UPL_COMMIT_FREE_ON_EMPTY);
}
upl_offset += io_size;
f_offset += io_size;
size -= io_size;
/*
* keep track of how much of the original request
* that we've actually completed... non_rounded_size
* may go negative due to us rounding the request
* to a page size multiple (i.e. size > non_rounded_size)
*/
non_rounded_size -= io_size;
if (non_rounded_size <= 0) {
/*
* we've transferred all of the data in the original
* request, but we were unable to complete the tail
* of the last page because the file didn't have
* an allocation to back that portion... this is ok.
*/
size = 0;
}
if (cbp_head && (complete_transaction_now || size == 0)) {
cluster_wait_IO(cbp_head, (flags & CL_ASYNC));
cluster_EOT(cbp_head, cbp_tail, size == 0 ? zero_offset : 0);
cluster_complete_transaction(&cbp_head, callback_arg, &retval, flags, 0);
trans_count = 0;
}
continue;
}
if (pg_count > max_vectors) {
if (((pg_count - max_vectors) * PAGE_SIZE) > io_size) {
io_size = PAGE_SIZE - pg_offset;
pg_count = 1;
} else {
io_size -= (pg_count - max_vectors) * PAGE_SIZE;
pg_count = max_vectors;
}
}
/*
* If the transaction is going to reach the maximum number of
* desired elements, truncate the i/o to the nearest page so
* that the actual i/o is initiated after this buffer is
* created and added to the i/o chain.
*
* I/O directed to physically contiguous memory
* doesn't have a requirement to make sure we 'fill' a page
*/
if (!(flags & CL_DEV_MEMORY) && trans_count >= max_trans_count &&
((upl_offset + io_size) & PAGE_MASK)) {
vm_offset_t aligned_ofs;
aligned_ofs = (upl_offset + io_size) & ~PAGE_MASK;
/*
* If the io_size does not actually finish off even a
* single page we have to keep adding buffers to the
* transaction despite having reached the desired limit.
*
* Eventually we get here with the page being finished
* off (and exceeded) and then we truncate the size of
* this i/o request so that it is page aligned so that
* we can finally issue the i/o on the transaction.
*/
if (aligned_ofs > upl_offset) {
io_size = (u_int)(aligned_ofs - upl_offset);
pg_count--;
}
}
if (!(mp->mnt_kern_flag & MNTK_VIRTUALDEV)) {
/*
* if we're not targeting a virtual device i.e. a disk image
* it's safe to dip into the reserve pool since real devices
* can complete this I/O request without requiring additional
* bufs from the alloc_io_buf pool
*/
priv = 1;
} else if ((flags & CL_ASYNC) && !(flags & CL_PAGEOUT) && !cbp_head) {
/*
* Throttle the speculative IO
*
* We can only throttle this if it is the first iobuf
* for the transaction. alloc_io_buf implements
* additional restrictions for diskimages anyway.
*/
priv = 0;
} else {
priv = 1;
}
cbp = alloc_io_buf(vp, priv);
if (flags & CL_PAGEOUT) {
u_int i;
/*
* since blocks are in offsets of 0x1000, scale
* iteration to (PAGE_SIZE * pg_count) of blks.
*/
for (i = 0; i < (PAGE_SIZE * pg_count) / 0x1000; i++) {
if (buf_invalblkno(vp, lblkno + i, 0) == EBUSY) {
panic("BUSY bp found in cluster_io");
}
}
}
if (flags & CL_ASYNC) {
if (buf_setcallback(cbp, (void *)cluster_iodone, callback_arg)) {
panic("buf_setcallback failed\n");
}
}
cbp->b_cliodone = (void *)callback;
cbp->b_flags |= io_flags;
if (flags & CL_NOCACHE) {
cbp->b_attr.ba_flags |= BA_NOCACHE;
}
cbp->b_lblkno = lblkno;
cbp->b_blkno = blkno;
cbp->b_bcount = io_size;
if (buf_setupl(cbp, upl, (uint32_t)upl_offset)) {
panic("buf_setupl failed\n");
}
#if CONFIG_IOSCHED
upl_set_blkno(upl, upl_offset, io_size, blkno);
#endif
cbp->b_trans_next = (buf_t)NULL;
if ((cbp->b_iostate = (void *)iostate)) {
/*
* caller wants to track the state of this
* io... bump the amount issued against this stream
*/
iostate->io_issued += io_size;
}
if (flags & CL_READ) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 26)) | DBG_FUNC_NONE,
(int)cbp->b_lblkno, (int)cbp->b_blkno, upl_offset, io_size, 0);
} else {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 27)) | DBG_FUNC_NONE,
(int)cbp->b_lblkno, (int)cbp->b_blkno, upl_offset, io_size, 0);
}
if (cbp_head) {
cbp_tail->b_trans_next = cbp;
cbp_tail = cbp;
} else {
cbp_head = cbp;
cbp_tail = cbp;
if ((cbp_head->b_real_bp = real_bp)) {
real_bp = (buf_t)NULL;
}
}
*(buf_t *)(&cbp->b_trans_head) = cbp_head;
trans_count++;
upl_offset += io_size;
f_offset += io_size;
size -= io_size;
/*
* keep track of how much of the original request
* that we've actually completed... non_rounded_size
* may go negative due to us rounding the request
* to a page size multiple (i.e. size > non_rounded_size)
*/
non_rounded_size -= io_size;
if (non_rounded_size <= 0) {
/*
* we've transferred all of the data in the original
* request, but we were unable to complete the tail
* of the last page because the file didn't have
* an allocation to back that portion... this is ok.
*/
size = 0;
}
if (size == 0) {
/*
* we have no more I/O to issue, so go
* finish the final transaction
*/
need_EOT = TRUE;
} else if (((flags & CL_DEV_MEMORY) || (upl_offset & PAGE_MASK) == 0) &&
((flags & CL_ASYNC) || trans_count > max_trans_count)) {
/*
* I/O directed to physically contiguous memory...
* which doesn't have a requirement to make sure we 'fill' a page
* or...
* the current I/O we've prepared fully
* completes the last page in this request
* and ...
* it's either an ASYNC request or
* we've already accumulated more than 8 I/O's into
* this transaction so mark it as complete so that
* it can finish asynchronously or via the cluster_complete_transaction
* below if the request is synchronous
*/
need_EOT = TRUE;
}
if (need_EOT == TRUE) {
cluster_EOT(cbp_head, cbp_tail, size == 0 ? zero_offset : 0);
}
if (flags & CL_THROTTLE) {
(void)vnode_waitforwrites(vp, async_throttle, 0, 0, "cluster_io");
}
if (!(io_flags & B_READ)) {
vnode_startwrite(vp);
}
if (flags & CL_RAW_ENCRYPTED) {
/*
* User requested raw encrypted bytes.
* Twiddle the bit in the ba_flags for the buffer
*/
cbp->b_attr.ba_flags |= BA_RAW_ENCRYPTED_IO;
}
(void) VNOP_STRATEGY(cbp);
if (need_EOT == TRUE) {
if (!(flags & CL_ASYNC)) {
cluster_complete_transaction(&cbp_head, callback_arg, &retval, flags, 1);
}
need_EOT = FALSE;
trans_count = 0;
cbp_head = NULL;
}
}
if (error) {
int abort_size;
io_size = 0;
if (cbp_head) {
/*
* Wait until all of the outstanding I/O
* for this partial transaction has completed
*/
cluster_wait_IO(cbp_head, (flags & CL_ASYNC));
/*
* Rewind the upl offset to the beginning of the
* transaction.
*/
upl_offset = cbp_head->b_uploffset;
}
if (ISSET(flags, CL_COMMIT)) {
cluster_handle_associated_upl(iostate, upl,
(upl_offset_t)upl_offset,
(upl_size_t)(upl_end_offset - upl_offset));
}
// Free all the IO buffers in this transaction
for (cbp = cbp_head; cbp;) {
buf_t cbp_next;
size += cbp->b_bcount;
io_size += cbp->b_bcount;
cbp_next = cbp->b_trans_next;
free_io_buf(cbp);
cbp = cbp_next;
}
if (iostate) {
int need_wakeup = 0;
/*
* update the error condition for this stream
* since we never really issued the io
* just go ahead and adjust it back
*/
lck_mtx_lock_spin(&iostate->io_mtxp);
if (iostate->io_error == 0) {
iostate->io_error = error;
}
iostate->io_issued -= io_size;
if (iostate->io_wanted) {
/*
* someone is waiting for the state of
* this io stream to change
*/
iostate->io_wanted = 0;
need_wakeup = 1;
}
lck_mtx_unlock(&iostate->io_mtxp);
if (need_wakeup) {
wakeup((caddr_t)&iostate->io_wanted);
}
}
if (flags & CL_COMMIT) {
int upl_flags;
pg_offset = upl_offset & PAGE_MASK;
abort_size = (int)((upl_end_offset - upl_offset + PAGE_MASK) & ~PAGE_MASK);
upl_flags = cluster_ioerror(upl, (int)(upl_offset - pg_offset),
abort_size, error, io_flags, vp);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 28)) | DBG_FUNC_NONE,
upl, upl_offset - pg_offset, abort_size, (error << 24) | upl_flags, 0);
}
if (retval == 0) {
retval = error;
}
} else if (cbp_head) {
panic("%s(): cbp_head is not NULL.\n", __FUNCTION__);
}
if (real_bp) {
/*
* can get here if we either encountered an error
* or we completely zero-filled the request and
* no I/O was issued
*/
if (error) {
real_bp->b_flags |= B_ERROR;
real_bp->b_error = error;
}
buf_biodone(real_bp);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 22)) | DBG_FUNC_END, (int)f_offset, size, upl_offset, retval, 0);
return retval;
}
#define reset_vector_run_state() \
issueVectorUPL = vector_upl_offset = vector_upl_index = vector_upl_iosize = vector_upl_size = 0;
static int
vector_cluster_io(vnode_t vp, upl_t vector_upl, vm_offset_t vector_upl_offset, off_t v_upl_uio_offset, int vector_upl_iosize,
int io_flag, buf_t real_bp, struct clios *iostate, int (*callback)(buf_t, void *), void *callback_arg)
{
vector_upl_set_pagelist(vector_upl);
if (io_flag & CL_READ) {
if (vector_upl_offset == 0 && ((vector_upl_iosize & PAGE_MASK) == 0)) {
io_flag &= ~CL_PRESERVE; /*don't zero fill*/
} else {
io_flag |= CL_PRESERVE; /*zero fill*/
}
}
return cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, real_bp, iostate, callback, callback_arg);
}
static int
cluster_read_prefetch(vnode_t vp, off_t f_offset, u_int size, off_t filesize, int (*callback)(buf_t, void *), void *callback_arg, int bflag)
{
int pages_in_prefetch;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 49)) | DBG_FUNC_START,
(int)f_offset, size, (int)filesize, 0, 0);
if (f_offset >= filesize) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 49)) | DBG_FUNC_END,
(int)f_offset, 0, 0, 0, 0);
return 0;
}
if ((off_t)size > (filesize - f_offset)) {
size = (u_int)(filesize - f_offset);
}
pages_in_prefetch = (size + (PAGE_SIZE - 1)) / PAGE_SIZE;
advisory_read_ext(vp, filesize, f_offset, size, callback, callback_arg, bflag);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 49)) | DBG_FUNC_END,
(int)f_offset + size, pages_in_prefetch, 0, 1, 0);
return pages_in_prefetch;
}
static void
cluster_read_ahead(vnode_t vp, struct cl_extent *extent, off_t filesize, struct cl_readahead *rap, int (*callback)(buf_t, void *), void *callback_arg,
int bflag)
{
daddr64_t r_addr;
off_t f_offset;
int size_of_prefetch;
u_int max_prefetch;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_START,
(int)extent->b_addr, (int)extent->e_addr, (int)rap->cl_lastr, 0, 0);
if (extent->b_addr == rap->cl_lastr && extent->b_addr == extent->e_addr) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_END,
rap->cl_ralen, (int)rap->cl_maxra, (int)rap->cl_lastr, 0, 0);
return;
}
if (rap->cl_lastr == -1 || (extent->b_addr != rap->cl_lastr && extent->b_addr != (rap->cl_lastr + 1))) {
rap->cl_ralen = 0;
rap->cl_maxra = 0;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_END,
rap->cl_ralen, (int)rap->cl_maxra, (int)rap->cl_lastr, 1, 0);
return;
}
max_prefetch = MAX_PREFETCH(vp, cluster_max_io_size(vp->v_mount, CL_READ), disk_conditioner_mount_is_ssd(vp->v_mount));
if (max_prefetch > speculative_prefetch_max) {
max_prefetch = speculative_prefetch_max;
}
if (max_prefetch <= PAGE_SIZE) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_END,
rap->cl_ralen, (int)rap->cl_maxra, (int)rap->cl_lastr, 6, 0);
return;
}
if (extent->e_addr < rap->cl_maxra && rap->cl_ralen >= 4) {
if ((rap->cl_maxra - extent->e_addr) > (rap->cl_ralen / 4)) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_END,
rap->cl_ralen, (int)rap->cl_maxra, (int)rap->cl_lastr, 2, 0);
return;
}
}
r_addr = MAX(extent->e_addr, rap->cl_maxra) + 1;
f_offset = (off_t)(r_addr * PAGE_SIZE_64);
size_of_prefetch = 0;
ubc_range_op(vp, f_offset, f_offset + PAGE_SIZE_64, UPL_ROP_PRESENT, &size_of_prefetch);
if (size_of_prefetch) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_END,
rap->cl_ralen, (int)rap->cl_maxra, (int)rap->cl_lastr, 3, 0);
return;
}
if (f_offset < filesize) {
daddr64_t read_size;
rap->cl_ralen = rap->cl_ralen ? min(max_prefetch / PAGE_SIZE, rap->cl_ralen << 1) : 1;
read_size = (extent->e_addr + 1) - extent->b_addr;
if (read_size > rap->cl_ralen) {
if (read_size > max_prefetch / PAGE_SIZE) {
rap->cl_ralen = max_prefetch / PAGE_SIZE;
} else {
rap->cl_ralen = (int)read_size;
}
}
size_of_prefetch = cluster_read_prefetch(vp, f_offset, rap->cl_ralen * PAGE_SIZE, filesize, callback, callback_arg, bflag);
if (size_of_prefetch) {
rap->cl_maxra = (r_addr + size_of_prefetch) - 1;
}
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 48)) | DBG_FUNC_END,
rap->cl_ralen, (int)rap->cl_maxra, (int)rap->cl_lastr, 4, 0);
}
int
cluster_pageout(vnode_t vp, upl_t upl, upl_offset_t upl_offset, off_t f_offset,
int size, off_t filesize, int flags)
{
return cluster_pageout_ext(vp, upl, upl_offset, f_offset, size, filesize, flags, NULL, NULL);
}
int
cluster_pageout_ext(vnode_t vp, upl_t upl, upl_offset_t upl_offset, off_t f_offset,
int size, off_t filesize, int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
int io_size;
int rounded_size;
off_t max_size;
int local_flags;
local_flags = CL_PAGEOUT | CL_THROTTLE;
if ((flags & UPL_IOSYNC) == 0) {
local_flags |= CL_ASYNC;
}
if ((flags & UPL_NOCOMMIT) == 0) {
local_flags |= CL_COMMIT;
}
if ((flags & UPL_KEEPCACHED)) {
local_flags |= CL_KEEPCACHED;
}
if (flags & UPL_PAGING_ENCRYPTED) {
local_flags |= CL_ENCRYPTED;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 52)) | DBG_FUNC_NONE,
(int)f_offset, size, (int)filesize, local_flags, 0);
/*
* If they didn't specify any I/O, then we are done...
* we can't issue an abort because we don't know how
* big the upl really is
*/
if (size <= 0) {
return EINVAL;
}
if (vp->v_mount->mnt_flag & MNT_RDONLY) {
if (local_flags & CL_COMMIT) {
ubc_upl_abort_range(upl, upl_offset, size, UPL_ABORT_FREE_ON_EMPTY);
}
return EROFS;
}
/*
* can't page-in from a negative offset
* or if we're starting beyond the EOF
* or if the file offset isn't page aligned
* or the size requested isn't a multiple of PAGE_SIZE
*/
if (f_offset < 0 || f_offset >= filesize ||
(f_offset & PAGE_MASK_64) || (size & PAGE_MASK)) {
if (local_flags & CL_COMMIT) {
ubc_upl_abort_range(upl, upl_offset, size, UPL_ABORT_FREE_ON_EMPTY);
}
return EINVAL;
}
max_size = filesize - f_offset;
if (size < max_size) {
io_size = size;
} else {
io_size = (int)max_size;
}
rounded_size = (io_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
if (size > rounded_size) {
if (local_flags & CL_COMMIT) {
ubc_upl_abort_range(upl, upl_offset + rounded_size, size - rounded_size,
UPL_ABORT_FREE_ON_EMPTY);
}
}
return cluster_io(vp, upl, upl_offset, f_offset, io_size,
local_flags, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
}
int
cluster_pagein(vnode_t vp, upl_t upl, upl_offset_t upl_offset, off_t f_offset,
int size, off_t filesize, int flags)
{
return cluster_pagein_ext(vp, upl, upl_offset, f_offset, size, filesize, flags, NULL, NULL);
}
int
cluster_pagein_ext(vnode_t vp, upl_t upl, upl_offset_t upl_offset, off_t f_offset,
int size, off_t filesize, int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
u_int io_size;
int rounded_size;
off_t max_size;
int retval;
int local_flags = 0;
if (upl == NULL || size < 0) {
panic("cluster_pagein: NULL upl passed in");
}
if ((flags & UPL_IOSYNC) == 0) {
local_flags |= CL_ASYNC;
}
if ((flags & UPL_NOCOMMIT) == 0) {
local_flags |= CL_COMMIT;
}
if (flags & UPL_IOSTREAMING) {
local_flags |= CL_IOSTREAMING;
}
if (flags & UPL_PAGING_ENCRYPTED) {
local_flags |= CL_ENCRYPTED;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 56)) | DBG_FUNC_NONE,
(int)f_offset, size, (int)filesize, local_flags, 0);
/*
* can't page-in from a negative offset
* or if we're starting beyond the EOF
* or if the file offset isn't page aligned
* or the size requested isn't a multiple of PAGE_SIZE
*/
if (f_offset < 0 || f_offset >= filesize ||
(f_offset & PAGE_MASK_64) || (size & PAGE_MASK) || (upl_offset & PAGE_MASK)) {
if (local_flags & CL_COMMIT) {
ubc_upl_abort_range(upl, upl_offset, size, UPL_ABORT_FREE_ON_EMPTY | UPL_ABORT_ERROR);
}
return EINVAL;
}
max_size = filesize - f_offset;
if (size < max_size) {
io_size = size;
} else {
io_size = (int)max_size;
}
rounded_size = (io_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
if (size > rounded_size && (local_flags & CL_COMMIT)) {
ubc_upl_abort_range(upl, upl_offset + rounded_size,
size - rounded_size, UPL_ABORT_FREE_ON_EMPTY | UPL_ABORT_ERROR);
}
retval = cluster_io(vp, upl, upl_offset, f_offset, io_size,
local_flags | CL_READ | CL_PAGEIN, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
return retval;
}
int
cluster_bp(buf_t bp)
{
return cluster_bp_ext(bp, NULL, NULL);
}
int
cluster_bp_ext(buf_t bp, int (*callback)(buf_t, void *), void *callback_arg)
{
off_t f_offset;
int flags;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 19)) | DBG_FUNC_START,
bp, (int)bp->b_lblkno, bp->b_bcount, bp->b_flags, 0);
if (bp->b_flags & B_READ) {
flags = CL_ASYNC | CL_READ;
} else {
flags = CL_ASYNC;
}
if (bp->b_flags & B_PASSIVE) {
flags |= CL_PASSIVE;
}
f_offset = ubc_blktooff(bp->b_vp, bp->b_lblkno);
return cluster_io(bp->b_vp, bp->b_upl, 0, f_offset, bp->b_bcount, flags, bp, (struct clios *)NULL, callback, callback_arg);
}
int
cluster_write(vnode_t vp, struct uio *uio, off_t oldEOF, off_t newEOF, off_t headOff, off_t tailOff, int xflags)
{
return cluster_write_ext(vp, uio, oldEOF, newEOF, headOff, tailOff, xflags, NULL, NULL);
}
int
cluster_write_ext(vnode_t vp, struct uio *uio, off_t oldEOF, off_t newEOF, off_t headOff, off_t tailOff,
int xflags, int (*callback)(buf_t, void *), void *callback_arg)
{
user_ssize_t cur_resid;
int retval = 0;
int flags;
int zflags;
int bflag;
int write_type = IO_COPY;
u_int32_t write_length;
flags = xflags;
if (flags & IO_PASSIVE) {
bflag = CL_PASSIVE;
} else {
bflag = 0;
}
if (vp->v_flag & VNOCACHE_DATA) {
flags |= IO_NOCACHE;
bflag |= CL_NOCACHE;
}
if (uio == NULL) {
/*
* no user data...
* this call is being made to zero-fill some range in the file
*/
retval = cluster_write_copy(vp, NULL, (u_int32_t)0, oldEOF, newEOF, headOff, tailOff, flags, callback, callback_arg);
return retval;
}
/*
* do a write through the cache if one of the following is true....
* NOCACHE is not true or NODIRECT is true
* the uio request doesn't target USERSPACE
* otherwise, find out if we want the direct or contig variant for
* the first vector in the uio request
*/
if (((flags & (IO_NOCACHE | IO_NODIRECT)) == IO_NOCACHE) && UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
retval = cluster_io_type(uio, &write_type, &write_length, MIN_DIRECT_WRITE_SIZE);
}
if ((flags & (IO_TAILZEROFILL | IO_HEADZEROFILL)) && write_type == IO_DIRECT) {
/*
* must go through the cached variant in this case
*/
write_type = IO_COPY;
}
while ((cur_resid = uio_resid(uio)) && uio->uio_offset < newEOF && retval == 0) {
switch (write_type) {
case IO_COPY:
/*
* make sure the uio_resid isn't too big...
* internally, we want to handle all of the I/O in
* chunk sizes that fit in a 32 bit int
*/
if (cur_resid > (user_ssize_t)(MAX_IO_REQUEST_SIZE)) {
/*
* we're going to have to call cluster_write_copy
* more than once...
*
* only want the last call to cluster_write_copy to
* have the IO_TAILZEROFILL flag set and only the
* first call should have IO_HEADZEROFILL
*/
zflags = flags & ~IO_TAILZEROFILL;
flags &= ~IO_HEADZEROFILL;
write_length = MAX_IO_REQUEST_SIZE;
} else {
/*
* last call to cluster_write_copy
*/
zflags = flags;
write_length = (u_int32_t)cur_resid;
}
retval = cluster_write_copy(vp, uio, write_length, oldEOF, newEOF, headOff, tailOff, zflags, callback, callback_arg);
break;
case IO_CONTIG:
zflags = flags & ~(IO_TAILZEROFILL | IO_HEADZEROFILL);
if (flags & IO_HEADZEROFILL) {
/*
* only do this once per request
*/
flags &= ~IO_HEADZEROFILL;
retval = cluster_write_copy(vp, (struct uio *)0, (u_int32_t)0, (off_t)0, uio->uio_offset,
headOff, (off_t)0, zflags | IO_HEADZEROFILL | IO_SYNC, callback, callback_arg);
if (retval) {
break;
}
}
retval = cluster_write_contig(vp, uio, newEOF, &write_type, &write_length, callback, callback_arg, bflag);
if (retval == 0 && (flags & IO_TAILZEROFILL) && uio_resid(uio) == 0) {
/*
* we're done with the data from the user specified buffer(s)
* and we've been requested to zero fill at the tail
* treat this as an IO_HEADZEROFILL which doesn't require a uio
* by rearranging the args and passing in IO_HEADZEROFILL
*/
retval = cluster_write_copy(vp, (struct uio *)0, (u_int32_t)0, (off_t)0, tailOff, uio->uio_offset,
(off_t)0, zflags | IO_HEADZEROFILL | IO_SYNC, callback, callback_arg);
}
break;
case IO_DIRECT:
/*
* cluster_write_direct is never called with IO_TAILZEROFILL || IO_HEADZEROFILL
*/
retval = cluster_write_direct(vp, uio, oldEOF, newEOF, &write_type, &write_length, flags, callback, callback_arg);
break;
case IO_UNKNOWN:
retval = cluster_io_type(uio, &write_type, &write_length, MIN_DIRECT_WRITE_SIZE);
break;
}
/*
* in case we end up calling cluster_write_copy (from cluster_write_direct)
* multiple times to service a multi-vector request that is not aligned properly
* we need to update the oldEOF so that we
* don't zero-fill the head of a page if we've successfully written
* data to that area... 'cluster_write_copy' will zero-fill the head of a
* page that is beyond the oldEOF if the write is unaligned... we only
* want that to happen for the very first page of the cluster_write,
* NOT the first page of each vector making up a multi-vector write.
*/
if (uio->uio_offset > oldEOF) {
oldEOF = uio->uio_offset;
}
}
return retval;
}
static int
cluster_write_direct(vnode_t vp, struct uio *uio, off_t oldEOF, off_t newEOF, int *write_type, u_int32_t *write_length,
int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
upl_t upl;
upl_page_info_t *pl;
vm_offset_t upl_offset;
vm_offset_t vector_upl_offset = 0;
u_int32_t io_req_size;
u_int32_t offset_in_file;
u_int32_t offset_in_iovbase;
u_int32_t io_size;
int io_flag = 0;
upl_size_t upl_size, vector_upl_size = 0;
vm_size_t upl_needed_size;
mach_msg_type_number_t pages_in_pl;
upl_control_flags_t upl_flags;
kern_return_t kret;
mach_msg_type_number_t i;
int force_data_sync;
int retval = 0;
int first_IO = 1;
struct clios iostate;
user_addr_t iov_base;
u_int32_t mem_alignment_mask;
u_int32_t devblocksize;
u_int32_t max_io_size;
u_int32_t max_upl_size;
u_int32_t max_vector_size;
u_int32_t bytes_outstanding_limit;
boolean_t io_throttled = FALSE;
u_int32_t vector_upl_iosize = 0;
int issueVectorUPL = 0, useVectorUPL = (uio->uio_iovcnt > 1);
off_t v_upl_uio_offset = 0;
int vector_upl_index = 0;
upl_t vector_upl = NULL;
/*
* When we enter this routine, we know
* -- the resid will not exceed iov_len
*/
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 75)) | DBG_FUNC_START,
(int)uio->uio_offset, *write_length, (int)newEOF, 0, 0);
assert(vm_map_page_shift(current_map()) >= PAGE_SHIFT);
max_upl_size = cluster_max_io_size(vp->v_mount, CL_WRITE);
io_flag = CL_ASYNC | CL_PRESERVE | CL_COMMIT | CL_THROTTLE | CL_DIRECT_IO;
if (flags & IO_PASSIVE) {
io_flag |= CL_PASSIVE;
}
if (flags & IO_NOCACHE) {
io_flag |= CL_NOCACHE;
}
if (flags & IO_SKIP_ENCRYPTION) {
io_flag |= CL_ENCRYPTED;
}
iostate.io_completed = 0;
iostate.io_issued = 0;
iostate.io_error = 0;
iostate.io_wanted = 0;
lck_mtx_init(&iostate.io_mtxp, &cl_mtx_grp, LCK_ATTR_NULL);
mem_alignment_mask = (u_int32_t)vp->v_mount->mnt_alignmentmask;
devblocksize = (u_int32_t)vp->v_mount->mnt_devblocksize;
if (devblocksize == 1) {
/*
* the AFP client advertises a devblocksize of 1
* however, its BLOCKMAP routine maps to physical
* blocks that are PAGE_SIZE in size...
* therefore we can't ask for I/Os that aren't page aligned
* or aren't multiples of PAGE_SIZE in size
* by setting devblocksize to PAGE_SIZE, we re-instate
* the old behavior we had before the mem_alignment_mask
* changes went in...
*/
devblocksize = PAGE_SIZE;
}
next_dwrite:
io_req_size = *write_length;
iov_base = uio_curriovbase(uio);
offset_in_file = (u_int32_t)uio->uio_offset & PAGE_MASK;
offset_in_iovbase = (u_int32_t)iov_base & mem_alignment_mask;
if (offset_in_file || offset_in_iovbase) {
/*
* one of the 2 important offsets is misaligned
* so fire an I/O through the cache for this entire vector
*/
goto wait_for_dwrites;
}
if (iov_base & (devblocksize - 1)) {
/*
* the offset in memory must be on a device block boundary
* so that we can guarantee that we can generate an
* I/O that ends on a page boundary in cluster_io
*/
goto wait_for_dwrites;
}
task_update_logical_writes(current_task(), (io_req_size & ~PAGE_MASK), TASK_WRITE_IMMEDIATE, vp);
while (io_req_size >= PAGE_SIZE && uio->uio_offset < newEOF && retval == 0) {
int throttle_type;
if ((throttle_type = cluster_is_throttled(vp))) {
/*
* we're in the throttle window, at the very least
* we want to limit the size of the I/O we're about
* to issue
*/
if ((flags & IO_RETURN_ON_THROTTLE) && throttle_type == THROTTLE_NOW) {
/*
* we're in the throttle window and at least 1 I/O
* has already been issued by a throttleable thread
* in this window, so return with EAGAIN to indicate
* to the FS issuing the cluster_write call that it
* should now throttle after dropping any locks
*/
throttle_info_update_by_mount(vp->v_mount);
io_throttled = TRUE;
goto wait_for_dwrites;
}
max_vector_size = THROTTLE_MAX_IOSIZE;
max_io_size = THROTTLE_MAX_IOSIZE;
} else {
max_vector_size = MAX_VECTOR_UPL_SIZE;
max_io_size = max_upl_size;
}
if (first_IO) {
cluster_syncup(vp, newEOF, callback, callback_arg, callback ? PUSH_SYNC : 0);
first_IO = 0;
}
io_size = io_req_size & ~PAGE_MASK;
iov_base = uio_curriovbase(uio);
if (io_size > max_io_size) {
io_size = max_io_size;
}
if (useVectorUPL && (iov_base & PAGE_MASK)) {
/*
* We have an iov_base that's not page-aligned.
* Issue all I/O's that have been collected within
* this Vectored UPL.
*/
if (vector_upl_index) {
retval = vector_cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
reset_vector_run_state();
}
/*
* After this point, if we are using the Vector UPL path and the base is
* not page-aligned then the UPL with that base will be the first in the vector UPL.
*/
}
upl_offset = (vm_offset_t)((u_int32_t)iov_base & PAGE_MASK);
upl_needed_size = (upl_offset + io_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 76)) | DBG_FUNC_START,
(int)upl_offset, upl_needed_size, (int)iov_base, io_size, 0);
vm_map_t map = UIO_SEG_IS_USER_SPACE(uio->uio_segflg) ? current_map() : kernel_map;
for (force_data_sync = 0; force_data_sync < 3; force_data_sync++) {
pages_in_pl = 0;
upl_size = (upl_size_t)upl_needed_size;
upl_flags = UPL_FILE_IO | UPL_COPYOUT_FROM | UPL_NO_SYNC |
UPL_CLEAN_IN_PLACE | UPL_SET_INTERNAL | UPL_SET_LITE | UPL_SET_IO_WIRE;
kret = vm_map_get_upl(map,
vm_map_trunc_page(iov_base, vm_map_page_mask(map)),
&upl_size,
&upl,
NULL,
&pages_in_pl,
&upl_flags,
VM_KERN_MEMORY_FILE,
force_data_sync);
if (kret != KERN_SUCCESS) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 76)) | DBG_FUNC_END,
0, 0, 0, kret, 0);
/*
* failed to get pagelist
*
* we may have already spun some portion of this request
* off as async requests... we need to wait for the I/O
* to complete before returning
*/
goto wait_for_dwrites;
}
pl = UPL_GET_INTERNAL_PAGE_LIST(upl);
pages_in_pl = upl_size / PAGE_SIZE;
for (i = 0; i < pages_in_pl; i++) {
if (!upl_valid_page(pl, i)) {
break;
}
}
if (i == pages_in_pl) {
break;
}
/*
* didn't get all the pages back that we
* needed... release this upl and try again
*/
ubc_upl_abort(upl, 0);
}
if (force_data_sync >= 3) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 76)) | DBG_FUNC_END,
i, pages_in_pl, upl_size, kret, 0);
/*
* for some reason, we couldn't acquire a hold on all
* the pages needed in the user's address space
*
* we may have already spun some portion of this request
* off as async requests... we need to wait for the I/O
* to complete before returning
*/
goto wait_for_dwrites;
}
/*
* Consider the possibility that upl_size wasn't satisfied.
*/
if (upl_size < upl_needed_size) {
if (upl_size && upl_offset == 0) {
io_size = upl_size;
} else {
io_size = 0;
}
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 76)) | DBG_FUNC_END,
(int)upl_offset, upl_size, (int)iov_base, io_size, 0);
if (io_size == 0) {
ubc_upl_abort(upl, 0);
/*
* we may have already spun some portion of this request
* off as async requests... we need to wait for the I/O
* to complete before returning
*/
goto wait_for_dwrites;
}
if (useVectorUPL) {
vm_offset_t end_off = ((iov_base + io_size) & PAGE_MASK);
if (end_off) {
issueVectorUPL = 1;
}
/*
* After this point, if we are using a vector UPL, then
* either all the UPL elements end on a page boundary OR
* this UPL is the last element because it does not end
* on a page boundary.
*/
}
/*
* we want push out these writes asynchronously so that we can overlap
* the preparation of the next I/O
* if there are already too many outstanding writes
* wait until some complete before issuing the next
*/
if (vp->v_mount->mnt_minsaturationbytecount) {
bytes_outstanding_limit = vp->v_mount->mnt_minsaturationbytecount;
} else {
bytes_outstanding_limit = max_upl_size * IO_SCALE(vp, 2);
}
cluster_iostate_wait(&iostate, bytes_outstanding_limit, "cluster_write_direct");
if (iostate.io_error) {
/*
* one of the earlier writes we issued ran into a hard error
* don't issue any more writes, cleanup the UPL
* that was just created but not used, then
* go wait for all writes that are part of this stream
* to complete before returning the error to the caller
*/
ubc_upl_abort(upl, 0);
goto wait_for_dwrites;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 77)) | DBG_FUNC_START,
(int)upl_offset, (int)uio->uio_offset, io_size, io_flag, 0);
if (!useVectorUPL) {
retval = cluster_io(vp, upl, upl_offset, uio->uio_offset,
io_size, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
} else {
if (!vector_upl_index) {
vector_upl = vector_upl_create(upl_offset);
v_upl_uio_offset = uio->uio_offset;
vector_upl_offset = upl_offset;
}
vector_upl_set_subupl(vector_upl, upl, upl_size);
vector_upl_set_iostate(vector_upl, upl, vector_upl_size, upl_size);
vector_upl_index++;
vector_upl_iosize += io_size;
vector_upl_size += upl_size;
if (issueVectorUPL || vector_upl_index == MAX_VECTOR_UPL_ELEMENTS || vector_upl_size >= max_vector_size) {
retval = vector_cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
reset_vector_run_state();
}
}
/*
* update the uio structure to
* reflect the I/O that we just issued
*/
uio_update(uio, (user_size_t)io_size);
/*
* in case we end up calling through to cluster_write_copy to finish
* the tail of this request, we need to update the oldEOF so that we
* don't zero-fill the head of a page if we've successfully written
* data to that area... 'cluster_write_copy' will zero-fill the head of a
* page that is beyond the oldEOF if the write is unaligned... we only
* want that to happen for the very first page of the cluster_write,
* NOT the first page of each vector making up a multi-vector write.
*/
if (uio->uio_offset > oldEOF) {
oldEOF = uio->uio_offset;
}
io_req_size -= io_size;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 77)) | DBG_FUNC_END,
(int)upl_offset, (int)uio->uio_offset, io_req_size, retval, 0);
} /* end while */
if (retval == 0 && iostate.io_error == 0 && io_req_size == 0) {
retval = cluster_io_type(uio, write_type, write_length, MIN_DIRECT_WRITE_SIZE);
if (retval == 0 && *write_type == IO_DIRECT) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 75)) | DBG_FUNC_NONE,
(int)uio->uio_offset, *write_length, (int)newEOF, 0, 0);
goto next_dwrite;
}
}
wait_for_dwrites:
if (retval == 0 && iostate.io_error == 0 && useVectorUPL && vector_upl_index) {
retval = vector_cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
reset_vector_run_state();
}
/*
* make sure all async writes issued as part of this stream
* have completed before we return
*/
cluster_iostate_wait(&iostate, 0, "cluster_write_direct");
if (iostate.io_error) {
retval = iostate.io_error;
}
lck_mtx_destroy(&iostate.io_mtxp, &cl_mtx_grp);
if (io_throttled == TRUE && retval == 0) {
retval = EAGAIN;
}
if (io_req_size && retval == 0) {
/*
* we couldn't handle the tail of this request in DIRECT mode
* so fire it through the copy path
*
* note that flags will never have IO_HEADZEROFILL or IO_TAILZEROFILL set
* so we can just pass 0 in for the headOff and tailOff
*/
if (uio->uio_offset > oldEOF) {
oldEOF = uio->uio_offset;
}
retval = cluster_write_copy(vp, uio, io_req_size, oldEOF, newEOF, (off_t)0, (off_t)0, flags, callback, callback_arg);
*write_type = IO_UNKNOWN;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 75)) | DBG_FUNC_END,
(int)uio->uio_offset, io_req_size, retval, 4, 0);
return retval;
}
static int
cluster_write_contig(vnode_t vp, struct uio *uio, off_t newEOF, int *write_type, u_int32_t *write_length,
int (*callback)(buf_t, void *), void *callback_arg, int bflag)
{
upl_page_info_t *pl;
addr64_t src_paddr = 0;
upl_t upl[MAX_VECTS];
vm_offset_t upl_offset;
u_int32_t tail_size = 0;
u_int32_t io_size;
u_int32_t xsize;
upl_size_t upl_size;
vm_size_t upl_needed_size;
mach_msg_type_number_t pages_in_pl;
upl_control_flags_t upl_flags;
kern_return_t kret;
struct clios iostate;
int error = 0;
int cur_upl = 0;
int num_upl = 0;
int n;
user_addr_t iov_base;
u_int32_t devblocksize;
u_int32_t mem_alignment_mask;
/*
* When we enter this routine, we know
* -- the io_req_size will not exceed iov_len
* -- the target address is physically contiguous
*/
cluster_syncup(vp, newEOF, callback, callback_arg, callback ? PUSH_SYNC : 0);
devblocksize = (u_int32_t)vp->v_mount->mnt_devblocksize;
mem_alignment_mask = (u_int32_t)vp->v_mount->mnt_alignmentmask;
iostate.io_completed = 0;
iostate.io_issued = 0;
iostate.io_error = 0;
iostate.io_wanted = 0;
lck_mtx_init(&iostate.io_mtxp, &cl_mtx_grp, LCK_ATTR_NULL);
next_cwrite:
io_size = *write_length;
iov_base = uio_curriovbase(uio);
upl_offset = (vm_offset_t)((u_int32_t)iov_base & PAGE_MASK);
upl_needed_size = upl_offset + io_size;
pages_in_pl = 0;
upl_size = (upl_size_t)upl_needed_size;
upl_flags = UPL_FILE_IO | UPL_COPYOUT_FROM | UPL_NO_SYNC |
UPL_CLEAN_IN_PLACE | UPL_SET_INTERNAL | UPL_SET_LITE | UPL_SET_IO_WIRE;
vm_map_t map = UIO_SEG_IS_USER_SPACE(uio->uio_segflg) ? current_map() : kernel_map;
kret = vm_map_get_upl(map,
vm_map_trunc_page(iov_base, vm_map_page_mask(map)),
&upl_size, &upl[cur_upl], NULL, &pages_in_pl, &upl_flags, VM_KERN_MEMORY_FILE, 0);
if (kret != KERN_SUCCESS) {
/*
* failed to get pagelist
*/
error = EINVAL;
goto wait_for_cwrites;
}
num_upl++;
/*
* Consider the possibility that upl_size wasn't satisfied.
*/
if (upl_size < upl_needed_size) {
/*
* This is a failure in the physical memory case.
*/
error = EINVAL;
goto wait_for_cwrites;
}
pl = ubc_upl_pageinfo(upl[cur_upl]);
src_paddr = ((addr64_t)upl_phys_page(pl, 0) << PAGE_SHIFT) + (addr64_t)upl_offset;
while (((uio->uio_offset & (devblocksize - 1)) || io_size < devblocksize) && io_size) {
u_int32_t head_size;
head_size = devblocksize - (u_int32_t)(uio->uio_offset & (devblocksize - 1));
if (head_size > io_size) {
head_size = io_size;
}
error = cluster_align_phys_io(vp, uio, src_paddr, head_size, 0, callback, callback_arg);
if (error) {
goto wait_for_cwrites;
}
upl_offset += head_size;
src_paddr += head_size;
io_size -= head_size;
iov_base += head_size;
}
if ((u_int32_t)iov_base & mem_alignment_mask) {
/*
* request doesn't set up on a memory boundary
* the underlying DMA engine can handle...
* return an error instead of going through
* the slow copy path since the intent of this
* path is direct I/O from device memory
*/
error = EINVAL;
goto wait_for_cwrites;
}
tail_size = io_size & (devblocksize - 1);
io_size -= tail_size;
while (io_size && error == 0) {
if (io_size > MAX_IO_CONTIG_SIZE) {
xsize = MAX_IO_CONTIG_SIZE;
} else {
xsize = io_size;
}
/*
* request asynchronously so that we can overlap
* the preparation of the next I/O... we'll do
* the commit after all the I/O has completed
* since its all issued against the same UPL
* if there are already too many outstanding writes
* wait until some have completed before issuing the next
*/
cluster_iostate_wait(&iostate, MAX_IO_CONTIG_SIZE * IO_SCALE(vp, 2), "cluster_write_contig");
if (iostate.io_error) {
/*
* one of the earlier writes we issued ran into a hard error
* don't issue any more writes...
* go wait for all writes that are part of this stream
* to complete before returning the error to the caller
*/
goto wait_for_cwrites;
}
/*
* issue an asynchronous write to cluster_io
*/
error = cluster_io(vp, upl[cur_upl], upl_offset, uio->uio_offset,
xsize, CL_DEV_MEMORY | CL_ASYNC | bflag, (buf_t)NULL, (struct clios *)&iostate, callback, callback_arg);
if (error == 0) {
/*
* The cluster_io write completed successfully,
* update the uio structure
*/
uio_update(uio, (user_size_t)xsize);
upl_offset += xsize;
src_paddr += xsize;
io_size -= xsize;
}
}
if (error == 0 && iostate.io_error == 0 && tail_size == 0 && num_upl < MAX_VECTS) {
error = cluster_io_type(uio, write_type, write_length, 0);
if (error == 0 && *write_type == IO_CONTIG) {
cur_upl++;
goto next_cwrite;
}
} else {
*write_type = IO_UNKNOWN;
}
wait_for_cwrites:
/*
* make sure all async writes that are part of this stream
* have completed before we proceed
*/
cluster_iostate_wait(&iostate, 0, "cluster_write_contig");
if (iostate.io_error) {
error = iostate.io_error;
}
lck_mtx_destroy(&iostate.io_mtxp, &cl_mtx_grp);
if (error == 0 && tail_size) {
error = cluster_align_phys_io(vp, uio, src_paddr, tail_size, 0, callback, callback_arg);
}
for (n = 0; n < num_upl; n++) {
/*
* just release our hold on each physically contiguous
* region without changing any state
*/
ubc_upl_abort(upl[n], 0);
}
return error;
}
/*
* need to avoid a race between an msync of a range of pages dirtied via mmap
* vs a filesystem such as HFS deciding to write a 'hole' to disk via cluster_write's
* zerofill mechanism before it has seen the VNOP_PAGEOUTs for the pages being msync'd
*
* we should never force-zero-fill pages that are already valid in the cache...
* the entire page contains valid data (either from disk, zero-filled or dirtied
* via an mmap) so we can only do damage by trying to zero-fill
*
*/
static int
cluster_zero_range(upl_t upl, upl_page_info_t *pl, int flags, int io_offset, off_t zero_off, off_t upl_f_offset, int bytes_to_zero)
{
int zero_pg_index;
boolean_t need_cluster_zero = TRUE;
if ((flags & (IO_NOZEROVALID | IO_NOZERODIRTY))) {
bytes_to_zero = min(bytes_to_zero, PAGE_SIZE - (int)(zero_off & PAGE_MASK_64));
zero_pg_index = (int)((zero_off - upl_f_offset) / PAGE_SIZE_64);
if (upl_valid_page(pl, zero_pg_index)) {
/*
* never force zero valid pages - dirty or clean
* we'll leave these in the UPL for cluster_write_copy to deal with
*/
need_cluster_zero = FALSE;
}
}
if (need_cluster_zero == TRUE) {
cluster_zero(upl, io_offset, bytes_to_zero, NULL);
}
return bytes_to_zero;
}
void
cluster_update_state(vnode_t vp, vm_object_offset_t s_offset, vm_object_offset_t e_offset, boolean_t vm_initiated)
{
struct cl_extent cl;
boolean_t first_pass = TRUE;
assert(s_offset < e_offset);
assert((s_offset & PAGE_MASK_64) == 0);
assert((e_offset & PAGE_MASK_64) == 0);
cl.b_addr = (daddr64_t)(s_offset / PAGE_SIZE_64);
cl.e_addr = (daddr64_t)(e_offset / PAGE_SIZE_64);
cluster_update_state_internal(vp, &cl, 0, TRUE, &first_pass, s_offset, (int)(e_offset - s_offset),
vp->v_un.vu_ubcinfo->ui_size, NULL, NULL, vm_initiated);
}
static void
cluster_update_state_internal(vnode_t vp, struct cl_extent *cl, int flags, boolean_t defer_writes,
boolean_t *first_pass, off_t write_off, int write_cnt, off_t newEOF,
int (*callback)(buf_t, void *), void *callback_arg, boolean_t vm_initiated)
{
struct cl_writebehind *wbp;
int cl_index;
int ret_cluster_try_push;
u_int max_cluster_pgcount;
max_cluster_pgcount = MAX_CLUSTER_SIZE(vp) / PAGE_SIZE;
/*
* take the lock to protect our accesses
* of the writebehind and sparse cluster state
*/
wbp = cluster_get_wbp(vp, CLW_ALLOCATE | CLW_RETURNLOCKED);
if (wbp->cl_scmap) {
if (!(flags & IO_NOCACHE)) {
/*
* we've fallen into the sparse
* cluster method of delaying dirty pages
*/
sparse_cluster_add(wbp, &(wbp->cl_scmap), vp, cl, newEOF, callback, callback_arg, vm_initiated);
lck_mtx_unlock(&wbp->cl_lockw);
return;
}
/*
* must have done cached writes that fell into
* the sparse cluster mechanism... we've switched
* to uncached writes on the file, so go ahead
* and push whatever's in the sparse map
* and switch back to normal clustering
*/
wbp->cl_number = 0;
sparse_cluster_push(wbp, &(wbp->cl_scmap), vp, newEOF, PUSH_ALL, 0, callback, callback_arg, vm_initiated);
/*
* no clusters of either type present at this point
* so just go directly to start_new_cluster since
* we know we need to delay this I/O since we've
* already released the pages back into the cache
* to avoid the deadlock with sparse_cluster_push
*/
goto start_new_cluster;
}
if (*first_pass == TRUE) {
if (write_off == wbp->cl_last_write) {
wbp->cl_seq_written += write_cnt;
} else {
wbp->cl_seq_written = write_cnt;
}
wbp->cl_last_write = write_off + write_cnt;
*first_pass = FALSE;
}
if (wbp->cl_number == 0) {
/*
* no clusters currently present
*/
goto start_new_cluster;
}
for (cl_index = 0; cl_index < wbp->cl_number; cl_index++) {
/*
* check each cluster that we currently hold
* try to merge some or all of this write into
* one or more of the existing clusters... if
* any portion of the write remains, start a
* new cluster
*/
if (cl->b_addr >= wbp->cl_clusters[cl_index].b_addr) {
/*
* the current write starts at or after the current cluster
*/
if (cl->e_addr <= (wbp->cl_clusters[cl_index].b_addr + max_cluster_pgcount)) {
/*
* we have a write that fits entirely
* within the existing cluster limits
*/
if (cl->e_addr > wbp->cl_clusters[cl_index].e_addr) {
/*
* update our idea of where the cluster ends
*/
wbp->cl_clusters[cl_index].e_addr = cl->e_addr;
}
break;
}
if (cl->b_addr < (wbp->cl_clusters[cl_index].b_addr + max_cluster_pgcount)) {
/*
* we have a write that starts in the middle of the current cluster
* but extends beyond the cluster's limit... we know this because
* of the previous checks
* we'll extend the current cluster to the max
* and update the b_addr for the current write to reflect that
* the head of it was absorbed into this cluster...
* note that we'll always have a leftover tail in this case since
* full absorbtion would have occurred in the clause above
*/
wbp->cl_clusters[cl_index].e_addr = wbp->cl_clusters[cl_index].b_addr + max_cluster_pgcount;
cl->b_addr = wbp->cl_clusters[cl_index].e_addr;
}
/*
* we come here for the case where the current write starts
* beyond the limit of the existing cluster or we have a leftover
* tail after a partial absorbtion
*
* in either case, we'll check the remaining clusters before
* starting a new one
*/
} else {
/*
* the current write starts in front of the cluster we're currently considering
*/
if ((wbp->cl_clusters[cl_index].e_addr - cl->b_addr) <= max_cluster_pgcount) {
/*
* we can just merge the new request into
* this cluster and leave it in the cache
* since the resulting cluster is still
* less than the maximum allowable size
*/
wbp->cl_clusters[cl_index].b_addr = cl->b_addr;
if (cl->e_addr > wbp->cl_clusters[cl_index].e_addr) {
/*
* the current write completely
* envelops the existing cluster and since
* each write is limited to at most max_cluster_pgcount pages
* we can just use the start and last blocknos of the write
* to generate the cluster limits
*/
wbp->cl_clusters[cl_index].e_addr = cl->e_addr;
}
break;
}
/*
* if we were to combine this write with the current cluster
* we would exceed the cluster size limit.... so,
* let's see if there's any overlap of the new I/O with
* the cluster we're currently considering... in fact, we'll
* stretch the cluster out to it's full limit and see if we
* get an intersection with the current write
*
*/
if (cl->e_addr > wbp->cl_clusters[cl_index].e_addr - max_cluster_pgcount) {
/*
* the current write extends into the proposed cluster
* clip the length of the current write after first combining it's
* tail with the newly shaped cluster
*/
wbp->cl_clusters[cl_index].b_addr = wbp->cl_clusters[cl_index].e_addr - max_cluster_pgcount;
cl->e_addr = wbp->cl_clusters[cl_index].b_addr;
}
/*
* if we get here, there was no way to merge
* any portion of this write with this cluster
* or we could only merge part of it which
* will leave a tail...
* we'll check the remaining clusters before starting a new one
*/
}
}
if (cl_index < wbp->cl_number) {
/*
* we found an existing cluster(s) that we
* could entirely merge this I/O into
*/
goto delay_io;
}
if (defer_writes == FALSE &&
wbp->cl_number == MAX_CLUSTERS &&
wbp->cl_seq_written >= (MAX_CLUSTERS * (max_cluster_pgcount * PAGE_SIZE))) {
uint32_t n;
if (vp->v_mount->mnt_minsaturationbytecount) {
n = vp->v_mount->mnt_minsaturationbytecount / MAX_CLUSTER_SIZE(vp);
if (n > MAX_CLUSTERS) {
n = MAX_CLUSTERS;
}
} else {
n = 0;
}
if (n == 0) {
if (disk_conditioner_mount_is_ssd(vp->v_mount)) {
n = WRITE_BEHIND_SSD;
} else {
n = WRITE_BEHIND;
}
}
while (n--) {
cluster_try_push(wbp, vp, newEOF, 0, 0, callback, callback_arg, NULL, vm_initiated);
}
}
if (wbp->cl_number < MAX_CLUSTERS) {
/*
* we didn't find an existing cluster to
* merge into, but there's room to start
* a new one
*/
goto start_new_cluster;
}
/*
* no exisitng cluster to merge with and no
* room to start a new one... we'll try
* pushing one of the existing ones... if none of
* them are able to be pushed, we'll switch
* to the sparse cluster mechanism
* cluster_try_push updates cl_number to the
* number of remaining clusters... and
* returns the number of currently unused clusters
*/
ret_cluster_try_push = 0;
/*
* if writes are not deferred, call cluster push immediately
*/
if (defer_writes == FALSE) {
ret_cluster_try_push = cluster_try_push(wbp, vp, newEOF, (flags & IO_NOCACHE) ? 0 : PUSH_DELAY, 0, callback, callback_arg, NULL, vm_initiated);
}
/*
* execute following regardless of writes being deferred or not
*/
if (ret_cluster_try_push == 0) {
/*
* no more room in the normal cluster mechanism
* so let's switch to the more expansive but expensive
* sparse mechanism....
*/
sparse_cluster_switch(wbp, vp, newEOF, callback, callback_arg, vm_initiated);
sparse_cluster_add(wbp, &(wbp->cl_scmap), vp, cl, newEOF, callback, callback_arg, vm_initiated);
lck_mtx_unlock(&wbp->cl_lockw);
return;
}
start_new_cluster:
wbp->cl_clusters[wbp->cl_number].b_addr = cl->b_addr;
wbp->cl_clusters[wbp->cl_number].e_addr = cl->e_addr;
wbp->cl_clusters[wbp->cl_number].io_flags = 0;
if (flags & IO_NOCACHE) {
wbp->cl_clusters[wbp->cl_number].io_flags |= CLW_IONOCACHE;
}
if (flags & IO_PASSIVE) {
wbp->cl_clusters[wbp->cl_number].io_flags |= CLW_IOPASSIVE;
}
wbp->cl_number++;
delay_io:
lck_mtx_unlock(&wbp->cl_lockw);
return;
}
static int
cluster_write_copy(vnode_t vp, struct uio *uio, u_int32_t io_req_size, off_t oldEOF, off_t newEOF, off_t headOff,
off_t tailOff, int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
upl_page_info_t *pl;
upl_t upl;
vm_offset_t upl_offset = 0;
vm_size_t upl_size;
off_t upl_f_offset;
int pages_in_upl;
int start_offset;
int xfer_resid;
int io_size;
int io_offset;
int bytes_to_zero;
int bytes_to_move;
kern_return_t kret;
int retval = 0;
int io_resid;
long long total_size;
long long zero_cnt;
off_t zero_off;
long long zero_cnt1;
off_t zero_off1;
off_t write_off = 0;
int write_cnt = 0;
boolean_t first_pass = FALSE;
struct cl_extent cl;
int bflag;
u_int max_io_size;
if (uio) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 40)) | DBG_FUNC_START,
(int)uio->uio_offset, io_req_size, (int)oldEOF, (int)newEOF, 0);
io_resid = io_req_size;
} else {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 40)) | DBG_FUNC_START,
0, 0, (int)oldEOF, (int)newEOF, 0);
io_resid = 0;
}
if (flags & IO_PASSIVE) {
bflag = CL_PASSIVE;
} else {
bflag = 0;
}
if (flags & IO_NOCACHE) {
bflag |= CL_NOCACHE;
}
if (flags & IO_SKIP_ENCRYPTION) {
bflag |= CL_ENCRYPTED;
}
zero_cnt = 0;
zero_cnt1 = 0;
zero_off = 0;
zero_off1 = 0;
max_io_size = cluster_max_io_size(vp->v_mount, CL_WRITE);
if (flags & IO_HEADZEROFILL) {
/*
* some filesystems (HFS is one) don't support unallocated holes within a file...
* so we zero fill the intervening space between the old EOF and the offset
* where the next chunk of real data begins.... ftruncate will also use this
* routine to zero fill to the new EOF when growing a file... in this case, the
* uio structure will not be provided
*/
if (uio) {
if (headOff < uio->uio_offset) {
zero_cnt = uio->uio_offset - headOff;
zero_off = headOff;
}
} else if (headOff < newEOF) {
zero_cnt = newEOF - headOff;
zero_off = headOff;
}
} else {
if (uio && uio->uio_offset > oldEOF) {
zero_off = uio->uio_offset & ~PAGE_MASK_64;
if (zero_off >= oldEOF) {
zero_cnt = uio->uio_offset - zero_off;
flags |= IO_HEADZEROFILL;
}
}
}
if (flags & IO_TAILZEROFILL) {
if (uio) {
zero_off1 = uio->uio_offset + io_req_size;
if (zero_off1 < tailOff) {
zero_cnt1 = tailOff - zero_off1;
}
}
} else {
if (uio && newEOF > oldEOF) {
zero_off1 = uio->uio_offset + io_req_size;
if (zero_off1 == newEOF && (zero_off1 & PAGE_MASK_64)) {
zero_cnt1 = PAGE_SIZE_64 - (zero_off1 & PAGE_MASK_64);
flags |= IO_TAILZEROFILL;
}
}
}
if (zero_cnt == 0 && uio == (struct uio *) 0) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 40)) | DBG_FUNC_END,
retval, 0, 0, 0, 0);
return 0;
}
if (uio) {
write_off = uio->uio_offset;
write_cnt = (int)uio_resid(uio);
/*
* delay updating the sequential write info
* in the control block until we've obtained
* the lock for it
*/
first_pass = TRUE;
}
while ((total_size = (io_resid + zero_cnt + zero_cnt1)) && retval == 0) {
/*
* for this iteration of the loop, figure out where our starting point is
*/
if (zero_cnt) {
start_offset = (int)(zero_off & PAGE_MASK_64);
upl_f_offset = zero_off - start_offset;
} else if (io_resid) {
start_offset = (int)(uio->uio_offset & PAGE_MASK_64);
upl_f_offset = uio->uio_offset - start_offset;
} else {
start_offset = (int)(zero_off1 & PAGE_MASK_64);
upl_f_offset = zero_off1 - start_offset;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 46)) | DBG_FUNC_NONE,
(int)zero_off, (int)zero_cnt, (int)zero_off1, (int)zero_cnt1, 0);
if (total_size > max_io_size) {
total_size = max_io_size;
}
cl.b_addr = (daddr64_t)(upl_f_offset / PAGE_SIZE_64);
if (uio && ((flags & (IO_SYNC | IO_HEADZEROFILL | IO_TAILZEROFILL)) == 0)) {
/*
* assumption... total_size <= io_resid
* because IO_HEADZEROFILL and IO_TAILZEROFILL not set
*/
if ((start_offset + total_size) > max_io_size) {
total_size = max_io_size - start_offset;
}
xfer_resid = (int)total_size;
retval = cluster_copy_ubc_data_internal(vp, uio, &xfer_resid, 1, 1);
if (retval) {
break;
}
io_resid -= (total_size - xfer_resid);
total_size = xfer_resid;
start_offset = (int)(uio->uio_offset & PAGE_MASK_64);
upl_f_offset = uio->uio_offset - start_offset;
if (total_size == 0) {
if (start_offset) {
/*
* the write did not finish on a page boundary
* which will leave upl_f_offset pointing to the
* beginning of the last page written instead of
* the page beyond it... bump it in this case
* so that the cluster code records the last page
* written as dirty
*/
upl_f_offset += PAGE_SIZE_64;
}
upl_size = 0;
goto check_cluster;
}
}
/*
* compute the size of the upl needed to encompass
* the requested write... limit each call to cluster_io
* to the maximum UPL size... cluster_io will clip if
* this exceeds the maximum io_size for the device,
* make sure to account for
* a starting offset that's not page aligned
*/
upl_size = (start_offset + total_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
if (upl_size > max_io_size) {
upl_size = max_io_size;
}
pages_in_upl = (int)(upl_size / PAGE_SIZE);
io_size = (int)(upl_size - start_offset);
if ((long long)io_size > total_size) {
io_size = (int)total_size;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 41)) | DBG_FUNC_START, upl_size, io_size, total_size, 0, 0);
/*
* Gather the pages from the buffer cache.
* The UPL_WILL_MODIFY flag lets the UPL subsystem know
* that we intend to modify these pages.
*/
kret = ubc_create_upl_kernel(vp,
upl_f_offset,
(int)upl_size,
&upl,
&pl,
UPL_SET_LITE | ((uio != NULL && (uio->uio_flags & UIO_FLAGS_IS_COMPRESSED_FILE)) ? 0 : UPL_WILL_MODIFY),
VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
panic("cluster_write_copy: failed to get pagelist");
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 41)) | DBG_FUNC_END,
upl, (int)upl_f_offset, start_offset, 0, 0);
if (start_offset && upl_f_offset < oldEOF && !upl_valid_page(pl, 0)) {
int read_size;
/*
* we're starting in the middle of the first page of the upl
* and the page isn't currently valid, so we're going to have
* to read it in first... this is a synchronous operation
*/
read_size = PAGE_SIZE;
if ((upl_f_offset + read_size) > oldEOF) {
read_size = (int)(oldEOF - upl_f_offset);
}
retval = cluster_io(vp, upl, 0, upl_f_offset, read_size,
CL_READ | bflag, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
if (retval) {
/*
* we had an error during the read which causes us to abort
* the current cluster_write request... before we do, we need
* to release the rest of the pages in the upl without modifying
* there state and mark the failed page in error
*/
ubc_upl_abort_range(upl, 0, PAGE_SIZE, UPL_ABORT_DUMP_PAGES | UPL_ABORT_FREE_ON_EMPTY);
if (upl_size > PAGE_SIZE) {
ubc_upl_abort_range(upl, 0, (upl_size_t)upl_size,
UPL_ABORT_FREE_ON_EMPTY);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 45)) | DBG_FUNC_NONE,
upl, 0, 0, retval, 0);
break;
}
}
if ((start_offset == 0 || upl_size > PAGE_SIZE) && ((start_offset + io_size) & PAGE_MASK)) {
/*
* the last offset we're writing to in this upl does not end on a page
* boundary... if it's not beyond the old EOF, then we'll also need to
* pre-read this page in if it isn't already valid
*/
upl_offset = upl_size - PAGE_SIZE;
if ((upl_f_offset + start_offset + io_size) < oldEOF &&
!upl_valid_page(pl, (int)(upl_offset / PAGE_SIZE))) {
int read_size;
read_size = PAGE_SIZE;
if ((off_t)(upl_f_offset + upl_offset + read_size) > oldEOF) {
read_size = (int)(oldEOF - (upl_f_offset + upl_offset));
}
retval = cluster_io(vp, upl, upl_offset, upl_f_offset + upl_offset, read_size,
CL_READ | bflag, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
if (retval) {
/*
* we had an error during the read which causes us to abort
* the current cluster_write request... before we do, we
* need to release the rest of the pages in the upl without
* modifying there state and mark the failed page in error
*/
ubc_upl_abort_range(upl, (upl_offset_t)upl_offset, PAGE_SIZE, UPL_ABORT_DUMP_PAGES | UPL_ABORT_FREE_ON_EMPTY);
if (upl_size > PAGE_SIZE) {
ubc_upl_abort_range(upl, 0, (upl_size_t)upl_size, UPL_ABORT_FREE_ON_EMPTY);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 45)) | DBG_FUNC_NONE,
upl, 0, 0, retval, 0);
break;
}
}
}
xfer_resid = io_size;
io_offset = start_offset;
while (zero_cnt && xfer_resid) {
if (zero_cnt < (long long)xfer_resid) {
bytes_to_zero = (int)zero_cnt;
} else {
bytes_to_zero = xfer_resid;
}
bytes_to_zero = cluster_zero_range(upl, pl, flags, io_offset, zero_off, upl_f_offset, bytes_to_zero);
xfer_resid -= bytes_to_zero;
zero_cnt -= bytes_to_zero;
zero_off += bytes_to_zero;
io_offset += bytes_to_zero;
}
if (xfer_resid && io_resid) {
u_int32_t io_requested;
bytes_to_move = min(io_resid, xfer_resid);
io_requested = bytes_to_move;
retval = cluster_copy_upl_data(uio, upl, io_offset, (int *)&io_requested);
if (retval) {
ubc_upl_abort_range(upl, 0, (upl_size_t)upl_size, UPL_ABORT_FREE_ON_EMPTY);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 45)) | DBG_FUNC_NONE,
upl, 0, 0, retval, 0);
} else {
io_resid -= bytes_to_move;
xfer_resid -= bytes_to_move;
io_offset += bytes_to_move;
}
}
while (xfer_resid && zero_cnt1 && retval == 0) {
if (zero_cnt1 < (long long)xfer_resid) {
bytes_to_zero = (int)zero_cnt1;
} else {
bytes_to_zero = xfer_resid;
}
bytes_to_zero = cluster_zero_range(upl, pl, flags, io_offset, zero_off1, upl_f_offset, bytes_to_zero);
xfer_resid -= bytes_to_zero;
zero_cnt1 -= bytes_to_zero;
zero_off1 += bytes_to_zero;
io_offset += bytes_to_zero;
}
if (retval == 0) {
int do_zeroing = 1;
io_size += start_offset;
/* Force more restrictive zeroing behavior only on APFS */
if ((vnode_tag(vp) == VT_APFS) && (newEOF < oldEOF)) {
do_zeroing = 0;
}
if (do_zeroing && (upl_f_offset + io_size) >= newEOF && (u_int)io_size < upl_size) {
/*
* if we're extending the file with this write
* we'll zero fill the rest of the page so that
* if the file gets extended again in such a way as to leave a
* hole starting at this EOF, we'll have zero's in the correct spot
*/
cluster_zero(upl, io_size, (int)(upl_size - io_size), NULL);
}
/*
* release the upl now if we hold one since...
* 1) pages in it may be present in the sparse cluster map
* and may span 2 separate buckets there... if they do and
* we happen to have to flush a bucket to make room and it intersects
* this upl, a deadlock may result on page BUSY
* 2) we're delaying the I/O... from this point forward we're just updating
* the cluster state... no need to hold the pages, so commit them
* 3) IO_SYNC is set...
* because we had to ask for a UPL that provides currenty non-present pages, the
* UPL has been automatically set to clear the dirty flags (both software and hardware)
* upon committing it... this is not the behavior we want since it's possible for
* pages currently present as part of a mapped file to be dirtied while the I/O is in flight.
* we'll pick these pages back up later with the correct behavior specified.
* 4) we don't want to hold pages busy in a UPL and then block on the cluster lock... if a flush
* of this vnode is in progress, we will deadlock if the pages being flushed intersect the pages
* we hold since the flushing context is holding the cluster lock.
*/
ubc_upl_commit_range(upl, 0, (upl_size_t)upl_size,
UPL_COMMIT_SET_DIRTY | UPL_COMMIT_INACTIVATE | UPL_COMMIT_FREE_ON_EMPTY);
check_cluster:
/*
* calculate the last logical block number
* that this delayed I/O encompassed
*/
cl.e_addr = (daddr64_t)((upl_f_offset + (off_t)upl_size) / PAGE_SIZE_64);
if (flags & IO_SYNC) {
/*
* if the IO_SYNC flag is set than we need to bypass
* any clustering and immediately issue the I/O
*
* we don't hold the lock at this point
*
* we've already dropped the current upl, so pick it back up with COPYOUT_FROM set
* so that we correctly deal with a change in state of the hardware modify bit...
* we do this via cluster_push_now... by passing along the IO_SYNC flag, we force
* cluster_push_now to wait until all the I/Os have completed... cluster_push_now is also
* responsible for generating the correct sized I/O(s)
*/
retval = cluster_push_now(vp, &cl, newEOF, flags, callback, callback_arg, FALSE);
} else {
boolean_t defer_writes = FALSE;
if (vfs_flags(vp->v_mount) & MNT_DEFWRITE) {
defer_writes = TRUE;
}
cluster_update_state_internal(vp, &cl, flags, defer_writes, &first_pass,
write_off, write_cnt, newEOF, callback, callback_arg, FALSE);
}
}
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 40)) | DBG_FUNC_END, retval, 0, io_resid, 0, 0);
return retval;
}
int
cluster_read(vnode_t vp, struct uio *uio, off_t filesize, int xflags)
{
return cluster_read_ext(vp, uio, filesize, xflags, NULL, NULL);
}
int
cluster_read_ext(vnode_t vp, struct uio *uio, off_t filesize, int xflags, int (*callback)(buf_t, void *), void *callback_arg)
{
int retval = 0;
int flags;
user_ssize_t cur_resid;
u_int32_t io_size;
u_int32_t read_length = 0;
int read_type = IO_COPY;
flags = xflags;
if (vp->v_flag & VNOCACHE_DATA) {
flags |= IO_NOCACHE;
}
if ((vp->v_flag & VRAOFF) || speculative_reads_disabled) {
flags |= IO_RAOFF;
}
if (flags & IO_SKIP_ENCRYPTION) {
flags |= IO_ENCRYPTED;
}
/*
* do a read through the cache if one of the following is true....
* NOCACHE is not true
* the uio request doesn't target USERSPACE
* Alternatively, if IO_ENCRYPTED is set, then we want to bypass the cache as well.
* Reading encrypted data from a CP filesystem should never result in the data touching
* the UBC.
*
* otherwise, find out if we want the direct or contig variant for
* the first vector in the uio request
*/
if (((flags & IO_NOCACHE) && UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) || (flags & IO_ENCRYPTED)) {
retval = cluster_io_type(uio, &read_type, &read_length, 0);
}
while ((cur_resid = uio_resid(uio)) && uio->uio_offset < filesize && retval == 0) {
switch (read_type) {
case IO_COPY:
/*
* make sure the uio_resid isn't too big...
* internally, we want to handle all of the I/O in
* chunk sizes that fit in a 32 bit int
*/
if (cur_resid > (user_ssize_t)(MAX_IO_REQUEST_SIZE)) {
io_size = MAX_IO_REQUEST_SIZE;
} else {
io_size = (u_int32_t)cur_resid;
}
retval = cluster_read_copy(vp, uio, io_size, filesize, flags, callback, callback_arg);
break;
case IO_DIRECT:
retval = cluster_read_direct(vp, uio, filesize, &read_type, &read_length, flags, callback, callback_arg);
break;
case IO_CONTIG:
retval = cluster_read_contig(vp, uio, filesize, &read_type, &read_length, callback, callback_arg, flags);
break;
case IO_UNKNOWN:
retval = cluster_io_type(uio, &read_type, &read_length, 0);
break;
}
}
return retval;
}
static void
cluster_read_upl_release(upl_t upl, int start_pg, int last_pg, int take_reference)
{
int range;
int abort_flags = UPL_ABORT_FREE_ON_EMPTY;
if ((range = last_pg - start_pg)) {
if (take_reference) {
abort_flags |= UPL_ABORT_REFERENCE;
}
ubc_upl_abort_range(upl, start_pg * PAGE_SIZE, range * PAGE_SIZE, abort_flags);
}
}
static int
cluster_read_copy(vnode_t vp, struct uio *uio, u_int32_t io_req_size, off_t filesize, int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
upl_page_info_t *pl;
upl_t upl;
vm_offset_t upl_offset;
u_int32_t upl_size;
off_t upl_f_offset;
int start_offset;
int start_pg;
int last_pg;
int uio_last = 0;
int pages_in_upl;
off_t max_size;
off_t last_ioread_offset;
off_t last_request_offset;
kern_return_t kret;
int error = 0;
int retval = 0;
u_int32_t size_of_prefetch;
u_int32_t xsize;
u_int32_t io_size;
u_int32_t max_rd_size;
u_int32_t max_io_size;
u_int32_t max_prefetch;
u_int rd_ahead_enabled = 1;
u_int prefetch_enabled = 1;
struct cl_readahead * rap;
struct clios iostate;
struct cl_extent extent;
int bflag;
int take_reference = 1;
int policy = IOPOL_DEFAULT;
boolean_t iolock_inited = FALSE;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 32)) | DBG_FUNC_START,
(int)uio->uio_offset, io_req_size, (int)filesize, flags, 0);
if (flags & IO_ENCRYPTED) {
panic("encrypted blocks will hit UBC!");
}
policy = throttle_get_io_policy(NULL);
if (policy == THROTTLE_LEVEL_TIER3 || policy == THROTTLE_LEVEL_TIER2 || (flags & IO_NOCACHE)) {
take_reference = 0;
}
if (flags & IO_PASSIVE) {
bflag = CL_PASSIVE;
} else {
bflag = 0;
}
if (flags & IO_NOCACHE) {
bflag |= CL_NOCACHE;
}
if (flags & IO_SKIP_ENCRYPTION) {
bflag |= CL_ENCRYPTED;
}
max_io_size = cluster_max_io_size(vp->v_mount, CL_READ);
max_prefetch = MAX_PREFETCH(vp, max_io_size, disk_conditioner_mount_is_ssd(vp->v_mount));
max_rd_size = max_prefetch;
last_request_offset = uio->uio_offset + io_req_size;
if (last_request_offset > filesize) {
last_request_offset = filesize;
}
if ((flags & (IO_RAOFF | IO_NOCACHE)) || ((last_request_offset & ~PAGE_MASK_64) == (uio->uio_offset & ~PAGE_MASK_64))) {
rd_ahead_enabled = 0;
rap = NULL;
} else {
if (cluster_is_throttled(vp)) {
/*
* we're in the throttle window, at the very least
* we want to limit the size of the I/O we're about
* to issue
*/
rd_ahead_enabled = 0;
prefetch_enabled = 0;
max_rd_size = THROTTLE_MAX_IOSIZE;
}
if ((rap = cluster_get_rap(vp)) == NULL) {
rd_ahead_enabled = 0;
} else {
extent.b_addr = uio->uio_offset / PAGE_SIZE_64;
extent.e_addr = (last_request_offset - 1) / PAGE_SIZE_64;
}
}
if (rap != NULL && rap->cl_ralen && (rap->cl_lastr == extent.b_addr || (rap->cl_lastr + 1) == extent.b_addr)) {
/*
* determine if we already have a read-ahead in the pipe courtesy of the
* last read systemcall that was issued...
* if so, pick up it's extent to determine where we should start
* with respect to any read-ahead that might be necessary to
* garner all the data needed to complete this read systemcall
*/
last_ioread_offset = (rap->cl_maxra * PAGE_SIZE_64) + PAGE_SIZE_64;
if (last_ioread_offset < uio->uio_offset) {
last_ioread_offset = (off_t)0;
} else if (last_ioread_offset > last_request_offset) {
last_ioread_offset = last_request_offset;
}
} else {
last_ioread_offset = (off_t)0;
}
while (io_req_size && uio->uio_offset < filesize && retval == 0) {
max_size = filesize - uio->uio_offset;
bool leftover_upl_aborted = false;
if ((off_t)(io_req_size) < max_size) {
io_size = io_req_size;
} else {
io_size = (u_int32_t)max_size;
}
if (!(flags & IO_NOCACHE)) {
while (io_size) {
u_int32_t io_resid;
u_int32_t io_requested;
/*
* if we keep finding the pages we need already in the cache, then
* don't bother to call cluster_read_prefetch since it costs CPU cycles
* to determine that we have all the pages we need... once we miss in
* the cache and have issued an I/O, than we'll assume that we're likely
* to continue to miss in the cache and it's to our advantage to try and prefetch
*/
if (last_request_offset && last_ioread_offset && (size_of_prefetch = (u_int32_t)(last_request_offset - last_ioread_offset))) {
if ((last_ioread_offset - uio->uio_offset) <= max_rd_size && prefetch_enabled) {
/*
* we've already issued I/O for this request and
* there's still work to do and
* our prefetch stream is running dry, so issue a
* pre-fetch I/O... the I/O latency will overlap
* with the copying of the data
*/
if (size_of_prefetch > max_rd_size) {
size_of_prefetch = max_rd_size;
}
size_of_prefetch = cluster_read_prefetch(vp, last_ioread_offset, size_of_prefetch, filesize, callback, callback_arg, bflag);
last_ioread_offset += (off_t)(size_of_prefetch * PAGE_SIZE);
if (last_ioread_offset > last_request_offset) {
last_ioread_offset = last_request_offset;
}
}
}
/*
* limit the size of the copy we're about to do so that
* we can notice that our I/O pipe is running dry and
* get the next I/O issued before it does go dry
*/
if (last_ioread_offset && io_size > (max_io_size / 4)) {
io_resid = (max_io_size / 4);
} else {
io_resid = io_size;
}
io_requested = io_resid;
retval = cluster_copy_ubc_data_internal(vp, uio, (int *)&io_resid, 0, take_reference);
xsize = io_requested - io_resid;
io_size -= xsize;
io_req_size -= xsize;
if (retval || io_resid) {
/*
* if we run into a real error or
* a page that is not in the cache
* we need to leave streaming mode
*/
break;
}
if (rd_ahead_enabled && (io_size == 0 || last_ioread_offset == last_request_offset)) {
/*
* we're already finished the I/O for this read request
* let's see if we should do a read-ahead
*/
cluster_read_ahead(vp, &extent, filesize, rap, callback, callback_arg, bflag);
}
}
if (retval) {
break;
}
if (io_size == 0) {
if (rap != NULL) {
if (extent.e_addr < rap->cl_lastr) {
rap->cl_maxra = 0;
}
rap->cl_lastr = extent.e_addr;
}
break;
}
/*
* recompute max_size since cluster_copy_ubc_data_internal
* may have advanced uio->uio_offset
*/
max_size = filesize - uio->uio_offset;
}
iostate.io_completed = 0;
iostate.io_issued = 0;
iostate.io_error = 0;
iostate.io_wanted = 0;
if ((flags & IO_RETURN_ON_THROTTLE)) {
if (cluster_is_throttled(vp) == THROTTLE_NOW) {
if (!cluster_io_present_in_BC(vp, uio->uio_offset)) {
/*
* we're in the throttle window and at least 1 I/O
* has already been issued by a throttleable thread
* in this window, so return with EAGAIN to indicate
* to the FS issuing the cluster_read call that it
* should now throttle after dropping any locks
*/
throttle_info_update_by_mount(vp->v_mount);
retval = EAGAIN;
break;
}
}
}
/*
* compute the size of the upl needed to encompass
* the requested read... limit each call to cluster_io
* to the maximum UPL size... cluster_io will clip if
* this exceeds the maximum io_size for the device,
* make sure to account for
* a starting offset that's not page aligned
*/
start_offset = (int)(uio->uio_offset & PAGE_MASK_64);
upl_f_offset = uio->uio_offset - (off_t)start_offset;
if (io_size > max_rd_size) {
io_size = max_rd_size;
}
upl_size = (start_offset + io_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
if (flags & IO_NOCACHE) {
if (upl_size > max_io_size) {
upl_size = max_io_size;
}
} else {
if (upl_size > max_io_size / 4) {
upl_size = max_io_size / 4;
upl_size &= ~PAGE_MASK;
if (upl_size == 0) {
upl_size = PAGE_SIZE;
}
}
}
pages_in_upl = upl_size / PAGE_SIZE;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 33)) | DBG_FUNC_START,
upl, (int)upl_f_offset, upl_size, start_offset, 0);
kret = ubc_create_upl_kernel(vp,
upl_f_offset,
upl_size,
&upl,
&pl,
UPL_FILE_IO | UPL_SET_LITE,
VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
panic("cluster_read_copy: failed to get pagelist");
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 33)) | DBG_FUNC_END,
upl, (int)upl_f_offset, upl_size, start_offset, 0);
/*
* scan from the beginning of the upl looking for the first
* non-valid page.... this will become the first page in
* the request we're going to make to 'cluster_io'... if all
* of the pages are valid, we won't call through to 'cluster_io'
*/
for (start_pg = 0; start_pg < pages_in_upl; start_pg++) {
if (!upl_valid_page(pl, start_pg)) {
break;
}
}
/*
* scan from the starting invalid page looking for a valid
* page before the end of the upl is reached, if we
* find one, then it will be the last page of the request to
* 'cluster_io'
*/
for (last_pg = start_pg; last_pg < pages_in_upl; last_pg++) {
if (upl_valid_page(pl, last_pg)) {
break;
}
}
if (start_pg < last_pg) {
/*
* we found a range of 'invalid' pages that must be filled
* if the last page in this range is the last page of the file
* we may have to clip the size of it to keep from reading past
* the end of the last physical block associated with the file
*/
if (iolock_inited == FALSE) {
lck_mtx_init(&iostate.io_mtxp, &cl_mtx_grp, LCK_ATTR_NULL);
iolock_inited = TRUE;
}
upl_offset = start_pg * PAGE_SIZE;
io_size = (last_pg - start_pg) * PAGE_SIZE;
if ((off_t)(upl_f_offset + upl_offset + io_size) > filesize) {
io_size = (u_int32_t)(filesize - (upl_f_offset + upl_offset));
}
/*
* Find out if this needs verification, we'll have to manage the UPL
* diffrently if so. Note that this call only lets us know if
* verification is enabled on this mount point, the actual verification
* is performed in the File system.
*/
size_t verify_block_size = 0;
if ((VNOP_VERIFY(vp, start_offset, NULL, 0, &verify_block_size, VNODE_VERIFY_DEFAULT, NULL) == 0) /* && verify_block_size */) {
for (uio_last = last_pg; uio_last < pages_in_upl; uio_last++) {
if (!upl_valid_page(pl, uio_last)) {
break;
}
}
if (uio_last < pages_in_upl) {
/*
* there were some invalid pages beyond the valid pages
* that we didn't issue an I/O for, just release them
* unchanged now, so that any prefetch/readahed can
* include them
*/
ubc_upl_abort_range(upl, uio_last * PAGE_SIZE,
(pages_in_upl - uio_last) * PAGE_SIZE, UPL_ABORT_FREE_ON_EMPTY);
leftover_upl_aborted = true;
}
}
/*
* issue an asynchronous read to cluster_io
*/
error = cluster_io(vp, upl, upl_offset, upl_f_offset + upl_offset,
io_size, CL_READ | CL_ASYNC | bflag, (buf_t)NULL, &iostate, callback, callback_arg);
if (rap) {
if (extent.e_addr < rap->cl_maxra) {
/*
* we've just issued a read for a block that should have been
* in the cache courtesy of the read-ahead engine... something
* has gone wrong with the pipeline, so reset the read-ahead
* logic which will cause us to restart from scratch
*/
rap->cl_maxra = 0;
}
}
}
if (error == 0) {
/*
* if the read completed successfully, or there was no I/O request
* issued, than copy the data into user land via 'cluster_upl_copy_data'
* we'll first add on any 'valid'
* pages that were present in the upl when we acquired it.
*/
u_int val_size;
if (!leftover_upl_aborted) {
for (uio_last = last_pg; uio_last < pages_in_upl; uio_last++) {
if (!upl_valid_page(pl, uio_last)) {
break;
}
}
if (uio_last < pages_in_upl) {
/*
* there were some invalid pages beyond the valid pages
* that we didn't issue an I/O for, just release them
* unchanged now, so that any prefetch/readahed can
* include them
*/
ubc_upl_abort_range(upl, uio_last * PAGE_SIZE,
(pages_in_upl - uio_last) * PAGE_SIZE, UPL_ABORT_FREE_ON_EMPTY);
}
}
/*
* compute size to transfer this round, if io_req_size is
* still non-zero after this attempt, we'll loop around and
* set up for another I/O.
*/
val_size = (uio_last * PAGE_SIZE) - start_offset;
if (val_size > max_size) {
val_size = (u_int)max_size;
}
if (val_size > io_req_size) {
val_size = io_req_size;
}
if ((uio->uio_offset + val_size) > last_ioread_offset) {
last_ioread_offset = uio->uio_offset + val_size;
}
if ((size_of_prefetch = (u_int32_t)(last_request_offset - last_ioread_offset)) && prefetch_enabled) {
if ((last_ioread_offset - (uio->uio_offset + val_size)) <= upl_size) {
/*
* if there's still I/O left to do for this request, and...
* we're not in hard throttle mode, and...
* we're close to using up the previous prefetch, then issue a
* new pre-fetch I/O... the I/O latency will overlap
* with the copying of the data
*/
if (size_of_prefetch > max_rd_size) {
size_of_prefetch = max_rd_size;
}
size_of_prefetch = cluster_read_prefetch(vp, last_ioread_offset, size_of_prefetch, filesize, callback, callback_arg, bflag);
last_ioread_offset += (off_t)(size_of_prefetch * PAGE_SIZE);
if (last_ioread_offset > last_request_offset) {
last_ioread_offset = last_request_offset;
}
}
} else if ((uio->uio_offset + val_size) == last_request_offset) {
/*
* this transfer will finish this request, so...
* let's try to read ahead if we're in
* a sequential access pattern and we haven't
* explicitly disabled it
*/
if (rd_ahead_enabled) {
cluster_read_ahead(vp, &extent, filesize, rap, callback, callback_arg, bflag);
}
if (rap != NULL) {
if (extent.e_addr < rap->cl_lastr) {
rap->cl_maxra = 0;
}
rap->cl_lastr = extent.e_addr;
}
}
if (iolock_inited == TRUE) {
cluster_iostate_wait(&iostate, 0, "cluster_read_copy");
}
if (iostate.io_error) {
error = iostate.io_error;
} else {
u_int32_t io_requested;
io_requested = val_size;
retval = cluster_copy_upl_data(uio, upl, start_offset, (int *)&io_requested);
io_req_size -= (val_size - io_requested);
}
} else {
if (iolock_inited == TRUE) {
cluster_iostate_wait(&iostate, 0, "cluster_read_copy");
}
}
if (start_pg < last_pg) {
/*
* compute the range of pages that we actually issued an I/O for
* and either commit them as valid if the I/O succeeded
* or abort them if the I/O failed or we're not supposed to
* keep them in the cache
*/
io_size = (last_pg - start_pg) * PAGE_SIZE;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 35)) | DBG_FUNC_START, upl, start_pg * PAGE_SIZE, io_size, error, 0);
if (error || (flags & IO_NOCACHE)) {
ubc_upl_abort_range(upl, start_pg * PAGE_SIZE, io_size,
UPL_ABORT_DUMP_PAGES | UPL_ABORT_FREE_ON_EMPTY);
} else {
int commit_flags = UPL_COMMIT_CLEAR_DIRTY | UPL_COMMIT_FREE_ON_EMPTY;
if (take_reference) {
commit_flags |= UPL_COMMIT_INACTIVATE;
} else {
commit_flags |= UPL_COMMIT_SPECULATE;
}
ubc_upl_commit_range(upl, start_pg * PAGE_SIZE, io_size, commit_flags);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 35)) | DBG_FUNC_END, upl, start_pg * PAGE_SIZE, io_size, error, 0);
}
if ((last_pg - start_pg) < pages_in_upl) {
/*
* the set of pages that we issued an I/O for did not encompass
* the entire upl... so just release these without modifying
* their state
*/
if (error) {
if (leftover_upl_aborted) {
ubc_upl_abort_range(upl, start_pg * PAGE_SIZE, (uio_last - start_pg) * PAGE_SIZE,
UPL_ABORT_FREE_ON_EMPTY);
} else {
ubc_upl_abort_range(upl, 0, upl_size, UPL_ABORT_FREE_ON_EMPTY);
}
} else {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 35)) | DBG_FUNC_START,
upl, -1, pages_in_upl - (last_pg - start_pg), 0, 0);
/*
* handle any valid pages at the beginning of
* the upl... release these appropriately
*/
cluster_read_upl_release(upl, 0, start_pg, take_reference);
/*
* handle any valid pages immediately after the
* pages we issued I/O for... ... release these appropriately
*/
cluster_read_upl_release(upl, last_pg, uio_last, take_reference);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 35)) | DBG_FUNC_END, upl, -1, -1, 0, 0);
}
}
if (retval == 0) {
retval = error;
}
if (io_req_size) {
if (cluster_is_throttled(vp)) {
/*
* we're in the throttle window, at the very least
* we want to limit the size of the I/O we're about
* to issue
*/
rd_ahead_enabled = 0;
prefetch_enabled = 0;
max_rd_size = THROTTLE_MAX_IOSIZE;
} else {
if (max_rd_size == THROTTLE_MAX_IOSIZE) {
/*
* coming out of throttled state
*/
if (policy != THROTTLE_LEVEL_TIER3 && policy != THROTTLE_LEVEL_TIER2) {
if (rap != NULL) {
rd_ahead_enabled = 1;
}
prefetch_enabled = 1;
}
max_rd_size = max_prefetch;
last_ioread_offset = 0;
}
}
}
}
if (iolock_inited == TRUE) {
/*
* cluster_io returned an error after it
* had already issued some I/O. we need
* to wait for that I/O to complete before
* we can destroy the iostate mutex...
* 'retval' already contains the early error
* so no need to pick it up from iostate.io_error
*/
cluster_iostate_wait(&iostate, 0, "cluster_read_copy");
lck_mtx_destroy(&iostate.io_mtxp, &cl_mtx_grp);
}
if (rap != NULL) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 32)) | DBG_FUNC_END,
(int)uio->uio_offset, io_req_size, rap->cl_lastr, retval, 0);
lck_mtx_unlock(&rap->cl_lockr);
} else {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 32)) | DBG_FUNC_END,
(int)uio->uio_offset, io_req_size, 0, retval, 0);
}
return retval;
}
/*
* We don't want another read/write lock for every vnode in the system
* so we keep a hash of them here. There should never be very many of
* these around at any point in time.
*/
cl_direct_read_lock_t *
cluster_lock_direct_read(vnode_t vp, lck_rw_type_t type)
{
struct cl_direct_read_locks *head
= &cl_direct_read_locks[(uintptr_t)vp / sizeof(*vp)
% CL_DIRECT_READ_LOCK_BUCKETS];
struct cl_direct_read_lock *lck, *new_lck = NULL;
for (;;) {
lck_spin_lock(&cl_direct_read_spin_lock);
LIST_FOREACH(lck, head, chain) {
if (lck->vp == vp) {
++lck->ref_count;
lck_spin_unlock(&cl_direct_read_spin_lock);
if (new_lck) {
// Someone beat us to it, ditch the allocation
lck_rw_destroy(&new_lck->rw_lock, &cl_mtx_grp);
kheap_free(KHEAP_DEFAULT, new_lck, sizeof(cl_direct_read_lock_t));
}
lck_rw_lock(&lck->rw_lock, type);
return lck;
}
}
if (new_lck) {
// Use the lock we allocated
LIST_INSERT_HEAD(head, new_lck, chain);
lck_spin_unlock(&cl_direct_read_spin_lock);
lck_rw_lock(&new_lck->rw_lock, type);
return new_lck;
}
lck_spin_unlock(&cl_direct_read_spin_lock);
// Allocate a new lock
new_lck = kheap_alloc(KHEAP_DEFAULT, sizeof(cl_direct_read_lock_t),
Z_WAITOK);
lck_rw_init(&new_lck->rw_lock, &cl_mtx_grp, LCK_ATTR_NULL);
new_lck->vp = vp;
new_lck->ref_count = 1;
// Got to go round again
}
}
void
cluster_unlock_direct_read(cl_direct_read_lock_t *lck)
{
lck_rw_done(&lck->rw_lock);
lck_spin_lock(&cl_direct_read_spin_lock);
if (lck->ref_count == 1) {
LIST_REMOVE(lck, chain);
lck_spin_unlock(&cl_direct_read_spin_lock);
lck_rw_destroy(&lck->rw_lock, &cl_mtx_grp);
kheap_free(KHEAP_DEFAULT, lck, sizeof(cl_direct_read_lock_t));
} else {
--lck->ref_count;
lck_spin_unlock(&cl_direct_read_spin_lock);
}
}
static int
cluster_read_direct(vnode_t vp, struct uio *uio, off_t filesize, int *read_type, u_int32_t *read_length,
int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
upl_t upl;
upl_page_info_t *pl;
off_t max_io_size;
vm_offset_t upl_offset, vector_upl_offset = 0;
upl_size_t upl_size, vector_upl_size = 0;
vm_size_t upl_needed_size;
unsigned int pages_in_pl;
upl_control_flags_t upl_flags;
kern_return_t kret;
unsigned int i;
int force_data_sync;
int retval = 0;
int no_zero_fill = 0;
int io_flag = 0;
int misaligned = 0;
struct clios iostate;
user_addr_t iov_base;
u_int32_t io_req_size;
u_int32_t offset_in_file;
u_int32_t offset_in_iovbase;
u_int32_t io_size;
u_int32_t io_min;
u_int32_t xsize;
u_int32_t devblocksize;
u_int32_t mem_alignment_mask;
u_int32_t max_upl_size;
u_int32_t max_rd_size;
u_int32_t max_rd_ahead;
u_int32_t max_vector_size;
boolean_t io_throttled = FALSE;
u_int32_t vector_upl_iosize = 0;
int issueVectorUPL = 0, useVectorUPL = (uio->uio_iovcnt > 1);
off_t v_upl_uio_offset = 0;
int vector_upl_index = 0;
upl_t vector_upl = NULL;
cl_direct_read_lock_t *lock = NULL;
user_addr_t orig_iov_base = 0;
user_addr_t last_iov_base = 0;
user_addr_t next_iov_base = 0;
assert(vm_map_page_shift(current_map()) >= PAGE_SHIFT);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 70)) | DBG_FUNC_START,
(int)uio->uio_offset, (int)filesize, *read_type, *read_length, 0);
max_upl_size = cluster_max_io_size(vp->v_mount, CL_READ);
max_rd_size = max_upl_size;
max_rd_ahead = max_rd_size * IO_SCALE(vp, 2);
io_flag = CL_COMMIT | CL_READ | CL_ASYNC | CL_NOZERO | CL_DIRECT_IO;
if (flags & IO_PASSIVE) {
io_flag |= CL_PASSIVE;
}
if (flags & IO_ENCRYPTED) {
io_flag |= CL_RAW_ENCRYPTED;
}
if (flags & IO_NOCACHE) {
io_flag |= CL_NOCACHE;
}
if (flags & IO_SKIP_ENCRYPTION) {
io_flag |= CL_ENCRYPTED;
}
iostate.io_completed = 0;
iostate.io_issued = 0;
iostate.io_error = 0;
iostate.io_wanted = 0;
lck_mtx_init(&iostate.io_mtxp, &cl_mtx_grp, LCK_ATTR_NULL);
devblocksize = (u_int32_t)vp->v_mount->mnt_devblocksize;
mem_alignment_mask = (u_int32_t)vp->v_mount->mnt_alignmentmask;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 70)) | DBG_FUNC_NONE,
(int)devblocksize, (int)mem_alignment_mask, 0, 0, 0);
if (devblocksize == 1) {
/*
* the AFP client advertises a devblocksize of 1
* however, its BLOCKMAP routine maps to physical
* blocks that are PAGE_SIZE in size...
* therefore we can't ask for I/Os that aren't page aligned
* or aren't multiples of PAGE_SIZE in size
* by setting devblocksize to PAGE_SIZE, we re-instate
* the old behavior we had before the mem_alignment_mask
* changes went in...
*/
devblocksize = PAGE_SIZE;
}
orig_iov_base = uio_curriovbase(uio);
last_iov_base = orig_iov_base;
next_dread:
io_req_size = *read_length;
iov_base = uio_curriovbase(uio);
offset_in_file = (u_int32_t)uio->uio_offset & (devblocksize - 1);
offset_in_iovbase = (u_int32_t)iov_base & mem_alignment_mask;
if (vm_map_page_mask(current_map()) < PAGE_MASK) {
/*
* XXX TODO4K
* Direct I/O might not work as expected from a 16k kernel space
* to a 4k user space because each 4k chunk might point to
* a different 16k physical page...
* Let's go the "misaligned" way.
*/
if (!misaligned) {
DEBUG4K_VFS("forcing misaligned\n");
}
misaligned = 1;
}
if (offset_in_file || offset_in_iovbase) {
/*
* one of the 2 important offsets is misaligned
* so fire an I/O through the cache for this entire vector
*/
misaligned = 1;
}
if (iov_base & (devblocksize - 1)) {
/*
* the offset in memory must be on a device block boundary
* so that we can guarantee that we can generate an
* I/O that ends on a page boundary in cluster_io
*/
misaligned = 1;
}
max_io_size = filesize - uio->uio_offset;
/*
* The user must request IO in aligned chunks. If the
* offset into the file is bad, or the userland pointer
* is non-aligned, then we cannot service the encrypted IO request.
*/
if (flags & IO_ENCRYPTED) {
if (misaligned || (io_req_size & (devblocksize - 1))) {
retval = EINVAL;
}
max_io_size = roundup(max_io_size, devblocksize);
}
if ((off_t)io_req_size > max_io_size) {
io_req_size = (u_int32_t)max_io_size;
}
/*
* When we get to this point, we know...
* -- the offset into the file is on a devblocksize boundary
*/
while (io_req_size && retval == 0) {
u_int32_t io_start;
if (cluster_is_throttled(vp)) {
/*
* we're in the throttle window, at the very least
* we want to limit the size of the I/O we're about
* to issue
*/
max_rd_size = THROTTLE_MAX_IOSIZE;
max_rd_ahead = THROTTLE_MAX_IOSIZE - 1;
max_vector_size = THROTTLE_MAX_IOSIZE;
} else {
max_rd_size = max_upl_size;
max_rd_ahead = max_rd_size * IO_SCALE(vp, 2);
max_vector_size = MAX_VECTOR_UPL_SIZE;
}
io_start = io_size = io_req_size;
/*
* First look for pages already in the cache
* and move them to user space. But only do this
* check if we are not retrieving encrypted data directly
* from the filesystem; those blocks should never
* be in the UBC.
*
* cluster_copy_ubc_data returns the resid
* in io_size
*/
if ((flags & IO_ENCRYPTED) == 0) {
retval = cluster_copy_ubc_data_internal(vp, uio, (int *)&io_size, 0, 0);
}
/*
* calculate the number of bytes actually copied
* starting size - residual
*/
xsize = io_start - io_size;
io_req_size -= xsize;
if (useVectorUPL && (xsize || (iov_base & PAGE_MASK))) {
/*
* We found something in the cache or we have an iov_base that's not
* page-aligned.
*
* Issue all I/O's that have been collected within this Vectored UPL.
*/
if (vector_upl_index) {
retval = vector_cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
reset_vector_run_state();
}
if (xsize) {
useVectorUPL = 0;
}
/*
* After this point, if we are using the Vector UPL path and the base is
* not page-aligned then the UPL with that base will be the first in the vector UPL.
*/
}
/*
* check to see if we are finished with this request.
*
* If we satisfied this IO already, then io_req_size will be 0.
* Otherwise, see if the IO was mis-aligned and needs to go through
* the UBC to deal with the 'tail'.
*
*/
if (io_req_size == 0 || (misaligned)) {
/*
* see if there's another uio vector to
* process that's of type IO_DIRECT
*
* break out of while loop to get there
*/
break;
}
/*
* assume the request ends on a device block boundary
*/
io_min = devblocksize;
/*
* we can handle I/O's in multiples of the device block size
* however, if io_size isn't a multiple of devblocksize we
* want to clip it back to the nearest page boundary since
* we are going to have to go through cluster_read_copy to
* deal with the 'overhang'... by clipping it to a PAGE_SIZE
* multiple, we avoid asking the drive for the same physical
* blocks twice.. once for the partial page at the end of the
* request and a 2nd time for the page we read into the cache
* (which overlaps the end of the direct read) in order to
* get at the overhang bytes
*/
if (io_size & (devblocksize - 1)) {
assert(!(flags & IO_ENCRYPTED));
/*
* Clip the request to the previous page size boundary
* since request does NOT end on a device block boundary
*/
io_size &= ~PAGE_MASK;
io_min = PAGE_SIZE;
}
if (retval || io_size < io_min) {
/*
* either an error or we only have the tail left to
* complete via the copy path...
* we may have already spun some portion of this request
* off as async requests... we need to wait for the I/O
* to complete before returning
*/
goto wait_for_dreads;
}
/*
* Don't re-check the UBC data if we are looking for uncached IO
* or asking for encrypted blocks.
*/
if ((flags & IO_ENCRYPTED) == 0) {
if ((xsize = io_size) > max_rd_size) {
xsize = max_rd_size;
}
io_size = 0;
if (!lock) {
/*
* We hold a lock here between the time we check the
* cache and the time we issue I/O. This saves us
* from having to lock the pages in the cache. Not
* all clients will care about this lock but some
* clients may want to guarantee stability between
* here and when the I/O is issued in which case they
* will take the lock exclusively.
*/
lock = cluster_lock_direct_read(vp, LCK_RW_TYPE_SHARED);
}
ubc_range_op(vp, uio->uio_offset, uio->uio_offset + xsize, UPL_ROP_ABSENT, (int *)&io_size);
if (io_size == 0) {
/*
* a page must have just come into the cache
* since the first page in this range is no
* longer absent, go back and re-evaluate
*/
continue;
}
}
if ((flags & IO_RETURN_ON_THROTTLE)) {
if (cluster_is_throttled(vp) == THROTTLE_NOW) {
if (!cluster_io_present_in_BC(vp, uio->uio_offset)) {
/*
* we're in the throttle window and at least 1 I/O
* has already been issued by a throttleable thread
* in this window, so return with EAGAIN to indicate
* to the FS issuing the cluster_read call that it
* should now throttle after dropping any locks
*/
throttle_info_update_by_mount(vp->v_mount);
io_throttled = TRUE;
goto wait_for_dreads;
}
}
}
if (io_size > max_rd_size) {
io_size = max_rd_size;
}
iov_base = uio_curriovbase(uio);
upl_offset = (vm_offset_t)((u_int32_t)iov_base & PAGE_MASK);
upl_needed_size = (upl_offset + io_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 72)) | DBG_FUNC_START,
(int)upl_offset, upl_needed_size, (int)iov_base, io_size, 0);
if (upl_offset == 0 && ((io_size & PAGE_MASK) == 0)) {
no_zero_fill = 1;
} else {
no_zero_fill = 0;
}
vm_map_t map = UIO_SEG_IS_USER_SPACE(uio->uio_segflg) ? current_map() : kernel_map;
for (force_data_sync = 0; force_data_sync < 3; force_data_sync++) {
pages_in_pl = 0;
upl_size = (upl_size_t)upl_needed_size;
upl_flags = UPL_FILE_IO | UPL_NO_SYNC | UPL_SET_INTERNAL | UPL_SET_LITE | UPL_SET_IO_WIRE;
if (no_zero_fill) {
upl_flags |= UPL_NOZEROFILL;
}
if (force_data_sync) {
upl_flags |= UPL_FORCE_DATA_SYNC;
}
kret = vm_map_create_upl(map,
(vm_map_offset_t)(iov_base & ~((user_addr_t)PAGE_MASK)),
&upl_size, &upl, NULL, &pages_in_pl, &upl_flags, VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 72)) | DBG_FUNC_END,
(int)upl_offset, upl_size, io_size, kret, 0);
/*
* failed to get pagelist
*
* we may have already spun some portion of this request
* off as async requests... we need to wait for the I/O
* to complete before returning
*/
goto wait_for_dreads;
}
pages_in_pl = upl_size / PAGE_SIZE;
pl = UPL_GET_INTERNAL_PAGE_LIST(upl);
for (i = 0; i < pages_in_pl; i++) {
if (!upl_page_present(pl, i)) {
break;
}
}
if (i == pages_in_pl) {
break;
}
ubc_upl_abort(upl, 0);
}
if (force_data_sync >= 3) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 72)) | DBG_FUNC_END,
(int)upl_offset, upl_size, io_size, kret, 0);
goto wait_for_dreads;
}
/*
* Consider the possibility that upl_size wasn't satisfied.
*/
if (upl_size < upl_needed_size) {
if (upl_size && upl_offset == 0) {
io_size = upl_size;
} else {
io_size = 0;
}
}
if (io_size == 0) {
ubc_upl_abort(upl, 0);
goto wait_for_dreads;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 72)) | DBG_FUNC_END,
(int)upl_offset, upl_size, io_size, kret, 0);
if (useVectorUPL) {
vm_offset_t end_off = ((iov_base + io_size) & PAGE_MASK);
if (end_off) {
issueVectorUPL = 1;
}
/*
* After this point, if we are using a vector UPL, then
* either all the UPL elements end on a page boundary OR
* this UPL is the last element because it does not end
* on a page boundary.
*/
}
/*
* request asynchronously so that we can overlap
* the preparation of the next I/O
* if there are already too many outstanding reads
* wait until some have completed before issuing the next read
*/
cluster_iostate_wait(&iostate, max_rd_ahead, "cluster_read_direct");
if (iostate.io_error) {
/*
* one of the earlier reads we issued ran into a hard error
* don't issue any more reads, cleanup the UPL
* that was just created but not used, then
* go wait for any other reads to complete before
* returning the error to the caller
*/
ubc_upl_abort(upl, 0);
goto wait_for_dreads;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 73)) | DBG_FUNC_START,
upl, (int)upl_offset, (int)uio->uio_offset, io_size, 0);
if (!useVectorUPL) {
if (no_zero_fill) {
io_flag &= ~CL_PRESERVE;
} else {
io_flag |= CL_PRESERVE;
}
retval = cluster_io(vp, upl, upl_offset, uio->uio_offset, io_size, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
} else {
if (!vector_upl_index) {
vector_upl = vector_upl_create(upl_offset);
v_upl_uio_offset = uio->uio_offset;
vector_upl_offset = upl_offset;
}
vector_upl_set_subupl(vector_upl, upl, upl_size);
vector_upl_set_iostate(vector_upl, upl, vector_upl_size, upl_size);
vector_upl_index++;
vector_upl_size += upl_size;
vector_upl_iosize += io_size;
if (issueVectorUPL || vector_upl_index == MAX_VECTOR_UPL_ELEMENTS || vector_upl_size >= max_vector_size) {
retval = vector_cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
reset_vector_run_state();
}
}
last_iov_base = iov_base + io_size;
if (lock) {
// We don't need to wait for the I/O to complete
cluster_unlock_direct_read(lock);
lock = NULL;
}
/*
* update the uio structure
*/
if ((flags & IO_ENCRYPTED) && (max_io_size < io_size)) {
uio_update(uio, (user_size_t)max_io_size);
} else {
uio_update(uio, (user_size_t)io_size);
}
io_req_size -= io_size;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 73)) | DBG_FUNC_END,
upl, (int)uio->uio_offset, io_req_size, retval, 0);
} /* end while */
if (retval == 0 && iostate.io_error == 0 && io_req_size == 0 && uio->uio_offset < filesize) {
retval = cluster_io_type(uio, read_type, read_length, 0);
if (retval == 0 && *read_type == IO_DIRECT) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 70)) | DBG_FUNC_NONE,
(int)uio->uio_offset, (int)filesize, *read_type, *read_length, 0);
goto next_dread;
}
}
wait_for_dreads:
if (retval == 0 && iostate.io_error == 0 && useVectorUPL && vector_upl_index) {
retval = vector_cluster_io(vp, vector_upl, vector_upl_offset, v_upl_uio_offset, vector_upl_iosize, io_flag, (buf_t)NULL, &iostate, callback, callback_arg);
reset_vector_run_state();
}
// We don't need to wait for the I/O to complete
if (lock) {
cluster_unlock_direct_read(lock);
}
/*
* make sure all async reads that are part of this stream
* have completed before we return
*/
cluster_iostate_wait(&iostate, 0, "cluster_read_direct");
if (iostate.io_error) {
retval = iostate.io_error;
}
lck_mtx_destroy(&iostate.io_mtxp, &cl_mtx_grp);
if (io_throttled == TRUE && retval == 0) {
retval = EAGAIN;
}
vm_map_offset_t current_page_size, current_page_mask;
current_page_size = vm_map_page_size(current_map());
current_page_mask = vm_map_page_mask(current_map());
for (next_iov_base = orig_iov_base;
next_iov_base < last_iov_base;
next_iov_base += current_page_size) {
/*
* This is specifically done for pmap accounting purposes.
* vm_pre_fault() will call vm_fault() to enter the page into
* the pmap if there isn't _a_ physical page for that VA already.
*/
vm_pre_fault(vm_map_trunc_page(next_iov_base, current_page_mask), VM_PROT_READ);
}
if (io_req_size && retval == 0) {
/*
* we couldn't handle the tail of this request in DIRECT mode
* so fire it through the copy path
*/
if (flags & IO_ENCRYPTED) {
/*
* We cannot fall back to the copy path for encrypted I/O. If this
* happens, there is something wrong with the user buffer passed
* down.
*/
retval = EFAULT;
} else {
retval = cluster_read_copy(vp, uio, io_req_size, filesize, flags, callback, callback_arg);
}
*read_type = IO_UNKNOWN;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 70)) | DBG_FUNC_END,
(int)uio->uio_offset, (int)uio_resid(uio), io_req_size, retval, 0);
return retval;
}
static int
cluster_read_contig(vnode_t vp, struct uio *uio, off_t filesize, int *read_type, u_int32_t *read_length,
int (*callback)(buf_t, void *), void *callback_arg, int flags)
{
upl_page_info_t *pl;
upl_t upl[MAX_VECTS];
vm_offset_t upl_offset;
addr64_t dst_paddr = 0;
user_addr_t iov_base;
off_t max_size;
upl_size_t upl_size;
vm_size_t upl_needed_size;
mach_msg_type_number_t pages_in_pl;
upl_control_flags_t upl_flags;
kern_return_t kret;
struct clios iostate;
int error = 0;
int cur_upl = 0;
int num_upl = 0;
int n;
u_int32_t xsize;
u_int32_t io_size;
u_int32_t devblocksize;
u_int32_t mem_alignment_mask;
u_int32_t tail_size = 0;
int bflag;
if (flags & IO_PASSIVE) {
bflag = CL_PASSIVE;
} else {
bflag = 0;
}
if (flags & IO_NOCACHE) {
bflag |= CL_NOCACHE;
}
/*
* When we enter this routine, we know
* -- the read_length will not exceed the current iov_len
* -- the target address is physically contiguous for read_length
*/
cluster_syncup(vp, filesize, callback, callback_arg, PUSH_SYNC);
devblocksize = (u_int32_t)vp->v_mount->mnt_devblocksize;
mem_alignment_mask = (u_int32_t)vp->v_mount->mnt_alignmentmask;
iostate.io_completed = 0;
iostate.io_issued = 0;
iostate.io_error = 0;
iostate.io_wanted = 0;
lck_mtx_init(&iostate.io_mtxp, &cl_mtx_grp, LCK_ATTR_NULL);
next_cread:
io_size = *read_length;
max_size = filesize - uio->uio_offset;
if (io_size > max_size) {
io_size = (u_int32_t)max_size;
}
iov_base = uio_curriovbase(uio);
upl_offset = (vm_offset_t)((u_int32_t)iov_base & PAGE_MASK);
upl_needed_size = upl_offset + io_size;
pages_in_pl = 0;
upl_size = (upl_size_t)upl_needed_size;
upl_flags = UPL_FILE_IO | UPL_NO_SYNC | UPL_CLEAN_IN_PLACE | UPL_SET_INTERNAL | UPL_SET_LITE | UPL_SET_IO_WIRE;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 92)) | DBG_FUNC_START,
(int)upl_offset, (int)upl_size, (int)iov_base, io_size, 0);
vm_map_t map = UIO_SEG_IS_USER_SPACE(uio->uio_segflg) ? current_map() : kernel_map;
kret = vm_map_get_upl(map,
vm_map_trunc_page(iov_base, vm_map_page_mask(map)),
&upl_size, &upl[cur_upl], NULL, &pages_in_pl, &upl_flags, VM_KERN_MEMORY_FILE, 0);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 92)) | DBG_FUNC_END,
(int)upl_offset, upl_size, io_size, kret, 0);
if (kret != KERN_SUCCESS) {
/*
* failed to get pagelist
*/
error = EINVAL;
goto wait_for_creads;
}
num_upl++;
if (upl_size < upl_needed_size) {
/*
* The upl_size wasn't satisfied.
*/
error = EINVAL;
goto wait_for_creads;
}
pl = ubc_upl_pageinfo(upl[cur_upl]);
dst_paddr = ((addr64_t)upl_phys_page(pl, 0) << PAGE_SHIFT) + (addr64_t)upl_offset;
while (((uio->uio_offset & (devblocksize - 1)) || io_size < devblocksize) && io_size) {
u_int32_t head_size;
head_size = devblocksize - (u_int32_t)(uio->uio_offset & (devblocksize - 1));
if (head_size > io_size) {
head_size = io_size;
}
error = cluster_align_phys_io(vp, uio, dst_paddr, head_size, CL_READ, callback, callback_arg);
if (error) {
goto wait_for_creads;
}
upl_offset += head_size;
dst_paddr += head_size;
io_size -= head_size;
iov_base += head_size;
}
if ((u_int32_t)iov_base & mem_alignment_mask) {
/*
* request doesn't set up on a memory boundary
* the underlying DMA engine can handle...
* return an error instead of going through
* the slow copy path since the intent of this
* path is direct I/O to device memory
*/
error = EINVAL;
goto wait_for_creads;
}
tail_size = io_size & (devblocksize - 1);
io_size -= tail_size;
while (io_size && error == 0) {
if (io_size > MAX_IO_CONTIG_SIZE) {
xsize = MAX_IO_CONTIG_SIZE;
} else {
xsize = io_size;
}
/*
* request asynchronously so that we can overlap
* the preparation of the next I/O... we'll do
* the commit after all the I/O has completed
* since its all issued against the same UPL
* if there are already too many outstanding reads
* wait until some have completed before issuing the next
*/
cluster_iostate_wait(&iostate, MAX_IO_CONTIG_SIZE * IO_SCALE(vp, 2), "cluster_read_contig");
if (iostate.io_error) {
/*
* one of the earlier reads we issued ran into a hard error
* don't issue any more reads...
* go wait for any other reads to complete before
* returning the error to the caller
*/
goto wait_for_creads;
}
error = cluster_io(vp, upl[cur_upl], upl_offset, uio->uio_offset, xsize,
CL_READ | CL_NOZERO | CL_DEV_MEMORY | CL_ASYNC | bflag,
(buf_t)NULL, &iostate, callback, callback_arg);
/*
* The cluster_io read was issued successfully,
* update the uio structure
*/
if (error == 0) {
uio_update(uio, (user_size_t)xsize);
dst_paddr += xsize;
upl_offset += xsize;
io_size -= xsize;
}
}
if (error == 0 && iostate.io_error == 0 && tail_size == 0 && num_upl < MAX_VECTS && uio->uio_offset < filesize) {
error = cluster_io_type(uio, read_type, read_length, 0);
if (error == 0 && *read_type == IO_CONTIG) {
cur_upl++;
goto next_cread;
}
} else {
*read_type = IO_UNKNOWN;
}
wait_for_creads:
/*
* make sure all async reads that are part of this stream
* have completed before we proceed
*/
cluster_iostate_wait(&iostate, 0, "cluster_read_contig");
if (iostate.io_error) {
error = iostate.io_error;
}
lck_mtx_destroy(&iostate.io_mtxp, &cl_mtx_grp);
if (error == 0 && tail_size) {
error = cluster_align_phys_io(vp, uio, dst_paddr, tail_size, CL_READ, callback, callback_arg);
}
for (n = 0; n < num_upl; n++) {
/*
* just release our hold on each physically contiguous
* region without changing any state
*/
ubc_upl_abort(upl[n], 0);
}
return error;
}
static int
cluster_io_type(struct uio *uio, int *io_type, u_int32_t *io_length, u_int32_t min_length)
{
user_size_t iov_len;
user_addr_t iov_base = 0;
upl_t upl;
upl_size_t upl_size;
upl_control_flags_t upl_flags;
int retval = 0;
/*
* skip over any emtpy vectors
*/
uio_update(uio, (user_size_t)0);
iov_len = uio_curriovlen(uio);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 94)) | DBG_FUNC_START, uio, (int)iov_len, 0, 0, 0);
if (iov_len) {
iov_base = uio_curriovbase(uio);
/*
* make sure the size of the vector isn't too big...
* internally, we want to handle all of the I/O in
* chunk sizes that fit in a 32 bit int
*/
if (iov_len > (user_size_t)MAX_IO_REQUEST_SIZE) {
upl_size = MAX_IO_REQUEST_SIZE;
} else {
upl_size = (u_int32_t)iov_len;
}
upl_flags = UPL_QUERY_OBJECT_TYPE;
vm_map_t map = UIO_SEG_IS_USER_SPACE(uio->uio_segflg) ? current_map() : kernel_map;
if ((vm_map_get_upl(map,
vm_map_trunc_page(iov_base, vm_map_page_mask(map)),
&upl_size, &upl, NULL, NULL, &upl_flags, VM_KERN_MEMORY_FILE, 0)) != KERN_SUCCESS) {
/*
* the user app must have passed in an invalid address
*/
retval = EFAULT;
}
if (upl_size == 0) {
retval = EFAULT;
}
*io_length = upl_size;
if (upl_flags & UPL_PHYS_CONTIG) {
*io_type = IO_CONTIG;
} else if (iov_len >= min_length) {
*io_type = IO_DIRECT;
} else {
*io_type = IO_COPY;
}
} else {
/*
* nothing left to do for this uio
*/
*io_length = 0;
*io_type = IO_UNKNOWN;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 94)) | DBG_FUNC_END, iov_base, *io_type, *io_length, retval, 0);
if (*io_type == IO_DIRECT &&
vm_map_page_shift(current_map()) < PAGE_SHIFT) {
/* no direct I/O for sub-page-size address spaces */
DEBUG4K_VFS("io_type IO_DIRECT -> IO_COPY\n");
*io_type = IO_COPY;
}
return retval;
}
/*
* generate advisory I/O's in the largest chunks possible
* the completed pages will be released into the VM cache
*/
int
advisory_read(vnode_t vp, off_t filesize, off_t f_offset, int resid)
{
return advisory_read_ext(vp, filesize, f_offset, resid, NULL, NULL, CL_PASSIVE);
}
int
advisory_read_ext(vnode_t vp, off_t filesize, off_t f_offset, int resid, int (*callback)(buf_t, void *), void *callback_arg, int bflag)
{
upl_page_info_t *pl;
upl_t upl;
vm_offset_t upl_offset;
int upl_size;
off_t upl_f_offset;
int start_offset;
int start_pg;
int last_pg;
int pages_in_upl;
off_t max_size;
int io_size;
kern_return_t kret;
int retval = 0;
int issued_io;
int skip_range;
uint32_t max_io_size;
if (!UBCINFOEXISTS(vp)) {
return EINVAL;
}
if (f_offset < 0 || resid < 0) {
return EINVAL;
}
max_io_size = cluster_max_io_size(vp->v_mount, CL_READ);
if (disk_conditioner_mount_is_ssd(vp->v_mount)) {
if (max_io_size > speculative_prefetch_max_iosize) {
max_io_size = speculative_prefetch_max_iosize;
}
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 60)) | DBG_FUNC_START,
(int)f_offset, resid, (int)filesize, 0, 0);
while (resid && f_offset < filesize && retval == 0) {
/*
* compute the size of the upl needed to encompass
* the requested read... limit each call to cluster_io
* to the maximum UPL size... cluster_io will clip if
* this exceeds the maximum io_size for the device,
* make sure to account for
* a starting offset that's not page aligned
*/
start_offset = (int)(f_offset & PAGE_MASK_64);
upl_f_offset = f_offset - (off_t)start_offset;
max_size = filesize - f_offset;
if (resid < max_size) {
io_size = resid;
} else {
io_size = (int)max_size;
}
upl_size = (start_offset + io_size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
if ((uint32_t)upl_size > max_io_size) {
upl_size = max_io_size;
}
skip_range = 0;
/*
* return the number of contiguously present pages in the cache
* starting at upl_f_offset within the file
*/
ubc_range_op(vp, upl_f_offset, upl_f_offset + upl_size, UPL_ROP_PRESENT, &skip_range);
if (skip_range) {
/*
* skip over pages already present in the cache
*/
io_size = skip_range - start_offset;
f_offset += io_size;
resid -= io_size;
if (skip_range == upl_size) {
continue;
}
/*
* have to issue some real I/O
* at this point, we know it's starting on a page boundary
* because we've skipped over at least the first page in the request
*/
start_offset = 0;
upl_f_offset += skip_range;
upl_size -= skip_range;
}
pages_in_upl = upl_size / PAGE_SIZE;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 61)) | DBG_FUNC_START,
upl, (int)upl_f_offset, upl_size, start_offset, 0);
kret = ubc_create_upl_kernel(vp,
upl_f_offset,
upl_size,
&upl,
&pl,
UPL_RET_ONLY_ABSENT | UPL_SET_LITE,
VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
return retval;
}
issued_io = 0;
/*
* before we start marching forward, we must make sure we end on
* a present page, otherwise we will be working with a freed
* upl
*/
for (last_pg = pages_in_upl - 1; last_pg >= 0; last_pg--) {
if (upl_page_present(pl, last_pg)) {
break;
}
}
pages_in_upl = last_pg + 1;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 61)) | DBG_FUNC_END,
upl, (int)upl_f_offset, upl_size, start_offset, 0);
for (last_pg = 0; last_pg < pages_in_upl;) {
/*
* scan from the beginning of the upl looking for the first
* page that is present.... this will become the first page in
* the request we're going to make to 'cluster_io'... if all
* of the pages are absent, we won't call through to 'cluster_io'
*/
for (start_pg = last_pg; start_pg < pages_in_upl; start_pg++) {
if (upl_page_present(pl, start_pg)) {
break;
}
}
/*
* scan from the starting present page looking for an absent
* page before the end of the upl is reached, if we
* find one, then it will terminate the range of pages being
* presented to 'cluster_io'
*/
for (last_pg = start_pg; last_pg < pages_in_upl; last_pg++) {
if (!upl_page_present(pl, last_pg)) {
break;
}
}
if (last_pg > start_pg) {
/*
* we found a range of pages that must be filled
* if the last page in this range is the last page of the file
* we may have to clip the size of it to keep from reading past
* the end of the last physical block associated with the file
*/
upl_offset = start_pg * PAGE_SIZE;
io_size = (last_pg - start_pg) * PAGE_SIZE;
if ((off_t)(upl_f_offset + upl_offset + io_size) > filesize) {
io_size = (int)(filesize - (upl_f_offset + upl_offset));
}
/*
* issue an asynchronous read to cluster_io
*/
retval = cluster_io(vp, upl, upl_offset, upl_f_offset + upl_offset, io_size,
CL_ASYNC | CL_READ | CL_COMMIT | CL_AGE | bflag, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
issued_io = 1;
}
}
if (issued_io == 0) {
ubc_upl_abort(upl, 0);
}
io_size = upl_size - start_offset;
if (io_size > resid) {
io_size = resid;
}
f_offset += io_size;
resid -= io_size;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 60)) | DBG_FUNC_END,
(int)f_offset, resid, retval, 0, 0);
return retval;
}
int
cluster_push(vnode_t vp, int flags)
{
return cluster_push_ext(vp, flags, NULL, NULL);
}
int
cluster_push_ext(vnode_t vp, int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
return cluster_push_err(vp, flags, callback, callback_arg, NULL);
}
/* write errors via err, but return the number of clusters written */
int
cluster_push_err(vnode_t vp, int flags, int (*callback)(buf_t, void *), void *callback_arg, int *err)
{
int retval;
int my_sparse_wait = 0;
struct cl_writebehind *wbp;
int local_err = 0;
if (err) {
*err = 0;
}
if (!UBCINFOEXISTS(vp)) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 53)) | DBG_FUNC_NONE, kdebug_vnode(vp), flags, 0, -1, 0);
return 0;
}
/* return if deferred write is set */
if (((unsigned int)vfs_flags(vp->v_mount) & MNT_DEFWRITE) && (flags & IO_DEFWRITE)) {
return 0;
}
if ((wbp = cluster_get_wbp(vp, CLW_RETURNLOCKED)) == NULL) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 53)) | DBG_FUNC_NONE, kdebug_vnode(vp), flags, 0, -2, 0);
return 0;
}
if (!ISSET(flags, IO_SYNC) && wbp->cl_number == 0 && wbp->cl_scmap == NULL) {
lck_mtx_unlock(&wbp->cl_lockw);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 53)) | DBG_FUNC_NONE, kdebug_vnode(vp), flags, 0, -3, 0);
return 0;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 53)) | DBG_FUNC_START,
wbp->cl_scmap, wbp->cl_number, flags, 0, 0);
/*
* if we have an fsync in progress, we don't want to allow any additional
* sync/fsync/close(s) to occur until it finishes.
* note that its possible for writes to continue to occur to this file
* while we're waiting and also once the fsync starts to clean if we're
* in the sparse map case
*/
while (wbp->cl_sparse_wait) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_START, kdebug_vnode(vp), 0, 0, 0, 0);
msleep((caddr_t)&wbp->cl_sparse_wait, &wbp->cl_lockw, PRIBIO + 1, "cluster_push_ext", NULL);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 97)) | DBG_FUNC_END, kdebug_vnode(vp), 0, 0, 0, 0);
}
if (flags & IO_SYNC) {
my_sparse_wait = 1;
wbp->cl_sparse_wait = 1;
/*
* this is an fsync (or equivalent)... we must wait for any existing async
* cleaning operations to complete before we evaulate the current state
* and finish cleaning... this insures that all writes issued before this
* fsync actually get cleaned to the disk before this fsync returns
*/
while (wbp->cl_sparse_pushes) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 98)) | DBG_FUNC_START, kdebug_vnode(vp), 0, 0, 0, 0);
msleep((caddr_t)&wbp->cl_sparse_pushes, &wbp->cl_lockw, PRIBIO + 1, "cluster_push_ext", NULL);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 98)) | DBG_FUNC_END, kdebug_vnode(vp), 0, 0, 0, 0);
}
}
if (wbp->cl_scmap) {
void *scmap;
if (wbp->cl_sparse_pushes < SPARSE_PUSH_LIMIT) {
scmap = wbp->cl_scmap;
wbp->cl_scmap = NULL;
wbp->cl_sparse_pushes++;
lck_mtx_unlock(&wbp->cl_lockw);
retval = sparse_cluster_push(wbp, &scmap, vp, ubc_getsize(vp), PUSH_ALL, flags, callback, callback_arg, FALSE);
lck_mtx_lock(&wbp->cl_lockw);
wbp->cl_sparse_pushes--;
if (retval) {
if (wbp->cl_scmap != NULL) {
panic("cluster_push_err: Expected NULL cl_scmap\n");
}
wbp->cl_scmap = scmap;
}
if (wbp->cl_sparse_wait && wbp->cl_sparse_pushes == 0) {
wakeup((caddr_t)&wbp->cl_sparse_pushes);
}
} else {
retval = sparse_cluster_push(wbp, &(wbp->cl_scmap), vp, ubc_getsize(vp), PUSH_ALL, flags, callback, callback_arg, FALSE);
}
local_err = retval;
if (err) {
*err = retval;
}
retval = 1;
} else {
retval = cluster_try_push(wbp, vp, ubc_getsize(vp), PUSH_ALL, flags, callback, callback_arg, &local_err, FALSE);
if (err) {
*err = local_err;
}
}
lck_mtx_unlock(&wbp->cl_lockw);
if (flags & IO_SYNC) {
(void)vnode_waitforwrites(vp, 0, 0, 0, "cluster_push");
}
if (my_sparse_wait) {
/*
* I'm the owner of the serialization token
* clear it and wakeup anyone that is waiting
* for me to finish
*/
lck_mtx_lock(&wbp->cl_lockw);
wbp->cl_sparse_wait = 0;
wakeup((caddr_t)&wbp->cl_sparse_wait);
lck_mtx_unlock(&wbp->cl_lockw);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 53)) | DBG_FUNC_END,
wbp->cl_scmap, wbp->cl_number, retval, local_err, 0);
return retval;
}
__private_extern__ void
cluster_release(struct ubc_info *ubc)
{
struct cl_writebehind *wbp;
struct cl_readahead *rap;
if ((wbp = ubc->cl_wbehind)) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 81)) | DBG_FUNC_START, ubc, wbp->cl_scmap, 0, 0, 0);
if (wbp->cl_scmap) {
vfs_drt_control(&(wbp->cl_scmap), 0);
}
lck_mtx_destroy(&wbp->cl_lockw, &cl_mtx_grp);
zfree(cl_wr_zone, wbp);
ubc->cl_wbehind = NULL;
} else {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 81)) | DBG_FUNC_START, ubc, 0, 0, 0, 0);
}
if ((rap = ubc->cl_rahead)) {
lck_mtx_destroy(&rap->cl_lockr, &cl_mtx_grp);
zfree(cl_rd_zone, rap);
ubc->cl_rahead = NULL;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 81)) | DBG_FUNC_END, ubc, rap, wbp, 0, 0);
}
static int
cluster_try_push(struct cl_writebehind *wbp, vnode_t vp, off_t EOF, int push_flag, int io_flags, int (*callback)(buf_t, void *), void *callback_arg, int *err, boolean_t vm_initiated)
{
int cl_index;
int cl_index1;
int min_index;
int cl_len;
int cl_pushed = 0;
struct cl_wextent l_clusters[MAX_CLUSTERS];
u_int max_cluster_pgcount;
int error = 0;
max_cluster_pgcount = MAX_CLUSTER_SIZE(vp) / PAGE_SIZE;
/*
* the write behind context exists and has
* already been locked...
*/
if (wbp->cl_number == 0) {
/*
* no clusters to push
* return number of empty slots
*/
return MAX_CLUSTERS;
}
/*
* make a local 'sorted' copy of the clusters
* and clear wbp->cl_number so that new clusters can
* be developed
*/
for (cl_index = 0; cl_index < wbp->cl_number; cl_index++) {
for (min_index = -1, cl_index1 = 0; cl_index1 < wbp->cl_number; cl_index1++) {
if (wbp->cl_clusters[cl_index1].b_addr == wbp->cl_clusters[cl_index1].e_addr) {
continue;
}
if (min_index == -1) {
min_index = cl_index1;
} else if (wbp->cl_clusters[cl_index1].b_addr < wbp->cl_clusters[min_index].b_addr) {
min_index = cl_index1;
}
}
if (min_index == -1) {
break;
}
l_clusters[cl_index].b_addr = wbp->cl_clusters[min_index].b_addr;
l_clusters[cl_index].e_addr = wbp->cl_clusters[min_index].e_addr;
l_clusters[cl_index].io_flags = wbp->cl_clusters[min_index].io_flags;
wbp->cl_clusters[min_index].b_addr = wbp->cl_clusters[min_index].e_addr;
}
wbp->cl_number = 0;
cl_len = cl_index;
/* skip switching to the sparse cluster mechanism if on diskimage */
if (((push_flag & PUSH_DELAY) && cl_len == MAX_CLUSTERS) &&
!(vp->v_mount->mnt_kern_flag & MNTK_VIRTUALDEV)) {
int i;
/*
* determine if we appear to be writing the file sequentially
* if not, by returning without having pushed any clusters
* we will cause this vnode to be pushed into the sparse cluster mechanism
* used for managing more random I/O patterns
*
* we know that we've got all clusters currently in use and the next write doesn't fit into one of them...
* that's why we're in try_push with PUSH_DELAY...
*
* check to make sure that all the clusters except the last one are 'full'... and that each cluster
* is adjacent to the next (i.e. we're looking for sequential writes) they were sorted above
* so we can just make a simple pass through, up to, but not including the last one...
* note that e_addr is not inclusive, so it will be equal to the b_addr of the next cluster if they
* are sequential
*
* we let the last one be partial as long as it was adjacent to the previous one...
* we need to do this to deal with multi-threaded servers that might write an I/O or 2 out
* of order... if this occurs at the tail of the last cluster, we don't want to fall into the sparse cluster world...
*/
for (i = 0; i < MAX_CLUSTERS - 1; i++) {
if ((l_clusters[i].e_addr - l_clusters[i].b_addr) != max_cluster_pgcount) {
goto dont_try;
}
if (l_clusters[i].e_addr != l_clusters[i + 1].b_addr) {
goto dont_try;
}
}
}
if (vm_initiated == TRUE) {
lck_mtx_unlock(&wbp->cl_lockw);
}
for (cl_index = 0; cl_index < cl_len; cl_index++) {
int flags;
struct cl_extent cl;
int retval;
flags = io_flags & (IO_PASSIVE | IO_CLOSE);
/*
* try to push each cluster in turn...
*/
if (l_clusters[cl_index].io_flags & CLW_IONOCACHE) {
flags |= IO_NOCACHE;
}
if (l_clusters[cl_index].io_flags & CLW_IOPASSIVE) {
flags |= IO_PASSIVE;
}
if (push_flag & PUSH_SYNC) {
flags |= IO_SYNC;
}
cl.b_addr = l_clusters[cl_index].b_addr;
cl.e_addr = l_clusters[cl_index].e_addr;
retval = cluster_push_now(vp, &cl, EOF, flags, callback, callback_arg, vm_initiated);
if (retval == 0) {
cl_pushed++;
l_clusters[cl_index].b_addr = 0;
l_clusters[cl_index].e_addr = 0;
} else if (error == 0) {
error = retval;
}
if (!(push_flag & PUSH_ALL)) {
break;
}
}
if (vm_initiated == TRUE) {
lck_mtx_lock(&wbp->cl_lockw);
}
if (err) {
*err = error;
}
dont_try:
if (cl_len > cl_pushed) {
/*
* we didn't push all of the clusters, so
* lets try to merge them back in to the vnode
*/
if ((MAX_CLUSTERS - wbp->cl_number) < (cl_len - cl_pushed)) {
/*
* we picked up some new clusters while we were trying to
* push the old ones... this can happen because I've dropped
* the vnode lock... the sum of the
* leftovers plus the new cluster count exceeds our ability
* to represent them, so switch to the sparse cluster mechanism
*
* collect the active public clusters...
*/
sparse_cluster_switch(wbp, vp, EOF, callback, callback_arg, vm_initiated);
for (cl_index = 0, cl_index1 = 0; cl_index < cl_len; cl_index++) {
if (l_clusters[cl_index].b_addr == l_clusters[cl_index].e_addr) {
continue;
}
wbp->cl_clusters[cl_index1].b_addr = l_clusters[cl_index].b_addr;
wbp->cl_clusters[cl_index1].e_addr = l_clusters[cl_index].e_addr;
wbp->cl_clusters[cl_index1].io_flags = l_clusters[cl_index].io_flags;
cl_index1++;
}
/*
* update the cluster count
*/
wbp->cl_number = cl_index1;
/*
* and collect the original clusters that were moved into the
* local storage for sorting purposes
*/
sparse_cluster_switch(wbp, vp, EOF, callback, callback_arg, vm_initiated);
} else {
/*
* we've got room to merge the leftovers back in
* just append them starting at the next 'hole'
* represented by wbp->cl_number
*/
for (cl_index = 0, cl_index1 = wbp->cl_number; cl_index < cl_len; cl_index++) {
if (l_clusters[cl_index].b_addr == l_clusters[cl_index].e_addr) {
continue;
}
wbp->cl_clusters[cl_index1].b_addr = l_clusters[cl_index].b_addr;
wbp->cl_clusters[cl_index1].e_addr = l_clusters[cl_index].e_addr;
wbp->cl_clusters[cl_index1].io_flags = l_clusters[cl_index].io_flags;
cl_index1++;
}
/*
* update the cluster count
*/
wbp->cl_number = cl_index1;
}
}
return MAX_CLUSTERS - wbp->cl_number;
}
static int
cluster_push_now(vnode_t vp, struct cl_extent *cl, off_t EOF, int flags,
int (*callback)(buf_t, void *), void *callback_arg, boolean_t vm_initiated)
{
upl_page_info_t *pl;
upl_t upl;
vm_offset_t upl_offset;
int upl_size;
off_t upl_f_offset;
int pages_in_upl;
int start_pg;
int last_pg;
int io_size;
int io_flags;
int upl_flags;
int bflag;
int size;
int error = 0;
int retval;
kern_return_t kret;
if (flags & IO_PASSIVE) {
bflag = CL_PASSIVE;
} else {
bflag = 0;
}
if (flags & IO_SKIP_ENCRYPTION) {
bflag |= CL_ENCRYPTED;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 51)) | DBG_FUNC_START,
(int)cl->b_addr, (int)cl->e_addr, (int)EOF, flags, 0);
if ((pages_in_upl = (int)(cl->e_addr - cl->b_addr)) == 0) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 51)) | DBG_FUNC_END, 1, 0, 0, 0, 0);
return 0;
}
upl_size = pages_in_upl * PAGE_SIZE;
upl_f_offset = (off_t)(cl->b_addr * PAGE_SIZE_64);
if (upl_f_offset + upl_size >= EOF) {
if (upl_f_offset >= EOF) {
/*
* must have truncated the file and missed
* clearing a dangling cluster (i.e. it's completely
* beyond the new EOF
*/
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 51)) | DBG_FUNC_END, 1, 1, 0, 0, 0);
return 0;
}
size = (int)(EOF - upl_f_offset);
upl_size = (size + (PAGE_SIZE - 1)) & ~PAGE_MASK;
pages_in_upl = upl_size / PAGE_SIZE;
} else {
size = upl_size;
}
if (vm_initiated) {
vnode_pageout(vp, NULL, (upl_offset_t)0, upl_f_offset, (upl_size_t)upl_size,
UPL_MSYNC | UPL_VNODE_PAGER | UPL_KEEPCACHED, &error);
return error;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 41)) | DBG_FUNC_START, upl_size, size, 0, 0, 0);
/*
* by asking for UPL_COPYOUT_FROM and UPL_RET_ONLY_DIRTY, we get the following desirable behavior
*
* - only pages that are currently dirty are returned... these are the ones we need to clean
* - the hardware dirty bit is cleared when the page is gathered into the UPL... the software dirty bit is set
* - if we have to abort the I/O for some reason, the software dirty bit is left set since we didn't clean the page
* - when we commit the page, the software dirty bit is cleared... the hardware dirty bit is untouched so that if
* someone dirties this page while the I/O is in progress, we don't lose track of the new state
*
* when the I/O completes, we no longer ask for an explicit clear of the DIRTY state (either soft or hard)
*/
if ((vp->v_flag & VNOCACHE_DATA) || (flags & IO_NOCACHE)) {
upl_flags = UPL_COPYOUT_FROM | UPL_RET_ONLY_DIRTY | UPL_SET_LITE | UPL_WILL_BE_DUMPED;
} else {
upl_flags = UPL_COPYOUT_FROM | UPL_RET_ONLY_DIRTY | UPL_SET_LITE;
}
kret = ubc_create_upl_kernel(vp,
upl_f_offset,
upl_size,
&upl,
&pl,
upl_flags,
VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
panic("cluster_push: failed to get pagelist");
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 41)) | DBG_FUNC_END, upl, upl_f_offset, 0, 0, 0);
/*
* since we only asked for the dirty pages back
* it's possible that we may only get a few or even none, so...
* before we start marching forward, we must make sure we know
* where the last present page is in the UPL, otherwise we could
* end up working with a freed upl due to the FREE_ON_EMPTY semantics
* employed by commit_range and abort_range.
*/
for (last_pg = pages_in_upl - 1; last_pg >= 0; last_pg--) {
if (upl_page_present(pl, last_pg)) {
break;
}
}
pages_in_upl = last_pg + 1;
if (pages_in_upl == 0) {
ubc_upl_abort(upl, 0);
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 51)) | DBG_FUNC_END, 1, 2, 0, 0, 0);
return 0;
}
for (last_pg = 0; last_pg < pages_in_upl;) {
/*
* find the next dirty page in the UPL
* this will become the first page in the
* next I/O to generate
*/
for (start_pg = last_pg; start_pg < pages_in_upl; start_pg++) {
if (upl_dirty_page(pl, start_pg)) {
break;
}
if (upl_page_present(pl, start_pg)) {
/*
* RET_ONLY_DIRTY will return non-dirty 'precious' pages
* just release these unchanged since we're not going
* to steal them or change their state
*/
ubc_upl_abort_range(upl, start_pg * PAGE_SIZE, PAGE_SIZE, UPL_ABORT_FREE_ON_EMPTY);
}
}
if (start_pg >= pages_in_upl) {
/*
* done... no more dirty pages to push
*/
break;
}
if (start_pg > last_pg) {
/*
* skipped over some non-dirty pages
*/
size -= ((start_pg - last_pg) * PAGE_SIZE);
}
/*
* find a range of dirty pages to write
*/
for (last_pg = start_pg; last_pg < pages_in_upl; last_pg++) {
if (!upl_dirty_page(pl, last_pg)) {
break;
}
}
upl_offset = start_pg * PAGE_SIZE;
io_size = min(size, (last_pg - start_pg) * PAGE_SIZE);
io_flags = CL_THROTTLE | CL_COMMIT | CL_AGE | bflag;
if (!(flags & IO_SYNC)) {
io_flags |= CL_ASYNC;
}
if (flags & IO_CLOSE) {
io_flags |= CL_CLOSE;
}
if (flags & IO_NOCACHE) {
io_flags |= CL_NOCACHE;
}
retval = cluster_io(vp, upl, upl_offset, upl_f_offset + upl_offset, io_size,
io_flags, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
if (error == 0 && retval) {
error = retval;
}
size -= io_size;
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 51)) | DBG_FUNC_END, 1, 3, error, 0, 0);
return error;
}
/*
* sparse_cluster_switch is called with the write behind lock held
*/
static int
sparse_cluster_switch(struct cl_writebehind *wbp, vnode_t vp, off_t EOF, int (*callback)(buf_t, void *), void *callback_arg, boolean_t vm_initiated)
{
int cl_index;
int error;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 78)) | DBG_FUNC_START, kdebug_vnode(vp), wbp->cl_scmap, wbp->cl_number, 0, 0);
for (cl_index = 0; cl_index < wbp->cl_number; cl_index++) {
int flags;
struct cl_extent cl;
for (cl.b_addr = wbp->cl_clusters[cl_index].b_addr; cl.b_addr < wbp->cl_clusters[cl_index].e_addr; cl.b_addr++) {
if (ubc_page_op(vp, (off_t)(cl.b_addr * PAGE_SIZE_64), 0, NULL, &flags) == KERN_SUCCESS) {
if (flags & UPL_POP_DIRTY) {
cl.e_addr = cl.b_addr + 1;
error = sparse_cluster_add(wbp, &(wbp->cl_scmap), vp, &cl, EOF, callback, callback_arg, vm_initiated);
if (error) {
break;
}
}
}
}
}
wbp->cl_number -= cl_index;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 78)) | DBG_FUNC_END, kdebug_vnode(vp), wbp->cl_scmap, wbp->cl_number, error, 0);
return error;
}
/*
* sparse_cluster_push must be called with the write-behind lock held if the scmap is
* still associated with the write-behind context... however, if the scmap has been disassociated
* from the write-behind context (the cluster_push case), the wb lock is not held
*/
static int
sparse_cluster_push(struct cl_writebehind *wbp, void **scmap, vnode_t vp, off_t EOF, int push_flag,
int io_flags, int (*callback)(buf_t, void *), void *callback_arg, boolean_t vm_initiated)
{
struct cl_extent cl;
off_t offset;
u_int length;
void *l_scmap;
int error = 0;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 79)) | DBG_FUNC_START, kdebug_vnode(vp), (*scmap), 0, push_flag, 0);
if (push_flag & PUSH_ALL) {
vfs_drt_control(scmap, 1);
}
l_scmap = *scmap;
for (;;) {
int retval;
if (vfs_drt_get_cluster(scmap, &offset, &length) != KERN_SUCCESS) {
break;
}
if (vm_initiated == TRUE) {
lck_mtx_unlock(&wbp->cl_lockw);
}
cl.b_addr = (daddr64_t)(offset / PAGE_SIZE_64);
cl.e_addr = (daddr64_t)((offset + length) / PAGE_SIZE_64);
retval = cluster_push_now(vp, &cl, EOF, io_flags, callback, callback_arg, vm_initiated);
if (error == 0 && retval) {
error = retval;
}
if (vm_initiated == TRUE) {
lck_mtx_lock(&wbp->cl_lockw);
if (*scmap != l_scmap) {
break;
}
}
if (error) {
if (vfs_drt_mark_pages(scmap, offset, length, NULL) != KERN_SUCCESS) {
panic("Failed to restore dirty state on failure\n");
}
break;
}
if (!(push_flag & PUSH_ALL)) {
break;
}
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 79)) | DBG_FUNC_END, kdebug_vnode(vp), (*scmap), error, 0, 0);
return error;
}
/*
* sparse_cluster_add is called with the write behind lock held
*/
static int
sparse_cluster_add(struct cl_writebehind *wbp, void **scmap, vnode_t vp, struct cl_extent *cl, off_t EOF,
int (*callback)(buf_t, void *), void *callback_arg, boolean_t vm_initiated)
{
u_int new_dirty;
u_int length;
off_t offset;
int error;
int push_flag = 0; /* Is this a valid value? */
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 80)) | DBG_FUNC_START, (*scmap), 0, cl->b_addr, (int)cl->e_addr, 0);
offset = (off_t)(cl->b_addr * PAGE_SIZE_64);
length = ((u_int)(cl->e_addr - cl->b_addr)) * PAGE_SIZE;
while (vfs_drt_mark_pages(scmap, offset, length, &new_dirty) != KERN_SUCCESS) {
/*
* no room left in the map
* only a partial update was done
* push out some pages and try again
*/
if (vfs_get_scmap_push_behavior_internal(scmap, &push_flag)) {
push_flag = 0;
}
error = sparse_cluster_push(wbp, scmap, vp, EOF, push_flag, 0, callback, callback_arg, vm_initiated);
if (error) {
break;
}
offset += (new_dirty * PAGE_SIZE_64);
length -= (new_dirty * PAGE_SIZE);
}
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 80)) | DBG_FUNC_END, kdebug_vnode(vp), (*scmap), error, 0, 0);
return error;
}
static int
cluster_align_phys_io(vnode_t vp, struct uio *uio, addr64_t usr_paddr, u_int32_t xsize, int flags, int (*callback)(buf_t, void *), void *callback_arg)
{
upl_page_info_t *pl;
upl_t upl;
addr64_t ubc_paddr;
kern_return_t kret;
int error = 0;
int did_read = 0;
int abort_flags;
int upl_flags;
int bflag;
if (flags & IO_PASSIVE) {
bflag = CL_PASSIVE;
} else {
bflag = 0;
}
if (flags & IO_NOCACHE) {
bflag |= CL_NOCACHE;
}
upl_flags = UPL_SET_LITE;
if (!(flags & CL_READ)) {
/*
* "write" operation: let the UPL subsystem know
* that we intend to modify the buffer cache pages
* we're gathering.
*/
upl_flags |= UPL_WILL_MODIFY;
} else {
/*
* indicate that there is no need to pull the
* mapping for this page... we're only going
* to read from it, not modify it.
*/
upl_flags |= UPL_FILE_IO;
}
kret = ubc_create_upl_kernel(vp,
uio->uio_offset & ~PAGE_MASK_64,
PAGE_SIZE,
&upl,
&pl,
upl_flags,
VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
return EINVAL;
}
if (!upl_valid_page(pl, 0)) {
/*
* issue a synchronous read to cluster_io
*/
error = cluster_io(vp, upl, 0, uio->uio_offset & ~PAGE_MASK_64, PAGE_SIZE,
CL_READ | bflag, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
if (error) {
ubc_upl_abort_range(upl, 0, PAGE_SIZE, UPL_ABORT_DUMP_PAGES | UPL_ABORT_FREE_ON_EMPTY);
return error;
}
did_read = 1;
}
ubc_paddr = ((addr64_t)upl_phys_page(pl, 0) << PAGE_SHIFT) + (addr64_t)(uio->uio_offset & PAGE_MASK_64);
/*
* NOTE: There is no prototype for the following in BSD. It, and the definitions
* of the defines for cppvPsrc, cppvPsnk, cppvFsnk, and cppvFsrc will be found in
* osfmk/ppc/mappings.h. They are not included here because there appears to be no
* way to do so without exporting them to kexts as well.
*/
if (flags & CL_READ) {
// copypv(ubc_paddr, usr_paddr, xsize, cppvPsrc | cppvPsnk | cppvFsnk); /* Copy physical to physical and flush the destination */
copypv(ubc_paddr, usr_paddr, xsize, 2 | 1 | 4); /* Copy physical to physical and flush the destination */
} else {
// copypv(usr_paddr, ubc_paddr, xsize, cppvPsrc | cppvPsnk | cppvFsrc); /* Copy physical to physical and flush the source */
copypv(usr_paddr, ubc_paddr, xsize, 2 | 1 | 8); /* Copy physical to physical and flush the source */
}
if (!(flags & CL_READ) || (upl_valid_page(pl, 0) && upl_dirty_page(pl, 0))) {
/*
* issue a synchronous write to cluster_io
*/
error = cluster_io(vp, upl, 0, uio->uio_offset & ~PAGE_MASK_64, PAGE_SIZE,
bflag, (buf_t)NULL, (struct clios *)NULL, callback, callback_arg);
}
if (error == 0) {
uio_update(uio, (user_size_t)xsize);
}
if (did_read) {
abort_flags = UPL_ABORT_FREE_ON_EMPTY;
} else {
abort_flags = UPL_ABORT_FREE_ON_EMPTY | UPL_ABORT_DUMP_PAGES;
}
ubc_upl_abort_range(upl, 0, PAGE_SIZE, abort_flags);
return error;
}
int
cluster_copy_upl_data(struct uio *uio, upl_t upl, int upl_offset, int *io_resid)
{
int pg_offset;
int pg_index;
int csize;
int segflg;
int retval = 0;
int xsize;
upl_page_info_t *pl;
int dirty_count;
xsize = *io_resid;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 34)) | DBG_FUNC_START,
(int)uio->uio_offset, upl_offset, xsize, 0, 0);
segflg = uio->uio_segflg;
switch (segflg) {
case UIO_USERSPACE32:
case UIO_USERISPACE32:
uio->uio_segflg = UIO_PHYS_USERSPACE32;
break;
case UIO_USERSPACE:
case UIO_USERISPACE:
uio->uio_segflg = UIO_PHYS_USERSPACE;
break;
case UIO_USERSPACE64:
case UIO_USERISPACE64:
uio->uio_segflg = UIO_PHYS_USERSPACE64;
break;
case UIO_SYSSPACE:
uio->uio_segflg = UIO_PHYS_SYSSPACE;
break;
}
pl = ubc_upl_pageinfo(upl);
pg_index = upl_offset / PAGE_SIZE;
pg_offset = upl_offset & PAGE_MASK;
csize = min(PAGE_SIZE - pg_offset, xsize);
dirty_count = 0;
while (xsize && retval == 0) {
addr64_t paddr;
paddr = ((addr64_t)upl_phys_page(pl, pg_index) << PAGE_SHIFT) + pg_offset;
if ((uio->uio_rw == UIO_WRITE) && (upl_dirty_page(pl, pg_index) == FALSE)) {
dirty_count++;
}
retval = uiomove64(paddr, csize, uio);
pg_index += 1;
pg_offset = 0;
xsize -= csize;
csize = min(PAGE_SIZE, xsize);
}
*io_resid = xsize;
uio->uio_segflg = segflg;
task_update_logical_writes(current_task(), (dirty_count * PAGE_SIZE), TASK_WRITE_DEFERRED, upl_lookup_vnode(upl));
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 34)) | DBG_FUNC_END,
(int)uio->uio_offset, xsize, retval, segflg, 0);
return retval;
}
int
cluster_copy_ubc_data(vnode_t vp, struct uio *uio, int *io_resid, int mark_dirty)
{
return cluster_copy_ubc_data_internal(vp, uio, io_resid, mark_dirty, 1);
}
static int
cluster_copy_ubc_data_internal(vnode_t vp, struct uio *uio, int *io_resid, int mark_dirty, int take_reference)
{
int segflg;
int io_size;
int xsize;
int start_offset;
int retval = 0;
memory_object_control_t control;
io_size = *io_resid;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 34)) | DBG_FUNC_START,
(int)uio->uio_offset, io_size, mark_dirty, take_reference, 0);
control = ubc_getobject(vp, UBC_FLAGS_NONE);
if (control == MEMORY_OBJECT_CONTROL_NULL) {
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 34)) | DBG_FUNC_END,
(int)uio->uio_offset, io_size, retval, 3, 0);
return 0;
}
segflg = uio->uio_segflg;
switch (segflg) {
case UIO_USERSPACE32:
case UIO_USERISPACE32:
uio->uio_segflg = UIO_PHYS_USERSPACE32;
break;
case UIO_USERSPACE64:
case UIO_USERISPACE64:
uio->uio_segflg = UIO_PHYS_USERSPACE64;
break;
case UIO_USERSPACE:
case UIO_USERISPACE:
uio->uio_segflg = UIO_PHYS_USERSPACE;
break;
case UIO_SYSSPACE:
uio->uio_segflg = UIO_PHYS_SYSSPACE;
break;
}
if ((io_size = *io_resid)) {
start_offset = (int)(uio->uio_offset & PAGE_MASK_64);
xsize = (int)uio_resid(uio);
retval = memory_object_control_uiomove(control, uio->uio_offset - start_offset, uio,
start_offset, io_size, mark_dirty, take_reference);
xsize -= uio_resid(uio);
io_size -= xsize;
}
uio->uio_segflg = segflg;
*io_resid = io_size;
KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 34)) | DBG_FUNC_END,
(int)uio->uio_offset, io_size, retval, 0x80000000 | segflg, 0);
return retval;
}
int
is_file_clean(vnode_t vp, off_t filesize)
{
off_t f_offset;
int flags;
int total_dirty = 0;
for (f_offset = 0; f_offset < filesize; f_offset += PAGE_SIZE_64) {
if (ubc_page_op(vp, f_offset, 0, NULL, &flags) == KERN_SUCCESS) {
if (flags & UPL_POP_DIRTY) {
total_dirty++;
}
}
}
if (total_dirty) {
return EINVAL;
}
return 0;
}
/*
* Dirty region tracking/clustering mechanism.
*
* This code (vfs_drt_*) provides a mechanism for tracking and clustering
* dirty regions within a larger space (file). It is primarily intended to
* support clustering in large files with many dirty areas.
*
* The implementation assumes that the dirty regions are pages.
*
* To represent dirty pages within the file, we store bit vectors in a
* variable-size circular hash.
*/
/*
* Bitvector size. This determines the number of pages we group in a
* single hashtable entry. Each hashtable entry is aligned to this
* size within the file.
*/
#define DRT_BITVECTOR_PAGES ((1024 * 256) / PAGE_SIZE)
/*
* File offset handling.
*
* DRT_ADDRESS_MASK is dependent on DRT_BITVECTOR_PAGES;
* the correct formula is (~((DRT_BITVECTOR_PAGES * PAGE_SIZE) - 1))
*/
#define DRT_ADDRESS_MASK (~((DRT_BITVECTOR_PAGES * PAGE_SIZE) - 1))
#define DRT_ALIGN_ADDRESS(addr) ((addr) & DRT_ADDRESS_MASK)
/*
* Hashtable address field handling.
*
* The low-order bits of the hashtable address are used to conserve
* space.
*
* DRT_HASH_COUNT_MASK must be large enough to store the range
* 0-DRT_BITVECTOR_PAGES inclusive, as well as have one value
* to indicate that the bucket is actually unoccupied.
*/
#define DRT_HASH_GET_ADDRESS(scm, i) ((scm)->scm_hashtable[(i)].dhe_control & DRT_ADDRESS_MASK)
#define DRT_HASH_SET_ADDRESS(scm, i, a) \
do { \
(scm)->scm_hashtable[(i)].dhe_control = \
((scm)->scm_hashtable[(i)].dhe_control & ~DRT_ADDRESS_MASK) | DRT_ALIGN_ADDRESS(a); \
} while (0)
#define DRT_HASH_COUNT_MASK 0x1ff
#define DRT_HASH_GET_COUNT(scm, i) ((scm)->scm_hashtable[(i)].dhe_control & DRT_HASH_COUNT_MASK)
#define DRT_HASH_SET_COUNT(scm, i, c) \
do { \
(scm)->scm_hashtable[(i)].dhe_control = \
((scm)->scm_hashtable[(i)].dhe_control & ~DRT_HASH_COUNT_MASK) | ((c) & DRT_HASH_COUNT_MASK); \
} while (0)
#define DRT_HASH_CLEAR(scm, i) \
do { \
(scm)->scm_hashtable[(i)].dhe_control = 0; \
} while (0)
#define DRT_HASH_VACATE(scm, i) DRT_HASH_SET_COUNT((scm), (i), DRT_HASH_COUNT_MASK)
#define DRT_HASH_VACANT(scm, i) (DRT_HASH_GET_COUNT((scm), (i)) == DRT_HASH_COUNT_MASK)
#define DRT_HASH_COPY(oscm, oi, scm, i) \
do { \
(scm)->scm_hashtable[(i)].dhe_control = (oscm)->scm_hashtable[(oi)].dhe_control; \
DRT_BITVECTOR_COPY(oscm, oi, scm, i); \
} while(0);
#if !defined(XNU_TARGET_OS_OSX)
/*
* Hash table moduli.
*
* Since the hashtable entry's size is dependent on the size of
* the bitvector, and since the hashtable size is constrained to
* both being prime and fitting within the desired allocation
* size, these values need to be manually determined.
*
* For DRT_BITVECTOR_SIZE = 64, the entry size is 16 bytes.
*
* The small hashtable allocation is 4096 bytes, so the modulus is 251.
* The large hashtable allocation is 32768 bytes, so the modulus is 2039.
* The xlarge hashtable allocation is 131072 bytes, so the modulus is 8179.
*/
#define DRT_HASH_SMALL_MODULUS 251
#define DRT_HASH_LARGE_MODULUS 2039
#define DRT_HASH_XLARGE_MODULUS 8179
/*
* Physical memory required before the large hash modulus is permitted.
*
* On small memory systems, the large hash modulus can lead to phsyical
* memory starvation, so we avoid using it there.
*/
#define DRT_HASH_LARGE_MEMORY_REQUIRED (1024LL * 1024LL * 1024LL) /* 1GiB */
#define DRT_HASH_XLARGE_MEMORY_REQUIRED (8 * 1024LL * 1024LL * 1024LL) /* 8GiB */
#define DRT_SMALL_ALLOCATION 4096 /* 80 bytes spare */
#define DRT_LARGE_ALLOCATION 32768 /* 144 bytes spare */
#define DRT_XLARGE_ALLOCATION 131072 /* 208 bytes spare */
#else /* XNU_TARGET_OS_OSX */
/*
* Hash table moduli.
*
* Since the hashtable entry's size is dependent on the size of
* the bitvector, and since the hashtable size is constrained to
* both being prime and fitting within the desired allocation
* size, these values need to be manually determined.
*
* For DRT_BITVECTOR_SIZE = 64, the entry size is 16 bytes.
*
* The small hashtable allocation is 16384 bytes, so the modulus is 1019.
* The large hashtable allocation is 131072 bytes, so the modulus is 8179.
* The xlarge hashtable allocation is 524288 bytes, so the modulus is 32749.
*/
#define DRT_HASH_SMALL_MODULUS 1019
#define DRT_HASH_LARGE_MODULUS 8179
#define DRT_HASH_XLARGE_MODULUS 32749
/*
* Physical memory required before the large hash modulus is permitted.
*
* On small memory systems, the large hash modulus can lead to phsyical
* memory starvation, so we avoid using it there.
*/
#define DRT_HASH_LARGE_MEMORY_REQUIRED (4 * 1024LL * 1024LL * 1024LL) /* 4GiB */
#define DRT_HASH_XLARGE_MEMORY_REQUIRED (32 * 1024LL * 1024LL * 1024LL) /* 32GiB */
#define DRT_SMALL_ALLOCATION 16384 /* 80 bytes spare */
#define DRT_LARGE_ALLOCATION 131072 /* 208 bytes spare */
#define DRT_XLARGE_ALLOCATION 524288 /* 304 bytes spare */
#endif /* ! XNU_TARGET_OS_OSX */
/* *** nothing below here has secret dependencies on DRT_BITVECTOR_PAGES *** */
/*
* Hashtable entry.
*/
struct vfs_drt_hashentry {
u_int64_t dhe_control;
/*
* dhe_bitvector was declared as dhe_bitvector[DRT_BITVECTOR_PAGES / 32];
* DRT_BITVECTOR_PAGES is defined as ((1024 * 256) / PAGE_SIZE)
* Since PAGE_SIZE is only known at boot time,
* -define MAX_DRT_BITVECTOR_PAGES for smallest supported page size (4k)
* -declare dhe_bitvector array for largest possible length
*/
#define MAX_DRT_BITVECTOR_PAGES (1024 * 256)/( 4 * 1024)
u_int32_t dhe_bitvector[MAX_DRT_BITVECTOR_PAGES / 32];
};
/*
* Hashtable bitvector handling.
*
* Bitvector fields are 32 bits long.
*/
#define DRT_HASH_SET_BIT(scm, i, bit) \
(scm)->scm_hashtable[(i)].dhe_bitvector[(bit) / 32] |= (1 << ((bit) % 32))
#define DRT_HASH_CLEAR_BIT(scm, i, bit) \
(scm)->scm_hashtable[(i)].dhe_bitvector[(bit) / 32] &= ~(1 << ((bit) % 32))
#define DRT_HASH_TEST_BIT(scm, i, bit) \
((scm)->scm_hashtable[(i)].dhe_bitvector[(bit) / 32] & (1 << ((bit) % 32)))
#define DRT_BITVECTOR_CLEAR(scm, i) \
bzero(&(scm)->scm_hashtable[(i)].dhe_bitvector[0], (MAX_DRT_BITVECTOR_PAGES / 32) * sizeof(u_int32_t))
#define DRT_BITVECTOR_COPY(oscm, oi, scm, i) \
bcopy(&(oscm)->scm_hashtable[(oi)].dhe_bitvector[0], \
&(scm)->scm_hashtable[(i)].dhe_bitvector[0], \
(MAX_DRT_BITVECTOR_PAGES / 32) * sizeof(u_int32_t))
/*
* Dirty Region Tracking structure.
*
* The hashtable is allocated entirely inside the DRT structure.
*
* The hash is a simple circular prime modulus arrangement, the structure
* is resized from small to large if it overflows.
*/
struct vfs_drt_clustermap {
u_int32_t scm_magic; /* sanity/detection */
#define DRT_SCM_MAGIC 0x12020003
u_int32_t scm_modulus; /* current ring size */
u_int32_t scm_buckets; /* number of occupied buckets */
u_int32_t scm_lastclean; /* last entry we cleaned */
u_int32_t scm_iskips; /* number of slot skips */
struct vfs_drt_hashentry scm_hashtable[0];
};
#define DRT_HASH(scm, addr) ((addr) % (scm)->scm_modulus)
#define DRT_HASH_NEXT(scm, addr) (((addr) + 1) % (scm)->scm_modulus)
/*
* Debugging codes and arguments.
*/
#define DRT_DEBUG_EMPTYFREE (FSDBG_CODE(DBG_FSRW, 82)) /* nil */
#define DRT_DEBUG_RETCLUSTER (FSDBG_CODE(DBG_FSRW, 83)) /* offset, length */
#define DRT_DEBUG_ALLOC (FSDBG_CODE(DBG_FSRW, 84)) /* copycount */
#define DRT_DEBUG_INSERT (FSDBG_CODE(DBG_FSRW, 85)) /* offset, iskip */
#define DRT_DEBUG_MARK (FSDBG_CODE(DBG_FSRW, 86)) /* offset, length,
* dirty */
/* 0, setcount */
/* 1 (clean, no map) */
/* 2 (map alloc fail) */
/* 3, resid (partial) */
#define DRT_DEBUG_6 (FSDBG_CODE(DBG_FSRW, 87))
#define DRT_DEBUG_SCMDATA (FSDBG_CODE(DBG_FSRW, 88)) /* modulus, buckets,
* lastclean, iskips */
static kern_return_t vfs_drt_alloc_map(struct vfs_drt_clustermap **cmapp);
static kern_return_t vfs_drt_free_map(struct vfs_drt_clustermap *cmap);
static kern_return_t vfs_drt_search_index(struct vfs_drt_clustermap *cmap,
u_int64_t offset, int *indexp);
static kern_return_t vfs_drt_get_index(struct vfs_drt_clustermap **cmapp,
u_int64_t offset,
int *indexp,
int recursed);
static kern_return_t vfs_drt_do_mark_pages(
void **cmapp,
u_int64_t offset,
u_int length,
u_int *setcountp,
int dirty);
static void vfs_drt_trace(
struct vfs_drt_clustermap *cmap,
int code,
int arg1,
int arg2,
int arg3,
int arg4);
/*
* Allocate and initialise a sparse cluster map.
*
* Will allocate a new map, resize or compact an existing map.
*
* XXX we should probably have at least one intermediate map size,
* as the 1:16 ratio seems a bit drastic.
*/
static kern_return_t
vfs_drt_alloc_map(struct vfs_drt_clustermap **cmapp)
{
struct vfs_drt_clustermap *cmap = NULL, *ocmap = NULL;
kern_return_t kret = KERN_SUCCESS;
u_int64_t offset = 0;
u_int32_t i = 0;
int modulus_size = 0, map_size = 0, active_buckets = 0, index = 0, copycount = 0;
ocmap = NULL;
if (cmapp != NULL) {
ocmap = *cmapp;
}
/*
* Decide on the size of the new map.
*/
if (ocmap == NULL) {
modulus_size = DRT_HASH_SMALL_MODULUS;
map_size = DRT_SMALL_ALLOCATION;
} else {
/* count the number of active buckets in the old map */
active_buckets = 0;
for (i = 0; i < ocmap->scm_modulus; i++) {
if (!DRT_HASH_VACANT(ocmap, i) &&
(DRT_HASH_GET_COUNT(ocmap, i) != 0)) {
active_buckets++;
}
}
/*
* If we're currently using the small allocation, check to
* see whether we should grow to the large one.
*/
if (ocmap->scm_modulus == DRT_HASH_SMALL_MODULUS) {
/*
* If the ring is nearly full and we are allowed to
* use the large modulus, upgrade.
*/
if ((active_buckets > (DRT_HASH_SMALL_MODULUS - 5)) &&
(max_mem >= DRT_HASH_LARGE_MEMORY_REQUIRED)) {
modulus_size = DRT_HASH_LARGE_MODULUS;
map_size = DRT_LARGE_ALLOCATION;
} else {
modulus_size = DRT_HASH_SMALL_MODULUS;
map_size = DRT_SMALL_ALLOCATION;
}
} else if (ocmap->scm_modulus == DRT_HASH_LARGE_MODULUS) {
if ((active_buckets > (DRT_HASH_LARGE_MODULUS - 5)) &&
(max_mem >= DRT_HASH_XLARGE_MEMORY_REQUIRED)) {
modulus_size = DRT_HASH_XLARGE_MODULUS;
map_size = DRT_XLARGE_ALLOCATION;
} else {
/*
* If the ring is completely full and we can't
* expand, there's nothing useful for us to do.
* Behave as though we had compacted into the new
* array and return.
*/
return KERN_SUCCESS;
}
} else {
/* already using the xlarge modulus */
modulus_size = DRT_HASH_XLARGE_MODULUS;
map_size = DRT_XLARGE_ALLOCATION;
/*
* If the ring is completely full, there's
* nothing useful for us to do. Behave as
* though we had compacted into the new
* array and return.
*/
if (active_buckets >= DRT_HASH_XLARGE_MODULUS) {
return KERN_SUCCESS;
}
}
}
/*
* Allocate and initialise the new map.
*/
kret = kmem_alloc(kernel_map, (vm_offset_t *)&cmap, map_size, VM_KERN_MEMORY_FILE);
if (kret != KERN_SUCCESS) {
return kret;
}
cmap->scm_magic = DRT_SCM_MAGIC;
cmap->scm_modulus = modulus_size;
cmap->scm_buckets = 0;
cmap->scm_lastclean = 0;
cmap->scm_iskips = 0;
for (i = 0; i < cmap->scm_modulus; i++) {
DRT_HASH_CLEAR(cmap, i);
DRT_HASH_VACATE(cmap, i);
DRT_BITVECTOR_CLEAR(cmap, i);
}
/*
* If there's an old map, re-hash entries from it into the new map.
*/
copycount = 0;
if (ocmap != NULL) {
for (i = 0; i < ocmap->scm_modulus; i++) {
/* skip empty buckets */
if (DRT_HASH_VACANT(ocmap, i) ||
(DRT_HASH_GET_COUNT(ocmap, i) == 0)) {
continue;
}
/* get new index */
offset = DRT_HASH_GET_ADDRESS(ocmap, i);
kret = vfs_drt_get_index(&cmap, offset, &index, 1);
if (kret != KERN_SUCCESS) {
/* XXX need to bail out gracefully here */
panic("vfs_drt: new cluster map mysteriously too small");
index = 0;
}
/* copy */
DRT_HASH_COPY(ocmap, i, cmap, index);
copycount++;
}
}
/* log what we've done */
vfs_drt_trace(cmap, DRT_DEBUG_ALLOC, copycount, 0, 0, 0);
/*
* It's important to ensure that *cmapp always points to
* a valid map, so we must overwrite it before freeing
* the old map.
*/
*cmapp = cmap;
if (ocmap != NULL) {
/* emit stats into trace buffer */
vfs_drt_trace(ocmap, DRT_DEBUG_SCMDATA,
ocmap->scm_modulus,
ocmap->scm_buckets,
ocmap->scm_lastclean,
ocmap->scm_iskips);
vfs_drt_free_map(ocmap);
}
return KERN_SUCCESS;
}
/*
* Free a sparse cluster map.
*/
static kern_return_t
vfs_drt_free_map(struct vfs_drt_clustermap *cmap)
{
vm_size_t map_size = 0;
if (cmap->scm_modulus == DRT_HASH_SMALL_MODULUS) {
map_size = DRT_SMALL_ALLOCATION;
} else if (cmap->scm_modulus == DRT_HASH_LARGE_MODULUS) {
map_size = DRT_LARGE_ALLOCATION;
} else if (cmap->scm_modulus == DRT_HASH_XLARGE_MODULUS) {
map_size = DRT_XLARGE_ALLOCATION;
} else {
panic("vfs_drt_free_map: Invalid modulus %d\n", cmap->scm_modulus);
}
kmem_free(kernel_map, (vm_offset_t)cmap, map_size);
return KERN_SUCCESS;
}
/*
* Find the hashtable slot currently occupied by an entry for the supplied offset.
*/
static kern_return_t
vfs_drt_search_index(struct vfs_drt_clustermap *cmap, u_int64_t offset, int *indexp)
{
int index;
u_int32_t i;
offset = DRT_ALIGN_ADDRESS(offset);
index = DRT_HASH(cmap, offset);
/* traverse the hashtable */
for (i = 0; i < cmap->scm_modulus; i++) {
/*
* If the slot is vacant, we can stop.
*/
if (DRT_HASH_VACANT(cmap, index)) {
break;
}
/*
* If the address matches our offset, we have success.
*/
if (DRT_HASH_GET_ADDRESS(cmap, index) == offset) {
*indexp = index;
return KERN_SUCCESS;
}
/*
* Move to the next slot, try again.
*/
index = DRT_HASH_NEXT(cmap, index);
}
/*
* It's not there.
*/
return KERN_FAILURE;
}
/*
* Find the hashtable slot for the supplied offset. If we haven't allocated
* one yet, allocate one and populate the address field. Note that it will
* not have a nonzero page count and thus will still technically be free, so
* in the case where we are called to clean pages, the slot will remain free.
*/
static kern_return_t
vfs_drt_get_index(struct vfs_drt_clustermap **cmapp, u_int64_t offset, int *indexp, int recursed)
{
struct vfs_drt_clustermap *cmap;
kern_return_t kret;
u_int32_t index;
u_int32_t i;
cmap = *cmapp;
/* look for an existing entry */
kret = vfs_drt_search_index(cmap, offset, indexp);
if (kret == KERN_SUCCESS) {
return kret;
}
/* need to allocate an entry */
offset = DRT_ALIGN_ADDRESS(offset);
index = DRT_HASH(cmap, offset);
/* scan from the index forwards looking for a vacant slot */
for (i = 0; i < cmap->scm_modulus; i++) {
/* slot vacant? */
if (DRT_HASH_VACANT(cmap, index) || DRT_HASH_GET_COUNT(cmap, index) == 0) {
cmap->scm_buckets++;
if (index < cmap->scm_lastclean) {
cmap->scm_lastclean = index;
}
DRT_HASH_SET_ADDRESS(cmap, index, offset);
DRT_HASH_SET_COUNT(cmap, index, 0);
DRT_BITVECTOR_CLEAR(cmap, index);
*indexp = index;
vfs_drt_trace(cmap, DRT_DEBUG_INSERT, (int)offset, i, 0, 0);
return KERN_SUCCESS;
}
cmap->scm_iskips += i;
index = DRT_HASH_NEXT(cmap, index);
}
/*
* We haven't found a vacant slot, so the map is full. If we're not
* already recursed, try reallocating/compacting it.
*/
if (recursed) {
return KERN_FAILURE;
}
kret = vfs_drt_alloc_map(cmapp);
if (kret == KERN_SUCCESS) {
/* now try to insert again */
kret = vfs_drt_get_index(cmapp, offset, indexp, 1);
}
return kret;
}
/*
* Implementation of set dirty/clean.
*
* In the 'clean' case, not finding a map is OK.
*/
static kern_return_t
vfs_drt_do_mark_pages(
void **private,
u_int64_t offset,
u_int length,
u_int *setcountp,
int dirty)
{
struct vfs_drt_clustermap *cmap, **cmapp;
kern_return_t kret;
int i, index, pgoff, pgcount, setcount, ecount;
cmapp = (struct vfs_drt_clustermap **)private;
cmap = *cmapp;
vfs_drt_trace(cmap, DRT_DEBUG_MARK | DBG_FUNC_START, (int)offset, (int)length, dirty, 0);
if (setcountp != NULL) {
*setcountp = 0;
}
/* allocate a cluster map if we don't already have one */
if (cmap == NULL) {
/* no cluster map, nothing to clean */
if (!dirty) {
vfs_drt_trace(cmap, DRT_DEBUG_MARK | DBG_FUNC_END, 1, 0, 0, 0);
return KERN_SUCCESS;
}
kret = vfs_drt_alloc_map(cmapp);
if (kret != KERN_SUCCESS) {
vfs_drt_trace(cmap, DRT_DEBUG_MARK | DBG_FUNC_END, 2, 0, 0, 0);
return kret;
}
}
setcount = 0;
/*
* Iterate over the length of the region.
*/
while (length > 0) {
/*
* Get the hashtable index for this offset.
*
* XXX this will add blank entries if we are clearing a range
* that hasn't been dirtied.
*/
kret = vfs_drt_get_index(cmapp, offset, &index, 0);
cmap = *cmapp; /* may have changed! */
/* this may be a partial-success return */
if (kret != KERN_SUCCESS) {
if (setcountp != NULL) {
*setcountp = setcount;
}
vfs_drt_trace(cmap, DRT_DEBUG_MARK | DBG_FUNC_END, 3, (int)length, 0, 0);
return kret;
}
/*
* Work out how many pages we're modifying in this
* hashtable entry.
*/
pgoff = (int)((offset - DRT_ALIGN_ADDRESS(offset)) / PAGE_SIZE);
pgcount = min((length / PAGE_SIZE), (DRT_BITVECTOR_PAGES - pgoff));
/*
* Iterate over pages, dirty/clearing as we go.
*/
ecount = DRT_HASH_GET_COUNT(cmap, index);
for (i = 0; i < pgcount; i++) {
if (dirty) {
if (!DRT_HASH_TEST_BIT(cmap, index, pgoff + i)) {
if (ecount >= DRT_BITVECTOR_PAGES) {
panic("ecount >= DRT_BITVECTOR_PAGES, cmap = %p, index = %d, bit = %d", cmap, index, pgoff + i);
}
DRT_HASH_SET_BIT(cmap, index, pgoff + i);
ecount++;
setcount++;
}
} else {
if (DRT_HASH_TEST_BIT(cmap, index, pgoff + i)) {
if (ecount <= 0) {
panic("ecount <= 0, cmap = %p, index = %d, bit = %d", cmap, index, pgoff + i);
}
assert(ecount > 0);
DRT_HASH_CLEAR_BIT(cmap, index, pgoff + i);
ecount--;
setcount++;
}
}
}
DRT_HASH_SET_COUNT(cmap, index, ecount);
offset += pgcount * PAGE_SIZE;
length -= pgcount * PAGE_SIZE;
}
if (setcountp != NULL) {
*setcountp = setcount;
}
vfs_drt_trace(cmap, DRT_DEBUG_MARK | DBG_FUNC_END, 0, setcount, 0, 0);
return KERN_SUCCESS;
}
/*
* Mark a set of pages as dirty/clean.
*
* This is a public interface.
*
* cmapp
* Pointer to storage suitable for holding a pointer. Note that
* this must either be NULL or a value set by this function.
*
* size
* Current file size in bytes.
*
* offset
* Offset of the first page to be marked as dirty, in bytes. Must be
* page-aligned.
*
* length
* Length of dirty region, in bytes. Must be a multiple of PAGE_SIZE.
*
* setcountp
* Number of pages newly marked dirty by this call (optional).
*
* Returns KERN_SUCCESS if all the pages were successfully marked.
*/
static kern_return_t
vfs_drt_mark_pages(void **cmapp, off_t offset, u_int length, u_int *setcountp)
{
/* XXX size unused, drop from interface */
return vfs_drt_do_mark_pages(cmapp, offset, length, setcountp, 1);
}
#if 0
static kern_return_t
vfs_drt_unmark_pages(void **cmapp, off_t offset, u_int length)
{
return vfs_drt_do_mark_pages(cmapp, offset, length, NULL, 0);
}
#endif
/*
* Get a cluster of dirty pages.
*
* This is a public interface.
*
* cmapp
* Pointer to storage managed by drt_mark_pages. Note that this must
* be NULL or a value set by drt_mark_pages.
*
* offsetp
* Returns the byte offset into the file of the first page in the cluster.
*
* lengthp
* Returns the length in bytes of the cluster of dirty pages.
*
* Returns success if a cluster was found. If KERN_FAILURE is returned, there
* are no dirty pages meeting the minmum size criteria. Private storage will
* be released if there are no more dirty pages left in the map
*
*/
static kern_return_t
vfs_drt_get_cluster(void **cmapp, off_t *offsetp, u_int *lengthp)
{
struct vfs_drt_clustermap *cmap;
u_int64_t offset;
u_int length;
u_int32_t j;
int index, i, fs, ls;
/* sanity */
if ((cmapp == NULL) || (*cmapp == NULL)) {
return KERN_FAILURE;
}
cmap = *cmapp;
/* walk the hashtable */
for (offset = 0, j = 0; j < cmap->scm_modulus; offset += (DRT_BITVECTOR_PAGES * PAGE_SIZE), j++) {
index = DRT_HASH(cmap, offset);
if (DRT_HASH_VACANT(cmap, index) || (DRT_HASH_GET_COUNT(cmap, index) == 0)) {
continue;
}
/* scan the bitfield for a string of bits */
fs = -1;
for (i = 0; i < DRT_BITVECTOR_PAGES; i++) {
if (DRT_HASH_TEST_BIT(cmap, index, i)) {
fs = i;
break;
}
}
if (fs == -1) {
/* didn't find any bits set */
panic("vfs_drt: entry summary count > 0 but no bits set in map, cmap = %p, index = %d, count = %lld",
cmap, index, DRT_HASH_GET_COUNT(cmap, index));
}
for (ls = 0; i < DRT_BITVECTOR_PAGES; i++, ls++) {
if (!DRT_HASH_TEST_BIT(cmap, index, i)) {
break;
}
}
/* compute offset and length, mark pages clean */
offset = DRT_HASH_GET_ADDRESS(cmap, index) + (PAGE_SIZE * fs);
length = ls * PAGE_SIZE;
vfs_drt_do_mark_pages(cmapp, offset, length, NULL, 0);
cmap->scm_lastclean = index;
/* return successful */
*offsetp = (off_t)offset;
*lengthp = length;
vfs_drt_trace(cmap, DRT_DEBUG_RETCLUSTER, (int)offset, (int)length, 0, 0);
return KERN_SUCCESS;
}
/*
* We didn't find anything... hashtable is empty
* emit stats into trace buffer and
* then free it
*/
vfs_drt_trace(cmap, DRT_DEBUG_SCMDATA,
cmap->scm_modulus,
cmap->scm_buckets,
cmap->scm_lastclean,
cmap->scm_iskips);
vfs_drt_free_map(cmap);
*cmapp = NULL;
return KERN_FAILURE;
}
static kern_return_t
vfs_drt_control(void **cmapp, int op_type)
{
struct vfs_drt_clustermap *cmap;
/* sanity */
if ((cmapp == NULL) || (*cmapp == NULL)) {
return KERN_FAILURE;
}
cmap = *cmapp;
switch (op_type) {
case 0:
/* emit stats into trace buffer */
vfs_drt_trace(cmap, DRT_DEBUG_SCMDATA,
cmap->scm_modulus,
cmap->scm_buckets,
cmap->scm_lastclean,
cmap->scm_iskips);
vfs_drt_free_map(cmap);
*cmapp = NULL;
break;
case 1:
cmap->scm_lastclean = 0;
break;
}
return KERN_SUCCESS;
}
/*
* Emit a summary of the state of the clustermap into the trace buffer
* along with some caller-provided data.
*/
#if KDEBUG
static void
vfs_drt_trace(__unused struct vfs_drt_clustermap *cmap, int code, int arg1, int arg2, int arg3, int arg4)
{
KERNEL_DEBUG(code, arg1, arg2, arg3, arg4, 0);
}
#else
static void
vfs_drt_trace(__unused struct vfs_drt_clustermap *cmap, __unused int code,
__unused int arg1, __unused int arg2, __unused int arg3,
__unused int arg4)
{
}
#endif
#if 0
/*
* Perform basic sanity check on the hash entry summary count
* vs. the actual bits set in the entry.
*/
static void
vfs_drt_sanity(struct vfs_drt_clustermap *cmap)
{
int index, i;
int bits_on;
for (index = 0; index < cmap->scm_modulus; index++) {
if (DRT_HASH_VACANT(cmap, index)) {
continue;
}
for (bits_on = 0, i = 0; i < DRT_BITVECTOR_PAGES; i++) {
if (DRT_HASH_TEST_BIT(cmap, index, i)) {
bits_on++;
}
}
if (bits_on != DRT_HASH_GET_COUNT(cmap, index)) {
panic("bits_on = %d, index = %d\n", bits_on, index);
}
}
}
#endif
/*
* Internal interface only.
*/
static kern_return_t
vfs_get_scmap_push_behavior_internal(void **cmapp, int *push_flag)
{
struct vfs_drt_clustermap *cmap;
/* sanity */
if ((cmapp == NULL) || (*cmapp == NULL) || (push_flag == NULL)) {
return KERN_FAILURE;
}
cmap = *cmapp;
if (cmap->scm_modulus == DRT_HASH_XLARGE_MODULUS) {
/*
* If we have a full xlarge sparse cluster,
* we push it out all at once so the cluster
* map can be available to absorb more I/Os.
* This is done on large memory configs so
* the small I/Os don't interfere with the
* pro workloads.
*/
*push_flag = PUSH_ALL;
}
return KERN_SUCCESS;
}