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2e9b08e59e
xemu/block.c
aliguori a76bab4952 Refactor AIO to allow multiple AIO implementations 
This patch refactors the AIO layer to allow multiple AIO implementations.  It's
only possible because of the recent signalfd() patch.  

Right now, the AIO infrastructure is pretty specific to the block raw backend.
For other block devices to implement AIO, the qemu_aio_wait function must
support registration.  This patch introduces a new function,
qemu_aio_set_fd_handler, which can be used to register a file descriptor to be
called back.  qemu_aio_wait() now polls a set of file descriptors registered
with this function until one becomes readable or writable.

This patch should allow the implementation of alternative AIO backends (via a
thread pool or linux-aio) and AIO backends in non-traditional block devices
(like NBD).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5297 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-22 19:17:18 +00:00

1429 lines
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/*
* QEMU System Emulator block driver
*
* Copyright (c) 2003 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "console.h"
#include "block_int.h"
#ifdef _BSD
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/queue.h>
#include <sys/disk.h>
#endif
#define SECTOR_BITS 9
#define SECTOR_SIZE (1 << SECTOR_BITS)
typedef struct BlockDriverAIOCBSync {
BlockDriverAIOCB common;
QEMUBH *bh;
int ret;
} BlockDriverAIOCBSync;
static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
BlockDriverState *bdrv_first;
static BlockDriver *first_drv;
int path_is_absolute(const char *path)
{
const char *p;
#ifdef _WIN32
/* specific case for names like: "\\.\d:" */
if (*path == '/' || *path == '\\')
return 1;
#endif
p = strchr(path, ':');
if (p)
p++;
else
p = path;
#ifdef _WIN32
return (*p == '/' || *p == '\\');
#else
return (*p == '/');
#endif
}
/* if filename is absolute, just copy it to dest. Otherwise, build a
path to it by considering it is relative to base_path. URL are
supported. */
void path_combine(char *dest, int dest_size,
const char *base_path,
const char *filename)
{
const char *p, *p1;
int len;
if (dest_size <= 0)
return;
if (path_is_absolute(filename)) {
pstrcpy(dest, dest_size, filename);
} else {
p = strchr(base_path, ':');
if (p)
p++;
else
p = base_path;
p1 = strrchr(base_path, '/');
#ifdef _WIN32
{
const char *p2;
p2 = strrchr(base_path, '\\');
if (!p1 || p2 > p1)
p1 = p2;
}
#endif
if (p1)
p1++;
else
p1 = base_path;
if (p1 > p)
p = p1;
len = p - base_path;
if (len > dest_size - 1)
len = dest_size - 1;
memcpy(dest, base_path, len);
dest[len] = '\0';
pstrcat(dest, dest_size, filename);
}
}
static void bdrv_register(BlockDriver *bdrv)
{
if (!bdrv->bdrv_aio_read) {
/* add AIO emulation layer */
bdrv->bdrv_aio_read = bdrv_aio_read_em;
bdrv->bdrv_aio_write = bdrv_aio_write_em;
bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
} else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
/* add synchronous IO emulation layer */
bdrv->bdrv_read = bdrv_read_em;
bdrv->bdrv_write = bdrv_write_em;
}
bdrv->next = first_drv;
first_drv = bdrv;
}
/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
{
BlockDriverState **pbs, *bs;
bs = qemu_mallocz(sizeof(BlockDriverState));
if(!bs)
return NULL;
pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
if (device_name[0] != '\0') {
/* insert at the end */
pbs = &bdrv_first;
while (*pbs != NULL)
pbs = &(*pbs)->next;
*pbs = bs;
}
return bs;
}
BlockDriver *bdrv_find_format(const char *format_name)
{
BlockDriver *drv1;
for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
if (!strcmp(drv1->format_name, format_name))
return drv1;
}
return NULL;
}
int bdrv_create(BlockDriver *drv,
const char *filename, int64_t size_in_sectors,
const char *backing_file, int flags)
{
if (!drv->bdrv_create)
return -ENOTSUP;
return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
}
#ifdef _WIN32
void get_tmp_filename(char *filename, int size)
{
char temp_dir[MAX_PATH];
GetTempPath(MAX_PATH, temp_dir);
GetTempFileName(temp_dir, "qem", 0, filename);
}
#else
void get_tmp_filename(char *filename, int size)
{
int fd;
const char *tmpdir;
/* XXX: race condition possible */
tmpdir = getenv("TMPDIR");
if (!tmpdir)
tmpdir = "/tmp";
snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
fd = mkstemp(filename);
close(fd);
}
#endif
#ifdef _WIN32
static int is_windows_drive_prefix(const char *filename)
{
return (((filename[0] >= 'a' && filename[0] <= 'z') ||
(filename[0] >= 'A' && filename[0] <= 'Z')) &&
filename[1] == ':');
}
static int is_windows_drive(const char *filename)
{
if (is_windows_drive_prefix(filename) &&
filename[2] == '\0')
return 1;
if (strstart(filename, "\\\\.\\", NULL) ||
strstart(filename, "//./", NULL))
return 1;
return 0;
}
#endif
static BlockDriver *find_protocol(const char *filename)
{
BlockDriver *drv1;
char protocol[128];
int len;
const char *p;
#ifdef _WIN32
if (is_windows_drive(filename) ||
is_windows_drive_prefix(filename))
return &bdrv_raw;
#endif
p = strchr(filename, ':');
if (!p)
return &bdrv_raw;
len = p - filename;
if (len > sizeof(protocol) - 1)
len = sizeof(protocol) - 1;
memcpy(protocol, filename, len);
protocol[len] = '\0';
for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
if (drv1->protocol_name &&
!strcmp(drv1->protocol_name, protocol))
return drv1;
}
return NULL;
}
/* XXX: force raw format if block or character device ? It would
simplify the BSD case */
static BlockDriver *find_image_format(const char *filename)
{
int ret, score, score_max;
BlockDriver *drv1, *drv;
uint8_t buf[2048];
BlockDriverState *bs;
/* detect host devices. By convention, /dev/cdrom[N] is always
recognized as a host CDROM */
if (strstart(filename, "/dev/cdrom", NULL))
return &bdrv_host_device;
#ifdef _WIN32
if (is_windows_drive(filename))
return &bdrv_host_device;
#else
{
struct stat st;
if (stat(filename, &st) >= 0 &&
(S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
return &bdrv_host_device;
}
}
#endif
drv = find_protocol(filename);
/* no need to test disk image formats for vvfat */
if (drv == &bdrv_vvfat)
return drv;
ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
if (ret < 0)
return NULL;
ret = bdrv_pread(bs, 0, buf, sizeof(buf));
bdrv_delete(bs);
if (ret < 0) {
return NULL;
}
score_max = 0;
for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
if (drv1->bdrv_probe) {
score = drv1->bdrv_probe(buf, ret, filename);
if (score > score_max) {
score_max = score;
drv = drv1;
}
}
}
return drv;
}
int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
{
BlockDriverState *bs;
int ret;
bs = bdrv_new("");
if (!bs)
return -ENOMEM;
ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
if (ret < 0) {
bdrv_delete(bs);
return ret;
}
*pbs = bs;
return 0;
}
int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
{
return bdrv_open2(bs, filename, flags, NULL);
}
int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
BlockDriver *drv)
{
int ret, open_flags;
char tmp_filename[PATH_MAX];
char backing_filename[PATH_MAX];
bs->read_only = 0;
bs->is_temporary = 0;
bs->encrypted = 0;
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
int64_t total_size;
int is_protocol = 0;
/* if snapshot, we create a temporary backing file and open it
instead of opening 'filename' directly */
/* if there is a backing file, use it */
bs1 = bdrv_new("");
if (!bs1) {
return -ENOMEM;
}
if (bdrv_open(bs1, filename, 0) < 0) {
bdrv_delete(bs1);
return -1;
}
total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
if (bs1->drv && bs1->drv->protocol_name)
is_protocol = 1;
bdrv_delete(bs1);
get_tmp_filename(tmp_filename, sizeof(tmp_filename));
/* Real path is meaningless for protocols */
if (is_protocol)
snprintf(backing_filename, sizeof(backing_filename),
"%s", filename);
else
realpath(filename, backing_filename);
if (bdrv_create(&bdrv_qcow2, tmp_filename,
total_size, backing_filename, 0) < 0) {
return -1;
}
filename = tmp_filename;
bs->is_temporary = 1;
}
pstrcpy(bs->filename, sizeof(bs->filename), filename);
if (flags & BDRV_O_FILE) {
drv = find_protocol(filename);
if (!drv)
return -ENOENT;
} else {
if (!drv) {
drv = find_image_format(filename);
if (!drv)
return -1;
}
}
bs->drv = drv;
bs->opaque = qemu_mallocz(drv->instance_size);
if (bs->opaque == NULL && drv->instance_size > 0)
return -1;
/* Note: for compatibility, we open disk image files as RDWR, and
RDONLY as fallback */
if (!(flags & BDRV_O_FILE))
open_flags = BDRV_O_RDWR | (flags & BDRV_O_DIRECT);
else
open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
ret = drv->bdrv_open(bs, filename, open_flags);
if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
bs->read_only = 1;
}
if (ret < 0) {
qemu_free(bs->opaque);
bs->opaque = NULL;
bs->drv = NULL;
return ret;
}
if (drv->bdrv_getlength) {
bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
}
#ifndef _WIN32
if (bs->is_temporary) {
unlink(filename);
}
#endif
if (bs->backing_file[0] != '\0') {
/* if there is a backing file, use it */
bs->backing_hd = bdrv_new("");
if (!bs->backing_hd) {
fail:
bdrv_close(bs);
return -ENOMEM;
}
path_combine(backing_filename, sizeof(backing_filename),
filename, bs->backing_file);
if (bdrv_open(bs->backing_hd, backing_filename, 0) < 0)
goto fail;
}
/* call the change callback */
bs->media_changed = 1;
if (bs->change_cb)
bs->change_cb(bs->change_opaque);
return 0;
}
void bdrv_close(BlockDriverState *bs)
{
if (bs->drv) {
if (bs->backing_hd)
bdrv_delete(bs->backing_hd);
bs->drv->bdrv_close(bs);
qemu_free(bs->opaque);
#ifdef _WIN32
if (bs->is_temporary) {
unlink(bs->filename);
}
#endif
bs->opaque = NULL;
bs->drv = NULL;
/* call the change callback */
bs->media_changed = 1;
if (bs->change_cb)
bs->change_cb(bs->change_opaque);
}
}
void bdrv_delete(BlockDriverState *bs)
{
BlockDriverState **pbs;
pbs = &bdrv_first;
while (*pbs != bs && *pbs != NULL)
pbs = &(*pbs)->next;
if (*pbs == bs)
*pbs = bs->next;
bdrv_close(bs);
qemu_free(bs);
}
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
int64_t i, total_sectors;
int n, j;
unsigned char sector[512];
if (!drv)
return -ENOMEDIUM;
if (bs->read_only) {
return -EACCES;
}
if (!bs->backing_hd) {
return -ENOTSUP;
}
total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
for (i = 0; i < total_sectors;) {
if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
for(j = 0; j < n; j++) {
if (bdrv_read(bs, i, sector, 1) != 0) {
return -EIO;
}
if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
return -EIO;
}
i++;
}
} else {
i += n;
}
}
if (drv->bdrv_make_empty)
return drv->bdrv_make_empty(bs);
return 0;
}
/* return < 0 if error. See bdrv_write() for the return codes */
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(buf, bs->boot_sector_data, 512);
sector_num++;
nb_sectors--;
buf += 512;
if (nb_sectors == 0)
return 0;
}
if (drv->bdrv_pread) {
int ret, len;
len = nb_sectors * 512;
ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
if (ret < 0)
return ret;
else if (ret != len)
return -EINVAL;
else {
bs->rd_bytes += (unsigned) len;
bs->rd_ops ++;
return 0;
}
} else {
return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
}
}
/* Return < 0 if error. Important errors are:
-EIO generic I/O error (may happen for all errors)
-ENOMEDIUM No media inserted.
-EINVAL Invalid sector number or nb_sectors
-EACCES Trying to write a read-only device
*/
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
BlockDriver *drv = bs->drv;
if (!bs->drv)
return -ENOMEDIUM;
if (bs->read_only)
return -EACCES;
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(bs->boot_sector_data, buf, 512);
}
if (drv->bdrv_pwrite) {
int ret, len;
len = nb_sectors * 512;
ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
if (ret < 0)
return ret;
else if (ret != len)
return -EIO;
else {
bs->wr_bytes += (unsigned) len;
bs->wr_ops ++;
return 0;
}
} else {
return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
}
}
static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
uint8_t *buf, int count1)
{
uint8_t tmp_buf[SECTOR_SIZE];
int len, nb_sectors, count;
int64_t sector_num;
count = count1;
/* first read to align to sector start */
len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
if (len > count)
len = count;
sector_num = offset >> SECTOR_BITS;
if (len > 0) {
if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
return -EIO;
memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
count -= len;
if (count == 0)
return count1;
sector_num++;
buf += len;
}
/* read the sectors "in place" */
nb_sectors = count >> SECTOR_BITS;
if (nb_sectors > 0) {
if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
return -EIO;
sector_num += nb_sectors;
len = nb_sectors << SECTOR_BITS;
buf += len;
count -= len;
}
/* add data from the last sector */
if (count > 0) {
if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
return -EIO;
memcpy(buf, tmp_buf, count);
}
return count1;
}
static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
const uint8_t *buf, int count1)
{
uint8_t tmp_buf[SECTOR_SIZE];
int len, nb_sectors, count;
int64_t sector_num;
count = count1;
/* first write to align to sector start */
len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
if (len > count)
len = count;
sector_num = offset >> SECTOR_BITS;
if (len > 0) {
if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
return -EIO;
memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
return -EIO;
count -= len;
if (count == 0)
return count1;
sector_num++;
buf += len;
}
/* write the sectors "in place" */
nb_sectors = count >> SECTOR_BITS;
if (nb_sectors > 0) {
if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
return -EIO;
sector_num += nb_sectors;
len = nb_sectors << SECTOR_BITS;
buf += len;
count -= len;
}
/* add data from the last sector */
if (count > 0) {
if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
return -EIO;
memcpy(tmp_buf, buf, count);
if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
return -EIO;
}
return count1;
}
/**
* Read with byte offsets (needed only for file protocols)
*/
int bdrv_pread(BlockDriverState *bs, int64_t offset,
void *buf1, int count1)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_pread)
return bdrv_pread_em(bs, offset, buf1, count1);
return drv->bdrv_pread(bs, offset, buf1, count1);
}
/**
* Write with byte offsets (needed only for file protocols)
*/
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
const void *buf1, int count1)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_pwrite)
return bdrv_pwrite_em(bs, offset, buf1, count1);
return drv->bdrv_pwrite(bs, offset, buf1, count1);
}
/**
* Truncate file to 'offset' bytes (needed only for file protocols)
*/
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_truncate)
return -ENOTSUP;
return drv->bdrv_truncate(bs, offset);
}
/**
* Length of a file in bytes. Return < 0 if error or unknown.
*/
int64_t bdrv_getlength(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_getlength) {
/* legacy mode */
return bs->total_sectors * SECTOR_SIZE;
}
return drv->bdrv_getlength(bs);
}
/* return 0 as number of sectors if no device present or error */
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
{
int64_t length;
length = bdrv_getlength(bs);
if (length < 0)
length = 0;
else
length = length >> SECTOR_BITS;
*nb_sectors_ptr = length;
}
/* force a given boot sector. */
void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
{
bs->boot_sector_enabled = 1;
if (size > 512)
size = 512;
memcpy(bs->boot_sector_data, data, size);
memset(bs->boot_sector_data + size, 0, 512 - size);
}
void bdrv_set_geometry_hint(BlockDriverState *bs,
int cyls, int heads, int secs)
{
bs->cyls = cyls;
bs->heads = heads;
bs->secs = secs;
}
void bdrv_set_type_hint(BlockDriverState *bs, int type)
{
bs->type = type;
bs->removable = ((type == BDRV_TYPE_CDROM ||
type == BDRV_TYPE_FLOPPY));
}
void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
{
bs->translation = translation;
}
void bdrv_get_geometry_hint(BlockDriverState *bs,
int *pcyls, int *pheads, int *psecs)
{
*pcyls = bs->cyls;
*pheads = bs->heads;
*psecs = bs->secs;
}
int bdrv_get_type_hint(BlockDriverState *bs)
{
return bs->type;
}
int bdrv_get_translation_hint(BlockDriverState *bs)
{
return bs->translation;
}
int bdrv_is_removable(BlockDriverState *bs)
{
return bs->removable;
}
int bdrv_is_read_only(BlockDriverState *bs)
{
return bs->read_only;
}
int bdrv_is_sg(BlockDriverState *bs)
{
return bs->sg;
}
/* XXX: no longer used */
void bdrv_set_change_cb(BlockDriverState *bs,
void (*change_cb)(void *opaque), void *opaque)
{
bs->change_cb = change_cb;
bs->change_opaque = opaque;
}
int bdrv_is_encrypted(BlockDriverState *bs)
{
if (bs->backing_hd && bs->backing_hd->encrypted)
return 1;
return bs->encrypted;
}
int bdrv_set_key(BlockDriverState *bs, const char *key)
{
int ret;
if (bs->backing_hd && bs->backing_hd->encrypted) {
ret = bdrv_set_key(bs->backing_hd, key);
if (ret < 0)
return ret;
if (!bs->encrypted)
return 0;
}
if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
return -1;
return bs->drv->bdrv_set_key(bs, key);
}
void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
{
if (!bs->drv) {
buf[0] = '\0';
} else {
pstrcpy(buf, buf_size, bs->drv->format_name);
}
}
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
void *opaque)
{
BlockDriver *drv;
for (drv = first_drv; drv != NULL; drv = drv->next) {
it(opaque, drv->format_name);
}
}
BlockDriverState *bdrv_find(const char *name)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
if (!strcmp(name, bs->device_name))
return bs;
}
return NULL;
}
void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
it(opaque, bs->device_name);
}
}
const char *bdrv_get_device_name(BlockDriverState *bs)
{
return bs->device_name;
}
void bdrv_flush(BlockDriverState *bs)
{
if (bs->drv->bdrv_flush)
bs->drv->bdrv_flush(bs);
if (bs->backing_hd)
bdrv_flush(bs->backing_hd);
}
/*
* Returns true iff the specified sector is present in the disk image. Drivers
* not implementing the functionality are assumed to not support backing files,
* hence all their sectors are reported as allocated.
*
* 'pnum' is set to the number of sectors (including and immediately following
* the specified sector) that are known to be in the same
* allocated/unallocated state.
*
* 'nb_sectors' is the max value 'pnum' should be set to.
*/
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
int *pnum)
{
int64_t n;
if (!bs->drv->bdrv_is_allocated) {
if (sector_num >= bs->total_sectors) {
*pnum = 0;
return 0;
}
n = bs->total_sectors - sector_num;
*pnum = (n < nb_sectors) ? (n) : (nb_sectors);
return 1;
}
return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
}
void bdrv_info(void)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
term_printf("%s:", bs->device_name);
term_printf(" type=");
switch(bs->type) {
case BDRV_TYPE_HD:
term_printf("hd");
break;
case BDRV_TYPE_CDROM:
term_printf("cdrom");
break;
case BDRV_TYPE_FLOPPY:
term_printf("floppy");
break;
}
term_printf(" removable=%d", bs->removable);
if (bs->removable) {
term_printf(" locked=%d", bs->locked);
}
if (bs->drv) {
term_printf(" file=");
term_print_filename(bs->filename);
if (bs->backing_file[0] != '\0') {
term_printf(" backing_file=");
term_print_filename(bs->backing_file);
}
term_printf(" ro=%d", bs->read_only);
term_printf(" drv=%s", bs->drv->format_name);
if (bs->encrypted)
term_printf(" encrypted");
} else {
term_printf(" [not inserted]");
}
term_printf("\n");
}
}
/* The "info blockstats" command. */
void bdrv_info_stats (void)
{
BlockDriverState *bs;
for (bs = bdrv_first; bs != NULL; bs = bs->next) {
term_printf ("%s:"
" rd_bytes=%" PRIu64
" wr_bytes=%" PRIu64
" rd_operations=%" PRIu64
" wr_operations=%" PRIu64
"\n",
bs->device_name,
bs->rd_bytes, bs->wr_bytes,
bs->rd_ops, bs->wr_ops);
}
}
void bdrv_get_backing_filename(BlockDriverState *bs,
char *filename, int filename_size)
{
if (!bs->backing_hd) {
pstrcpy(filename, filename_size, "");
} else {
pstrcpy(filename, filename_size, bs->backing_file);
}
}
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_write_compressed)
return -ENOTSUP;
return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_get_info)
return -ENOTSUP;
memset(bdi, 0, sizeof(*bdi));
return drv->bdrv_get_info(bs, bdi);
}
/**************************************************************/
/* handling of snapshots */
int bdrv_snapshot_create(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_create)
return -ENOTSUP;
return drv->bdrv_snapshot_create(bs, sn_info);
}
int bdrv_snapshot_goto(BlockDriverState *bs,
const char *snapshot_id)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_goto)
return -ENOTSUP;
return drv->bdrv_snapshot_goto(bs, snapshot_id);
}
int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_delete)
return -ENOTSUP;
return drv->bdrv_snapshot_delete(bs, snapshot_id);
}
int bdrv_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info)
{
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
if (!drv->bdrv_snapshot_list)
return -ENOTSUP;
return drv->bdrv_snapshot_list(bs, psn_info);
}
#define NB_SUFFIXES 4
char *get_human_readable_size(char *buf, int buf_size, int64_t size)
{
static const char suffixes[NB_SUFFIXES] = "KMGT";
int64_t base;
int i;
if (size <= 999) {
snprintf(buf, buf_size, "%" PRId64, size);
} else {
base = 1024;
for(i = 0; i < NB_SUFFIXES; i++) {
if (size < (10 * base)) {
snprintf(buf, buf_size, "%0.1f%c",
(double)size / base,
suffixes[i]);
break;
} else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
snprintf(buf, buf_size, "%" PRId64 "%c",
((size + (base >> 1)) / base),
suffixes[i]);
break;
}
base = base * 1024;
}
}
return buf;
}
char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
{
char buf1[128], date_buf[128], clock_buf[128];
#ifdef _WIN32
struct tm *ptm;
#else
struct tm tm;
#endif
time_t ti;
int64_t secs;
if (!sn) {
snprintf(buf, buf_size,
"%-10s%-20s%7s%20s%15s",
"ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
} else {
ti = sn->date_sec;
#ifdef _WIN32
ptm = localtime(&ti);
strftime(date_buf, sizeof(date_buf),
"%Y-%m-%d %H:%M:%S", ptm);
#else
localtime_r(&ti, &tm);
strftime(date_buf, sizeof(date_buf),
"%Y-%m-%d %H:%M:%S", &tm);
#endif
secs = sn->vm_clock_nsec / 1000000000;
snprintf(clock_buf, sizeof(clock_buf),
"%02d:%02d:%02d.%03d",
(int)(secs / 3600),
(int)((secs / 60) % 60),
(int)(secs % 60),
(int)((sn->vm_clock_nsec / 1000000) % 1000));
snprintf(buf, buf_size,
"%-10s%-20s%7s%20s%15s",
sn->id_str, sn->name,
get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
date_buf,
clock_buf);
}
return buf;
}
/**************************************************************/
/* async I/Os */
BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
BlockDriverAIOCB *ret;
if (!drv)
return NULL;
/* XXX: we assume that nb_sectors == 0 is suppored by the async read */
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(buf, bs->boot_sector_data, 512);
sector_num++;
nb_sectors--;
buf += 512;
}
ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
bs->rd_ops ++;
}
return ret;
}
BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
BlockDriverAIOCB *ret;
if (!drv)
return NULL;
if (bs->read_only)
return NULL;
if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
memcpy(bs->boot_sector_data, buf, 512);
}
ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
bs->wr_ops ++;
}
return ret;
}
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
{
BlockDriver *drv = acb->bs->drv;
drv->bdrv_aio_cancel(acb);
}
/**************************************************************/
/* async block device emulation */
static void bdrv_aio_bh_cb(void *opaque)
{
BlockDriverAIOCBSync *acb = opaque;
acb->common.cb(acb->common.opaque, acb->ret);
qemu_aio_release(acb);
}
static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriverAIOCBSync *acb;
int ret;
acb = qemu_aio_get(bs, cb, opaque);
if (!acb->bh)
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
ret = bdrv_read(bs, sector_num, buf, nb_sectors);
acb->ret = ret;
qemu_bh_schedule(acb->bh);
return &acb->common;
}
static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriverAIOCBSync *acb;
int ret;
acb = qemu_aio_get(bs, cb, opaque);
if (!acb->bh)
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
ret = bdrv_write(bs, sector_num, buf, nb_sectors);
acb->ret = ret;
qemu_bh_schedule(acb->bh);
return &acb->common;
}
static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
{
BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
qemu_bh_cancel(acb->bh);
qemu_aio_release(acb);
}
/**************************************************************/
/* sync block device emulation */
static void bdrv_rw_em_cb(void *opaque, int ret)
{
*(int *)opaque = ret;
}
#define NOT_DONE 0x7fffffff
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
int async_ret;
BlockDriverAIOCB *acb;
async_ret = NOT_DONE;
acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL)
return -1;
while (async_ret == NOT_DONE) {
qemu_aio_wait();
}
return async_ret;
}
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
int async_ret;
BlockDriverAIOCB *acb;
async_ret = NOT_DONE;
acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL)
return -1;
while (async_ret == NOT_DONE) {
qemu_aio_wait();
}
return async_ret;
}
void bdrv_init(void)
{
bdrv_register(&bdrv_raw);
bdrv_register(&bdrv_host_device);
#ifndef _WIN32
bdrv_register(&bdrv_cow);
#endif
bdrv_register(&bdrv_qcow);
bdrv_register(&bdrv_vmdk);
bdrv_register(&bdrv_cloop);
bdrv_register(&bdrv_dmg);
bdrv_register(&bdrv_bochs);
bdrv_register(&bdrv_vpc);
bdrv_register(&bdrv_vvfat);
bdrv_register(&bdrv_qcow2);
bdrv_register(&bdrv_parallels);
bdrv_register(&bdrv_nbd);
}
void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
void *opaque)
{
BlockDriver *drv;
BlockDriverAIOCB *acb;
drv = bs->drv;
if (drv->free_aiocb) {
acb = drv->free_aiocb;
drv->free_aiocb = acb->next;
} else {
acb = qemu_mallocz(drv->aiocb_size);
if (!acb)
return NULL;
}
acb->bs = bs;
acb->cb = cb;
acb->opaque = opaque;
return acb;
}
void qemu_aio_release(void *p)
{
BlockDriverAIOCB *acb = p;
BlockDriver *drv = acb->bs->drv;
acb->next = drv->free_aiocb;
drv->free_aiocb = acb;
}
/**************************************************************/
/* removable device support */
/**
* Return TRUE if the media is present
*/
int bdrv_is_inserted(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
int ret;
if (!drv)
return 0;
if (!drv->bdrv_is_inserted)
return 1;
ret = drv->bdrv_is_inserted(bs);
return ret;
}
/**
* Return TRUE if the media changed since the last call to this
* function. It is currently only used for floppy disks
*/
int bdrv_media_changed(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
int ret;
if (!drv || !drv->bdrv_media_changed)
ret = -ENOTSUP;
else
ret = drv->bdrv_media_changed(bs);
if (ret == -ENOTSUP)
ret = bs->media_changed;
bs->media_changed = 0;
return ret;
}
/**
* If eject_flag is TRUE, eject the media. Otherwise, close the tray
*/
void bdrv_eject(BlockDriverState *bs, int eject_flag)
{
BlockDriver *drv = bs->drv;
int ret;
if (!drv || !drv->bdrv_eject) {
ret = -ENOTSUP;
} else {
ret = drv->bdrv_eject(bs, eject_flag);
}
if (ret == -ENOTSUP) {
if (eject_flag)
bdrv_close(bs);
}
}
int bdrv_is_locked(BlockDriverState *bs)
{
return bs->locked;
}
/**
* Lock or unlock the media (if it is locked, the user won't be able
* to eject it manually).
*/
void bdrv_set_locked(BlockDriverState *bs, int locked)
{
BlockDriver *drv = bs->drv;
bs->locked = locked;
if (drv && drv->bdrv_set_locked) {
drv->bdrv_set_locked(bs, locked);
}
}
/* needed for generic scsi interface */
int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
{
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_ioctl)
return drv->bdrv_ioctl(bs, req, buf);
return -ENOTSUP;
}
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