From 64bc06bb32ee9cf458f432097113c8b495d75757 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sun, 24 Jun 2018 15:04:04 +0100 Subject: [PATCH] gfs2: iomap buffered write support With the traditional page-based writes, blocks are allocated separately for each page written to. With iomap writes, we can allocate a lot more blocks at once, with a fraction of the allocation overhead for each page. Split calculating the number of blocks that can be allocated at a given position (gfs2_alloc_size) off from gfs2_iomap_alloc: that size determines the number of blocks to allocate and reserve in the journal. Signed-off-by: Andreas Gruenbacher Reviewed-by: Bob Peterson --- fs/gfs2/aops.c | 20 ++-- fs/gfs2/aops.h | 19 ++++ fs/gfs2/bmap.c | 298 ++++++++++++++++++++++++++++++++++++++++++++----- fs/gfs2/file.c | 44 +++++++- 4 files changed, 338 insertions(+), 43 deletions(-) create mode 100644 fs/gfs2/aops.h diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 35f5ee23566d..ecfbca9c88ff 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" @@ -36,10 +37,11 @@ #include "super.h" #include "util.h" #include "glops.h" +#include "aops.h" -static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, - unsigned int from, unsigned int len) +void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, + unsigned int from, unsigned int len) { struct buffer_head *head = page_buffers(page); unsigned int bsize = head->b_size; @@ -462,7 +464,7 @@ static int gfs2_jdata_writepages(struct address_space *mapping, * Returns: errno */ -static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) +int stuffed_readpage(struct gfs2_inode *ip, struct page *page) { struct buffer_head *dibh; u64 dsize = i_size_read(&ip->i_inode); @@ -776,7 +778,7 @@ out_uninit: * adjust_fs_space - Adjusts the free space available due to gfs2_grow * @inode: the rindex inode */ -static void adjust_fs_space(struct inode *inode) +void adjust_fs_space(struct inode *inode) { struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); @@ -822,11 +824,11 @@ out: * This copies the data from the page into the inode block after * the inode data structure itself. * - * Returns: errno + * Returns: copied bytes or errno */ -static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, - loff_t pos, unsigned copied, - struct page *page) +int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, + loff_t pos, unsigned copied, + struct page *page) { struct gfs2_inode *ip = GFS2_I(inode); u64 to = pos + copied; @@ -865,7 +867,7 @@ static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, * The main write_end function for GFS2. We just put our locking around the VFS * provided functions. * - * Returns: errno + * Returns: copied bytes or errno */ static int gfs2_write_end(struct file *file, struct address_space *mapping, diff --git a/fs/gfs2/aops.h b/fs/gfs2/aops.h new file mode 100644 index 000000000000..fa8e5d0144dd --- /dev/null +++ b/fs/gfs2/aops.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Red Hat, Inc. All rights reserved. + */ + +#ifndef __AOPS_DOT_H__ +#define __AOPS_DOT_H__ + +#include "incore.h" + +extern int stuffed_readpage(struct gfs2_inode *ip, struct page *page); +extern int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, + loff_t pos, unsigned copied, + struct page *page); +extern void adjust_fs_space(struct inode *inode); +extern void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, + unsigned int from, unsigned int len); + +#endif /* __AOPS_DOT_H__ */ diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 33ee93344d18..9a699c0a5df1 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -28,6 +28,7 @@ #include "trans.h" #include "dir.h" #include "util.h" +#include "aops.h" #include "trace_gfs2.h" /* This doesn't need to be that large as max 64 bit pointers in a 4k @@ -41,6 +42,8 @@ struct metapath { int mp_aheight; /* actual height (lookup height) */ }; +static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length); + /** * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page * @ip: the inode @@ -389,7 +392,7 @@ static int fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, int h) return mp->mp_aheight - x - 1; } -static inline void release_metapath(struct metapath *mp) +static void release_metapath(struct metapath *mp) { int i; @@ -397,6 +400,7 @@ static inline void release_metapath(struct metapath *mp) if (mp->mp_bh[i] == NULL) break; brelse(mp->mp_bh[i]); + mp->mp_bh[i] = NULL; } } @@ -609,11 +613,13 @@ enum alloc_state { * ii) Indirect blocks to fill in lower part of the metadata tree * iii) Data blocks * - * The function is in two parts. The first part works out the total - * number of blocks which we need. The second part does the actual - * allocation asking for an extent at a time (if enough contiguous free - * blocks are available, there will only be one request per bmap call) - * and uses the state machine to initialise the blocks in order. + * This function is called after gfs2_iomap_get, which works out the + * total number of blocks which we need via gfs2_alloc_size. + * + * We then do the actual allocation asking for an extent at a time (if + * enough contiguous free blocks are available, there will only be one + * allocation request per call) and uses the state machine to initialise + * the blocks in order. * * Right now, this function will allocate at most one indirect block * worth of data -- with a default block size of 4K, that's slightly @@ -633,39 +639,26 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, struct buffer_head *dibh = mp->mp_bh[0]; u64 bn; unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0; - unsigned dblks = 0; - unsigned ptrs_per_blk; + size_t dblks = iomap->length >> inode->i_blkbits; const unsigned end_of_metadata = mp->mp_fheight - 1; int ret; enum alloc_state state; __be64 *ptr; __be64 zero_bn = 0; - size_t maxlen = iomap->length >> inode->i_blkbits; BUG_ON(mp->mp_aheight < 1); BUG_ON(dibh == NULL); + BUG_ON(dblks < 1); gfs2_trans_add_meta(ip->i_gl, dibh); down_write(&ip->i_rw_mutex); if (mp->mp_fheight == mp->mp_aheight) { - struct buffer_head *bh; - int eob; - - /* Bottom indirect block exists, find unalloced extent size */ - ptr = metapointer(end_of_metadata, mp); - bh = mp->mp_bh[end_of_metadata]; - dblks = gfs2_extent_length(bh->b_data, bh->b_size, ptr, - maxlen, &eob); - BUG_ON(dblks < 1); + /* Bottom indirect block exists */ state = ALLOC_DATA; } else { /* Need to allocate indirect blocks */ - ptrs_per_blk = mp->mp_fheight > 1 ? sdp->sd_inptrs : - sdp->sd_diptrs; - dblks = min(maxlen, (size_t)(ptrs_per_blk - - mp->mp_list[end_of_metadata])); if (mp->mp_fheight == ip->i_height) { /* Writing into existing tree, extend tree down */ iblks = mp->mp_fheight - mp->mp_aheight; @@ -762,6 +755,50 @@ out: #define IOMAP_F_GFS2_BOUNDARY IOMAP_F_PRIVATE +/** + * gfs2_alloc_size - Compute the maximum allocation size + * @inode: The inode + * @mp: The metapath + * @size: Requested size in blocks + * + * Compute the maximum size of the next allocation at @mp. + * + * Returns: size in blocks + */ +static u64 gfs2_alloc_size(struct inode *inode, struct metapath *mp, u64 size) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + const __be64 *first, *ptr, *end; + + /* + * For writes to stuffed files, this function is called twice via + * gfs2_iomap_get, before and after unstuffing. The size we return the + * first time needs to be large enough to get the reservation and + * allocation sizes right. The size we return the second time must + * be exact or else gfs2_iomap_alloc won't do the right thing. + */ + + if (gfs2_is_stuffed(ip) || mp->mp_fheight != mp->mp_aheight) { + unsigned int maxsize = mp->mp_fheight > 1 ? + sdp->sd_inptrs : sdp->sd_diptrs; + maxsize -= mp->mp_list[mp->mp_fheight - 1]; + if (size > maxsize) + size = maxsize; + return size; + } + + first = metapointer(ip->i_height - 1, mp); + end = metaend(ip->i_height - 1, mp); + if (end - first > size) + end = first + size; + for (ptr = first; ptr < end; ptr++) { + if (*ptr) + break; + } + return ptr - first; +} + /** * gfs2_iomap_get - Map blocks from an inode to disk blocks * @inode: The inode @@ -797,6 +834,7 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length, ret = gfs2_meta_inode_buffer(ip, &dibh); if (ret) goto unlock; + iomap->private = dibh; if (gfs2_is_stuffed(ip)) { if (flags & IOMAP_WRITE) { @@ -822,6 +860,7 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length, iomap->addr = (ip->i_no_addr << inode->i_blkbits) + sizeof(struct gfs2_dinode); iomap->type = IOMAP_INLINE; + iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode); goto out; } @@ -867,7 +906,7 @@ out: iomap->bdev = inode->i_sb->s_bdev; unlock: up_read(&ip->i_rw_mutex); - if (dibh) + if (ret && dibh) brelse(dibh); return ret; @@ -881,13 +920,168 @@ do_alloc: ret = gfs2_hole_size(inode, lblock, len, mp, iomap); else iomap->length = size - pos; - } else if (!(flags & IOMAP_WRITE)) { + } else if (flags & IOMAP_WRITE) { + u64 alloc_size; + + len = gfs2_alloc_size(inode, mp, len); + alloc_size = len << inode->i_blkbits; + if (alloc_size < iomap->length) + iomap->length = alloc_size; + } else { if (pos < size && height == ip->i_height) ret = gfs2_hole_size(inode, lblock, len, mp, iomap); } goto out; } +static int gfs2_write_lock(struct inode *inode) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + int error; + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh); + error = gfs2_glock_nq(&ip->i_gh); + if (error) + goto out_uninit; + if (&ip->i_inode == sdp->sd_rindex) { + struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); + + error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, + GL_NOCACHE, &m_ip->i_gh); + if (error) + goto out_unlock; + } + return 0; + +out_unlock: + gfs2_glock_dq(&ip->i_gh); +out_uninit: + gfs2_holder_uninit(&ip->i_gh); + return error; +} + +static void gfs2_write_unlock(struct inode *inode) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + + if (&ip->i_inode == sdp->sd_rindex) { + struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); + + gfs2_glock_dq_uninit(&m_ip->i_gh); + } + gfs2_glock_dq_uninit(&ip->i_gh); +} + +static void gfs2_iomap_journaled_page_done(struct inode *inode, loff_t pos, + unsigned copied, struct page *page, + struct iomap *iomap) +{ + struct gfs2_inode *ip = GFS2_I(inode); + + gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); +} + +static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, + loff_t length, unsigned flags, + struct iomap *iomap) +{ + struct metapath mp = { .mp_aheight = 1, }; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned int data_blocks = 0, ind_blocks = 0, rblocks; + bool unstuff, alloc_required; + int ret; + + ret = gfs2_write_lock(inode); + if (ret) + return ret; + + unstuff = gfs2_is_stuffed(ip) && + pos + length > gfs2_max_stuffed_size(ip); + + ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp); + if (ret) + goto out_release; + + alloc_required = unstuff || iomap->type == IOMAP_HOLE; + + if (alloc_required || gfs2_is_jdata(ip)) + gfs2_write_calc_reserv(ip, iomap->length, &data_blocks, + &ind_blocks); + + if (alloc_required) { + struct gfs2_alloc_parms ap = { + .target = data_blocks + ind_blocks + }; + + ret = gfs2_quota_lock_check(ip, &ap); + if (ret) + goto out_release; + + ret = gfs2_inplace_reserve(ip, &ap); + if (ret) + goto out_qunlock; + } + + rblocks = RES_DINODE + ind_blocks; + if (gfs2_is_jdata(ip)) + rblocks += data_blocks; + if (ind_blocks || data_blocks) + rblocks += RES_STATFS + RES_QUOTA; + if (inode == sdp->sd_rindex) + rblocks += 2 * RES_STATFS; + if (alloc_required) + rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks); + + ret = gfs2_trans_begin(sdp, rblocks, iomap->length >> inode->i_blkbits); + if (ret) + goto out_trans_fail; + + if (unstuff) { + ret = gfs2_unstuff_dinode(ip, NULL); + if (ret) + goto out_trans_end; + release_metapath(&mp); + brelse(iomap->private); + iomap->private = NULL; + ret = gfs2_iomap_get(inode, iomap->offset, iomap->length, + flags, iomap, &mp); + if (ret) + goto out_trans_end; + } + + if (iomap->type == IOMAP_HOLE) { + ret = gfs2_iomap_alloc(inode, iomap, flags, &mp); + if (ret) { + gfs2_trans_end(sdp); + gfs2_inplace_release(ip); + punch_hole(ip, iomap->offset, iomap->length); + goto out_qunlock; + } + } + release_metapath(&mp); + if (gfs2_is_jdata(ip)) + iomap->page_done = gfs2_iomap_journaled_page_done; + return 0; + +out_trans_end: + gfs2_trans_end(sdp); +out_trans_fail: + if (alloc_required) + gfs2_inplace_release(ip); +out_qunlock: + if (alloc_required) + gfs2_quota_unlock(ip); +out_release: + if (iomap->private) + brelse(iomap->private); + release_metapath(&mp); + gfs2_write_unlock(inode); + return ret; +} + static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length, unsigned flags, struct iomap *iomap) { @@ -897,10 +1091,7 @@ static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length, trace_gfs2_iomap_start(ip, pos, length, flags); if (flags & IOMAP_WRITE) { - ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp); - if (!ret && iomap->type == IOMAP_HOLE) - ret = gfs2_iomap_alloc(inode, iomap, flags, &mp); - release_metapath(&mp); + ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap); } else { ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp); release_metapath(&mp); @@ -909,8 +1100,59 @@ static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length, return ret; } +static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length, + ssize_t written, unsigned flags, struct iomap *iomap) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_trans *tr = current->journal_info; + struct buffer_head *dibh = iomap->private; + + if (!(flags & IOMAP_WRITE)) + goto out; + + if (iomap->type != IOMAP_INLINE) { + gfs2_ordered_add_inode(ip); + + if (tr->tr_num_buf_new) + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); + else + gfs2_trans_add_meta(ip->i_gl, dibh); + } + + if (inode == sdp->sd_rindex) { + adjust_fs_space(inode); + sdp->sd_rindex_uptodate = 0; + } + + gfs2_trans_end(sdp); + gfs2_inplace_release(ip); + + if (length != written && (iomap->flags & IOMAP_F_NEW)) { + /* Deallocate blocks that were just allocated. */ + loff_t blockmask = i_blocksize(inode) - 1; + loff_t end = (pos + length) & ~blockmask; + + pos = (pos + written + blockmask) & ~blockmask; + if (pos < end) { + truncate_pagecache_range(inode, pos, end - 1); + punch_hole(ip, pos, end - pos); + } + } + + if (ip->i_qadata && ip->i_qadata->qa_qd_num) + gfs2_quota_unlock(ip); + gfs2_write_unlock(inode); + +out: + if (dibh) + brelse(dibh); + return 0; +} + const struct iomap_ops gfs2_iomap_ops = { .iomap_begin = gfs2_iomap_begin, + .iomap_end = gfs2_iomap_end, }; /** diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 6f6bbfbff13d..16dd395479a5 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -26,10 +26,12 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" #include "bmap.h" +#include "aops.h" #include "dir.h" #include "glock.h" #include "glops.h" @@ -691,9 +693,7 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end, /** * gfs2_file_write_iter - Perform a write to a file * @iocb: The io context - * @iov: The data to write - * @nr_segs: Number of @iov segments - * @pos: The file position + * @from: The data to write * * We have to do a lock/unlock here to refresh the inode size for * O_APPEND writes, otherwise we can land up writing at the wrong @@ -705,8 +705,9 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end, static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; - struct gfs2_inode *ip = GFS2_I(file_inode(file)); - int ret; + struct inode *inode = file_inode(file); + struct gfs2_inode *ip = GFS2_I(inode); + ssize_t ret; ret = gfs2_rsqa_alloc(ip); if (ret) @@ -723,7 +724,38 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) gfs2_glock_dq_uninit(&gh); } - return generic_file_write_iter(iocb, from); + if (iocb->ki_flags & IOCB_DIRECT) + return generic_file_write_iter(iocb, from); + + inode_lock(inode); + ret = generic_write_checks(iocb, from); + if (ret <= 0) + goto out; + + /* We can write back this queue in page reclaim */ + current->backing_dev_info = inode_to_bdi(inode); + + ret = file_remove_privs(file); + if (ret) + goto out2; + + ret = file_update_time(file); + if (ret) + goto out2; + + ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops); + +out2: + current->backing_dev_info = NULL; +out: + inode_unlock(inode); + if (likely(ret > 0)) { + iocb->ki_pos += ret; + + /* Handle various SYNC-type writes */ + ret = generic_write_sync(iocb, ret); + } + return ret; } static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,