diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-11 11:42:06 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-11 11:42:06 -0800 |
commit | 7bc4a4ce68f8c6d064ea949446852e996526f692 (patch) | |
tree | 304fa48493bde1745b34920e39b7bd4340e2477c | |
parent | 498f7f505dc79934c878c7667840c50c64f232fc (diff) | |
parent | 92f1c008ae79e32b83c0607d184b194f302bb3ee (diff) |
Merge branch 'for-linus-merged' of git://oss.sgi.com/xfs/xfs
* 'for-linus-merged' of git://oss.sgi.com/xfs/xfs: (47 commits)
xfs: convert grant head manipulations to lockless algorithm
xfs: introduce new locks for the log grant ticket wait queues
xfs: convert log grant heads to atomic variables
xfs: convert l_tail_lsn to an atomic variable.
xfs: convert l_last_sync_lsn to an atomic variable
xfs: make AIL tail pushing independent of the grant lock
xfs: use wait queues directly for the log wait queues
xfs: combine grant heads into a single 64 bit integer
xfs: rework log grant space calculations
xfs: fact out common grant head/log tail verification code
xfs: convert log grant ticket queues to list heads
xfs: use AIL bulk delete function to implement single delete
xfs: use AIL bulk update function to implement single updates
xfs: remove all the inodes on a buffer from the AIL in bulk
xfs: consume iodone callback items on buffers as they are processed
xfs: reduce the number of AIL push wakeups
xfs: bulk AIL insertion during transaction commit
xfs: clean up xfs_ail_delete()
xfs: Pull EFI/EFD handling out from under the AIL lock
xfs: fix EFI transaction cancellation.
...
38 files changed, 1997 insertions, 1920 deletions
diff --git a/fs/xfs/linux-2.6/sv.h b/fs/xfs/linux-2.6/sv.h deleted file mode 100644 index 4dfc7c370819..000000000000 --- a/fs/xfs/linux-2.6/sv.h +++ /dev/null @@ -1,59 +0,0 @@ -/* - * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. - * All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it would be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - */ -#ifndef __XFS_SUPPORT_SV_H__ -#define __XFS_SUPPORT_SV_H__ - -#include <linux/wait.h> -#include <linux/sched.h> -#include <linux/spinlock.h> - -/* - * Synchronisation variables. - * - * (Parameters "pri", "svf" and "rts" are not implemented) - */ - -typedef struct sv_s { - wait_queue_head_t waiters; -} sv_t; - -static inline void _sv_wait(sv_t *sv, spinlock_t *lock) -{ - DECLARE_WAITQUEUE(wait, current); - - add_wait_queue_exclusive(&sv->waiters, &wait); - __set_current_state(TASK_UNINTERRUPTIBLE); - spin_unlock(lock); - - schedule(); - - remove_wait_queue(&sv->waiters, &wait); -} - -#define sv_init(sv,flag,name) \ - init_waitqueue_head(&(sv)->waiters) -#define sv_destroy(sv) \ - /*NOTHING*/ -#define sv_wait(sv, pri, lock, s) \ - _sv_wait(sv, lock) -#define sv_signal(sv) \ - wake_up(&(sv)->waiters) -#define sv_broadcast(sv) \ - wake_up_all(&(sv)->waiters) - -#endif /* __XFS_SUPPORT_SV_H__ */ diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 691f61223ed6..ec7bbb5645b6 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -38,15 +38,6 @@ #include <linux/pagevec.h> #include <linux/writeback.h> -/* - * Types of I/O for bmap clustering and I/O completion tracking. - */ -enum { - IO_READ, /* mapping for a read */ - IO_DELAY, /* mapping covers delalloc region */ - IO_UNWRITTEN, /* mapping covers allocated but uninitialized data */ - IO_NEW /* just allocated */ -}; /* * Prime number of hash buckets since address is used as the key. @@ -182,9 +173,6 @@ xfs_setfilesize( xfs_inode_t *ip = XFS_I(ioend->io_inode); xfs_fsize_t isize; - ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG); - ASSERT(ioend->io_type != IO_READ); - if (unlikely(ioend->io_error)) return 0; @@ -244,10 +232,8 @@ xfs_end_io( * We might have to update the on-disk file size after extending * writes. */ - if (ioend->io_type != IO_READ) { - error = xfs_setfilesize(ioend); - ASSERT(!error || error == EAGAIN); - } + error = xfs_setfilesize(ioend); + ASSERT(!error || error == EAGAIN); /* * If we didn't complete processing of the ioend, requeue it to the @@ -318,14 +304,63 @@ STATIC int xfs_map_blocks( struct inode *inode, loff_t offset, - ssize_t count, struct xfs_bmbt_irec *imap, - int flags) + int type, + int nonblocking) { - int nmaps = 1; - int new = 0; + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + ssize_t count = 1 << inode->i_blkbits; + xfs_fileoff_t offset_fsb, end_fsb; + int error = 0; + int bmapi_flags = XFS_BMAPI_ENTIRE; + int nimaps = 1; + + if (XFS_FORCED_SHUTDOWN(mp)) + return -XFS_ERROR(EIO); + + if (type == IO_UNWRITTEN) + bmapi_flags |= XFS_BMAPI_IGSTATE; + + if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) { + if (nonblocking) + return -XFS_ERROR(EAGAIN); + xfs_ilock(ip, XFS_ILOCK_SHARED); + } - return -xfs_iomap(XFS_I(inode), offset, count, flags, imap, &nmaps, &new); + ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE || + (ip->i_df.if_flags & XFS_IFEXTENTS)); + ASSERT(offset <= mp->m_maxioffset); + + if (offset + count > mp->m_maxioffset) + count = mp->m_maxioffset - offset; + end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); + offset_fsb = XFS_B_TO_FSBT(mp, offset); + error = xfs_bmapi(NULL, ip, offset_fsb, end_fsb - offset_fsb, + bmapi_flags, NULL, 0, imap, &nimaps, NULL); + xfs_iunlock(ip, XFS_ILOCK_SHARED); + + if (error) + return -XFS_ERROR(error); + + if (type == IO_DELALLOC && + (!nimaps || isnullstartblock(imap->br_startblock))) { + error = xfs_iomap_write_allocate(ip, offset, count, imap); + if (!error) + trace_xfs_map_blocks_alloc(ip, offset, count, type, imap); + return -XFS_ERROR(error); + } + +#ifdef DEBUG + if (type == IO_UNWRITTEN) { + ASSERT(nimaps); + ASSERT(imap->br_startblock != HOLESTARTBLOCK); + ASSERT(imap->br_startblock != DELAYSTARTBLOCK); + } +#endif + if (nimaps) + trace_xfs_map_blocks_found(ip, offset, count, type, imap); + return 0; } STATIC int @@ -380,26 +415,18 @@ xfs_submit_ioend_bio( submit_bio(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC_PLUG : WRITE, bio); - ASSERT(!bio_flagged(bio, BIO_EOPNOTSUPP)); - bio_put(bio); } STATIC struct bio * xfs_alloc_ioend_bio( struct buffer_head *bh) { - struct bio *bio; int nvecs = bio_get_nr_vecs(bh->b_bdev); - - do { - bio = bio_alloc(GFP_NOIO, nvecs); - nvecs >>= 1; - } while (!bio); + struct bio *bio = bio_alloc(GFP_NOIO, nvecs); ASSERT(bio->bi_private == NULL); bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; - bio_get(bio); return bio; } @@ -470,9 +497,8 @@ xfs_submit_ioend( /* Pass 1 - start writeback */ do { next = ioend->io_list; - for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) { + for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) xfs_start_buffer_writeback(bh); - } } while ((ioend = next) != NULL); /* Pass 2 - submit I/O */ @@ -600,117 +626,13 @@ xfs_map_at_offset( ASSERT(imap->br_startblock != HOLESTARTBLOCK); ASSERT(imap->br_startblock != DELAYSTARTBLOCK); - lock_buffer(bh); xfs_map_buffer(inode, bh, imap, offset); - bh->b_bdev = xfs_find_bdev_for_inode(inode); set_buffer_mapped(bh); clear_buffer_delay(bh); clear_buffer_unwritten(bh); } /* - * Look for a page at index that is suitable for clustering. - */ -STATIC unsigned int -xfs_probe_page( - struct page *page, - unsigned int pg_offset) -{ - struct buffer_head *bh, *head; - int ret = 0; - - if (PageWriteback(page)) - return 0; - if (!PageDirty(page)) - return 0; - if (!page->mapping) - return 0; - if (!page_has_buffers(page)) - return 0; - - bh = head = page_buffers(page); - do { - if (!buffer_uptodate(bh)) - break; - if (!buffer_mapped(bh)) - break; - ret += bh->b_size; - if (ret >= pg_offset) - break; - } while ((bh = bh->b_this_page) != head); - - return ret; -} - -STATIC size_t -xfs_probe_cluster( - struct inode *inode, - struct page *startpage, - struct buffer_head *bh, - struct buffer_head *head) -{ - struct pagevec pvec; - pgoff_t tindex, tlast, tloff; - size_t total = 0; - int done = 0, i; - - /* First sum forwards in this page */ - do { - if (!buffer_uptodate(bh) || !buffer_mapped(bh)) - return total; - total += bh->b_size; - } while ((bh = bh->b_this_page) != head); - - /* if we reached the end of the page, sum forwards in following pages */ - tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT; - tindex = startpage->index + 1; - - /* Prune this back to avoid pathological behavior */ - tloff = min(tlast, startpage->index + 64); - - pagevec_init(&pvec, 0); - while (!done && tindex <= tloff) { - unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1); - - if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len)) - break; - - for (i = 0; i < pagevec_count(&pvec); i++) { - struct page *page = pvec.pages[i]; - size_t pg_offset, pg_len = 0; - - if (tindex == tlast) { - pg_offset = - i_size_read(inode) & (PAGE_CACHE_SIZE - 1); - if (!pg_offset) { - done = 1; - break; - } - } else - pg_offset = PAGE_CACHE_SIZE; - - if (page->index == tindex && trylock_page(page)) { - pg_len = xfs_probe_page(page, pg_offset); - unlock_page(page); - } - - if (!pg_len) { - done = 1; - break; - } - - total += pg_len; - tindex++; - } - - pagevec_release(&pvec); - cond_resched(); - } - - return total; -} - -/* * Test if a given page is suitable for writing as part of an unwritten * or delayed allocate extent. */ @@ -731,9 +653,9 @@ xfs_is_delayed_page( if (buffer_unwritten(bh)) acceptable = (type == IO_UNWRITTEN); else if (buffer_delay(bh)) - acceptable = (type == IO_DELAY); + acceptable = (type == IO_DELALLOC); else if (buffer_dirty(bh) && buffer_mapped(bh)) - acceptable = (type == IO_NEW); + acceptable = (type == IO_OVERWRITE); else break; } while ((bh = bh->b_this_page) != head); @@ -758,8 +680,7 @@ xfs_convert_page( loff_t tindex, struct xfs_bmbt_irec *imap, xfs_ioend_t **ioendp, - struct writeback_control *wbc, - int all_bh) + struct writeback_control *wbc) { struct buffer_head *bh, *head; xfs_off_t end_offset; @@ -814,37 +735,30 @@ xfs_convert_page( continue; } - if (buffer_unwritten(bh) || buffer_delay(bh)) { + if (buffer_unwritten(bh) || buffer_delay(bh) || + buffer_mapped(bh)) { if (buffer_unwritten(bh)) type = IO_UNWRITTEN; + else if (buffer_delay(bh)) + type = IO_DELALLOC; else - type = IO_DELAY; + type = IO_OVERWRITE; if (!xfs_imap_valid(inode, imap, offset)) { done = 1; continue; } - ASSERT(imap->br_startblock != HOLESTARTBLOCK); - ASSERT(imap->br_startblock != DELAYSTARTBLOCK); - - xfs_map_at_offset(inode, bh, imap, offset); + lock_buffer(bh); + if (type != IO_OVERWRITE) + xfs_map_at_offset(inode, bh, imap, offset); xfs_add_to_ioend(inode, bh, offset, type, ioendp, done); page_dirty--; count++; } else { - type = IO_NEW; - if (buffer_mapped(bh) && all_bh) { - lock_buffer(bh); - xfs_add_to_ioend(inode, bh, offset, - type, ioendp, done); - count++; - page_dirty--; - } else { - done = 1; - } + done = 1; } } while (offset += len, (bh = bh->b_this_page) != head); @@ -876,7 +790,6 @@ xfs_cluster_write( struct xfs_bmbt_irec *imap, xfs_ioend_t **ioendp, struct writeback_control *wbc, - int all_bh, pgoff_t tlast) { struct pagevec pvec; @@ -891,7 +804,7 @@ xfs_cluster_write( for (i = 0; i < pagevec_count(&pvec); i++) { done = xfs_convert_page(inode, pvec.pages[i], tindex++, - imap, ioendp, wbc, all_bh); + imap, ioendp, wbc); if (done) break; } @@ -935,7 +848,7 @@ xfs_aops_discard_page( struct buffer_head *bh, *head; loff_t offset = page_offset(page); - if (!xfs_is_delayed_page(page, IO_DELAY)) + if (!xfs_is_delayed_page(page, IO_DELALLOC)) goto out_invalidate; if (XFS_FORCED_SHUTDOWN(ip->i_mount)) @@ -1002,10 +915,10 @@ xfs_vm_writepage( unsigned int type; __uint64_t end_offset; pgoff_t end_index, last_index; - ssize_t size, len; - int flags, err, imap_valid = 0, uptodate = 1; + ssize_t len; + int err, imap_valid = 0, uptodate = 1; int count = 0; - int all_bh = 0; + int nonblocking = 0; trace_xfs_writepage(inode, page, 0); @@ -1056,10 +969,14 @@ xfs_vm_writepage( bh = head = page_buffers(page); offset = page_offset(page); - flags = BMAPI_READ; - type = IO_NEW; + type = IO_OVERWRITE; + + if (wbc->sync_mode == WB_SYNC_NONE && wbc->nonblocking) + nonblocking = 1; do { + int new_ioend = 0; + if (offset >= end_offset) break; if (!buffer_uptodate(bh)) @@ -1076,90 +993,54 @@ xfs_vm_writepage( continue; } - if (imap_valid) - imap_valid = xfs_imap_valid(inode, &imap, offset); - - if (buffer_unwritten(bh) || buffer_delay(bh)) { - int new_ioend = 0; - - /* - * Make sure we don't use a read-only iomap - */ - if (flags == BMAPI_READ) - imap_valid = 0; - - if (buffer_unwritten(bh)) { + if (buffer_unwritten(bh)) { + if (type != IO_UNWRITTEN) { type = IO_UNWRITTEN; - flags = BMAPI_WRITE | BMAPI_IGNSTATE; - } else if (buffer_delay(bh)) { - type = IO_DELAY; - flags = BMAPI_ALLOCATE; - - if (wbc->sync_mode == WB_SYNC_NONE) - flags |= BMAPI_TRYLOCK; - } - - if (!imap_valid) { - /* - * If we didn't have a valid mapping then we - * need to ensure that we put the new mapping - * in a new ioend structure. This needs to be - * done to ensure that the ioends correctly - * reflect the block mappings at io completion - * for unwritten extent conversion. - */ - new_ioend = 1; - err = xfs_map_blocks(inode, offset, len, - &imap, flags); - if (err) - goto error; - imap_valid = xfs_imap_valid(inode, &imap, - offset); + imap_valid = 0; } - if (imap_valid) { - xfs_map_at_offset(inode, bh, &imap, offset); - xfs_add_to_ioend(inode, bh, offset, type, - &ioend, new_ioend); - count++; + } else if (buffer_delay(bh)) { + if (type != IO_DELALLOC) { + type = IO_DELALLOC; + imap_valid = 0; } } else if (buffer_uptodate(bh)) { - /* - * we got here because the buffer is already mapped. - * That means it must already have extents allocated - * underneath it. Map the extent by reading it. - */ - if (!imap_valid || flags != BMAPI_READ) { - flags = BMAPI_READ; - size = xfs_probe_cluster(inode, page, bh, head); - err = xfs_map_blocks(inode, offset, size, - &imap, flags); - if (err) - goto error; - imap_valid = xfs_imap_valid(inode, &imap, - offset); + if (type != IO_OVERWRITE) { + type = IO_OVERWRITE; + imap_valid = 0; } + } else { + if (PageUptodate(page)) { + ASSERT(buffer_mapped(bh)); + imap_valid = 0; + } + continue; + } + if (imap_valid) + imap_valid = xfs_imap_valid(inode, &imap, offset); + if (!imap_valid) { /* - * We set the type to IO_NEW in case we are doing a - * small write at EOF that is extending the file but - * without needing an allocation. We need to update the - * file size on I/O completion in this case so it is - * the same case as having just allocated a new extent - * that we are writing into for the first time. + * If we didn't have a valid mapping then we need to + * put the new mapping into a separate ioend structure. + * This ensures non-contiguous extents always have + * separate ioends, which is particularly important + * for unwritten extent conversion at I/O completion + * time. */ - type = IO_NEW; - if (trylock_buffer(bh)) { - if (imap_valid) - all_bh = 1; - xfs_add_to_ioend(inode, bh, offset, type, - &ioend, !imap_valid); - count++; - } else { - imap_valid = 0; - } - } else if (PageUptodate(page)) { - ASSERT(buffer_mapped(bh)); - imap_valid = 0; + new_ioend = 1; + err = xfs_map_blocks(inode, offset, &imap, type, + nonblocking); + if (err) + goto error; + imap_valid = xfs_imap_valid(inode, &imap, offset); + } + if (imap_valid) { + lock_buffer(bh); + if (type != IO_OVERWRITE) + xfs_map_at_offset(inode, bh, &imap, offset); + xfs_add_to_ioend(inode, bh, offset, type, &ioend, + new_ioend); + count++; } if (!iohead) @@ -1188,7 +1069,7 @@ xfs_vm_writepage( end_index = last_index; xfs_cluster_write(inode, page->index + 1, &imap, &ioend, - wbc, all_bh, end_index); + wbc, end_index); } if (iohead) @@ -1257,13 +1138,19 @@ __xfs_get_blocks( int create, int direct) { - int flags = create ? BMAPI_WRITE : BMAPI_READ; + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t offset_fsb, end_fsb; + int error = 0; + int lockmode = 0; struct xfs_bmbt_irec imap; + int nimaps = 1; xfs_off_t offset; ssize_t size; - int nimap = 1; int new = 0; - int error; + + if (XFS_FORCED_SHUTDOWN(mp)) + return -XFS_ERROR(EIO); offset = (xfs_off_t)iblock << inode->i_blkbits; ASSERT(bh_result->b_size >= (1 << inode->i_blkbits)); @@ -1272,15 +1159,45 @@ __xfs_get_blocks( if (!create && direct && offset >= i_size_read(inode)) return 0; - if (direct && create) - flags |= BMAPI_DIRECT; + if (create) { + lockmode = XFS_ILOCK_EXCL; + xfs_ilock(ip, lockmode); + } else { + lockmode = xfs_ilock_map_shared(ip); + } + + ASSERT(offset <= mp->m_maxioffset); + if (offset + size > mp->m_maxioffset) + size = mp->m_maxioffset - offset; + end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size); + offset_fsb = XFS_B_TO_FSBT(mp, offset); - error = xfs_iomap(XFS_I(inode), offset, size, flags, &imap, &nimap, - &new); + error = xfs_bmapi(NULL, ip, offset_fsb, end_fsb - offset_fsb, + XFS_BMAPI_ENTIRE, NULL, 0, &imap, &nimaps, NULL); if (error) - return -error; - if (nimap == 0) - return 0; + goto out_unlock; + + if (create && + (!nimaps || + (imap.br_startblock == HOLESTARTBLOCK || + imap.br_startblock == DELAYSTARTBLOCK))) { + if (direct) { + error = xfs_iomap_write_direct(ip, offset, size, + &imap, nimaps); + } else { + error = xfs_iomap_write_delay(ip, offset, size, &imap); + } + if (error) + goto out_unlock; + + trace_xfs_get_blocks_alloc(ip, offset, size, 0, &imap); + } else if (nimaps) { + trace_xfs_get_blocks_found(ip, offset, size, 0, &imap); + } else { + trace_xfs_get_blocks_notfound(ip, offset, size); + goto out_unlock; + } + xfs_iunlock(ip, lockmode); if (imap.br_startblock != HOLESTARTBLOCK && imap.br_startblock != DELAYSTARTBLOCK) { @@ -1347,6 +1264,10 @@ __xfs_get_blocks( } return 0; + +out_unlock: + xfs_iunlock(ip, lockmode); + return -error; } int @@ -1434,7 +1355,7 @@ xfs_vm_direct_IO( ssize_t ret; if (rw & WRITE) { - iocb->private = xfs_alloc_ioend(inode, IO_NEW); + iocb->private = xfs_alloc_ioend(inode, IO_DIRECT); ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset, nr_segs, diff --git a/fs/xfs/linux-2.6/xfs_aops.h b/fs/xfs/linux-2.6/xfs_aops.h index c5057fb6237a..71f721e1a71f 100644 --- a/fs/xfs/linux-2.6/xfs_aops.h +++ b/fs/xfs/linux-2.6/xfs_aops.h @@ -23,6 +23,22 @@ extern struct workqueue_struct *xfsconvertd_workqueue; extern mempool_t *xfs_ioend_pool; /* + * Types of I/O for bmap clustering and I/O completion tracking. + */ +enum { + IO_DIRECT = 0, /* special case for direct I/O ioends */ + IO_DELALLOC, /* mapping covers delalloc region */ + IO_UNWRITTEN, /* mapping covers allocated but uninitialized data */ + IO_OVERWRITE, /* mapping covers already allocated extent */ +}; + +#define XFS_IO_TYPES \ + { 0, "" }, \ + { IO_DELALLOC, "delalloc" }, \ + { IO_UNWRITTEN, "unwritten" }, \ + { IO_OVERWRITE, "overwrite" } + +/* * xfs_ioend struct manages large extent writes for XFS. * It can manage several multi-page bio's at once. */ diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index 4c5deb6e9e31..92f1f2acc6ab 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -44,12 +44,7 @@ static kmem_zone_t *xfs_buf_zone; STATIC int xfsbufd(void *); -STATIC int xfsbufd_wakeup(struct shrinker *, int, gfp_t); STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); -static struct shrinker xfs_buf_shake = { - .shrink = xfsbufd_wakeup, - .seeks = DEFAULT_SEEKS, -}; static struct workqueue_struct *xfslogd_workqueue; struct workqueue_struct *xfsdatad_workqueue; @@ -168,8 +163,79 @@ test_page_region( } /* - * Internal xfs_buf_t object manipulation + * xfs_buf_lru_add - add a buffer to the LRU. + * + * The LRU takes a new reference to the buffer so that it will only be freed + * once the shrinker takes the buffer off the LRU. */ +STATIC void +xfs_buf_lru_add( + struct xfs_buf *bp) +{ + struct xfs_buftarg *btp = bp->b_target; + + spin_lock(&btp->bt_lru_lock); + if (list_empty(&bp->b_lru)) { + atomic_inc(&bp->b_hold); + list_add_tail(&bp->b_lru, &btp->bt_lru); + btp->bt_lru_nr++; + } + spin_unlock(&btp->bt_lru_lock); +} + +/* + * xfs_buf_lru_del - remove a buffer from the LRU + * + * The unlocked check is safe here because it only occurs when there are not + * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there + * to optimise the shrinker removing the buffer from the LRU and calling + * xfs_buf_free(). i.e. it removes an unneccessary round trip on the + * bt_lru_lock. + */ +STATIC void +xfs_buf_lru_del( + struct xfs_buf *bp) +{ + struct xfs_buftarg *btp = bp->b_target; + + if (list_empty(&bp->b_lru)) + return; + + spin_lock(&btp->bt_lru_lock); + if (!list_empty(&bp->b_lru)) { + list_del_init(&bp->b_lru); + btp->bt_lru_nr--; + } + spin_unlock(&btp->bt_lru_lock); +} + +/* + * When we mark a buffer stale, we remove the buffer from the LRU and clear the + * b_lru_ref count so that the buffer is freed immediately when the buffer + * reference count falls to zero. If the buffer is already on the LRU, we need + * to remove the reference that LRU holds on the buffer. + * + * This prevents build-up of stale buffers on the LRU. + */ +void +xfs_buf_stale( + struct xfs_buf *bp) +{ + bp->b_flags |= XBF_STALE; + atomic_set(&(bp)->b_lru_ref, 0); + if (!list_empty(&bp->b_lru)) { + struct xfs_buftarg *btp = bp->b_target; + + spin_lock(&btp->bt_lru_lock); + if (!list_empty(&bp->b_lru)) { + list_del_init(&bp->b_lru); + btp->bt_lru_nr--; + atomic_dec(&bp->b_hold); + } + spin_unlock(&btp->bt_lru_lock); + } + ASSERT(atomic_read(&bp->b_hold) >= 1); +} STATIC void _xfs_buf_initialize( @@ -186,7 +252,9 @@ _xfs_buf_initialize( memset(bp, 0, sizeof(xfs_buf_t)); atomic_set(&bp->b_hold, 1); + atomic_set(&bp->b_lru_ref, 1); init_completion(&bp->b_iowait); + INIT_LIST_HEAD(&bp->b_lru); INIT_LIST_HEAD(&bp->b_list); RB_CLEAR_NODE(&bp->b_rbnode); sema_init(&bp->b_sema, 0); /* held, no waiters */ @@ -262,6 +330,8 @@ xfs_buf_free( { trace_xfs_buf_free(bp, _RET_IP_); + ASSERT(list_empty(&bp->b_lru)); + if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) { uint i; @@ -337,7 +407,6 @@ _xfs_buf_lookup_pages( __func__, gfp_mask); XFS_STATS_INC(xb_page_retries); - xfsbufd_wakeup(NULL, 0, gfp_mask); congestion_wait(BLK_RW_ASYNC, HZ/50); goto retry; } @@ -828,6 +897,7 @@ xfs_buf_rele( if (!pag) { ASSERT(!bp->b_relse); + ASSERT(list_empty(&bp->b_lru)); ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); if (atomic_dec_and_test(&bp->b_hold)) xfs_buf_free(bp); @@ -835,13 +905,19 @@ xfs_buf_rele( } ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); + ASSERT(atomic_read(&bp->b_hold) > 0); if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { if (bp->b_relse) { atomic_inc(&bp->b_hold); spin_unlock(&pag->pag_buf_lock); bp->b_relse(bp); + } else if (!(bp->b_flags & XBF_STALE) && + atomic_read(&bp->b_lru_ref)) |