From 5149fd327f16e393c1d04fa5325ab072c32472bf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 9 Jan 2017 13:36:30 -0800 Subject: [PATCH 1/6] xfs: bump up reserved blocks in xfs_alloc_set_aside Setting aside 4 blocks globally for bmbt splits isn't all that useful, as different threads can allocate space in parallel. Bump it to 4 blocks per AG to allow each thread that is currently doing an allocation to dip into it separately. Without that we may no have enough reserved blocks if there are enough parallel transactions in an almost out space file system that all run into bmap btree splits. Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 5050056a0b06..0a46f8488b8d 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -95,10 +95,7 @@ unsigned int xfs_alloc_set_aside( struct xfs_mount *mp) { - unsigned int blocks; - - blocks = 4 + (mp->m_sb.sb_agcount * XFS_ALLOC_AGFL_RESERVE); - return blocks; + return mp->m_sb.sb_agcount * (XFS_ALLOC_AGFL_RESERVE + 4); } /* From 255c516278175a6dc7037d1406307f35237d8688 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 9 Jan 2017 13:36:19 -0800 Subject: [PATCH 2/6] xfs: fix bogus minleft manipulations We can't just set minleft to 0 when we're low on space - that's exactly what we need minleft for: to protect space in the AG for btree block allocations when we are low on free space. Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 24 +++++++----------------- fs/xfs/libxfs/xfs_bmap.c | 3 --- fs/xfs/libxfs/xfs_bmap_btree.c | 3 +-- 3 files changed, 8 insertions(+), 22 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 0a46f8488b8d..fe925702c955 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -2635,12 +2635,10 @@ xfs_alloc_vextent( xfs_agblock_t agsize; /* allocation group size */ int error; int flags; /* XFS_ALLOC_FLAG_... locking flags */ - xfs_extlen_t minleft;/* minimum left value, temp copy */ xfs_mount_t *mp; /* mount structure pointer */ xfs_agnumber_t sagno; /* starting allocation group number */ xfs_alloctype_t type; /* input allocation type */ int bump_rotor = 0; - int no_min = 0; xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */ mp = args->mp; @@ -2669,7 +2667,6 @@ xfs_alloc_vextent( trace_xfs_alloc_vextent_badargs(args); return 0; } - minleft = args->minleft; switch (type) { case XFS_ALLOCTYPE_THIS_AG: @@ -2680,9 +2677,7 @@ xfs_alloc_vextent( */ args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno); args->pag = xfs_perag_get(mp, args->agno); - args->minleft = 0; error = xfs_alloc_fix_freelist(args, 0); - args->minleft = minleft; if (error) { trace_xfs_alloc_vextent_nofix(args); goto error0; @@ -2747,9 +2742,7 @@ xfs_alloc_vextent( */ for (;;) { args->pag = xfs_perag_get(mp, args->agno); - if (no_min) args->minleft = 0; error = xfs_alloc_fix_freelist(args, flags); - args->minleft = minleft; if (error) { trace_xfs_alloc_vextent_nofix(args); goto error0; @@ -2789,20 +2782,17 @@ xfs_alloc_vextent( * or switch to non-trylock mode. */ if (args->agno == sagno) { - if (no_min == 1) { + if (flags == 0) { args->agbno = NULLAGBLOCK; trace_xfs_alloc_vextent_allfailed(args); break; } - if (flags == 0) { - no_min = 1; - } else { - flags = 0; - if (type == XFS_ALLOCTYPE_START_BNO) { - args->agbno = XFS_FSB_TO_AGBNO(mp, - args->fsbno); - args->type = XFS_ALLOCTYPE_NEAR_BNO; - } + + flags = 0; + if (type == XFS_ALLOCTYPE_START_BNO) { + args->agbno = XFS_FSB_TO_AGBNO(mp, + args->fsbno); + args->type = XFS_ALLOCTYPE_NEAR_BNO; } } xfs_perag_put(args->pag); diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 2760bc3b2536..44773c9eb957 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3812,7 +3812,6 @@ xfs_bmap_btalloc( args.fsbno = 0; args.type = XFS_ALLOCTYPE_FIRST_AG; args.total = ap->minlen; - args.minleft = 0; if ((error = xfs_alloc_vextent(&args))) return error; ap->dfops->dop_low = true; @@ -4344,8 +4343,6 @@ xfs_bmapi_allocate( if (error) return error; - if (bma->dfops->dop_low) - bma->minleft = 0; if (bma->cur) bma->cur->bc_private.b.firstblock = *bma->firstblock; if (bma->blkno == NULLFSBLOCK) diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c index d6330c297ca0..d9be241fc86f 100644 --- a/fs/xfs/libxfs/xfs_bmap_btree.c +++ b/fs/xfs/libxfs/xfs_bmap_btree.c @@ -502,12 +502,11 @@ xfs_bmbt_alloc_block( if (args.fsbno == NULLFSBLOCK && args.minleft) { /* * Could not find an AG with enough free space to satisfy - * a full btree split. Try again without minleft and if + * a full btree split. Try again and if * successful activate the lowspace algorithm. */ args.fsbno = 0; args.type = XFS_ALLOCTYPE_FIRST_AG; - args.minleft = 0; error = xfs_alloc_vextent(&args); if (error) goto error0; From 54fee133ad59c87ab01dd84ab3e9397134b32acb Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 9 Jan 2017 13:44:30 -0800 Subject: [PATCH 3/6] xfs: adjust allocation length in xfs_alloc_space_available We must decide in xfs_alloc_fix_freelist if we can perform an allocation from a given AG is possible or not based on the available space, and should not fail the allocation past that point on a healthy file system. But currently we have two additional places that second-guess xfs_alloc_fix_freelist: xfs_alloc_ag_vextent tries to adjust the maxlen parameter to remove the reservation before doing the allocation (but ignores the various minium freespace requirements), and xfs_alloc_fix_minleft tries to fix up the allocated length after we've found an extent, but ignores the reservations and also doesn't take the AGFL into account (and thus fails allocations for not matching minlen in some cases). Remove all these later fixups and just correct the maxlen argument inside xfs_alloc_fix_freelist once we have the AGF buffer locked. Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 81 ++++++++------------------------------- fs/xfs/libxfs/xfs_alloc.h | 2 +- 2 files changed, 18 insertions(+), 65 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index fe925702c955..f2e7eb6e5243 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -362,35 +362,11 @@ xfs_alloc_fix_len( return; ASSERT(rlen >= args->minlen && rlen <= args->maxlen); ASSERT(rlen % args->prod == args->mod); + ASSERT(args->pag->pagf_freeblks + args->pag->pagf_flcount >= + rlen + args->minleft); args->len = rlen; } -/* - * Fix up length if there is too little space left in the a.g. - * Return 1 if ok, 0 if too little, should give up. - */ -STATIC int -xfs_alloc_fix_minleft( - xfs_alloc_arg_t *args) /* allocation argument structure */ -{ - xfs_agf_t *agf; /* a.g. freelist header */ - int diff; /* free space difference */ - - if (args->minleft == 0) - return 1; - agf = XFS_BUF_TO_AGF(args->agbp); - diff = be32_to_cpu(agf->agf_freeblks) - - args->len - args->minleft; - if (diff >= 0) - return 1; - args->len += diff; /* shrink the allocated space */ - /* casts to (int) catch length underflows */ - if ((int)args->len >= (int)args->minlen) - return 1; - args->agbno = NULLAGBLOCK; - return 0; -} - /* * Update the two btrees, logically removing from freespace the extent * starting at rbno, rlen blocks. The extent is contained within the @@ -686,8 +662,6 @@ xfs_alloc_ag_vextent( xfs_alloc_arg_t *args) /* argument structure for allocation */ { int error=0; - xfs_extlen_t reservation; - xfs_extlen_t oldmax; ASSERT(args->minlen > 0); ASSERT(args->maxlen > 0); @@ -695,20 +669,6 @@ xfs_alloc_ag_vextent( ASSERT(args->mod < args->prod); ASSERT(args->alignment > 0); - /* - * Clamp maxlen to the amount of free space minus any reservations - * that have been made. - */ - oldmax = args->maxlen; - reservation = xfs_ag_resv_needed(args->pag, args->resv); - if (args->maxlen > args->pag->pagf_freeblks - reservation) - args->maxlen = args->pag->pagf_freeblks - reservation; - if (args->maxlen == 0) { - args->agbno = NULLAGBLOCK; - args->maxlen = oldmax; - return 0; - } - /* * Branch to correct routine based on the type. */ @@ -728,8 +688,6 @@ xfs_alloc_ag_vextent( /* NOTREACHED */ } - args->maxlen = oldmax; - if (error || args->agbno == NULLAGBLOCK) return error; @@ -838,9 +796,6 @@ xfs_alloc_ag_vextent_exact( args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen) - args->agbno; xfs_alloc_fix_len(args); - if (!xfs_alloc_fix_minleft(args)) - goto not_found; - ASSERT(args->agbno + args->len <= tend); /* @@ -1146,12 +1101,7 @@ xfs_alloc_ag_vextent_near( XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); args->len = blen; - if (!xfs_alloc_fix_minleft(args)) { - xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); - trace_xfs_alloc_near_nominleft(args); - return 0; - } - blen = args->len; + /* * We are allocating starting at bnew for blen blocks. */ @@ -1343,12 +1293,6 @@ xfs_alloc_ag_vextent_near( */ args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); xfs_alloc_fix_len(args); - if (!xfs_alloc_fix_minleft(args)) { - trace_xfs_alloc_near_nominleft(args); - xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR); - xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); - return 0; - } rlen = args->len; (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, args->datatype, ltbnoa, ltlena, <new); @@ -1550,8 +1494,6 @@ xfs_alloc_ag_vextent_size( } xfs_alloc_fix_len(args); - if (!xfs_alloc_fix_minleft(args)) - goto out_nominleft; rlen = args->len; XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0); /* @@ -2070,10 +2012,20 @@ xfs_alloc_space_available( /* do we have enough free space remaining for the allocation? */ available = (int)(pag->pagf_freeblks + pag->pagf_flcount - - reservation - min_free - args->total); - if (available < (int)args->minleft || available <= 0) + reservation - min_free - args->minleft); + if (available < (int)args->total) return false; + /* + * Clamp maxlen to the amount of free space available for the actual + * extent allocation. + */ + if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) { + args->maxlen = available; + ASSERT(args->maxlen > 0); + ASSERT(args->maxlen >= args->minlen); + } + return true; } @@ -2119,7 +2071,8 @@ xfs_alloc_fix_freelist( } need = xfs_alloc_min_freelist(mp, pag); - if (!xfs_alloc_space_available(args, need, flags)) + if (!xfs_alloc_space_available(args, need, flags | + XFS_ALLOC_FLAG_CHECK)) goto out_agbp_relse; /* diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h index 7c404a6b0ae3..1d0f48a501a3 100644 --- a/fs/xfs/libxfs/xfs_alloc.h +++ b/fs/xfs/libxfs/xfs_alloc.h @@ -56,7 +56,7 @@ typedef unsigned int xfs_alloctype_t; #define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/ #define XFS_ALLOC_FLAG_NORMAP 0x00000004 /* don't modify the rmapbt */ #define XFS_ALLOC_FLAG_NOSHRINK 0x00000008 /* don't shrink the freelist */ - +#define XFS_ALLOC_FLAG_CHECK 0x00000010 /* test only, don't modify args */ /* * Argument structure for xfs_alloc routines. From 12ef830198b0d71668eb9b59f9ba69d32951a48a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 9 Jan 2017 13:39:35 -0800 Subject: [PATCH 4/6] xfs: don't rely on ->total in xfs_alloc_space_available ->total is a bit of an odd parameter passed down to the low-level allocator all the way from the high-level callers. It's supposed to contain the maximum number of blocks to be allocated for the whole transaction [1]. But in xfs_iomap_write_allocate we only convert existing delayed allocations and thus only have a minimal block reservation for the current transaction, so xfs_alloc_space_available can't use it for the allocation decisions. Use the maximum of args->total and the calculated block requirement to make a decision. We probably should get rid of args->total eventually and instead apply ->minleft more broadly, but that will require some extensive changes all over. [1] which creates lots of confusion as most callers don't decrement it once doing a first allocation. But that's for a separate series. Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index f2e7eb6e5243..9f06a211e157 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1995,7 +1995,7 @@ xfs_alloc_space_available( int flags) { struct xfs_perag *pag = args->pag; - xfs_extlen_t longest; + xfs_extlen_t alloc_len, longest; xfs_extlen_t reservation; /* blocks that are still reserved */ int available; @@ -2005,15 +2005,16 @@ xfs_alloc_space_available( reservation = xfs_ag_resv_needed(pag, args->resv); /* do we have enough contiguous free space for the allocation? */ + alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop; longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free, reservation); - if ((args->minlen + args->alignment + args->minalignslop - 1) > longest) + if (longest < alloc_len) return false; /* do we have enough free space remaining for the allocation? */ available = (int)(pag->pagf_freeblks + pag->pagf_flcount - reservation - min_free - args->minleft); - if (available < (int)args->total) + if (available < (int)max(args->total, alloc_len)) return false; /* From 84a4620cfe97c9d57e39b2369bfb77faff55063d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 9 Jan 2017 13:41:33 -0800 Subject: [PATCH 5/6] xfs: don't print warnings when xfs_log_force fails There are only two reasons for xfs_log_force / xfs_log_force_lsn to fail: one is an I/O error, for which xlog_bdstrat already logs a warning, and the second is an already shutdown log due to a previous I/O errors. In the latter case we'll already have a previous indication for the actual error, but the large stream of misleading warnings from xfs_log_force will probably scroll it out of the message buffer. Simply removing the warnings thus makes the XFS log reporting significantly better. Signed-off-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_log.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index c39ac14ff540..b1469f0a91a6 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3317,12 +3317,8 @@ xfs_log_force( xfs_mount_t *mp, uint flags) { - int error; - trace_xfs_log_force(mp, 0, _RET_IP_); - error = _xfs_log_force(mp, flags, NULL); - if (error) - xfs_warn(mp, "%s: error %d returned.", __func__, error); + _xfs_log_force(mp, flags, NULL); } /* @@ -3466,12 +3462,8 @@ xfs_log_force_lsn( xfs_lsn_t lsn, uint flags) { - int error; - trace_xfs_log_force(mp, lsn, _RET_IP_); - error = _xfs_log_force_lsn(mp, lsn, flags, NULL); - if (error) - xfs_warn(mp, "%s: error %d returned.", __func__, error); + _xfs_log_force_lsn(mp, lsn, flags, NULL); } /* From 0a417b8dc1f10b03e8f558b8a831f07ec4c23795 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 11 Jan 2017 10:20:04 -0800 Subject: [PATCH 6/6] xfs: Timely free truncated dirty pages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 99579ccec4e2 "xfs: skip dirty pages in ->releasepage()" started to skip dirty pages in xfs_vm_releasepage() which also has the effect that if a dirty page is truncated, it does not get freed by block_invalidatepage() and is lingering in LRU list waiting for reclaim. So a simple loop like: while true; do dd if=/dev/zero of=file bs=1M count=100 rm file done will keep using more and more memory until we hit low watermarks and start pagecache reclaim which will eventually reclaim also the truncate pages. Keeping these truncated (and thus never usable) pages in memory is just a waste of memory, is unnecessarily stressing page cache reclaim, and reportedly also leads to anonymous mmap(2) returning ENOMEM prematurely. So instead of just skipping dirty pages in xfs_vm_releasepage(), return to old behavior of skipping them only if they have delalloc or unwritten buffers and fix the spurious warnings by warning only if the page is clean. CC: stable@vger.kernel.org CC: Brian Foster CC: Vlastimil Babka Reported-by: Petr Tůma Fixes: 99579ccec4e271c3d4d4e7c946058766812afdab Signed-off-by: Jan Kara Reviewed-by: Brian Foster Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_aops.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 0f56fcd3a5d5..631e7c0e0a29 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1152,19 +1152,22 @@ xfs_vm_releasepage( * block_invalidatepage() can send pages that are still marked dirty * but otherwise have invalidated buffers. * - * We've historically freed buffers on the latter. Instead, quietly - * filter out all dirty pages to avoid spurious buffer state warnings. - * This can likely be removed once shrink_active_list() is fixed. + * We want to release the latter to avoid unnecessary buildup of the + * LRU, skip the former and warn if we've left any lingering + * delalloc/unwritten buffers on clean pages. Skip pages with delalloc + * or unwritten buffers and warn if the page is not dirty. Otherwise + * try to release the buffers. */ - if (PageDirty(page)) - return 0; - xfs_count_page_state(page, &delalloc, &unwritten); - if (WARN_ON_ONCE(delalloc)) + if (delalloc) { + WARN_ON_ONCE(!PageDirty(page)); return 0; - if (WARN_ON_ONCE(unwritten)) + } + if (unwritten) { + WARN_ON_ONCE(!PageDirty(page)); return 0; + } return try_to_free_buffers(page); }