From 292378edcb408c652e841fdc867fc14f8b4995fa Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 26 Sep 2016 08:21:28 +1000 Subject: [PATCH] xfs: remote attribute blocks aren't really userdata When adding a new remote attribute, we write the attribute to the new extent before the allocation transaction is committed. This means we cannot reuse busy extents as that violates crash consistency semantics. Hence we currently treat remote attribute extent allocation like userdata because it has the same overwrite ordering constraints as userdata. Unfortunately, this also allows the allocator to incorrectly apply extent size hints to the remote attribute extent allocation. This results in interesting failures, such as transaction block reservation overruns and in-memory inode attribute fork corruption. To fix this, we need to separate the busy extent reuse configuration from the userdata configuration. This changes the definition of XFS_BMAPI_METADATA slightly - it now means that allocation is metadata and reuse of busy extents is acceptible due to the metadata ordering semantics of the journal. If this flag is not set, it means the allocation is that has unordered data writeback, and hence busy extent reuse is not allowed. It no longer implies the allocation is for user data, just that the data write will not be strictly ordered. This matches the semantics for both user data and remote attribute block allocation. As such, This patch changes the "userdata" field to a "datatype" field, and adds a "no busy reuse" flag to the field. When we detect an unordered data extent allocation, we immediately set the no reuse flag. We then set the "user data" flags based on the inode fork we are allocating the extent to. Hence we only set userdata flags on data fork allocations now and consider attribute fork remote extents to be an unordered metadata extent. The result is that remote attribute extents now have the expected allocation semantics, and the data fork allocation behaviour is completely unchanged. It should be noted that there may be other ways to fix this (e.g. use ordered metadata buffers for the remote attribute extent data write) but they are more invasive and difficult to validate both from a design and implementation POV. Hence this patch takes the simple, obvious route to fixing the problem... Reported-and-tested-by: Ross Zwisler Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_alloc.c | 23 +++++++++++----------- fs/xfs/libxfs/xfs_alloc.h | 17 ++++++++++++++-- fs/xfs/libxfs/xfs_bmap.c | 41 +++++++++++++++++++++++++-------------- fs/xfs/libxfs/xfs_bmap.h | 2 +- fs/xfs/xfs_bmap_util.c | 2 +- fs/xfs/xfs_extent_busy.c | 2 +- fs/xfs/xfs_filestream.c | 9 ++++++--- fs/xfs/xfs_trace.h | 8 ++++---- 8 files changed, 66 insertions(+), 38 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 05b5243d89f6..1d530c253c0e 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -265,7 +265,7 @@ xfs_alloc_compute_diff( xfs_agblock_t wantbno, /* target starting block */ xfs_extlen_t wantlen, /* target length */ xfs_extlen_t alignment, /* target alignment */ - char userdata, /* are we allocating data? */ + int datatype, /* are we allocating data? */ xfs_agblock_t freebno, /* freespace's starting block */ xfs_extlen_t freelen, /* freespace's length */ xfs_agblock_t *newbnop) /* result: best start block from free */ @@ -276,6 +276,7 @@ xfs_alloc_compute_diff( xfs_extlen_t newlen1=0; /* length with newbno1 */ xfs_extlen_t newlen2=0; /* length with newbno2 */ xfs_agblock_t wantend; /* end of target extent */ + bool userdata = xfs_alloc_is_userdata(datatype); ASSERT(freelen >= wantlen); freeend = freebno + freelen; @@ -917,7 +918,7 @@ xfs_alloc_find_best_extent( sdiff = xfs_alloc_compute_diff(args->agbno, args->len, args->alignment, - args->userdata, *sbnoa, + args->datatype, *sbnoa, *slena, &new); /* @@ -1101,7 +1102,7 @@ restart: if (args->len < blen) continue; ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, - args->alignment, args->userdata, ltbnoa, + args->alignment, args->datatype, ltbnoa, ltlena, <new); if (ltnew != NULLAGBLOCK && (args->len > blen || ltdiff < bdiff)) { @@ -1254,7 +1255,7 @@ restart: args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); xfs_alloc_fix_len(args); ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, - args->alignment, args->userdata, ltbnoa, + args->alignment, args->datatype, ltbnoa, ltlena, <new); error = xfs_alloc_find_best_extent(args, @@ -1271,7 +1272,7 @@ restart: args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen); xfs_alloc_fix_len(args); gtdiff = xfs_alloc_compute_diff(args->agbno, args->len, - args->alignment, args->userdata, gtbnoa, + args->alignment, args->datatype, gtbnoa, gtlena, >new); error = xfs_alloc_find_best_extent(args, @@ -1331,7 +1332,7 @@ restart: } rlen = args->len; (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, - args->userdata, ltbnoa, ltlena, <new); + args->datatype, ltbnoa, ltlena, <new); ASSERT(ltnew >= ltbno); ASSERT(ltnew + rlen <= ltbnoa + ltlena); ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); @@ -1608,9 +1609,9 @@ xfs_alloc_ag_vextent_small( goto error0; if (fbno != NULLAGBLOCK) { xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1, - args->userdata); + xfs_alloc_allow_busy_reuse(args->datatype)); - if (args->userdata) { + if (xfs_alloc_is_userdata(args->datatype)) { xfs_buf_t *bp; bp = xfs_btree_get_bufs(args->mp, args->tp, @@ -2058,7 +2059,7 @@ xfs_alloc_fix_freelist( * somewhere else if we are not being asked to try harder at this * point */ - if (pag->pagf_metadata && args->userdata && + if (pag->pagf_metadata && xfs_alloc_is_userdata(args->datatype) && (flags & XFS_ALLOC_FLAG_TRYLOCK)) { ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); goto out_agbp_relse; @@ -2633,7 +2634,7 @@ xfs_alloc_vextent( * Try near allocation first, then anywhere-in-ag after * the first a.g. fails. */ - if ((args->userdata & XFS_ALLOC_INITIAL_USER_DATA) && + if ((args->datatype & XFS_ALLOC_INITIAL_USER_DATA) && (mp->m_flags & XFS_MOUNT_32BITINODES)) { args->fsbno = XFS_AGB_TO_FSB(mp, ((mp->m_agfrotor / rotorstep) % @@ -2766,7 +2767,7 @@ xfs_alloc_vextent( #endif /* Zero the extent if we were asked to do so */ - if (args->userdata & XFS_ALLOC_USERDATA_ZERO) { + if (args->datatype & XFS_ALLOC_USERDATA_ZERO) { error = xfs_zero_extent(args->ip, args->fsbno, args->len); if (error) goto error0; diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h index 6fe2d6b7cfe9..7fd8eafd9abe 100644 --- a/fs/xfs/libxfs/xfs_alloc.h +++ b/fs/xfs/libxfs/xfs_alloc.h @@ -85,20 +85,33 @@ typedef struct xfs_alloc_arg { xfs_extlen_t len; /* output: actual size of extent */ xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */ xfs_alloctype_t otype; /* original allocation type */ + int datatype; /* mask defining data type treatment */ char wasdel; /* set if allocation was prev delayed */ char wasfromfl; /* set if allocation is from freelist */ char isfl; /* set if is freelist blocks - !acctg */ - char userdata; /* mask defining userdata treatment */ xfs_fsblock_t firstblock; /* io first block allocated */ struct xfs_owner_info oinfo; /* owner of blocks being allocated */ } xfs_alloc_arg_t; /* - * Defines for userdata + * Defines for datatype */ #define XFS_ALLOC_USERDATA (1 << 0)/* allocation is for user data*/ #define XFS_ALLOC_INITIAL_USER_DATA (1 << 1)/* special case start of file */ #define XFS_ALLOC_USERDATA_ZERO (1 << 2)/* zero extent on allocation */ +#define XFS_ALLOC_NOBUSY (1 << 3)/* Busy extents not allowed */ + +static inline bool +xfs_alloc_is_userdata(int datatype) +{ + return (datatype & ~XFS_ALLOC_NOBUSY) != 0; +} + +static inline bool +xfs_alloc_allow_busy_reuse(int datatype) +{ + return (datatype & XFS_ALLOC_NOBUSY) == 0; +} /* freespace limit calculations */ #define XFS_ALLOC_AGFL_RESERVE 4 diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index b060bca93402..06d1201b4718 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3347,7 +3347,8 @@ xfs_bmap_adjacent( mp = ap->ip->i_mount; nullfb = *ap->firstblock == NULLFSBLOCK; - rt = XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata; + rt = XFS_IS_REALTIME_INODE(ap->ip) && + xfs_alloc_is_userdata(ap->datatype); fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, *ap->firstblock); /* * If allocating at eof, and there's a previous real block, @@ -3622,7 +3623,7 @@ xfs_bmap_btalloc( { xfs_mount_t *mp; /* mount point structure */ xfs_alloctype_t atype = 0; /* type for allocation routines */ - xfs_extlen_t align; /* minimum allocation alignment */ + xfs_extlen_t align = 0; /* minimum allocation alignment */ xfs_agnumber_t fb_agno; /* ag number of ap->firstblock */ xfs_agnumber_t ag; xfs_alloc_arg_t args; @@ -3645,7 +3646,8 @@ xfs_bmap_btalloc( else if (mp->m_dalign) stripe_align = mp->m_dalign; - align = ap->userdata ? xfs_get_extsz_hint(ap->ip) : 0; + if (xfs_alloc_is_userdata(ap->datatype)) + align = xfs_get_extsz_hint(ap->ip); if (unlikely(align)) { error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, align, 0, ap->eof, 0, ap->conv, @@ -3658,7 +3660,8 @@ xfs_bmap_btalloc( nullfb = *ap->firstblock == NULLFSBLOCK; fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, *ap->firstblock); if (nullfb) { - if (ap->userdata && xfs_inode_is_filestream(ap->ip)) { + if (xfs_alloc_is_userdata(ap->datatype) && + xfs_inode_is_filestream(ap->ip)) { ag = xfs_filestream_lookup_ag(ap->ip); ag = (ag != NULLAGNUMBER) ? ag : 0; ap->blkno = XFS_AGB_TO_FSB(mp, ag, 0); @@ -3698,7 +3701,8 @@ xfs_bmap_btalloc( * enough for the request. If one isn't found, then adjust * the minimum allocation size to the largest space found. */ - if (ap->userdata && xfs_inode_is_filestream(ap->ip)) + if (xfs_alloc_is_userdata(ap->datatype) && + xfs_inode_is_filestream(ap->ip)) error = xfs_bmap_btalloc_filestreams(ap, &args, &blen); else error = xfs_bmap_btalloc_nullfb(ap, &args, &blen); @@ -3782,8 +3786,8 @@ xfs_bmap_btalloc( args.minleft = ap->minleft; args.wasdel = ap->wasdel; args.isfl = 0; - args.userdata = ap->userdata; - if (ap->userdata & XFS_ALLOC_USERDATA_ZERO) + args.datatype = ap->datatype; + if (ap->datatype & XFS_ALLOC_USERDATA_ZERO) args.ip = ap->ip; error = xfs_alloc_vextent(&args); @@ -3877,7 +3881,8 @@ STATIC int xfs_bmap_alloc( struct xfs_bmalloca *ap) /* bmap alloc argument struct */ { - if (XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata) + if (XFS_IS_REALTIME_INODE(ap->ip) && + xfs_alloc_is_userdata(ap->datatype)) return xfs_bmap_rtalloc(ap); return xfs_bmap_btalloc(ap); } @@ -4287,15 +4292,21 @@ xfs_bmapi_allocate( } /* - * Indicate if this is the first user data in the file, or just any - * user data. And if it is userdata, indicate whether it needs to - * be initialised to zero during allocation. + * Set the data type being allocated. For the data fork, the first data + * in the file is treated differently to all other allocations. For the + * attribute fork, we only need to ensure the allocated range is not on + * the busy list. */ if (!(bma->flags & XFS_BMAPI_METADATA)) { - bma->userdata = (bma->offset == 0) ? - XFS_ALLOC_INITIAL_USER_DATA : XFS_ALLOC_USERDATA; + bma->datatype = XFS_ALLOC_NOBUSY; + if (whichfork == XFS_DATA_FORK) { + if (bma->offset == 0) + bma->datatype |= XFS_ALLOC_INITIAL_USER_DATA; + else + bma->datatype |= XFS_ALLOC_USERDATA; + } if (bma->flags & XFS_BMAPI_ZERO) - bma->userdata |= XFS_ALLOC_USERDATA_ZERO; + bma->datatype |= XFS_ALLOC_USERDATA_ZERO; } bma->minlen = (bma->flags & XFS_BMAPI_CONTIG) ? bma->length : 1; @@ -4565,7 +4576,7 @@ xfs_bmapi_write( bma.tp = tp; bma.ip = ip; bma.total = total; - bma.userdata = 0; + bma.datatype = 0; bma.dfops = dfops; bma.firstblock = firstblock; diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h index 254034f96941..05576b7263f6 100644 --- a/fs/xfs/libxfs/xfs_bmap.h +++ b/fs/xfs/libxfs/xfs_bmap.h @@ -54,7 +54,7 @@ struct xfs_bmalloca { bool wasdel; /* replacing a delayed allocation */ bool aeof; /* allocated space at eof */ bool conv; /* overwriting unwritten extents */ - char userdata;/* userdata mask */ + int datatype;/* data type being allocated */ int flags; }; diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 4ece4f2ffc72..e827d657c314 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -182,7 +182,7 @@ xfs_bmap_rtalloc( XFS_TRANS_DQ_RTBCOUNT, (long) ralen); /* Zero the extent if we were asked to do so */ - if (ap->userdata & XFS_ALLOC_USERDATA_ZERO) { + if (ap->datatype & XFS_ALLOC_USERDATA_ZERO) { error = xfs_zero_extent(ap->ip, ap->blkno, ap->length); if (error) return error; diff --git a/fs/xfs/xfs_extent_busy.c b/fs/xfs/xfs_extent_busy.c index c263e079273e..162dc186cf04 100644 --- a/fs/xfs/xfs_extent_busy.c +++ b/fs/xfs/xfs_extent_busy.c @@ -384,7 +384,7 @@ restart: * If this is a metadata allocation, try to reuse the busy * extent instead of trimming the allocation. */ - if (!args->userdata && + if (!xfs_alloc_is_userdata(args->datatype) && !(busyp->flags & XFS_EXTENT_BUSY_DISCARDED)) { if (!xfs_extent_busy_update_extent(args->mp, args->pag, busyp, fbno, flen, diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c index 4a33a3304369..a75f7ab0581c 100644 --- a/fs/xfs/xfs_filestream.c +++ b/fs/xfs/xfs_filestream.c @@ -369,7 +369,8 @@ xfs_filestream_new_ag( struct xfs_mount *mp = ip->i_mount; xfs_extlen_t minlen = ap->length; xfs_agnumber_t startag = 0; - int flags, err = 0; + int flags = 0; + int err = 0; struct xfs_mru_cache_elem *mru; *agp = NULLAGNUMBER; @@ -385,8 +386,10 @@ xfs_filestream_new_ag( startag = (item->ag + 1) % mp->m_sb.sb_agcount; } - flags = (ap->userdata ? XFS_PICK_USERDATA : 0) | - (ap->dfops->dop_low ? XFS_PICK_LOWSPACE : 0); + if (xfs_alloc_is_userdata(ap->datatype)) + flags |= XFS_PICK_USERDATA; + if (ap->dfops->dop_low) + flags |= XFS_PICK_LOWSPACE; err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen); diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index d303a665dba9..1144522799bb 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -1623,7 +1623,7 @@ DECLARE_EVENT_CLASS(xfs_alloc_class, __field(char, wasdel) __field(char, wasfromfl) __field(char, isfl) - __field(char, userdata) + __field(int, datatype) __field(xfs_fsblock_t, firstblock) ), TP_fast_assign( @@ -1644,13 +1644,13 @@ DECLARE_EVENT_CLASS(xfs_alloc_class, __entry->wasdel = args->wasdel; __entry->wasfromfl = args->wasfromfl; __entry->isfl = args->isfl; - __entry->userdata = args->userdata; + __entry->datatype = args->datatype; __entry->firstblock = args->firstblock; ), TP_printk("dev %d:%d agno %u agbno %u minlen %u maxlen %u mod %u " "prod %u minleft %u total %u alignment %u minalignslop %u " "len %u type %s otype %s wasdel %d wasfromfl %d isfl %d " - "userdata %d firstblock 0x%llx", + "datatype 0x%x firstblock 0x%llx", MAJOR(__entry->dev), MINOR(__entry->dev), __entry->agno, __entry->agbno, @@ -1668,7 +1668,7 @@ DECLARE_EVENT_CLASS(xfs_alloc_class, __entry->wasdel, __entry->wasfromfl, __entry->isfl, - __entry->userdata, + __entry->datatype, (unsigned long long)__entry->firstblock) )