Date: Sun, 6 Jun 2010 13:08:36 +0000 (UTC) From: Martin Matuska <mm@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r208869 - stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <201006061308.o56D8aRd049837@svn.freebsd.org>
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Author: mm Date: Sun Jun 6 13:08:36 2010 New Revision: 208869 URL: http://svn.freebsd.org/changeset/base/208869 Log: MFC r208775: Fix freeing space after deleting large files with holes. OpenSolaris onnv revision: 9950:78fc41aa9bc5 Reviewed by: pjd, delphij (mentor) Obtained from: OpenSolaris (Bug ID 6792701) Approved by: re (kib) Modified: stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/include/xen/ (props changed) stable/8/sys/cddl/contrib/opensolaris/ (props changed) stable/8/sys/contrib/dev/acpica/ (props changed) stable/8/sys/contrib/pf/ (props changed) stable/8/sys/dev/xen/xenpci/ (props changed) stable/8/sys/geom/sched/ (props changed) Modified: stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c ============================================================================== --- stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c Sun Jun 6 11:36:08 2010 (r208868) +++ stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c Sun Jun 6 13:08:36 2010 (r208869) @@ -371,56 +371,51 @@ dmu_prefetch(objset_t *os, uint64_t obje dnode_rele(dn, FTAG); } +/* + * Get the next "chunk" of file data to free. We traverse the file from + * the end so that the file gets shorter over time (if we crashes in the + * middle, this will leave us in a better state). We find allocated file + * data by simply searching the allocated level 1 indirects. + */ static int -get_next_chunk(dnode_t *dn, uint64_t *offset, uint64_t limit) +get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t limit) { - uint64_t len = *offset - limit; - uint64_t chunk_len = dn->dn_datablksz * DMU_MAX_DELETEBLKCNT; - uint64_t subchunk = + uint64_t len = *start - limit; + uint64_t blkcnt = 0; + uint64_t maxblks = DMU_MAX_ACCESS / (1ULL << (dn->dn_indblkshift + 1)); + uint64_t iblkrange = dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT); - ASSERT(limit <= *offset); + ASSERT(limit <= *start); - if (len <= chunk_len) { - *offset = limit; + if (len <= iblkrange * maxblks) { + *start = limit; return (0); } + ASSERT(ISP2(iblkrange)); - ASSERT(ISP2(subchunk)); - - while (*offset > limit) { - uint64_t initial_offset = P2ROUNDUP(*offset, subchunk); - uint64_t delta; + while (*start > limit && blkcnt < maxblks) { int err; - /* skip over allocated data */ + /* find next allocated L1 indirect */ err = dnode_next_offset(dn, - DNODE_FIND_HOLE|DNODE_FIND_BACKWARDS, offset, 1, 1, 0); - if (err == ESRCH) - *offset = limit; - else if (err) - return (err); + DNODE_FIND_BACKWARDS, start, 2, 1, 0); - ASSERT3U(*offset, <=, initial_offset); - *offset = P2ALIGN(*offset, subchunk); - delta = initial_offset - *offset; - if (delta >= chunk_len) { - *offset += delta - chunk_len; + /* if there are no more, then we are done */ + if (err == ESRCH) { + *start = limit; return (0); - } - chunk_len -= delta; - - /* skip over unallocated data */ - err = dnode_next_offset(dn, - DNODE_FIND_BACKWARDS, offset, 1, 1, 0); - if (err == ESRCH) - *offset = limit; - else if (err) + } else if (err) { return (err); + } + blkcnt += 1; - if (*offset < limit) - *offset = limit; - ASSERT3U(*offset, <, initial_offset); + /* reset offset to end of "next" block back */ + *start = P2ALIGN(*start, iblkrange); + if (*start <= limit) + *start = limit; + else + *start -= 1; } return (0); } Modified: stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c ============================================================================== --- stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c Sun Jun 6 11:36:08 2010 (r208868) +++ stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c Sun Jun 6 13:08:36 2010 (r208869) @@ -1239,6 +1239,22 @@ dnode_willuse_space(dnode_t *dn, int64_t dmu_tx_willuse_space(tx, space); } +/* + * This function scans a block at the indicated "level" looking for + * a hole or data (depending on 'flags'). If level > 0, then we are + * scanning an indirect block looking at its pointers. If level == 0, + * then we are looking at a block of dnodes. If we don't find what we + * are looking for in the block, we return ESRCH. Otherwise, return + * with *offset pointing to the beginning (if searching forwards) or + * end (if searching backwards) of the range covered by the block + * pointer we matched on (or dnode). + * + * The basic search algorithm used below by dnode_next_offset() is to + * use this function to search up the block tree (widen the search) until + * we find something (i.e., we don't return ESRCH) and then search back + * down the tree (narrow the search) until we reach our original search + * level. + */ static int dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, int lvl, uint64_t blkfill, uint64_t txg) @@ -1318,6 +1334,7 @@ dnode_next_offset_level(dnode_t *dn, int error = ESRCH; } else { blkptr_t *bp = data; + uint64_t start = *offset; span = (lvl - 1) * epbs + dn->dn_datablkshift; minfill = 0; maxfill = blkfill << ((lvl - 1) * epbs); @@ -1327,18 +1344,25 @@ dnode_next_offset_level(dnode_t *dn, int else minfill++; - for (i = (*offset >> span) & ((1ULL << epbs) - 1); + *offset = *offset >> span; + for (i = BF64_GET(*offset, 0, epbs); i >= 0 && i < epb; i += inc) { if (bp[i].blk_fill >= minfill && bp[i].blk_fill <= maxfill && (hole || bp[i].blk_birth > txg)) break; - if (inc < 0 && *offset < (1ULL << span)) - *offset = 0; - else - *offset += (1ULL << span) * inc; + if (inc > 0 || *offset > 0) + *offset += inc; + } + *offset = *offset << span; + if (inc < 0) { + /* traversing backwards; position offset at the end */ + ASSERT3U(*offset, <=, start); + *offset = MIN(*offset + (1ULL << span) - 1, start); + } else if (*offset < start) { + *offset = start; } - if (i < 0 || i == epb) + if (i < 0 || i >= epb) error = ESRCH; }
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