diff options
author | Darrick J. Wong <darrick.wong@oracle.com> | 2016-10-03 09:11:48 -0700 |
---|---|---|
committer | Darrick J. Wong <darrick.wong@oracle.com> | 2016-10-05 16:26:29 -0700 |
commit | ceeb9c832eeca5c1c2efc54a38f67283ccb60288 (patch) | |
tree | 9758e097e4b7ffcbca52b5689acc5588e83db920 /fs/xfs/libxfs/xfs_rmap.c | |
parent | 0e07c039bac5f6ce7e3bc512ab9efb4aaa76da94 (diff) | |
download | linux-ceeb9c832eeca5c1c2efc54a38f67283ccb60288.tar.bz2 |
xfs: use interval query for rmap alloc operations on shared files
When it's possible for reverse mappings to overlap (data fork extents
of files on reflink filesystems), use the interval query function to
find the left neighbor of an extent we're trying to add; and be
careful to use the lookup functions to update the neighbors and/or
add new extents.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/libxfs/xfs_rmap.c')
-rw-r--r-- | fs/xfs/libxfs/xfs_rmap.c | 514 |
1 files changed, 512 insertions, 2 deletions
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c index 1c40b851a21d..bb5e2f840370 100644 --- a/fs/xfs/libxfs/xfs_rmap.c +++ b/fs/xfs/libxfs/xfs_rmap.c @@ -148,6 +148,37 @@ done: return error; } +STATIC int +xfs_rmap_delete( + struct xfs_btree_cur *rcur, + xfs_agblock_t agbno, + xfs_extlen_t len, + uint64_t owner, + uint64_t offset, + unsigned int flags) +{ + int i; + int error; + + trace_xfs_rmap_delete(rcur->bc_mp, rcur->bc_private.a.agno, agbno, + len, owner, offset, flags); + + error = xfs_rmap_lookup_eq(rcur, agbno, len, owner, offset, flags, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(rcur->bc_mp, i == 1, done); + + error = xfs_btree_delete(rcur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(rcur->bc_mp, i == 1, done); +done: + if (error) + trace_xfs_rmap_delete_error(rcur->bc_mp, + rcur->bc_private.a.agno, error, _RET_IP_); + return error; +} + static int xfs_rmap_btrec_to_irec( union xfs_btree_rec *rec, @@ -180,6 +211,160 @@ xfs_rmap_get_rec( return xfs_rmap_btrec_to_irec(rec, irec); } +struct xfs_find_left_neighbor_info { + struct xfs_rmap_irec high; + struct xfs_rmap_irec *irec; + int *stat; +}; + +/* For each rmap given, figure out if it matches the key we want. */ +STATIC int +xfs_rmap_find_left_neighbor_helper( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_find_left_neighbor_info *info = priv; + + trace_xfs_rmap_find_left_neighbor_candidate(cur->bc_mp, + cur->bc_private.a.agno, rec->rm_startblock, + rec->rm_blockcount, rec->rm_owner, rec->rm_offset, + rec->rm_flags); + + if (rec->rm_owner != info->high.rm_owner) + return XFS_BTREE_QUERY_RANGE_CONTINUE; + if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) && + !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) && + rec->rm_offset + rec->rm_blockcount - 1 != info->high.rm_offset) + return XFS_BTREE_QUERY_RANGE_CONTINUE; + + *info->irec = *rec; + *info->stat = 1; + return XFS_BTREE_QUERY_RANGE_ABORT; +} + +/* + * Find the record to the left of the given extent, being careful only to + * return a match with the same owner and adjacent physical and logical + * block ranges. + */ +int +xfs_rmap_find_left_neighbor( + struct xfs_btree_cur *cur, + xfs_agblock_t bno, + uint64_t owner, + uint64_t offset, + unsigned int flags, + struct xfs_rmap_irec *irec, + int *stat) +{ + struct xfs_find_left_neighbor_info info; + int error; + + *stat = 0; + if (bno == 0) + return 0; + info.high.rm_startblock = bno - 1; + info.high.rm_owner = owner; + if (!XFS_RMAP_NON_INODE_OWNER(owner) && + !(flags & XFS_RMAP_BMBT_BLOCK)) { + if (offset == 0) + return 0; + info.high.rm_offset = offset - 1; + } else + info.high.rm_offset = 0; + info.high.rm_flags = flags; + info.high.rm_blockcount = 0; + info.irec = irec; + info.stat = stat; + + trace_xfs_rmap_find_left_neighbor_query(cur->bc_mp, + cur->bc_private.a.agno, bno, 0, owner, offset, flags); + + error = xfs_rmap_query_range(cur, &info.high, &info.high, + xfs_rmap_find_left_neighbor_helper, &info); + if (error == XFS_BTREE_QUERY_RANGE_ABORT) + error = 0; + if (*stat) + trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp, + cur->bc_private.a.agno, irec->rm_startblock, + irec->rm_blockcount, irec->rm_owner, + irec->rm_offset, irec->rm_flags); + return error; +} + +/* For each rmap given, figure out if it matches the key we want. */ +STATIC int +xfs_rmap_lookup_le_range_helper( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_find_left_neighbor_info *info = priv; + + trace_xfs_rmap_lookup_le_range_candidate(cur->bc_mp, + cur->bc_private.a.agno, rec->rm_startblock, + rec->rm_blockcount, rec->rm_owner, rec->rm_offset, + rec->rm_flags); + + if (rec->rm_owner != info->high.rm_owner) + return XFS_BTREE_QUERY_RANGE_CONTINUE; + if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) && + !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) && + (rec->rm_offset > info->high.rm_offset || + rec->rm_offset + rec->rm_blockcount <= info->high.rm_offset)) + return XFS_BTREE_QUERY_RANGE_CONTINUE; + + *info->irec = *rec; + *info->stat = 1; + return XFS_BTREE_QUERY_RANGE_ABORT; +} + +/* + * Find the record to the left of the given extent, being careful only to + * return a match with the same owner and overlapping physical and logical + * block ranges. This is the overlapping-interval version of + * xfs_rmap_lookup_le. + */ +int +xfs_rmap_lookup_le_range( + struct xfs_btree_cur *cur, + xfs_agblock_t bno, + uint64_t owner, + uint64_t offset, + unsigned int flags, + struct xfs_rmap_irec *irec, + int *stat) +{ + struct xfs_find_left_neighbor_info info; + int error; + + info.high.rm_startblock = bno; + info.high.rm_owner = owner; + if (!XFS_RMAP_NON_INODE_OWNER(owner) && !(flags & XFS_RMAP_BMBT_BLOCK)) + info.high.rm_offset = offset; + else + info.high.rm_offset = 0; + info.high.rm_flags = flags; + info.high.rm_blockcount = 0; + *stat = 0; + info.irec = irec; + info.stat = stat; + + trace_xfs_rmap_lookup_le_range(cur->bc_mp, + cur->bc_private.a.agno, bno, 0, owner, offset, flags); + error = xfs_rmap_query_range(cur, &info.high, &info.high, + xfs_rmap_lookup_le_range_helper, &info); + if (error == XFS_BTREE_QUERY_RANGE_ABORT) + error = 0; + if (*stat) + trace_xfs_rmap_lookup_le_range_result(cur->bc_mp, + cur->bc_private.a.agno, irec->rm_startblock, + irec->rm_blockcount, irec->rm_owner, + irec->rm_offset, irec->rm_flags); + return error; +} + /* * Find the extent in the rmap btree and remove it. * @@ -1098,6 +1283,321 @@ done: #undef RIGHT #undef PREV +/* + * Find an extent in the rmap btree and unmap it. For rmap extent types that + * can overlap (data fork rmaps on reflink filesystems) we must be careful + * that the prev/next records in the btree might belong to another owner. + * Therefore we must use delete+insert to alter any of the key fields. + * + * For every other situation there can only be one owner for a given extent, + * so we can call the regular _free function. + */ +STATIC int +xfs_rmap_unmap_shared( + struct xfs_btree_cur *cur, + xfs_agblock_t bno, + xfs_extlen_t len, + bool unwritten, + struct xfs_owner_info *oinfo) +{ + struct xfs_mount *mp = cur->bc_mp; + struct xfs_rmap_irec ltrec; + uint64_t ltoff; + int error = 0; + int i; + uint64_t owner; + uint64_t offset; + unsigned int flags; + + xfs_owner_info_unpack(oinfo, &owner, &offset, &flags); + if (unwritten) + flags |= XFS_RMAP_UNWRITTEN; + trace_xfs_rmap_unmap(mp, cur->bc_private.a.agno, bno, len, + unwritten, oinfo); + + /* + * We should always have a left record because there's a static record + * for the AG headers at rm_startblock == 0 created by mkfs/growfs that + * will not ever be removed from the tree. + */ + error = xfs_rmap_lookup_le_range(cur, bno, owner, offset, flags, + <rec, &i); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error); + ltoff = ltrec.rm_offset; + + /* Make sure the extent we found covers the entire freeing range. */ + XFS_WANT_CORRUPTED_GOTO(mp, ltrec.rm_startblock <= bno && + ltrec.rm_startblock + ltrec.rm_blockcount >= + bno + len, out_error); + + /* Make sure the owner matches what we expect to find in the tree. */ + XFS_WANT_CORRUPTED_GOTO(mp, owner == ltrec.rm_owner, out_error); + + /* Make sure the unwritten flag matches. */ + XFS_WANT_CORRUPTED_GOTO(mp, (flags & XFS_RMAP_UNWRITTEN) == + (ltrec.rm_flags & XFS_RMAP_UNWRITTEN), out_error); + + /* Check the offset. */ + XFS_WANT_CORRUPTED_GOTO(mp, ltrec.rm_offset <= offset, out_error); + XFS_WANT_CORRUPTED_GOTO(mp, offset <= ltoff + ltrec.rm_blockcount, + out_error); + + if (ltrec.rm_startblock == bno && ltrec.rm_blockcount == len) { + /* Exact match, simply remove the record from rmap tree. */ + error = xfs_rmap_delete(cur, ltrec.rm_startblock, + ltrec.rm_blockcount, ltrec.rm_owner, + ltrec.rm_offset, ltrec.rm_flags); + if (error) + goto out_error; + } else if (ltrec.rm_startblock == bno) { + /* + * Overlap left hand side of extent: move the start, trim the + * length and update the current record. + * + * ltbno ltlen + * Orig: |oooooooooooooooooooo| + * Freeing: |fffffffff| + * Result: |rrrrrrrrrr| + * bno len + */ + + /* Delete prev rmap. */ + error = xfs_rmap_delete(cur, ltrec.rm_startblock, + ltrec.rm_blockcount, ltrec.rm_owner, + ltrec.rm_offset, ltrec.rm_flags); + if (error) + goto out_error; + + /* Add an rmap at the new offset. */ + ltrec.rm_startblock += len; + ltrec.rm_blockcount -= len; + ltrec.rm_offset += len; + error = xfs_rmap_insert(cur, ltrec.rm_startblock, + ltrec.rm_blockcount, ltrec.rm_owner, + ltrec.rm_offset, ltrec.rm_flags); + if (error) + goto out_error; + } else if (ltrec.rm_startblock + ltrec.rm_blockcount == bno + len) { + /* + * Overlap right hand side of extent: trim the length and + * update the current record. + * + * ltbno ltlen + * Orig: |oooooooooooooooooooo| + * Freeing: |fffffffff| + * Result: |rrrrrrrrrr| + * bno len + */ + error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock, + ltrec.rm_blockcount, ltrec.rm_owner, + ltrec.rm_offset, ltrec.rm_flags, &i); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error); + ltrec.rm_blockcount -= len; + error = xfs_rmap_update(cur, <rec); + if (error) + goto out_error; + } else { + /* + * Overlap middle of extent: trim the length of the existing + * record to the length of the new left-extent size, increment + * the insertion position so we can insert a new record + * containing the remaining right-extent space. + * + * ltbno ltlen + * Orig: |oooooooooooooooooooo| + * Freeing: |fffffffff| + * Result: |rrrrr| |rrrr| + * bno len + */ + xfs_extlen_t orig_len = ltrec.rm_blockcount; + + /* Shrink the left side of the rmap */ + error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock, + ltrec.rm_blockcount, ltrec.rm_owner, + ltrec.rm_offset, ltrec.rm_flags, &i); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error); + ltrec.rm_blockcount = bno - ltrec.rm_startblock; + error = xfs_rmap_update(cur, <rec); + if (error) + goto out_error; + + /* Add an rmap at the new offset */ + error = xfs_rmap_insert(cur, bno + len, + orig_len - len - ltrec.rm_blockcount, + ltrec.rm_owner, offset + len, + ltrec.rm_flags); + if (error) + goto out_error; + } + + trace_xfs_rmap_unmap_done(mp, cur->bc_private.a.agno, bno, len, + unwritten, oinfo); +out_error: + if (error) + trace_xfs_rmap_unmap_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* + * Find an extent in the rmap btree and map it. For rmap extent types that + * can overlap (data fork rmaps on reflink filesystems) we must be careful + * that the prev/next records in the btree might belong to another owner. + * Therefore we must use delete+insert to alter any of the key fields. + * + * For every other situation there can only be one owner for a given extent, + * so we can call the regular _alloc function. + */ +STATIC int +xfs_rmap_map_shared( + struct xfs_btree_cur *cur, + xfs_agblock_t bno, + xfs_extlen_t len, + bool unwritten, + struct xfs_owner_info *oinfo) +{ + struct xfs_mount *mp = cur->bc_mp; + struct xfs_rmap_irec ltrec; + struct xfs_rmap_irec gtrec; + int have_gt; + int have_lt; + int error = 0; + int i; + uint64_t owner; + uint64_t offset; + unsigned int flags = 0; + + xfs_owner_info_unpack(oinfo, &owner, &offset, &flags); + if (unwritten) + flags |= XFS_RMAP_UNWRITTEN; + trace_xfs_rmap_map(mp, cur->bc_private.a.agno, bno, len, + unwritten, oinfo); + + /* Is there a left record that abuts our range? */ + error = xfs_rmap_find_left_neighbor(cur, bno, owner, offset, flags, + <rec, &have_lt); + if (error) + goto out_error; + if (have_lt && + !xfs_rmap_is_mergeable(<rec, owner, flags)) + have_lt = 0; + + /* Is there a right record that abuts our range? */ + error = xfs_rmap_lookup_eq(cur, bno + len, len, owner, offset + len, + flags, &have_gt); + if (error) + goto out_error; + if (have_gt) { + error = xfs_rmap_get_rec(cur, >rec, &have_gt); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(mp, have_gt == 1, out_error); + trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp, + cur->bc_private.a.agno, gtrec.rm_startblock, + gtrec.rm_blockcount, gtrec.rm_owner, + gtrec.rm_offset, gtrec.rm_flags); + + if (!xfs_rmap_is_mergeable(>rec, owner, flags)) + have_gt = 0; + } + + if (have_lt && + ltrec.rm_startblock + ltrec.rm_blockcount == bno && + ltrec.rm_offset + ltrec.rm_blockcount == offset) { + /* + * Left edge contiguous, merge into left record. + * + * ltbno ltlen + * orig: |ooooooooo| + * adding: |aaaaaaaaa| + * result: |rrrrrrrrrrrrrrrrrrr| + * bno len + */ + ltrec.rm_blockcount += len; + if (have_gt && + bno + len == gtrec.rm_startblock && + offset + len == gtrec.rm_offset) { + /* + * Right edge also contiguous, delete right record + * and merge into left record. + * + * ltbno ltlen gtbno gtlen + * orig: |ooooooooo| |ooooooooo| + * adding: |aaaaaaaaa| + * result: |rrrrrrrrrrrrrrrrrrrrrrrrrrrrr| + */ + ltrec.rm_blockcount += gtrec.rm_blockcount; + error = xfs_rmap_delete(cur, gtrec.rm_startblock, + gtrec.rm_blockcount, gtrec.rm_owner, + gtrec.rm_offset, gtrec.rm_flags); + if (error) + goto out_error; + } + + /* Point the cursor back to the left record and update. */ + error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock, + ltrec.rm_blockcount, ltrec.rm_owner, + ltrec.rm_offset, ltrec.rm_flags, &i); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error); + + error = xfs_rmap_update(cur, <rec); + if (error) + goto out_error; + } else if (have_gt && + bno + len == gtrec.rm_startblock && + offset + len == gtrec.rm_offset) { + /* + * Right edge contiguous, merge into right record. + * + * gtbno gtlen + * Orig: |ooooooooo| + * adding: |aaaaaaaaa| + * Result: |rrrrrrrrrrrrrrrrrrr| + * bno len + */ + /* Delete the old record. */ + error = xfs_rmap_delete(cur, gtrec.rm_startblock, + gtrec.rm_blockcount, gtrec.rm_owner, + gtrec.rm_offset, gtrec.rm_flags); + if (error) + goto out_error; + + /* Move the start and re-add it. */ + gtrec.rm_startblock = bno; + gtrec.rm_blockcount += len; + gtrec.rm_offset = offset; + error = xfs_rmap_insert(cur, gtrec.rm_startblock, + gtrec.rm_blockcount, gtrec.rm_owner, + gtrec.rm_offset, gtrec.rm_flags); + if (error) + goto out_error; + } else { + /* + * No contiguous edge with identical owner, insert + * new record at current cursor position. + */ + error = xfs_rmap_insert(cur, bno, len, owner, offset, flags); + if (error) + goto out_error; + } + + trace_xfs_rmap_map_done(mp, cur->bc_private.a.agno, bno, len, + unwritten, oinfo); +out_error: + if (error) + trace_xfs_rmap_map_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + struct xfs_rmap_query_range_info { xfs_rmap_query_range_fn fn; void *priv; @@ -1237,11 +1737,19 @@ xfs_rmap_finish_one( case XFS_RMAP_MAP: error = xfs_rmap_map(rcur, bno, blockcount, unwritten, &oinfo); break; + case XFS_RMAP_MAP_SHARED: + error = xfs_rmap_map_shared(rcur, bno, blockcount, unwritten, + &oinfo); + break; case XFS_RMAP_FREE: case XFS_RMAP_UNMAP: error = xfs_rmap_unmap(rcur, bno, blockcount, unwritten, &oinfo); break; + case XFS_RMAP_UNMAP_SHARED: + error = xfs_rmap_unmap_shared(rcur, bno, blockcount, unwritten, + &oinfo); + break; case XFS_RMAP_CONVERT: error = xfs_rmap_convert(rcur, bno, blockcount, !unwritten, &oinfo); @@ -1315,7 +1823,8 @@ xfs_rmap_map_extent( if (!xfs_rmap_update_is_needed(mp, whichfork)) return 0; - return __xfs_rmap_add(mp, dfops, XFS_RMAP_MAP, ip->i_ino, + return __xfs_rmap_add(mp, dfops, xfs_is_reflink_inode(ip) ? + XFS_RMAP_MAP_SHARED : XFS_RMAP_MAP, ip->i_ino, whichfork, PREV); } @@ -1331,7 +1840,8 @@ xfs_rmap_unmap_extent( if (!xfs_rmap_update_is_needed(mp, whichfork)) return 0; - return __xfs_rmap_add(mp, dfops, XFS_RMAP_UNMAP, ip->i_ino, + return __xfs_rmap_add(mp, dfops, xfs_is_reflink_inode(ip) ? + XFS_RMAP_UNMAP_SHARED : XFS_RMAP_UNMAP, ip->i_ino, whichfork, PREV); } |