diff options
-rw-r--r-- | fs/xfs/libxfs/xfs_rmap.c | 52 |
1 files changed, 38 insertions, 14 deletions
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c index 3eea8056e7bc..6f74dcda44b5 100644 --- a/fs/xfs/libxfs/xfs_rmap.c +++ b/fs/xfs/libxfs/xfs_rmap.c @@ -367,7 +367,6 @@ xfs_rmap_lookup_le_range_helper( return 0; *info->irec = *rec; - *info->stat = 1; return -ECANCELED; } @@ -388,6 +387,7 @@ xfs_rmap_lookup_le_range( int *stat) { struct xfs_find_left_neighbor_info info; + int found = 0; int error; info.high.rm_startblock = bno; @@ -400,20 +400,44 @@ xfs_rmap_lookup_le_range( info.high.rm_blockcount = 0; *stat = 0; info.irec = irec; - info.stat = stat; - trace_xfs_rmap_lookup_le_range(cur->bc_mp, - cur->bc_ag.pag->pag_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 == -ECANCELED) - error = 0; - if (*stat) - trace_xfs_rmap_lookup_le_range_result(cur->bc_mp, - cur->bc_ag.pag->pag_agno, irec->rm_startblock, - irec->rm_blockcount, irec->rm_owner, - irec->rm_offset, irec->rm_flags); - return error; + trace_xfs_rmap_lookup_le_range(cur->bc_mp, cur->bc_ag.pag->pag_agno, + bno, 0, owner, offset, flags); + + /* + * Historically, we always used the range query to walk every reverse + * mapping that could possibly overlap the key that the caller asked + * for, and filter out the ones that don't. That is very slow when + * there are a lot of records. + * + * However, there are two scenarios where the classic btree search can + * produce correct results -- if the index contains a record that is an + * exact match for the lookup key; and if there are no other records + * between the record we want and the key we supplied. + * + * As an optimization, try a non-overlapped lookup first. This makes + * scrub run much faster on most filesystems because bmbt records are + * usually an exact match for rmap records. If we don't find what we + * want, we fall back to the overlapped query. + */ + error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, irec, + &found); + if (error) + return error; + if (found) + error = xfs_rmap_lookup_le_range_helper(cur, irec, &info); + if (!error) + error = xfs_rmap_query_range(cur, &info.high, &info.high, + xfs_rmap_lookup_le_range_helper, &info); + if (error != -ECANCELED) + return error; + + *stat = 1; + trace_xfs_rmap_lookup_le_range_result(cur->bc_mp, + cur->bc_ag.pag->pag_agno, irec->rm_startblock, + irec->rm_blockcount, irec->rm_owner, irec->rm_offset, + irec->rm_flags); + return 0; } /* |