diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_rmap.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_rmap.c | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c index 0f49dd103f5e..a1211a2947df 100644 --- a/fs/xfs/libxfs/xfs_rmap.c +++ b/fs/xfs/libxfs/xfs_rmap.c @@ -297,7 +297,7 @@ xfs_rmap_find_left_neighbor_helper( * return a match with the same owner and adjacent physical and logical * block ranges. */ -int +STATIC int xfs_rmap_find_left_neighbor( struct xfs_btree_cur *cur, xfs_agblock_t bno, @@ -330,10 +330,35 @@ xfs_rmap_find_left_neighbor( trace_xfs_rmap_find_left_neighbor_query(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_find_left_neighbor_helper, &info); - if (error == -ECANCELED) - error = 0; + /* + * 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 + * extent conversion and remap operations run a bit faster if the + * physical extents aren't being shared. 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, stat); + if (error) + return error; + if (*stat) { + *stat = 0; + xfs_rmap_find_left_neighbor_helper(cur, irec, &info); + } + if (!(*stat)) { + error = xfs_rmap_query_range(cur, &info.high, &info.high, + xfs_rmap_find_left_neighbor_helper, &info); + if (error == -ECANCELED) + error = 0; + } if (*stat) trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp, cur->bc_ag.pag->pag_agno, irec->rm_startblock, |