From: Dave Chinner <dchinner@xxxxxxxxxx> Source kernel commit e35438196c6a1d8b206471d51e80c380e80e047b For large sparse or fragmented files, checking every single entry in the bmapbt on every operation is prohibitively expensive. Especially as such checks rarely discover problems during normal operations on high extent coutn files. Our regression tests don't tend to exercise files with hundreds of thousands to millions of extents, so mostly this isn't noticed. However, trying to run things like xfs_mdrestore of large filesystem dumps on a debug kernel quickly becomes impossible as the CPU is completely burnt up repeatedly walking the sparse file bmapbt that is generated for every allocation that is made. Hence, if the file has more than 10,000 extents, just don't bother with walking the tree to check it exhaustively. The btree code has checks that ensure that the newly inserted/removed/modified record is correctly ordered, so the entrie tree walk in thses cases has limited additional value. Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx> Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx> --- libxfs/xfs_bmap.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c index 70417fc..eb19133 100644 --- a/libxfs/xfs_bmap.c +++ b/libxfs/xfs_bmap.c @@ -317,9 +317,11 @@ xfs_check_block( /* * Check that the extents for the inode ip are in the right order in all - * btree leaves. + * btree leaves. THis becomes prohibitively expensive for large extent count + * files, so don't bother with inodes that have more than 10,000 extents in + * them. The btree record ordering checks will still be done, so for such large + * bmapbt constructs that is going to catch most corruptions. */ - STATIC void xfs_bmap_check_leaf_extents( xfs_btree_cur_t *cur, /* btree cursor or null */ @@ -344,6 +346,10 @@ xfs_bmap_check_leaf_extents( return; } + /* skip large extent count inodes */ + if (ip->i_d.di_nextents > 10000) + return; + bno = NULLFSBLOCK; mp = ip->i_mount; ifp = XFS_IFORK_PTR(ip, whichfork); -- 2.5.0 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
