From: Dave Chinner <dchinner@xxxxxxxxxx> We call xfs_dir_ino_validate() for every dir entry in a directory when doing validity checking of the directory. It calls xfs_verify_dir_ino() then emits a corruption report if bad or does error injection if good. It is extremely costly: 43.27% [kernel] [k] xfs_dir3_leaf_check_int 10.28% [kernel] [k] __xfs_dir3_data_check 6.61% [kernel] [k] xfs_verify_dir_ino 4.16% [kernel] [k] xfs_errortag_test 4.00% [kernel] [k] memcpy 3.48% [kernel] [k] xfs_dir_ino_validate 7% of the cpu usage in this directory traversal workload is xfs_dir_ino_validate() doing absolutely nothing. We don't need error injection to simulate a bad inode numbers in the directory structure because we can do that by fuzzing the structure on disk. And we don't need a corruption report, because the __xfs_dir3_data_check() will emit one if the inode number is bad. So just call xfs_verify_dir_ino() directly here, and get rid of all this unnecessary overhead: 40.30% [kernel] [k] xfs_dir3_leaf_check_int 10.98% [kernel] [k] __xfs_dir3_data_check 8.10% [kernel] [k] xfs_verify_dir_ino 4.42% [kernel] [k] memcpy 2.22% [kernel] [k] xfs_dir2_data_get_ftype 1.52% [kernel] [k] do_raw_spin_lock Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> --- fs/xfs/libxfs/xfs_dir2_data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c index 375b3edb2ad2..e67fa086f2c1 100644 --- a/fs/xfs/libxfs/xfs_dir2_data.c +++ b/fs/xfs/libxfs/xfs_dir2_data.c @@ -218,7 +218,7 @@ __xfs_dir3_data_check( */ if (dep->namelen == 0) return __this_address; - if (xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber))) + if (!xfs_verify_dir_ino(mp, be64_to_cpu(dep->inumber))) return __this_address; if (offset + xfs_dir2_data_entsize(mp, dep->namelen) > end) return __this_address; -- 2.28.0
