From: Dave Chinner <david@fromorbit.com>
To: linux-xfs@vger.kernel.org
Subject: [PATCH 6/8] xfs: No need for inode number error injection in __xfs_dir3_data_check
Date: Wed, 17 Mar 2021 15:57:04 +1100 [thread overview]
Message-ID: <20210317045706.651306-7-david@fromorbit.com> (raw)
In-Reply-To: <20210317045706.651306-1-david@fromorbit.com>
From: Dave Chinner <dchinner@redhat.com>
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@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
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;
--
2.30.1
next prev parent reply other threads:[~2021-03-17 4:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 4:56 [PATCH v4 0/8] xfs: miscellaneous optimisations Dave Chinner
2021-03-17 4:56 ` [PATCH 1/8] xfs: initialise attr fork on inode create Dave Chinner
2021-03-17 16:44 ` Gao Xiang
2021-03-17 4:57 ` [PATCH 2/8] xfs: reduce buffer log item shadow allocations Dave Chinner
2021-03-17 16:52 ` Gao Xiang
2021-03-17 4:57 ` [PATCH 3/8] xfs: xfs_buf_item_size_segment() needs to pass segment offset Dave Chinner
2021-03-17 4:57 ` [PATCH 4/8] xfs: optimise xfs_buf_item_size/format for contiguous regions Dave Chinner
2021-03-17 4:57 ` [PATCH 5/8] xfs: type verification is expensive Dave Chinner
2021-03-17 4:57 ` Dave Chinner [this message]
2021-03-17 4:57 ` [PATCH 7/8] xfs: reduce debug overhead of dir leaf/node checks Dave Chinner
2021-03-17 4:57 ` [PATCH 8/8] xfs: __percpu_counter_compare() inode count debug too expensive Dave Chinner
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