From: Dave Chinner <david@fromorbit.com>
To: linux-xfs@vger.kernel.org
Subject: [PATCH 2/3] xfs: No need for inode number error injection in __xfs_dir3_data_check
Date: Tue, 23 Feb 2021 16:47:47 +1100 [thread overview]
Message-ID: <20210223054748.3292734-3-david@fromorbit.com> (raw)
In-Reply-To: <20210223054748.3292734-1-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>
---
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
next prev parent reply other threads:[~2021-02-23 5:48 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 5:47 [PATCH 0/3] xfs: 64kb directory block verification hurts Dave Chinner
2021-02-23 5:47 ` [PATCH 1/3] xfs: type verification is expensive Dave Chinner
2021-02-24 21:46 ` Darrick J. Wong
2021-02-25 9:03 ` Christoph Hellwig
2021-02-25 22:04 ` Dave Chinner
2021-02-23 5:47 ` Dave Chinner [this message]
2021-02-24 21:47 ` [PATCH 2/3] xfs: No need for inode number error injection in __xfs_dir3_data_check Darrick J. Wong
2021-02-25 9:06 ` Christoph Hellwig
2021-02-23 5:47 ` [PATCH 3/3] xfs: reduce debug overhead of dir leaf/node checks Dave Chinner
2021-02-24 21:50 ` Darrick J. Wong
2021-02-25 9:09 ` Christoph Hellwig
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