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Message-Id: <20240924223958.347475-2-kuntal.nayak@broadcom.com>
Date: Tue, 24 Sep 2024 15:39:57 -0700
From: Kuntal Nayak <kuntal.nayak@...adcom.com>
To: leah.rumancik@...il.com,
jwong@...nel.org,
linux-xfs@...r.kernel.org,
linux-kernel@...r.kernel.org,
gregkh@...uxfoundation.org
Cc: ajay.kaher@...adcom.com,
alexey.makhalov@...adcom.com,
vasavi.sirnapalli@...adcom.com,
Dave Chinner <dchinner@...hat.com>,
"Darrick J . Wong" <djwong@...nel.org>,
Christoph Hellwig <hch@....de>,
Kuntal Nayak <kuntal.nayak@...adcom.com>
Subject: [PATCH v5.10] xfs: No need for inode number error injection in __xfs_dir3_data_check
From: Dave Chinner <dchinner@...hat.com>
[ Upstream commit 39d3c0b5968b5421922e2fc939b6d6158df8ac1c ]
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@...hat.com>
Reviewed-by: Darrick J. Wong <djwong@...nel.org>
Reviewed-by: Christoph Hellwig <hch@....de>
Signed-off-by: Darrick J. Wong <djwong@...nel.org>
Signed-off-by: Kuntal Nayak <kuntal.nayak@...adcom.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 375b3edb2..e67fa086f 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;
--
2.39.3
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