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| author | Uros Bizjak <ubizjak@gmail.com> | 2022-12-21 20:35:40 +0100 |
|---|---|---|
| committer | Christian Brauner (Microsoft) <brauner@kernel.org> | 2023-01-08 12:37:49 +0100 |
| commit | 4e1da8fe031303599e78f88e0dad9f44272e4f99 (patch) | |
| tree | be4f00de082d570ac06a21010528c2150bde5670 /fs/posix_acl.c | |
| parent | 1b929c02afd37871d5afb9d498426f83432e71c2 (diff) | |
| download | linux-stable-4e1da8fe031303599e78f88e0dad9f44272e4f99.tar.gz linux-stable-4e1da8fe031303599e78f88e0dad9f44272e4f99.tar.bz2 linux-stable-4e1da8fe031303599e78f88e0dad9f44272e4f99.zip | |
posix_acl: Use try_cmpxchg in get_acl
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old
in get_acl. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Diffstat (limited to 'fs/posix_acl.c')
| -rw-r--r-- | fs/posix_acl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/posix_acl.c b/fs/posix_acl.c index d7bc81fc0840..420c689e1bec 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -174,7 +174,7 @@ static struct posix_acl *__get_acl(struct user_namespace *mnt_userns, * Cache the result, but only if our sentinel is still in place. */ posix_acl_dup(acl); - if (unlikely(cmpxchg(p, sentinel, acl) != sentinel)) + if (unlikely(!try_cmpxchg(p, &sentinel, acl))) posix_acl_release(acl); return acl; } |