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| author | Will Deacon <will.deacon@arm.com> | 2018-02-19 14:55:55 +0000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2018-02-25 12:51:10 -0500 |
| commit | 8cc07c808c9d595e81cbe5aad419b7769eb2e5c9 (patch) | |
| tree | b67b43888c8f559aba6365fd2a9965584d626f41 /fs/dcache.c | |
| parent | 015555fd4d2930bc0c86952c46ad88b3392f66e4 (diff) | |
| download | lwn-8cc07c808c9d595e81cbe5aad419b7769eb2e5c9.tar.gz lwn-8cc07c808c9d595e81cbe5aad419b7769eb2e5c9.zip | |
fs: dcache: Use READ_ONCE when accessing i_dir_seq
i_dir_seq is subject to concurrent modification by a cmpxchg or
store-release operation, so ensure that the relaxed access in
d_alloc_parallel uses READ_ONCE.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index bde3b6662601..8945e6cabd93 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2507,7 +2507,7 @@ retry: } hlist_bl_lock(b); - if (unlikely(parent->d_inode->i_dir_seq != seq)) { + if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) { hlist_bl_unlock(b); rcu_read_unlock(); goto retry; |