iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fs: dcache: Use READ_ONCE when accessing i_dir_seq

Browse Source 
[ Upstream commit 8cc07c808c9d595e81cbe5aad419b7769eb2e5c9 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Will Deacon 2018-02-19 14:55:55 +00:00 committed by Greg Kroah-Hartman
parent 3623c1f37e
commit 2565b271ae
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/dcache.c
View File

@ -2510,7 +2510,7 @@ 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;