diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-03-04 11:28:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-25 08:06:14 +0100 |
| commit | e6d506cd2243aa8f6e19fdb4dc61d85275c2c918 (patch) | |
| tree | 3dd4a5b1323ad9761fac57ba2fcfdd38abeb58cc /include/linux/fs.h | |
| parent | af6bdc2a85a9078b88bb3922ebd7d0caa2e0a52c (diff) | |
futex: Fix inode life-time issue
commit 8019ad13ef7f64be44d4f892af9c840179009254 upstream.
As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.
This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 92420009b9bc..15b8e02880c3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -663,6 +663,7 @@ struct inode { struct rcu_head i_rcu; }; atomic64_t i_version; + atomic64_t i_sequence; /* see futex */ atomic_t i_count; atomic_t i_dio_count; atomic_t i_writecount; |