diff options
| author | Fabian Frederick <fabf@skynet.be> | 2015-02-17 13:45:31 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-17 14:34:51 -0800 |
| commit | ed3ad79f87f31beed64778af0b29aff3074f700e (patch) | |
| tree | 6bf46242e32c441b0e16ff95295507c0323ee833 | |
| parent | 61da3ae241f4382e30beb6de06c4dacada37f520 (diff) | |
fs/ufs/super.c: fix potential race condition
Let locking subsystem decide on mutex management. As reported by Andrew
Morton this patch fixes a bug:
: lock_ufs() is assuming that on non-preempt uniprocessor, the calling
: code will run atomically up to the matching unlock_ufs().
:
: But that isn't true. The very first site I looked at (ufs_frag_map)
: does sb_bread() under lock_ufs(). And sb_bread() will call schedule(),
: very commonly.
:
: The ->mutex_owner stuff is a bit hacky but should work OK.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ufs/super.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/fs/ufs/super.c b/fs/ufs/super.c index e515e99a02f9..8092d3759a5e 100644 --- a/fs/ufs/super.c +++ b/fs/ufs/super.c @@ -95,22 +95,18 @@ void lock_ufs(struct super_block *sb) { -#if defined(CONFIG_SMP) || defined (CONFIG_PREEMPT) struct ufs_sb_info *sbi = UFS_SB(sb); mutex_lock(&sbi->mutex); sbi->mutex_owner = current; -#endif } void unlock_ufs(struct super_block *sb) { -#if defined(CONFIG_SMP) || defined (CONFIG_PREEMPT) struct ufs_sb_info *sbi = UFS_SB(sb); sbi->mutex_owner = NULL; mutex_unlock(&sbi->mutex); -#endif } static struct inode *ufs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) |