path: root/fs/cachefiles/interface.c
diff options
authorChristoph Hellwig <hch@lst.de>2009-05-05 15:41:25 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2009-06-11 21:36:06 -0400
commit5af7926ff33b68b3ba46531471c6e0564b285efc (patch)
treea25266f9db482ce9dd8e663148ffb0f1a524bd83 /fs/cachefiles/interface.c
parente5004753388dcf5e1b8a52ac0ab807d232340fbb (diff)
enforce ->sync_fs is only called for rw superblock
Make sure a superblock really is writeable by checking MS_RDONLY under s_umount. sync_filesystems needed some re-arragement for that, but all but one sync_filesystem caller had the correct locking already so that we could add that check there. cachefiles grew s_umount locking. I've also added a WARN_ON to sync_filesystem to assert this for future callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/cachefiles/interface.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index dafd484d7bd..431accd475a 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -354,7 +354,9 @@ static void cachefiles_sync_cache(struct fscache_cache *_cache)
/* make sure all pages pinned by operations on behalf of the netfs are
* written to disc */
cachefiles_begin_secure(cache, &saved_cred);
+ down_read(&cache->mnt->mnt_sb->s_umount);
ret = sync_filesystem(cache->mnt->mnt_sb);
+ up_read(&cache->mnt->mnt_sb->s_umount);
cachefiles_end_secure(cache, saved_cred);
if (ret == -EIO)