From: Miklos Szeredi mszeredi@redhat.com
commit e4648309b85a78f8c787457832269a8712a8673e upstream.
Make sure cached writes are not reordered around open(..., O_TRUNC), with the obvious wrong results.
Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/fuse/file.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -201,7 +201,7 @@ int fuse_open_common(struct inode *inode { struct fuse_conn *fc = get_fuse_conn(inode); int err; - bool lock_inode = (file->f_flags & O_TRUNC) && + bool is_wb_truncate = (file->f_flags & O_TRUNC) && fc->atomic_o_trunc && fc->writeback_cache;
@@ -209,16 +209,20 @@ int fuse_open_common(struct inode *inode if (err) return err;
- if (lock_inode) + if (is_wb_truncate) { mutex_lock(&inode->i_mutex); + fuse_set_nowrite(inode); + }
err = fuse_do_open(fc, get_node_id(inode), file, isdir);
if (!err) fuse_finish_open(inode, file);
- if (lock_inode) + if (is_wb_truncate) { + fuse_release_nowrite(inode); mutex_unlock(&inode->i_mutex); + }
return err; }