3.16.80-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Miklos Szeredi <mszeredi@xxxxxxxxxx>
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")
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/fuse/file.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -237,7 +237,7 @@ 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;
@@ -245,16 +245,20 @@ 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;
}
