fuse: update mtime on open(O_TRUNC) in atomic_o_trunc mode
In case of fc->atomic_o_trunc is set, fuse does nothing in
fuse_do_setattr() while handling open(O_TRUNC). Hence, i_mtime must be
updated explicitly in fuse_finish_open(). The patch also adds extra locking
encompassing open(O_TRUNC) operation to avoid races between the truncation
and updating i_mtime.
Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 7ae1e69..e68d8c3f 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -223,6 +223,8 @@
i_size_write(inode, 0);
spin_unlock(&fc->lock);
fuse_invalidate_attr(inode);
+ if (fc->writeback_cache)
+ file_update_time(file);
}
if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
fuse_link_write_file(file);
@@ -232,18 +234,26 @@
{
struct fuse_conn *fc = get_fuse_conn(inode);
int err;
+ bool lock_inode = (file->f_flags & O_TRUNC) &&
+ fc->atomic_o_trunc &&
+ fc->writeback_cache;
err = generic_file_open(inode, file);
if (err)
return err;
+ if (lock_inode)
+ mutex_lock(&inode->i_mutex);
+
err = fuse_do_open(fc, get_node_id(inode), file, isdir);
- if (err)
- return err;
- fuse_finish_open(inode, file);
+ if (!err)
+ fuse_finish_open(inode, file);
- return 0;
+ if (lock_inode)
+ mutex_unlock(&inode->i_mutex);
+
+ return err;
}
static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)