fuse: llseek fix race

Fix race between lseek(fd, 0, SEEK_CUR) and read/write.  This was fixed in
generic code by commit 5b6f1eb97d (vfs: lseek(fd, 0, SEEK_CUR) race condition).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 19029e9..0c84100 100644 (file)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1567,6 +1567,10 @@ static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
                offset += i_size_read(inode);
                break;
        case SEEK_CUR:
+               if (offset == 0) {
+                       retval = file->f_pos;
+                       goto exit;
+               }
                offset += file->f_pos;
                break;
        case SEEK_DATA: