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>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 19029e97ca2f..0c84100acd44 100644
--- 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: