Unionfs: fix ->readdir

It's enough to use llseek to set lower dir pos.  No need to also set
lower_file->f_pos directly, as it breaks readdir for ext4 and other
ext-based file systems.  Reported by Vaibhav Nagarnaik and Ted Ts'o.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/dirfops.c b/fs/unionfs/dirfops.c
index d29b50d754a01f2278d1ffe5583a2d3717dadd44..bf609ce1f8e331a29f10755a55259f612068afda 100644 (file)
--- a/fs/unionfs/dirfops.c
+++ b/fs/unionfs/dirfops.c
@@ -156,9 +156,8 @@ static int unionfs_readdir(struct file *file, struct dir_context *ctx)
                        goto out;
                }
 
-               lower_file->f_pos = ctx->pos;
                err = iterate_dir(lower_file, &buf.ctx);
-               ctx->pos = buf.ctx.pos;
+               ctx->pos = buf.ctx.pos; /* XXX: not sure if needed (cf. ecryptfs) */
 
                /* Save the position for when we continue. */
                offset = vfs_llseek(lower_file, 0, SEEK_CUR);