nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition fa…

…ilure

commit 723ac751208f6d6540191689cfbf6c77135a7a1b upstream.

If creation or finalization of a checkpoint fails due to anomalies in the
checkpoint metadata on disk, a kernel warning is generated.

This patch replaces the WARN_ONs by nilfs_error, so that a kernel, booted
with panic_on_warn, does not panic.  A nilfs_error is appropriate here to
handle the abnormal filesystem condition.

This also replaces the detected error codes with an I/O error so that
neither of the internal error codes is returned to callers.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ryusuke Konishi <[email protected]>
Reported-by: [email protected]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

fs/nilfs2/segment.c

@@ -880,9 +880,11 @@ static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
  nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
  nilfs_cpfile_put_checkpoint(
  nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
- } else
- WARN_ON(err == -EINVAL || err == -ENOENT);
-
+ } else if (err == -EINVAL || err == -ENOENT) {
+ nilfs_error(sci->sc_super,
+ "checkpoint creation failed due to metadata corruption.");
+ err = -EIO;
+ }
  return err;
 }
 
@@ -896,7 +898,11 @@ static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
  err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
  &raw_cp, &bh_cp);
  if (unlikely(err)) {
- WARN_ON(err == -EINVAL || err == -ENOENT);
+ if (err == -EINVAL || err == -ENOENT) {
+ nilfs_error(sci->sc_super,
+ "checkpoint finalization failed due to metadata corruption.");
+ err = -EIO;
+ }
  goto failed_ibh;
  }
  raw_cp->cp_snapshot_list.ssl_next = 0;