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btrfs: always report error in run_one_delayed_ref()

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[ Upstream commit 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92 ]

Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but
if end users hit such problem, there will be no chance that
btrfs_debug() is enabled.  This can lead to very little useful info for
debugging.

This patch will:

- Add extra info for error reporting
  Including:
  * logical bytenr
  * num_bytes
  * type
  * action
  * ref_mod

- Replace the btrfs_debug() with btrfs_err()

- Move the error reporting into run_one_delayed_ref()
  This is to avoid use-after-free, the @node can be freed in the caller.

This error should only be triggered at most once.

As if run_one_delayed_ref() failed, we trigger the error message, then
causing the call chain to error out:

btrfs_run_delayed_refs()
`- btrfs_run_delayed_refs()
   `- btrfs_run_delayed_refs_for_head()
      `- run_one_delayed_ref()

And we will abort the current transaction in btrfs_run_delayed_refs().
If we have to run delayed refs for the abort transaction,
run_one_delayed_ref() will just cleanup the refs and do nothing, thus no
new error messages would be output.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Qu Wenruo 2022-12-26 09:00:40 +08:00 committed by Greg Kroah-Hartman
parent f641067ea2
commit fdb4a70bb7
1 changed files with 5 additions and 2 deletions
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7
fs/btrfs/extent-tree.c
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@ -1717,6 +1717,11 @@ static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
BUG();
if (ret && insert_reserved)
btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
if (ret < 0)
btrfs_err(trans->fs_info,
"failed to run delayed ref for logical %llu num_bytes %llu type %u action %u ref_mod %d: %d",
node->bytenr, node->num_bytes, node->type,
node->action, node->ref_mod, ret);
return ret;
}
@ -1955,8 +1960,6 @@ static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans,
if (ret) {
unselect_delayed_ref_head(delayed_refs, locked_ref);
btrfs_put_delayed_ref(ref);
btrfs_debug(fs_info, "run_one_delayed_ref returned %d",
ret);
return ret;
}