From 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Mon, 26 Dec 2022 09:00:40 +0800
Subject: [PATCH] btrfs: always report error in run_one_delayed_ref()
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>
---
fs/btrfs/extent-tree.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 892d78c1853c7..72ba13b027a9e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1713,6 +1713,11 @@ 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;
}
@@ -1954,8 +1959,6 @@ 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;
}
--
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