Skip to contentSkip to conversation

FAILED: patch "[PATCH] btrfs: fix error handling in btrfs_del_csums" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Jun 8, 2021

Subsystems (2)
Stable branch Btrfs file system
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b86652be7c83f70bf406bed18ecf55adb9bfb91b Mon Sep 17 00:00:00 2001
From: Josef Bacik <[email protected]>
Date: Wed, 19 May 2021 10:52:45 -0400
Subject: [PATCH] btrfs: fix error handling in btrfs_del_csums

Error injection stress would sometimes fail with checksums on disk that did not have a corresponding extent. This occurred because the pattern in btrfs_del_csums was

	while (1) {
		ret = btrfs_search_slot();
		if (ret < 0)
			break;
	}
	ret = 0;
out:
	btrfs_free_path(path);
	return ret;

If we got an error from btrfs_search_slot we'd clear the error because we were breaking instead of goto out. Instead of using goto out, simply handle the cases where we may leave a random value in ret, and get rid of the

	ret = 0;

out:

pattern and simply allow break to have the proper error reporting. With this fix we properly abort the transaction and do not commit thinking we successfully deleted the csum.

Reviewed-by Qu Wenruo <[email protected]>
CC [email protected] # 4.4+
Signed-off-by Josef Bacik <[email protected]>
Reviewed-by David Sterba <[email protected]>
Signed-off-by David Sterba <[email protected]>
fs/btrfs/file-item.c +5 -5
index 294602f139ef..a5a8dac334e8 100644
@@ -788,7 +788,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 	u64 end_byte = bytenr + len;
 	u64 csum_end;
 	struct extent_buffer *leaf;
-	int ret;
+	int ret = 0;
 	const u32 csum_size = fs_info->csum_size;
 	u32 blocksize_bits = fs_info->sectorsize_bits;
 

@@ -806,6 +806,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 
 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 		if (ret > 0) {
+			ret = 0;
 			if (path->slots[0] == 0)
 				break;
 			path->slots[0]--;

@@ -862,7 +863,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 			ret = btrfs_del_items(trans, root, path,
 					      path->slots[0], del_nr);
 			if (ret)
-				goto out;
+				break;
 			if (key.offset == bytenr)
 				break;
 		} else if (key.offset < bytenr && csum_end > end_byte) {

@@ -906,8 +907,9 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 			ret = btrfs_split_item(trans, root, path, &key, offset);
 			if (ret && ret != -EAGAIN) {
 				btrfs_abort_transaction(trans, ret);
-				goto out;
+				break;
 			}
+			ret = 0;
 
 			key.offset = end_byte - 1;
 		} else {

@@ -917,8 +919,6 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 		}
 		btrfs_release_path(path);
 	}
-	ret = 0;
-out:
 	btrfs_free_path(path);
 	return ret;
 }