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 stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b86652be7c83f70bf406bed18ecf55adb9bfb91b Mon Sep 17 00:00:00 2001
From: Josef Bacik josef@toxicpanda.com 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 wqu@suse.com CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik josef@toxicpanda.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 294602f139ef..a5a8dac334e8 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -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; }