Re: [PATCH 1/2] btrfs: fix error handling in btrfs_del_csums
From: Qu Wenruo <hidden>
Date: 2021-05-20 01:02:21
On 2021/5/19 下午10:52, Josef Bacik wrote:
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:Such "ret = 0;" is definitely causing problem when break is used.
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. Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <redacted> Thanks, Qu
quoted hunk ↗ jump to hunk
--- fs/btrfs/file-item.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)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; }