From 011b28acf940eb61c000059dd9e2cfcbf52ed96b Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 19 May 2021 13:13:15 -0400 Subject: btrfs: fixup error handling in fixup_inode_link_counts This function has the following pattern while (1) { ret = whatever(); if (ret) goto out; } ret = 0 out: return ret; However several places in this while loop we simply break; when there's a problem, thus clearing the return value, and in one case we do a return -EIO, and leak the memory for the path. Fix this by re-arranging the loop to deal with ret == 1 coming from btrfs_search_slot, and then simply delete the ret = 0; out: bit so everybody can break if there is an error, which will allow for proper error handling to occur. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/tree-log.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'fs/btrfs/tree-log.c') diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c17d6b827b42..375c4642f480 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -1787,6 +1787,7 @@ static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans, break; if (ret == 1) { + ret = 0; if (path->slots[0] == 0) break; path->slots[0]--; @@ -1799,17 +1800,19 @@ static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans, ret = btrfs_del_item(trans, root, path); if (ret) - goto out; + break; btrfs_release_path(path); inode = read_one_inode(root, key.offset); - if (!inode) - return -EIO; + if (!inode) { + ret = -EIO; + break; + } ret = fixup_inode_link_count(trans, root, inode); iput(inode); if (ret) - goto out; + break; /* * fixup on a directory may create new entries, @@ -1818,8 +1821,6 @@ static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans, */ key.offset = (u64)-1; } - ret = 0; -out: btrfs_release_path(path); return ret; } -- cgit v1.2.3 From f96d44743a44e3332f75d23d2075bb8270900e1d Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 19 May 2021 11:26:25 -0400 Subject: btrfs: check error value from btrfs_update_inode in tree log Error injection testing uncovered a case where we ended up with invalid link counts on an inode. This happened because we failed to notice an error when updating the inode while replaying the tree log, and committed the transaction with an invalid file system. Fix this by checking the return value of btrfs_update_inode. This resolved the link count errors I was seeing, and we already properly handle passing up the error values in these paths. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Johannes Thumshirn Reviewed-by: Qu Wenruo Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/tree-log.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/tree-log.c') diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 375c4642f480..e4820e88cba0 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -1574,7 +1574,9 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans, if (ret) goto out; - btrfs_update_inode(trans, root, BTRFS_I(inode)); + ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); + if (ret) + goto out; } ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen; @@ -1749,7 +1751,9 @@ static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans, if (nlink != inode->i_nlink) { set_nlink(inode, nlink); - btrfs_update_inode(trans, root, BTRFS_I(inode)); + ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); + if (ret) + goto out; } BTRFS_I(inode)->index_cnt = (u64)-1; -- cgit v1.2.3 From 165ea85f14831f27fc6fe3b02b35e42e50b9ed94 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 19 May 2021 17:15:53 -0400 Subject: btrfs: do not write supers if we have an fs error Error injection testing uncovered a pretty severe problem where we could end up committing a super that pointed to the wrong tree roots, resulting in transid mismatch errors. The way we commit the transaction is we update the super copy with the current generations and bytenrs of the important roots, and then copy that into our super_for_commit. Then we allow transactions to continue again, we write out the dirty pages for the transaction, and then we write the super. If the write out fails we'll bail and skip writing the supers. However since we've allowed a new transaction to start, we can have a log attempting to sync at this point, which would be blocked on fs_info->tree_log_mutex. Once the commit fails we're allowed to do the log tree commit, which uses super_for_commit, which now points at fs tree's that were not written out. Fix this by checking BTRFS_FS_STATE_ERROR once we acquire the tree_log_mutex. This way if the transaction commit fails we're sure to see this bit set and we can skip writing the super out. This patch fixes this specific transid mismatch error I was seeing with this particular error path. CC: stable@vger.kernel.org # 5.12+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/tree-log.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'fs/btrfs/tree-log.c') diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index e4820e88cba0..324a9a078b6a 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3302,6 +3302,22 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, * begins and releases it only after writing its superblock. */ mutex_lock(&fs_info->tree_log_mutex); + + /* + * The previous transaction writeout phase could have failed, and thus + * marked the fs in an error state. We must not commit here, as we + * could have updated our generation in the super_for_commit and + * writing the super here would result in transid mismatches. If there + * is an error here just bail. + */ + if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { + ret = -EIO; + btrfs_set_log_full_commit(trans); + btrfs_abort_transaction(trans, ret); + mutex_unlock(&fs_info->tree_log_mutex); + goto out_wake_log_root; + } + btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start); btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level); ret = write_all_supers(fs_info, 1); -- cgit v1.2.3