The patch below does not apply to the 5.4-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@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 40b0a749388517de244643c09bdbb98f7dcb6ef1 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023071602-oxford-etching-4c52@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 40b0a7493885 ("btrfs: do not BUG_ON() on tree mod log failure at __btrfs_cow_block()") 406808ab2f0b ("btrfs: use booleans where appropriate for the tree mod log functions") f3a84ccd28d0 ("btrfs: move the tree mod log code into its own file") dbcc7d57bffc ("btrfs: fix race when cloning extent buffer during rewind of an old root") cac06d843f25 ("btrfs: introduce the skeleton of btrfs_subpage structure") 1b7ec85ef490 ("btrfs: pass root owner to read_tree_block") bfb484d922a3 ("btrfs: cleanup extent buffer readahead") ac5887c8e013 ("btrfs: locking: remove all the blocking helpers") 196d59ab9ccc ("btrfs: switch extent buffer tree lock to rw_semaphore") bf77467a93bd ("btrfs: introduce BTRFS_NESTING_LEFT/BTRFS_NESTING_RIGHT") 9631e4cc1a03 ("btrfs: introduce BTRFS_NESTING_COW for cow'ing blocks") fd7ba1c1202d ("btrfs: add nesting tags to the locking helpers") 51899412dd95 ("btrfs: introduce btrfs_path::recurse") 329ced799be8 ("btrfs: rename extent_buffer::lock_nested to extent_buffer::lock_recursed") d16c702fe4f2 ("btrfs: ctree: check key order before merging tree blocks") d3beaa253fd6 ("btrfs: set the lockdep class for log tree extent buffers") ad24466588ab ("btrfs: set the correct lockdep class for new nodes") d85327b1d8b7 ("btrfs: prefetch chunk tree leaves at mount") 49e5fb46211d ("btrfs: qgroup: export qgroups in sysfs") 5958253cf65d ("btrfs: qgroup: catch reserved space leaks at unmount time") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 40b0a749388517de244643c09bdbb98f7dcb6ef1 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana@xxxxxxxx> Date: Thu, 8 Jun 2023 11:27:40 +0100 Subject: [PATCH] btrfs: do not BUG_ON() on tree mod log failure at __btrfs_cow_block() At __btrfs_cow_block(), instead of doing a BUG_ON() in case we fail to record a tree mod log root insertion operation, do a transaction abort instead. There's really no need for the BUG_ON(), we can properly release all resources in this context and turn the filesystem to RO mode and in an error state instead. CC: stable@xxxxxxxxxxxxxxx # 5.4+ Reviewed-by: Qu Wenruo <wqu@xxxxxxxx> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 8496535828de..d6c29564ce49 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -584,9 +584,14 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) parent_start = buf->start; - atomic_inc(&cow->refs); ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(cow); + free_extent_buffer(cow); + btrfs_abort_transaction(trans, ret); + return ret; + } + atomic_inc(&cow->refs); rcu_assign_pointer(root->node, cow); btrfs_free_tree_block(trans, btrfs_root_id(root), buf,
