The patch below does not apply to the 5.10-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.

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-5.10.y git checkout FETCH_HEAD git cherry-pick -x 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023071151-caddy-carded-8f7a@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce Mon Sep 17 00:00:00 2001 From: Filipe Manana fdmanana@suse.com Date: Thu, 8 Jun 2023 11:27:41 +0100 Subject: [PATCH] btrfs: do not BUG_ON() on tree mod log failure at balance_level()

At balance_level(), instead of doing a BUG_ON() in case we fail to record tree mod log operations, do a transaction abort and return the error to the callers. There's really no need for the BUG_ON() as we can release all resources in this context, and we have to abort because other future tree searches that use the tree mod log (btrfs_search_old_slot()) may get inconsistent results if other operations modify the tree after that failure and before the tree mod log based search.

CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index d6c29564ce49..d60b28c6bd1b 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1054,7 +1054,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, }

ret = btrfs_tree_mod_log_insert_root(root->node, child, true); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(child); + free_extent_buffer(child); + btrfs_abort_transaction(trans, ret); + goto enospc; + } rcu_assign_pointer(root->node, child);

add_root_to_dirty_list(root); @@ -1142,7 +1147,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_node_key(right, &right_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto enospc; + } btrfs_set_node_key(parent, &right_key, pslot + 1); btrfs_mark_buffer_dirty(parent); } @@ -1188,7 +1196,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_node_key(mid, &mid_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto enospc; + } btrfs_set_node_key(parent, &mid_key, pslot); btrfs_mark_buffer_dirty(parent); }