btrfs: do not BUG_ON() on tree mod log failure at balance_level()

[ Upstream commit 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Filipe Manana 2023-06-08 11:27:41 +01:00 committed by Greg Kroah-Hartman
parent 2445a35d05
commit b990e37603

View File

@ -935,7 +935,12 @@ 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);
@ -1017,7 +1022,10 @@ 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, GFP_NOFS);
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);
}
@ -1063,7 +1071,10 @@ 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, GFP_NOFS);
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);
}