This is a note to let you know that I've just added the patch titled
btrfs: do not BUG_ON() on tree mod log failure at balance_level()
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-do-not-bug_on-on-tree-mod-log-failure-at-balance_level.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@xxxxxxxx>
Date: Thu, 8 Jun 2023 11:27:41 +0100
Subject: btrfs: do not BUG_ON() on tree mod log failure at balance_level()
From: Filipe Manana <fdmanana@xxxxxxxx>
commit 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce upstream.
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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/ctree.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1042,7 +1042,12 @@ static noinline int balance_level(struct
}
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);
@@ -1130,7 +1135,10 @@ static noinline int balance_level(struct
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);
}
@@ -1176,7 +1184,10 @@ static noinline int balance_level(struct
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);
}
Patches currently in stable-queue which might be from fdmanana@xxxxxxxx are
queue-6.4/btrfs-fix-race-when-deleting-free-space-root-from-the-dirty-cow-roots-list.patch
queue-6.4/btrfs-do-not-bug_on-on-tree-mod-log-failure-at-balance_level.patch
