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authorFilipe Manana <fdmanana@suse.com>2023-08-28 11:06:44 +0300
committerDavid Sterba <dsterba@suse.com>2023-09-08 15:20:40 +0300
commita57c2d4e46f519b24558ae0752c17eec416ac72a (patch)
treec90bcac5a57122d0234e0a8880706bd7f588f2d1 /fs/btrfs
parent2c58c3931ede7cd08cbecf1f1a4acaf0a04a41a9 (diff)
downloadlinux-a57c2d4e46f519b24558ae0752c17eec416ac72a.tar.xz
btrfs: assert delayed node locked when removing delayed item
When removing a delayed item, or releasing which will remove it as well, we will modify one of the delayed node's rbtrees and item counter if the delayed item is in one of the rbtrees. This require having the delayed node's mutex locked, otherwise we will race with other tasks modifying the rbtrees and the counter. This is motivated by a previous version of another patch actually calling btrfs_release_delayed_item() after unlocking the delayed node's mutex and against a delayed item that is in a rbtree. So assert at __btrfs_remove_delayed_item() that the delayed node's mutex is locked. 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>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/delayed-inode.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 6e779bc16340..dfe29b29915f 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -412,6 +412,7 @@ static void finish_one_item(struct btrfs_delayed_root *delayed_root)
static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
{
+ struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;
struct rb_root_cached *root;
struct btrfs_delayed_root *delayed_root;
@@ -419,18 +420,21 @@ static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
if (RB_EMPTY_NODE(&delayed_item->rb_node))
return;
- delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
+ /* If it's in a rbtree, then we need to have delayed node locked. */
+ lockdep_assert_held(&delayed_node->mutex);
+
+ delayed_root = delayed_node->root->fs_info->delayed_root;
BUG_ON(!delayed_root);
if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
- root = &delayed_item->delayed_node->ins_root;
+ root = &delayed_node->ins_root;
else
- root = &delayed_item->delayed_node->del_root;
+ root = &delayed_node->del_root;
rb_erase_cached(&delayed_item->rb_node, root);
RB_CLEAR_NODE(&delayed_item->rb_node);
- delayed_item->delayed_node->count--;
+ delayed_node->count--;
finish_one_item(delayed_root);
}