This is a note to let you know that I've just added the patch titled
btrfs: add might_sleep() annotations
to the 5.15-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-add-might_sleep-annotations.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5e0677569d3f16e57d4a8ee631057a2965056cea
Author: ChenXiaoSong <chenxiaosong2@xxxxxxxxxx>
Date: Wed Nov 16 22:23:53 2022 +0800
btrfs: add might_sleep() annotations
[ Upstream commit a4c853af0c511d7e0f7cb306bbc8a4f1dbdb64ca ]
Add annotations to functions that might sleep due to allocations or IO
and could be called from various contexts. In case of btrfs_search_slot
it's not obvious why it would sleep:
btrfs_search_slot
setup_nodes_for_search
reada_for_balance
btrfs_readahead_node_child
btrfs_readahead_tree_block
btrfs_find_create_tree_block
alloc_extent_buffer
kmem_cache_zalloc
/* allocate memory non-atomically, might sleep */
kmem_cache_alloc(GFP_NOFS|__GFP_NOFAIL|__GFP_ZERO)
read_extent_buffer_pages
submit_extent_page
/* disk IO, might sleep */
submit_one_bio
Other examples where the sleeping could happen is in 3 places might
sleep in update_qgroup_limit_item(), as shown below:
update_qgroup_limit_item
btrfs_alloc_path
/* allocate memory non-atomically, might sleep */
kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS)
Signed-off-by: ChenXiaoSong <chenxiaosong2@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Stable-dep-of: 3ed51857a50f ("btrfs: add a sanity check for btrfs root in btrfs_search_slot()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0b8c8b5094efb..af6ddf1f913ae 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -76,6 +76,8 @@ size_t __attribute_const__ btrfs_get_num_csums(void)
struct btrfs_path *btrfs_alloc_path(void)
{
+ might_sleep();
+
return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
}
@@ -1774,6 +1776,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
int min_write_lock_level;
int prev_cmp;
+ might_sleep();
+
lowest_level = p->lowest_level;
WARN_ON(lowest_level && ins_len > 0);
WARN_ON(p->nodes[0] != NULL);
