From: Filipe Manana <fdmanana@suse.com>
Date: Mon, 20 Oct 2025 11:39:52 +0000 (+0100)
Subject: btrfs: reduce space_info critical section in btrfs_chunk_alloc()
X-Git-Tag: v6.19-rc1~167^2~87
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7a32dd2a616c333cff2d6fb7e3d854ec8d3ae41;p=thirdparty%2Fkernel%2Flinux.git

btrfs: reduce space_info critical section in btrfs_chunk_alloc()

There's no need to update local variables while holding the space_info's
spinlock, since the update isn't using anything from the space_info. So
move these updates outside the critical section to shorten it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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/block-group.c b/fs/btrfs/block-group.c
index ec1e4fc0cd51e..ebd4c514c2c85 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -4191,11 +4191,11 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans,
 		should_alloc = should_alloc_chunk(fs_info, space_info, force);
 		if (space_info->full) {
 			/* No more free physical space */
+			spin_unlock(&space_info->lock);
 			if (should_alloc)
 				ret = -ENOSPC;
 			else
 				ret = 0;
-			spin_unlock(&space_info->lock);
 			return ret;
 		} else if (!should_alloc) {
 			spin_unlock(&space_info->lock);
@@ -4207,16 +4207,16 @@ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans,
 			 * recheck if we should continue with our allocation
 			 * attempt.
 			 */
+			spin_unlock(&space_info->lock);
 			wait_for_alloc = true;
 			force = CHUNK_ALLOC_NO_FORCE;
-			spin_unlock(&space_info->lock);
 			mutex_lock(&fs_info->chunk_mutex);
 			mutex_unlock(&fs_info->chunk_mutex);
 		} else {
 			/* Proceed with allocation */
 			space_info->chunk_alloc = true;
-			wait_for_alloc = false;
 			spin_unlock(&space_info->lock);
+			wait_for_alloc = false;
 		}
 
 		cond_resched();