From: Filipe Manana <fdmanana@suse.com>
Date: Mon, 9 Dec 2024 16:43:44 +0000 (+0000)
Subject: btrfs: avoid monopolizing a core when activating a swap file
X-Git-Tag: v6.13-rc5~7^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2c8507c63f5498d4ee4af404a8e44ceae4345056;p=thirdparty%2Flinux.git

btrfs: avoid monopolizing a core when activating a swap file

During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c4675f4345fd7..623d9d7ab4803 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10078,6 +10078,8 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
 			ret = -EINTR;
 			goto out;
 		}
+
+		cond_resched();
 	}
 
 	if (bsi.block_len)