From: Filipe Manana <fdmanana@xxxxxxxx>
commit 2c8507c63f5498d4ee4af404a8e44ceae4345056 upstream.
This commit re-attempts the backport of the change to the linux-5.10.y
branch. Commit a1c3a19446a4 ("btrfs: avoid monopolizing a core when
activating a swap file") on this branch was reverted.
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@xxxxxxxxxxxxxxx # 5.4+
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Koichiro Den <koichiro.den@xxxxxxxxxxxxx>
---
fs/btrfs/inode.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 45c1732a9677..8d7ca8a21525 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10422,6 +10422,8 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
}
start += len;
+
+ cond_resched();
}
if (bsi.block_len)
--
2.45.2
