From 06bae876634ebf837ba70ea3de532b288326103d Mon Sep 17 00:00:00 2001 From: Niels Dossche Date: Fri, 25 Feb 2022 22:20:28 +0100 Subject: [PATCH] btrfs: extend locking to all space_info members accesses bytes_pinned is always accessed under space_info->lock, except in btrfs_preempt_reclaim_metadata_space, however the other members are accessed under that lock. The reserved member of the rsv's are also partially accessed under a lock and partially not. Move all these accesses into the same lock to ensure consistency. This could potentially race and lead to a flush instead of a commit but it's not a big problem as it's only for preemptive flush. CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Johannes Thumshirn Reviewed-by: Josef Bacik Signed-off-by: Niels Dossche Signed-off-by: Niels Dossche Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/space-info.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 294242c..62382ae 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -1061,7 +1061,6 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work) trans_rsv->reserved; if (block_rsv_size < space_info->bytes_may_use) delalloc_size = space_info->bytes_may_use - block_rsv_size; - spin_unlock(&space_info->lock); /* * We don't want to include the global_rsv in our calculation, @@ -1092,6 +1091,8 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work) flush = FLUSH_DELAYED_REFS_NR; } + spin_unlock(&space_info->lock); + /* * We don't want to reclaim everything, just a portion, so scale * down the to_reclaim by 1/4. If it takes us down to 0, -- 2.7.4