Commit 06bae876 authored by Niels Dossche's avatar Niels Dossche Committed by David Sterba
Browse files

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: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarNiels Dossche <niels.dossche@ugent.be>
Signed-off-by: default avatarNiels Dossche <dossche.niels@gmail.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ca5e4ea0

fs/btrfs/space-info.c

+2 −1
Original line number Diff line number Diff line
@@ -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,