Commit b36bbf9d authored Jan 05, 2018 by Hans Holmberg Committed by Jens Axboe Jan 05, 2018

lightnvm: pblk: prevent premature sync point resets



Unless we protect flush pointer updates with a lock, we risk
resetting new flush points before we've synced all sectors
up to that point.

This patch protects new flush points with the same spin lock
that is being held when advancing the sync pointer and
resetting completed flush points.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 533657c1

drivers/lightnvm/pblk-rb.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -367,17 +367,17 @@ static int pblk_rb_flush_point_set(struct pblk_rb rb, struct bio bio,
		flush_point = (pos == 0) ? (rb->nr_entries - 1) : (pos - 1);
		entry = &rb->entries[flush_point];

		pblk_rb_sync_init(rb, NULL);

		/* Protect flush points */
		smp_store_release(&rb->flush_point, flush_point);

		if (!bio)
		return 0;

		spin_lock_irq(&rb->s_lock);
		if (bio)
		bio_list_add(&entry->w_ctx.bios, bio);
		spin_unlock_irq(&rb->s_lock);

		return 1;
		pblk_rb_sync_end(rb, NULL);

		return bio ? 1 : 0;
		}

		static int __pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,

Admin message