Commit 63447b7d authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: scrub: update last_physical after scrubbing one stripe 



Currently sctx->stat.last_physical only got updated in the following
cases:

- When the last stripe of a non-RAID56 chunk is scrubbed
  This implies a pitfall, if the last stripe is at the chunk boundary,
  and we finished the scrub of the whole chunk, we won't update
  last_physical at all until the next chunk.

- When a P/Q stripe of a RAID56 chunk is scrubbed

This leads the following two problems:

- sctx->stat.last_physical is not updated for a almost full chunk
  This is especially bad, affecting scrub resume, as the resume would
  start from last_physical, causing unnecessary re-scrub.

- "btrfs scrub status" will not report any progress for a long time

Fix the problem by properly updating @last_physical after each stripe is
scrubbed.

And since we're here, for the sake of consistency, use spin lock to
protect the update of @last_physical, just like all the remaining
call sites touching sctx->stat.

Reported-by: default avatarMichel Palleau <michel.palleau@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAMFk-+igFTv2E8svg=cQ6o3e6CrR5QwgQ3Ok9EyRaEvvthpqCQ@mail.gmail.com/


Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 33eb1e5d

fs/btrfs/scrub.c

+9 −0
Original line number Diff line number Diff line
@@ -1875,6 +1875,9 @@ static int flush_scrub_stripes(struct scrub_ctx *sctx) 
		stripe = &sctx->stripes[i];



		wait_scrub_stripe_io(stripe);

		spin_lock(&sctx->stat_lock);

		sctx->stat.last_physical = stripe->physical + stripe_length(stripe);

		spin_unlock(&sctx->stat_lock);

		scrub_reset_stripe(stripe);

	}

out:
@@ -2143,7 +2146,9 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx, 
					 cur_physical, &found_logical);

		if (ret > 0) {

			/* No more extent, just update the accounting */

			spin_lock(&sctx->stat_lock);

			sctx->stat.last_physical = physical + logical_length;

			spin_unlock(&sctx->stat_lock);

			ret = 0;

			break;

		}
@@ -2340,6 +2345,10 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, 
			stripe_logical += chunk_logical;

			ret = scrub_raid56_parity_stripe(sctx, scrub_dev, bg,

							 map, stripe_logical);

			spin_lock(&sctx->stat_lock);

			sctx->stat.last_physical = min(physical + BTRFS_STRIPE_LEN,

						       physical_end);

			spin_unlock(&sctx->stat_lock);

			if (ret)

				goto out;

			goto next;