Commit 97cf8f37 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: scrub: introduce a helper to verify one scrub_stripe 



The new helper, scrub_verify_stripe(), shares the same main workflow of
the old scrub code.

The major differences are:

- How pages/page_offset is grabbed
  Everything can be grabbed from scrub_stripe easily.

- When error report happens
  Currently the helper only verifies the sectors, not really doing any
  error reporting.
  The error reporting would be done after we have done the repair.

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 a3ddbaeb

fs/btrfs/scrub.c

+76 −1
Original line number Diff line number Diff line
@@ -2175,7 +2175,7 @@ static unsigned int scrub_stripe_get_page_offset(struct scrub_stripe *stripe, 
	return offset_in_page(sector_nr << fs_info->sectorsize_bits);

}



void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr)

static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr)

{

	struct btrfs_fs_info *fs_info = stripe->bg->fs_info;

	const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
@@ -2265,6 +2265,81 @@ void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr) 
	bitmap_clear(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);

}



static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr)

{

	struct btrfs_fs_info *fs_info = stripe->bg->fs_info;

	struct scrub_sector_verification *sector = &stripe->sectors[sector_nr];

	const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;

	struct page *page = scrub_stripe_get_page(stripe, sector_nr);

	unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr);

	u8 csum_buf[BTRFS_CSUM_SIZE];

	int ret;



	ASSERT(sector_nr >= 0 && sector_nr < stripe->nr_sectors);



	/* Sector not utilized, skip it. */

	if (!test_bit(sector_nr, &stripe->extent_sector_bitmap))

		return;



	/* IO error, no need to check. */

	if (test_bit(sector_nr, &stripe->io_error_bitmap))

		return;



	/* Metadata, verify the full tree block. */

	if (sector->is_metadata) {

		/*

		 * Check if the tree block crosses the stripe boudary.  If

		 * crossed the boundary, we cannot verify it but only give a

		 * warning.

		 *

		 * This can only happen on a very old filesystem where chunks

		 * are not ensured to be stripe aligned.

		 */

		if (unlikely(sector_nr + sectors_per_tree > stripe->nr_sectors)) {

			btrfs_warn_rl(fs_info,

			"tree block at %llu crosses stripe boundary %llu",

				      stripe->logical +

				      (sector_nr << fs_info->sectorsize_bits),

				      stripe->logical);

			return;

		}

		scrub_verify_one_metadata(stripe, sector_nr);

		return;

	}



	/*

	 * Data is easier, we just verify the data csum (if we have it).  For

	 * cases without csum, we have no other choice but to trust it.

	 */

	if (!sector->csum) {

		clear_bit(sector_nr, &stripe->error_bitmap);

		return;

	}



	ret = btrfs_check_sector_csum(fs_info, page, pgoff, csum_buf, sector->csum);

	if (ret < 0) {

		set_bit(sector_nr, &stripe->csum_error_bitmap);

		set_bit(sector_nr, &stripe->error_bitmap);

	} else {

		clear_bit(sector_nr, &stripe->csum_error_bitmap);

		clear_bit(sector_nr, &stripe->error_bitmap);

	}

}



/* Verify specified sectors of a stripe. */

void scrub_verify_one_stripe(struct scrub_stripe *stripe, unsigned long bitmap)

{

	struct btrfs_fs_info *fs_info = stripe->bg->fs_info;

	const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;

	int sector_nr;



	for_each_set_bit(sector_nr, &bitmap, stripe->nr_sectors) {

		scrub_verify_one_sector(stripe, sector_nr);

		if (stripe->sectors[sector_nr].is_metadata)

			sector_nr += sectors_per_tree - 1;

	}

}



static int scrub_checksum_tree_block(struct scrub_block *sblock)

{

	struct scrub_ctx *sctx = sblock->sctx;

fs/btrfs/scrub.h

+1 −1
Original line number Diff line number Diff line
@@ -24,6 +24,6 @@ int scrub_find_fill_first_stripe(struct btrfs_block_group *bg, 
				 struct btrfs_device *dev, u64 physical,

				 int mirror_num, u64 logical_start,

				 u32 logical_len, struct scrub_stripe *stripe);

void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr);

void scrub_verify_one_stripe(struct scrub_stripe *stripe, unsigned long bitmap);



#endif