Commit e5219044 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: add a btrfs_data_csum_ok helper 



Add a new checksumming helper that wraps btrfs_check_data_csum and
does all the checks to if we're dealing with some form of nodatacsum
I/O.  This helper will be used by the new storage layer checksum
validation and repair code.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 1c2b3ee3

fs/btrfs/btrfs_inode.h

+2 −0
Original line number Diff line number Diff line
@@ -423,6 +423,8 @@ int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page, 
			    u32 pgoff, u8 *csum, const u8 * const csum_expected);

int btrfs_check_data_csum(struct btrfs_inode *inode, struct btrfs_bio *bbio,

			  u32 bio_offset, struct page *page, u32 pgoff);

bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,

			u32 bio_offset, struct bio_vec *bv);

unsigned int btrfs_verify_data_csum(struct btrfs_bio *bbio,

				    u32 bio_offset, struct page *page,

				    u64 start, u64 end);

fs/btrfs/inode.c

+38 −0
Original line number Diff line number Diff line
@@ -3495,6 +3495,44 @@ int btrfs_check_data_csum(struct btrfs_inode *inode, struct btrfs_bio *bbio, 
	return -EIO;

}



/*

 * Verify the checksum of a single data sector.

 *

 * @bbio:	btrfs_io_bio which contains the csum

 * @dev:	device the sector is on

 * @bio_offset:	offset to the beginning of the bio (in bytes)

 * @bv:		bio_vec to check

 *

 * Check if the checksum on a data block is valid.  When a checksum mismatch is

 * detected, report the error and fill the corrupted range with zero.

 *

 * Return %true if the sector is ok or had no checksum to start with, else %false.

 */

bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,

			u32 bio_offset, struct bio_vec *bv)

{

	struct btrfs_inode *inode = bbio->inode;

	u64 file_offset = bbio->file_offset + bio_offset;

	u64 end = file_offset + bv->bv_len - 1;



	if (!bbio->csum)

		return true;



	if (btrfs_is_data_reloc_root(inode->root) &&

	    test_range_bit(&inode->io_tree, file_offset, end, EXTENT_NODATASUM,

			   1, NULL)) {

		/* Skip the range without csum for data reloc inode */

		clear_extent_bits(&inode->io_tree, file_offset, end,

				  EXTENT_NODATASUM);

		return true;

	}



	if (btrfs_check_data_csum(inode, bbio, bio_offset, bv->bv_page,

				  bv->bv_offset) < 0)

		return false;

	return true;

}



/*

 * When reads are done, we need to check csums to verify the data is correct.

 * if there's a match, we allow the bio to finish.  If not, the code in