Commit 00d82525 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
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btrfs: fix direct I/O read repair for split bios 



When a bio is split in btrfs_submit_direct, dip->file_offset contains
the file offset for the first bio.  But this means the start value used
in btrfs_check_read_dio_bio is incorrect for subsequent bios.  Add
a file_offset field to struct btrfs_bio to pass along the correct offset.

Given that check_data_csum only uses start of an error message this
means problems with this miscalculation will only show up when I/O fails
or checksums mismatch.

The logic was removed in f4f39fc5 ("btrfs: remove btrfs_bio::logical
member") but we need it due to the bio splitting.

CC: stable@vger.kernel.org # 5.16+
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarSweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 50f1cff3

fs/btrfs/extent_io.c

+1 −0
Original line number Diff line number Diff line
@@ -2658,6 +2658,7 @@ int btrfs_repair_one_sector(struct inode *inode, 


	repair_bio = btrfs_bio_alloc(1);

	repair_bbio = btrfs_bio(repair_bio);

	repair_bbio->file_offset = start;

	repair_bio->bi_opf = REQ_OP_READ;

	repair_bio->bi_end_io = failed_bio->bi_end_io;

	repair_bio->bi_iter.bi_sector = failrec->logical >> 9;

fs/btrfs/inode.c

+5 −8
Original line number Diff line number Diff line
@@ -7809,8 +7809,6 @@ static blk_status_t btrfs_check_read_dio_bio(struct btrfs_dio_private *dip, 
	const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);

	struct bio_vec bvec;

	struct bvec_iter iter;

	const u64 orig_file_offset = dip->file_offset;

	u64 start = orig_file_offset;

	u32 bio_offset = 0;

	blk_status_t err = BLK_STS_OK;
@@ -7820,6 +7818,8 @@ static blk_status_t btrfs_check_read_dio_bio(struct btrfs_dio_private *dip, 
		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);

		pgoff = bvec.bv_offset;

		for (i = 0; i < nr_sectors; i++) {

			u64 start = bbio->file_offset + bio_offset;



			ASSERT(pgoff < PAGE_SIZE);

			if (uptodate &&

			    (!csum || !check_data_csum(inode, bbio,
@@ -7832,17 +7832,13 @@ static blk_status_t btrfs_check_read_dio_bio(struct btrfs_dio_private *dip, 
			} else {

				int ret;



				ASSERT((start - orig_file_offset) < UINT_MAX);

				ret = btrfs_repair_one_sector(inode,

						&bbio->bio,

						start - orig_file_offset,

						bvec.bv_page, pgoff,

				ret = btrfs_repair_one_sector(inode, &bbio->bio,

						bio_offset, bvec.bv_page, pgoff,

						start, bbio->mirror_num,

						submit_dio_repair_bio);

				if (ret)

					err = errno_to_blk_status(ret);

			}

			start += sectorsize;

			ASSERT(bio_offset + sectorsize > bio_offset);

			bio_offset += sectorsize;

			pgoff += sectorsize;
@@ -8045,6 +8041,7 @@ static void btrfs_submit_direct(const struct iomap_iter *iter, 
		bio = btrfs_bio_clone_partial(dio_bio, clone_offset, clone_len);

		bio->bi_private = dip;

		bio->bi_end_io = btrfs_end_dio_bio;

		btrfs_bio(bio)->file_offset = file_offset;



		if (bio_op(bio) == REQ_OP_ZONE_APPEND) {

			status = extract_ordered_extent(BTRFS_I(inode), bio,

fs/btrfs/volumes.h

+3 −0
Original line number Diff line number Diff line
@@ -328,6 +328,9 @@ struct btrfs_fs_devices { 
struct btrfs_bio {

	unsigned int mirror_num;



	/* for direct I/O */

	u64 file_offset;



	/* @device is for stripe IO submission. */

	struct btrfs_device *device;

	u8 *csum;