[PATCH 04/17] btrfs: refactor btrfs_map_bio()
From: Qu Wenruo <hidden>
Date: 2021-12-01 05:18:23
Also in:
dm-devel, linux-btrfs
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
Currently in btrfs_map_bio() we call __btrfs_map_block(), then using the returned bioc to submit real stripes. This is fine if we're only going to handle one bio a time. For the incoming bio split at btrfs_map_bio() time, we want to handle several different bios, thus there we introduce a new helper, submit_one_mapped_range() to handle the submission part, making it much easier to make it work in a loop. Signed-off-by: Qu Wenruo <redacted> --- fs/btrfs/volumes.c | 65 ++++++++++++++++++++++++++++------------------ 1 file changed, 40 insertions(+), 25 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index b70037cc1a51..3dc759996f55 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c@@ -6777,29 +6777,15 @@ static void bioc_error(struct btrfs_io_context *bioc, struct bio *bio, u64 logic } } -blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, - int mirror_num) +static int submit_one_mapped_range(struct btrfs_fs_info *fs_info, struct bio *bio, + struct btrfs_io_context *bioc, u64 map_length, + int mirror_num) { - struct btrfs_device *dev; struct bio *first_bio = bio; - u64 logical = bio->bi_iter.bi_sector << 9; - u64 length = 0; - u64 map_length; - int ret; - int dev_nr; + u64 logical = bio->bi_iter.bi_sector << SECTOR_SHIFT; int total_devs; - struct btrfs_io_context *bioc = NULL; - - length = bio->bi_iter.bi_size; - map_length = length; - - btrfs_bio_counter_inc_blocked(fs_info); - ret = __btrfs_map_block(fs_info, btrfs_op(bio), logical, - &map_length, &bioc, mirror_num, 1); - if (ret) { - btrfs_bio_counter_dec(fs_info); - return errno_to_blk_status(ret); - } + int dev_nr; + int ret; total_devs = bioc->num_stripes; bioc->orig_bio = first_bio;
@@ -6818,14 +6804,13 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, mirror_num, 1); } - btrfs_bio_counter_dec(fs_info); - return errno_to_blk_status(ret); + return ret; } - if (map_length < length) { + if (map_length < bio->bi_iter.bi_size) { btrfs_crit(fs_info, - "mapping failed logical %llu bio len %llu len %llu", - logical, length, map_length); + "mapping failed logical %llu bio len %u len %llu", + logical, bio->bi_iter.bi_size, map_length); BUG(); }
@@ -6844,6 +6829,8 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, btrfs_bio_save_iter(btrfs_bio(bio)); for (dev_nr = 0; dev_nr < total_devs; dev_nr++) { + struct btrfs_device *dev; + dev = bioc->stripes[dev_nr].dev; if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) ||
@@ -6860,6 +6847,34 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, submit_stripe_bio(bioc, bio, bioc->stripes[dev_nr].physical, dev); } + return 0; +} + +blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, + int mirror_num) +{ + u64 logical = bio->bi_iter.bi_sector << 9; + u64 length = 0; + u64 map_length; + int ret; + struct btrfs_io_context *bioc = NULL; + + length = bio->bi_iter.bi_size; + map_length = length; + + btrfs_bio_counter_inc_blocked(fs_info); + ret = __btrfs_map_block(fs_info, btrfs_op(bio), logical, + &map_length, &bioc, mirror_num, 1); + if (ret) { + btrfs_bio_counter_dec(fs_info); + return errno_to_blk_status(ret); + } + + ret = submit_one_mapped_range(fs_info, bio, bioc, map_length, mirror_num); + if (ret < 0) { + btrfs_bio_counter_dec(fs_info); + return errno_to_blk_status(ret); + } btrfs_bio_counter_dec(fs_info); return BLK_STS_OK; }
--
2.34.1