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| author | Christoph Hellwig <hch@lst.de> | 2022-03-24 17:52:10 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-04-19 15:44:49 +0200 |
| commit | 50f1cff3d8865909727fad6f960ce5a050799d00 (patch) | |
| tree | 9c33dbc94627dbac84e81fe092021c4bcc77e516 /fs/btrfs | |
| parent | 50ff57888d0b13440e7f4cde05dc339ee8d0f1f8 (diff) | |
| download | linux-50f1cff3d8865909727fad6f960ce5a050799d00.tar.bz2 | |
btrfs: fix and document the zoned device choice in alloc_new_bio
Zone Append bios only need a valid block device in struct bio, but
not the device in the btrfs_bio. Use the information from
btrfs_zoned_get_device to set up bi_bdev and fix zoned writes on
multi-device file system with non-homogeneous capabilities and remove
the pointless btrfs_bio.device assignment.
Add big fat comments explaining what is going on here.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/extent_io.c | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 78486bbd1ac9..49f789627d00 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3334,24 +3334,37 @@ static int alloc_new_bio(struct btrfs_inode *inode, ret = calc_bio_boundaries(bio_ctrl, inode, file_offset); if (ret < 0) goto error; - if (wbc) { - struct block_device *bdev; - bdev = fs_info->fs_devices->latest_dev->bdev; - bio_set_dev(bio, bdev); - wbc_init_bio(wbc, bio); - } - if (bio_op(bio) == REQ_OP_ZONE_APPEND) { - struct btrfs_device *device; + if (wbc) { + /* + * For Zone append we need the correct block_device that we are + * going to write to set in the bio to be able to respect the + * hardware limitation. Look it up here: + */ + if (bio_op(bio) == REQ_OP_ZONE_APPEND) { + struct btrfs_device *dev; + + dev = btrfs_zoned_get_device(fs_info, disk_bytenr, + fs_info->sectorsize); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto error; + } - device = btrfs_zoned_get_device(fs_info, disk_bytenr, - fs_info->sectorsize); - if (IS_ERR(device)) { - ret = PTR_ERR(device); - goto error; + bio_set_dev(bio, dev->bdev); + } else { + /* + * Otherwise pick the last added device to support + * cgroup writeback. For multi-device file systems this + * means blk-cgroup policies have to always be set on the + * last added/replaced device. This is a bit odd but has + * been like that for a long time. + */ + bio_set_dev(bio, fs_info->fs_devices->latest_dev->bdev); } - - btrfs_bio(bio)->device = device; + wbc_init_bio(wbc, bio); + } else { + ASSERT(bio_op(bio) != REQ_OP_ZONE_APPEND); } return 0; error: |