Commit a969324f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-5.9/dm-fixes-2' of... 

Merge tag 'for-5.9/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - DM core fix for incorrect double bio splitting. Keep "fixing" this
   because past attempts didn't fully appreciate the liability relative
   to recursive bio splitting. This fix limits DM's bio splitting to a
   single method and does _not_ use blk_queue_split() for normal IO.

 - DM crypt Documentation updates for features added during 5.9 merge.

* tag 'for-5.9/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm crypt: document encrypted keyring key option
  dm crypt: document new no_workqueue flags
  dm: fix comment in dm_process_bio()
  dm: fix bio splitting and its bio completion order for regular IO
parents bffac4b5 4c07ae0a

Documentation/admin-guide/device-mapper/dm-crypt.rst

+9 −1
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ Parameters:: 
    the value passed in <key_size>.



<key_type>

    Either 'logon' or 'user' kernel key type.

    Either 'logon', 'user' or 'encrypted' kernel key type.



<key_description>

    The kernel keyring key description crypt target should look for
@@ -121,6 +121,14 @@ submit_from_crypt_cpus 
    thread because it benefits CFQ to have writes submitted using the

    same context.



no_read_workqueue

    Bypass dm-crypt internal workqueue and process read requests synchronously.



no_write_workqueue

    Bypass dm-crypt internal workqueue and process write requests synchronously.

    This option is automatically enabled for host-managed zoned block devices

    (e.g. host-managed SMR hard-disks).



integrity:<bytes>:<type>

    The device requires additional <bytes> metadata per-sector stored

    in per-bio integrity structure. This metadata must by provided

drivers/md/dm.c

+5 −22
Original line number Diff line number Diff line
@@ -1724,23 +1724,6 @@ out: 
	return ret;

}



static void dm_queue_split(struct mapped_device *md, struct dm_target *ti, struct bio **bio)

{

	unsigned len, sector_count;



	sector_count = bio_sectors(*bio);

	len = min_t(sector_t, max_io_len((*bio)->bi_iter.bi_sector, ti), sector_count);



	if (sector_count > len) {

		struct bio *split = bio_split(*bio, len, GFP_NOIO, &md->queue->bio_split);



		bio_chain(split, *bio);

		trace_block_split(md->queue, split, (*bio)->bi_iter.bi_sector);

		submit_bio_noacct(*bio);

		*bio = split;

	}

}



static blk_qc_t dm_process_bio(struct mapped_device *md,

			       struct dm_table *map, struct bio *bio)

{
@@ -1761,20 +1744,20 @@ static blk_qc_t dm_process_bio(struct mapped_device *md, 
	}



	/*

	 * If in ->queue_bio we need to use blk_queue_split(), otherwise

	 * If in ->submit_bio we need to use blk_queue_split(), otherwise

	 * queue_limits for abnormal requests (e.g. discard, writesame, etc)

	 * won't be imposed.

	 * If called from dm_wq_work() for deferred bio processing, bio

	 * was already handled by following code with previous ->submit_bio.

	 */

	if (current->bio_list) {

		if (is_abnormal_io(bio))

			blk_queue_split(&bio);

		else

			dm_queue_split(md, ti, &bio);

		/* regular IO is split by __split_and_process_bio */

	}



	if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)

		return __process_bio(md, map, bio, ti);

	else

	return __split_and_process_bio(md, map, bio);

}

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