For an atomic write, a cloned bio must be same length as the original bio,
i.e. no splitting.

Error in case it is not.

Per-dm device queue limits should be setup to ensure that this does not
happen, but error this case as an insurance policy.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

REQ_NOWAIT for flushes cannot be easily supported by device mapper
because it may allocate multiple bios and its impossible to undo if one
of those allocations wants to wait. So, this patch disables REQ_NOWAIT
flushes in device mapper and we always return EAGAIN.

Previously, the code accepted REQ_NOWAIT flushes, but the non-blocking
execution was not guaranteed.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

The test gfp_flag & GFP_NOWAIT was always true, because both GFP_NOIO and
GFP_NOWAIT include the flag __GFP_KSWAPD_RECLAIM. Luckily, this oversight
didn't result in any harm; the loop always started with "try = 0".

This patch removes the faulty test and explicitly starts the loop with
"try = 0" (so that we don't hold the mutex in the first iteration).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

This adds support to obtain a device's unique id through dm, similar to the
existing ioctl and persistent resevation handling.  We limit this to
single-target devices.

This enables knfsd to export pNFS SCSI luns that have been exported from
multipath devices.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

dm_set_md_type() has been unused since commit
ba30585936b0 ("dm: move setting md->type into dm_setup_md_queue")

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

If blk_alloc_disk fails, the variable md->disk is set to an error value.
cleanup_mapped_device will see that md->disk is non-NULL and it will
attempt to access it, causing a crash on this statement
"md->disk->private_data = NULL;".

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Chenyuan Yang <chenyuan0y@gmail.com>
Closes: https://marc.info/?l=dm-devel&m=172824125004329&w=2
Cc: stable@vger.kernel.org
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>

This reverts commit fa247089de9936a46e290d4724cb5f0b845600f5.

The following sequence of commands causes a livelock - there will be
workqueue process looping and consuming 100% CPU:

dmsetup create --notable test
truncate -s 1MiB testdata
losetup /dev/loop0 testdata
dmsetup load test --table '0 2048 linear /dev/loop0 0'
dd if=/dev/zero of=/dev/dm-0 bs=16k count=1 conv=fdatasync

The livelock is caused by the commit fa247089de99. The commit claims that
it fixes a race condition, however, it is unknown what the actual race
condition is and what program is involved in the race condition.

When the inactive table is loaded, the nodes /dev/dm-0 and
/sys/block/dm-0 are created. /dev/dm-0 has zero size at this point. When
the device is suspended and resumed, the nodes /dev/mapper/test and
/dev/disk/* are created.

If some program opens a block device before it is created by dmsetup or
lvm, the program is buggy, so dm could just report an error as it used to
do before.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: fa247089de99 ("dm: requeue IO if mapping table not yet available")

This commit changes device mapper, so that it returns -ERESTARTSYS
instead of -EINTR when it is interrupted by a signal (so that the ioctl
can be restarted).

The manpage signal(7) says that the ioctl function should be restarted if
the signal was handled with SA_RESTART.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org

Pull block integrity mapping updates from Jens Axboe:
 "A set of cleanups and fixes for the block integrity support.

  Sent separately from the main block changes from last week, as they
  depended on later fixes in the 6.10-rc cycle"

* tag 'for-6.11/block-post-20240722' of git://git.kernel.dk/linux:
  block: don't free the integrity payload in bio_integrity_unmap_free_user
  block: don't free submitter owned integrity payload on I/O completion
  block: call bio_integrity_unmap_free_user from blk_rq_unmap_user
  block: don't call bio_uninit from bio_endio
  block: also return bio_integrity_payload * from stubs
  block: split integrity support out of bio.h

Pull device mapper updates from Mikulas Patocka:

 - Optimize processing of flush bios in the dm-linear and dm-stripe
   targets

 - Dm-io cleansups and refactoring

 - Remove unused 'struct thunk' in dm-cache

 - Handle minor device numbers > 255 in dm-init

 - Dm-verity refactoring & enabling platform keyring

 - Fix warning in dm-raid

 - Improve dm-crypt performance - split bios to smaller pieces, so that
   They could be processed concurrently

 - Stop using blk_limits_io_{min,opt}

 - Dm-vdo cleanup and refactoring

 - Remove max_write_zeroes_granularity and max_secure_erase_granularity

 - Dm-multipath cleanup & refactoring

 - Add dm-crypt and dm-integrity support for non-power-of-2 sector size

 - Fix reshape in dm-raid

 - Make dm_block_validator const

* tag 'for-6.11/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (33 commits)
  dm vdo: fix a minor formatting issue in vdo.rst
  dm vdo int-map: fix kerneldoc formatting
  dm vdo repair: add missing kerneldoc fields
  dm: Constify struct dm_block_validator
  dm-integrity: introduce the Inline mode
  dm: introduce the target flag mempool_needs_integrity
  dm raid: fix stripes adding reshape size issues
  dm raid: move _get_reshape_sectors() as prerequisite to fixing reshape size issues
  dm-crypt: support for per-sector NVMe metadata
  dm mpath: don't call dm_get_device in multipath_message
  dm: factor out helper function from dm_get_device
  dm-verity: fix dm_is_verity_target() when dm-verity is builtin
  dm: Remove max_secure_erase_granularity
  dm: Remove max_write_zeroes_granularity
  dm vdo indexer: use swap() instead of open coding it
  dm vdo: remove unused struct 'uds_attribute'
  dm: stop using blk_limits_io_{min,opt}
  dm-crypt: limit the size of encryption requests
  dm verity: add support for signature verification with platform keyring
  dm-raid: Fix WARN_ON_ONCE check for sync_thread in raid_resume
  ...