<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/md/dm-table.c, branch v5.16</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm</title>
<updated>2021-11-09T19:02:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-11-09T19:02:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c183e1707aba2c707837569b473d1e9fd48110c4'/>
<id>c183e1707aba2c707837569b473d1e9fd48110c4</id>
<content type='text'>
Pull device mapper updates from Mike Snitzer:

 - Add DM core support for emitting audit events through the audit
   subsystem. Also enhance both the integrity and crypt targets to emit
   events to via dm-audit.

 - Various other simple code improvements and cleanups.

* tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm table: log table creation error code
  dm: make workqueue names device-specific
  dm writecache: Make use of the helper macro kthread_run()
  dm crypt: Make use of the helper macro kthread_run()
  dm verity: use bvec_kmap_local in verity_for_bv_block
  dm log writes: use memcpy_from_bvec in log_writes_map
  dm integrity: use bvec_kmap_local in __journal_read_write
  dm integrity: use bvec_kmap_local in integrity_metadata
  dm: add add_disk() error handling
  dm: Remove redundant flush_workqueue() calls
  dm crypt: log aead integrity violations to audit subsystem
  dm integrity: log audit events for dm-integrity target
  dm: introduce audit event module for device mapper
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull device mapper updates from Mike Snitzer:

 - Add DM core support for emitting audit events through the audit
   subsystem. Also enhance both the integrity and crypt targets to emit
   events to via dm-audit.

 - Various other simple code improvements and cleanups.

* tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm table: log table creation error code
  dm: make workqueue names device-specific
  dm writecache: Make use of the helper macro kthread_run()
  dm crypt: Make use of the helper macro kthread_run()
  dm verity: use bvec_kmap_local in verity_for_bv_block
  dm log writes: use memcpy_from_bvec in log_writes_map
  dm integrity: use bvec_kmap_local in __journal_read_write
  dm integrity: use bvec_kmap_local in integrity_metadata
  dm: add add_disk() error handling
  dm: Remove redundant flush_workqueue() calls
  dm crypt: log aead integrity violations to audit subsystem
  dm integrity: log audit events for dm-integrity target
  dm: introduce audit event module for device mapper
</pre>
</div>
</content>
</entry>
<entry>
<title>dm table: log table creation error code</title>
<updated>2021-11-01T17:28:52+00:00</updated>
<author>
<name>Michał Mirosław</name>
<email>mirq-linux@rere.qmqm.pl</email>
</author>
<published>2021-10-21T21:13:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7552750d0494fdd12f71acd8a432f51334a4462d'/>
<id>7552750d0494fdd12f71acd8a432f51334a4462d</id>
<content type='text'>
Help debugging table creation errors by adding the error name in the log.

Signed-off-by: Michał Mirosław &lt;mirq-linux@rere.qmqm.pl&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Help debugging table creation errors by adding the error name in the log.

Signed-off-by: Michał Mirosław &lt;mirq-linux@rere.qmqm.pl&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block</title>
<updated>2021-11-01T16:50:37+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-11-01T16:50:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3f01727f750eae3e61b738b57355b2538ab179f4'/>
<id>3f01727f750eae3e61b738b57355b2538ab179f4</id>
<content type='text'>
Pull bdev size cleanups from Jens Axboe:
 "Clean up the bdev size handling with new bdev_nr_bytes() helper"

* tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block: (34 commits)
  partitions/ibm: use bdev_nr_sectors instead of open coding it
  partitions/efi: use bdev_nr_bytes instead of open coding it
  block/ioctl: use bdev_nr_sectors and bdev_nr_bytes
  block: cache inode size in bdev
  udf: use sb_bdev_nr_blocks
  reiserfs: use sb_bdev_nr_blocks
  ntfs: use sb_bdev_nr_blocks
  jfs: use sb_bdev_nr_blocks
  ext4: use sb_bdev_nr_blocks
  block: add a sb_bdev_nr_blocks helper
  block: use bdev_nr_bytes instead of open coding it in blkdev_fallocate
  squashfs: use bdev_nr_bytes instead of open coding it
  reiserfs: use bdev_nr_bytes instead of open coding it
  pstore/blk: use bdev_nr_bytes instead of open coding it
  ntfs3: use bdev_nr_bytes instead of open coding it
  nilfs2: use bdev_nr_bytes instead of open coding it
  nfs/blocklayout: use bdev_nr_bytes instead of open coding it
  jfs: use bdev_nr_bytes instead of open coding it
  hfsplus: use bdev_nr_sectors instead of open coding it
  hfs: use bdev_nr_sectors instead of open coding it
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bdev size cleanups from Jens Axboe:
 "Clean up the bdev size handling with new bdev_nr_bytes() helper"

* tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block: (34 commits)
  partitions/ibm: use bdev_nr_sectors instead of open coding it
  partitions/efi: use bdev_nr_bytes instead of open coding it
  block/ioctl: use bdev_nr_sectors and bdev_nr_bytes
  block: cache inode size in bdev
  udf: use sb_bdev_nr_blocks
  reiserfs: use sb_bdev_nr_blocks
  ntfs: use sb_bdev_nr_blocks
  jfs: use sb_bdev_nr_blocks
  ext4: use sb_bdev_nr_blocks
  block: add a sb_bdev_nr_blocks helper
  block: use bdev_nr_bytes instead of open coding it in blkdev_fallocate
  squashfs: use bdev_nr_bytes instead of open coding it
  reiserfs: use bdev_nr_bytes instead of open coding it
  pstore/blk: use bdev_nr_bytes instead of open coding it
  ntfs3: use bdev_nr_bytes instead of open coding it
  nilfs2: use bdev_nr_bytes instead of open coding it
  nfs/blocklayout: use bdev_nr_bytes instead of open coding it
  jfs: use bdev_nr_bytes instead of open coding it
  hfsplus: use bdev_nr_sectors instead of open coding it
  hfs: use bdev_nr_sectors instead of open coding it
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-crypto: rename blk_keyslot_manager to blk_crypto_profile</title>
<updated>2021-10-21T16:49:32+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2021-10-18T18:04:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cb77cb5abe1f4fae4a33b735606aae22f9eaa1c7'/>
<id>cb77cb5abe1f4fae4a33b735606aae22f9eaa1c7</id>
<content type='text'>
blk_keyslot_manager is misnamed because it doesn't necessarily manage
keyslots.  It actually does several different things:

  - Contains the crypto capabilities of the device.

  - Provides functions to control the inline encryption hardware.
    Originally these were just for programming/evicting keyslots;
    however, new functionality (hardware-wrapped keys) will require new
    functions here which are unrelated to keyslots.  Moreover,
    device-mapper devices already (ab)use "keyslot_evict" to pass key
    eviction requests to their underlying devices even though
    device-mapper devices don't have any keyslots themselves (so it
    really should be "evict_key", not "keyslot_evict").

  - Sometimes (but not always!) it manages keyslots.  Originally it
    always did, but device-mapper devices don't have keyslots
    themselves, so they use a "passthrough keyslot manager" which
    doesn't actually manage keyslots.  This hack works, but the
    terminology is unnatural.  Also, some hardware doesn't have keyslots
    and thus also uses a "passthrough keyslot manager" (support for such
    hardware is yet to be upstreamed, but it will happen eventually).

Let's stop having keyslot managers which don't actually manage keyslots.
Instead, rename blk_keyslot_manager to blk_crypto_profile.

This is a fairly big change, since for consistency it also has to update
keyslot manager-related function names, variable names, and comments --
not just the actual struct name.  However it's still a fairly
straightforward change, as it doesn't change any actual functionality.

Acked-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt; # For MMC
Reviewed-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20211018180453.40441-4-ebiggers@kernel.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
blk_keyslot_manager is misnamed because it doesn't necessarily manage
keyslots.  It actually does several different things:

  - Contains the crypto capabilities of the device.

  - Provides functions to control the inline encryption hardware.
    Originally these were just for programming/evicting keyslots;
    however, new functionality (hardware-wrapped keys) will require new
    functions here which are unrelated to keyslots.  Moreover,
    device-mapper devices already (ab)use "keyslot_evict" to pass key
    eviction requests to their underlying devices even though
    device-mapper devices don't have any keyslots themselves (so it
    really should be "evict_key", not "keyslot_evict").

  - Sometimes (but not always!) it manages keyslots.  Originally it
    always did, but device-mapper devices don't have keyslots
    themselves, so they use a "passthrough keyslot manager" which
    doesn't actually manage keyslots.  This hack works, but the
    terminology is unnatural.  Also, some hardware doesn't have keyslots
    and thus also uses a "passthrough keyslot manager" (support for such
    hardware is yet to be upstreamed, but it will happen eventually).

Let's stop having keyslot managers which don't actually manage keyslots.
Instead, rename blk_keyslot_manager to blk_crypto_profile.

This is a fairly big change, since for consistency it also has to update
keyslot manager-related function names, variable names, and comments --
not just the actual struct name.  However it's still a fairly
straightforward change, as it doesn't change any actual functionality.

Acked-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt; # For MMC
Reviewed-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20211018180453.40441-4-ebiggers@kernel.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm: use bdev_nr_sectors and bdev_nr_bytes instead of open coding them</title>
<updated>2021-10-18T20:43:22+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-10-18T10:11:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6dcbb52cddd9e50c8f6625b02a31f6dffc0d1a7b'/>
<id>6dcbb52cddd9e50c8f6625b02a31f6dffc0d1a7b</id>
<content type='text'>
Use the proper helpers to read the block device size.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the proper helpers to read the block device size.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: move integrity handling out of &lt;linux/blkdev.h&gt;</title>
<updated>2021-10-18T12:17:02+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-09-20T12:33:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fe45e630a1035aea94c29016f2598bbde149bbe3'/>
<id>fe45e630a1035aea94c29016f2598bbde149bbe3</id>
<content type='text'>
Split the integrity/metadata handling definitions out into a new header.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20210920123328.1399408-17-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Split the integrity/metadata handling definitions out into a new header.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20210920123328.1399408-17-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'libnvdimm-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm</title>
<updated>2021-09-09T18:39:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-09-09T18:39:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2e5fd489a4e5fcc97b035c03ace724c1d481a4c1'/>
<id>2e5fd489a4e5fcc97b035c03ace724c1d481a4c1</id>
<content type='text'>
Pull libnvdimm updates from Dan Williams:

 - Fix a race condition in the teardown path of raw mode pmem
   namespaces.

 - Cleanup the code that filesystems use to detect filesystem-dax
   capabilities of their underlying block device.

* tag 'libnvdimm-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: remove bdev_dax_supported
  xfs: factor out a xfs_buftarg_is_dax helper
  dax: stub out dax_supported for !CONFIG_FS_DAX
  dax: remove __generic_fsdax_supported
  dax: move the dax_read_lock() locking into dax_supported
  dax: mark dax_get_by_host static
  dm: use fs_dax_get_by_bdev instead of dax_get_by_host
  dax: stop using bdevname
  fsdax: improve the FS_DAX Kconfig description and help text
  libnvdimm/pmem: Fix crash triggered when I/O in-flight during unbind
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull libnvdimm updates from Dan Williams:

 - Fix a race condition in the teardown path of raw mode pmem
   namespaces.

 - Cleanup the code that filesystems use to detect filesystem-dax
   capabilities of their underlying block device.

* tag 'libnvdimm-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: remove bdev_dax_supported
  xfs: factor out a xfs_buftarg_is_dax helper
  dax: stub out dax_supported for !CONFIG_FS_DAX
  dax: remove __generic_fsdax_supported
  dax: move the dax_read_lock() locking into dax_supported
  dax: mark dax_get_by_host static
  dm: use fs_dax_get_by_bdev instead of dax_get_by_host
  dax: stop using bdevname
  fsdax: improve the FS_DAX Kconfig description and help text
  libnvdimm/pmem: Fix crash triggered when I/O in-flight during unbind
</pre>
</div>
</content>
</entry>
<entry>
<title>dax: move the dax_read_lock() locking into dax_supported</title>
<updated>2021-08-26T23:52:03+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-08-26T13:55:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=673a0658f6ac359131a881c0dcf1b91c2500ab9c'/>
<id>673a0658f6ac359131a881c0dcf1b91c2500ab9c</id>
<content type='text'>
Move the dax_read_lock/dax_read_unlock pair from the callers into
dax_supported to make it a little easier to use.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Link: https://lore.kernel.org/r/20210826135510.6293-6-hch@lst.de
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move the dax_read_lock/dax_read_unlock pair from the callers into
dax_supported to make it a little easier to use.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Link: https://lore.kernel.org/r/20210826135510.6293-6-hch@lst.de
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: pass a gendisk to blk_queue_update_readahead</title>
<updated>2021-08-09T17:52:28+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-08-09T14:17:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=471aa704db4904f7af5a50019ca3b5b018c0cf62'/>
<id>471aa704db4904f7af5a50019ca3b5b018c0cf62</id>
<content type='text'>
.. and rename the function to disk_update_readahead.  This is in
preparation for moving the BDI from the request_queue to the gendisk.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20210809141744.1203023-3-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
.. and rename the function to disk_update_readahead.  This is in
preparation for moving the BDI from the request_queue to the gendisk.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20210809141744.1203023-3-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm: introduce zone append emulation</title>
<updated>2021-06-04T16:07:37+00:00</updated>
<author>
<name>Damien Le Moal</name>
<email>damien.lemoal@wdc.com</email>
</author>
<published>2021-05-25T21:25:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bb37d77239af25cde59693dbe3fac04dd17d7b29'/>
<id>bb37d77239af25cde59693dbe3fac04dd17d7b29</id>
<content type='text'>
For zoned targets that cannot support zone append operations, implement
an emulation using regular write operations. If the original BIO
submitted by the user is a zone append operation, change its clone into
a regular write operation directed at the target zone write pointer
position.

To do so, an array of write pointer offsets (write pointer position
relative to the start of a zone) is added to struct mapped_device. All
operations that modify a sequential zone write pointer (writes, zone
reset, zone finish and zone append) are intersepted in __map_bio() and
processed using the new functions dm_zone_map_bio().

Detection of the target ability to natively support zone append
operations is done from dm_table_set_restrictions() by calling the
function dm_set_zones_restrictions(). A target that does not support
zone append operation, either by explicitly declaring it using the new
struct dm_target field zone_append_not_supported, or because the device
table contains a non-zoned device, has its mapped device marked with the
new flag DMF_ZONE_APPEND_EMULATED. The helper function
dm_emulate_zone_append() is introduced to test a mapped device for this
new flag.

Atomicity of the zones write pointer tracking and updates is done using
a zone write locking mechanism based on a bitmap. This is similar to
the block layer method but based on BIOs rather than struct request.
A zone write lock is taken in dm_zone_map_bio() for any clone BIO with
an operation type that changes the BIO target zone write pointer
position. The zone write lock is released if the clone BIO is failed
before submission or when dm_zone_endio() is called when the clone BIO
completes.

The zone write lock bitmap of the mapped device, together with a bitmap
indicating zone types (conv_zones_bitmap) and the write pointer offset
array (zwp_offset) are allocated and initialized with a full device zone
report in dm_set_zones_restrictions() using the function
dm_revalidate_zones().

For failed operations that may have modified a zone write pointer, the
zone write pointer offset is marked as invalid in dm_zone_endio().
Zones with an invalid write pointer offset are checked and the write
pointer updated using an internal report zone operation when the
faulty zone is accessed again by the user.

All functions added for this emulation have a minimal overhead for
zoned targets natively supporting zone append operations. Regular
device targets are also not affected. The added code also does not
impact builds with CONFIG_BLK_DEV_ZONED disabled by stubbing out all
dm zone related functions.

Signed-off-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Reviewed-by: Himanshu Madhani &lt;himanshu.madhani@oracle.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
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For zoned targets that cannot support zone append operations, implement
an emulation using regular write operations. If the original BIO
submitted by the user is a zone append operation, change its clone into
a regular write operation directed at the target zone write pointer
position.

To do so, an array of write pointer offsets (write pointer position
relative to the start of a zone) is added to struct mapped_device. All
operations that modify a sequential zone write pointer (writes, zone
reset, zone finish and zone append) are intersepted in __map_bio() and
processed using the new functions dm_zone_map_bio().

Detection of the target ability to natively support zone append
operations is done from dm_table_set_restrictions() by calling the
function dm_set_zones_restrictions(). A target that does not support
zone append operation, either by explicitly declaring it using the new
struct dm_target field zone_append_not_supported, or because the device
table contains a non-zoned device, has its mapped device marked with the
new flag DMF_ZONE_APPEND_EMULATED. The helper function
dm_emulate_zone_append() is introduced to test a mapped device for this
new flag.

Atomicity of the zones write pointer tracking and updates is done using
a zone write locking mechanism based on a bitmap. This is similar to
the block layer method but based on BIOs rather than struct request.
A zone write lock is taken in dm_zone_map_bio() for any clone BIO with
an operation type that changes the BIO target zone write pointer
position. The zone write lock is released if the clone BIO is failed
before submission or when dm_zone_endio() is called when the clone BIO
completes.

The zone write lock bitmap of the mapped device, together with a bitmap
indicating zone types (conv_zones_bitmap) and the write pointer offset
array (zwp_offset) are allocated and initialized with a full device zone
report in dm_set_zones_restrictions() using the function
dm_revalidate_zones().

For failed operations that may have modified a zone write pointer, the
zone write pointer offset is marked as invalid in dm_zone_endio().
Zones with an invalid write pointer offset are checked and the write
pointer updated using an internal report zone operation when the
faulty zone is accessed again by the user.

All functions added for this emulation have a minimal overhead for
zoned targets natively supporting zone append operations. Regular
device targets are also not affected. The added code also does not
impact builds with CONFIG_BLK_DEV_ZONED disabled by stubbing out all
dm zone related functions.

Signed-off-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Reviewed-by: Himanshu Madhani &lt;himanshu.madhani@oracle.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
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