These are only used by DM core, DM target modules should only use
dm_{get,put}_device.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Remove useless "while" loop. If the condition ci.sector_count && !error is
true, we go to a branch that ends with "break". If this condition is
false, the "while" loop will not be executed again. So, the loop can't be
executed more than once.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

When a DM device is first created it doesn't yet have an established
capacity, therefore the use of set_capacity_and_notify() should be
conditional given the potential for needless pr_info "detected
capacity change" noise even if capacity is 0.

One could argue that the pr_info() in set_capacity_and_notify() is
misplaced, but that position is not held uniformly.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Fixes: f64d9b2e ("dm: use set_capacity_and_notify")
Cc: stable@vger.kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

The system would deadlock when swapping to a dm-crypt device. The reason
is that for each incoming write bio, dm-crypt allocates memory that holds
encrypted data. These excessive allocations exhaust all the memory and the
result is either deadlock or OOM trigger.

This patch limits the number of in-flight swap bios, so that the memory
consumed by dm-crypt is limited. The limit is enforced if the target set
the "limit_swap_bios" variable and if the bio has REQ_SWAP set.

Non-swap bios are not affected becuase taking the semaphore would cause
performance degradation.

This is similar to request-based drivers - they will also block when the
number of requests is over the limit.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Update the device-mapper core to support exposing the inline crypto
support of the underlying device(s) through the device-mapper device.

This works by creating a "passthrough keyslot manager" for the dm
device, which declares support for encryption settings which all
underlying devices support.  When a supported setting is used, the bio
cloning code handles cloning the crypto context to the bios for all the
underlying devices.  When an unsupported setting is used, the blk-crypto
fallback is used as usual.

Crypto support on each underlying device is ignored unless the
corresponding dm target opts into exposing it.  This is needed because
for inline crypto to semantically operate on the original bio, the data
must not be transformed by the dm target.  Thus, targets like dm-linear
can expose crypto support of the underlying device, but targets like
dm-crypt can't.  (dm-crypt could use inline crypto itself, though.)

A DM device's table can only be changed if the "new" inline encryption
capabilities are a (*not* necessarily strict) superset of the "old" inline
encryption capabilities.  Attempts to make changes to the table that result
in some inline encryption capability becoming no longer supported will be
rejected.

For the sake of clarity, key eviction from underlying devices will be
handled in a future patch.
Co-developed-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NSatya Tangirala <satyat@google.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Fix dm_table_supports_dax() and invert logic of both
iterate_devices_callout_fn so that all devices' DAX capabilities are
properly checked.

Fixes: 545ed20e ("dm: add infrastructure for DAX support")
Cc: stable@vger.kernel.org
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Add two helper macros calculating the offset of bio in struct dm_io and
struct dm_target_io respectively.

Besides, simplify the front padding calculation in
dm_alloc_md_mempools().
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

There wasn't ever a real need to log an error in the kernel log for
ioctls issued with insufficient permissions. Simply return an error
and if an admin/user is sufficiently motivated they can enable DM's
dynamic debugging to see an explanation for why the ioctls were
disallowed.
Reported-by: NNir Soffer <nsoffer@redhat.com>
Fixes: e980f623 ("dm: don't allow ioctls to targets that don't map to whole devices")
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

The depth-first splitting is introduced in commit 18a25da8 ("dm:
ensure bio submission follows a depth-first tree walk"), which is used
to fix the potential deadlock in case of the misordering handling of
bios caused by bio_list. There're two paths submitting split bios,
dm_wq_work() from worker thread and submit_bio() from application. Back
upon that time, dm_wq_work() thread calls __split_and_process_bio()
directly and thus will not trigger this issue since bio_list doesn't
exist here. So this issue will only be triggered from application
calling submit_bio(), and the fix has to check if current->bio_list is
non-NULL to distinguish this case.

However since commit 0c2915b8 ("dm: fix missing imposition of
queue_limits from dm_wq_work() thread"), dm_wq_work() thread calls
submit_bio_noacct() and thus also uses bio_list. Since then all entries
into __split_and_process_bio() are under protection of bio_list, and
thus the checking of current->bio_list when determinning if the
depth-first principle should be used, seems kind of nonsense. After all
the checking always succeeds now.

Fixes: 0c2915b8 ("dm: fix missing imposition of queue_limits from dm_wq_work() thread")
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Fixes sparse warnings:
drivers/md/dm.c:508:12: warning: context imbalance in 'dm_prepare_ioctl' - wrong count at exit
drivers/md/dm.c:543:13: warning: context imbalance in 'dm_unprepare_ioctl' - wrong count at exit

Fixes: 971888c4 ("dm: hold DM table for duration of ioctl rather than use blkdev_get")
Cc: stable@vger.kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Remove redundant dm_put_live_table() in dm_dax_zero_page_range() error
path to fix sparse warning:
drivers/md/dm.c:1208:9: warning: context imbalance in 'dm_dax_zero_page_range' - unexpected unlock

Fixes: cdf6cdcd ("dm,dax: Add dax zero_page_range operation")
Cc: stable@vger.kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Commit 882ec4e6 ("dm table: stack 'chunk_sectors' limit to account
for target-specific splitting") caused a couple regressions:
1) Using lcm_not_zero() when stacking chunk_sectors was a bug because
   chunk_sectors must reflect the most limited of all devices in the
   IO stack.
2) DM targets that set max_io_len but that do _not_ provide an
   .iterate_devices method no longer had there IO split properly.

And commit 5091cdec ("dm: change max_io_len() to use
blk_max_size_offset()") also caused a regression where DM no longer
supported varied (per target) IO splitting. The implication being the
potential for severely reduced performance for IO stacks that use a DM
target like dm-cache to hide performance limitations of a slower
device (e.g. one that requires 4K IO splitting).

Coming full circle: Fix all these issues by discontinuing stacking
chunk_sectors up using ti->max_io_len in dm_calculate_queue_limits(),
add optional chunk_sectors override argument to blk_max_size_offset()
and update DM's max_io_len() to pass ti->max_io_len to its
blk_max_size_offset() call.

Passing in an optional chunk_sectors override to blk_max_size_offset()
allows for code reuse of block's centralized calculation for max IO
size based on provided offset and split boundary.

Fixes: 882ec4e6 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting")
Fixes: 5091cdec ("dm: change max_io_len() to use blk_max_size_offset()")
Cc: stable@vger.kernel.org
Reported-by: NJohn Dorminy <jdorminy@redhat.com>
Reported-by: NBruce Johnston <bjohnsto@redhat.com>
Reported-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: NJohn Dorminy <jdorminy@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Reviewed-by: NJens Axboe <axboe@kernel.dk>

The request_queue can trivially be derived from the bio.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The request_queue can trivially be derived from the bio.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We can just dereference the point in struct gendisk instead.  Also
remove the now unused export.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use struct block_device to lookup partitions on a disk.  This removes
all usage of struct hd_struct from the I/O path.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de>			[bcache]
Acked-by: Chao Yu <yuchao0@huawei.com>			[f2fs]
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Allocate hd_struct together with struct block_device to pre-load
the lifetime rule changes in preparation of merging the two structures.

Note that part0 was previously embedded into struct gendisk, but is
a separate allocation now, and already points to the block_device instead
of the hd_struct.  The lifetime of struct gendisk is still controlled by
the struct device embedded in the part0 hd_struct.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Get rid of the long-lasting struct block_device reference in
struct mapped_device.  The only remaining user is the freeze code,
where we can trivially look up the block device at freeze time
and release the reference at thaw time.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We don't really need the struct block_device to initialize a bio.  So
switch from using bio_set_dev to manually setting up bi_disk (bi_partno
will always be zero and has been cleared by bio_init already).
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Store the frozen superblock in struct block_device to avoid the awkward
interface that can return a sb only used a cookie, an ERR_PTR or NULL.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Acked-by: Chao Yu <yuchao0@huawei.com>		[f2fs]
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The dm_get_live_table() function makes RCU read lock so
dm_put_live_table() must be called even if dm_table map is not found.

Fixes: e76239a3 ("block: add a report_zones method")
Cc: stable@vger.kernel.org
Signed-off-by: NSergei Shtepa <sergei.shtepa@veeam.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Use set_capacity_and_notify to set the size of both the disk and block
device.  This also gets the uevent notifications for the resize for free.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Just open code it in the few callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

It is unnecessary to force request-based DM to call into bio-based
dm_submit_bio (via indirect disk->fops->submit_bio) only to have it then
call blk_mq_submit_bio().

Fix this by establishing a request-based DM block_device_operations
(dm_rq_blk_dops, which doesn't have .submit_bio) and update
dm_setup_md_queue() to set md->disk->fops to it for
DM_TYPE_REQUEST_BASED.

Remove DM_TYPE_REQUEST_BASED conditional in dm_submit_bio and unexport
blk_mq_submit_bio.

Fixes: c62b37d9 ("block: move ->make_request_fn to struct block_device_operations")
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Since commit 5a6c35f9 ("block: remove direct_make_request") there
is no benefit to DM special-casing NVMe. Remove all code used to
establish DM_TYPE_NVME_BIO_BASED.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

bio_crypt_clone() assumes its gfp_mask argument always includes
__GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed.

However, bio_crypt_clone() might be called with GFP_ATOMIC via
setup_clone() in drivers/md/dm-rq.c, or with GFP_NOWAIT via
kcryptd_io_read() in drivers/md/dm-crypt.c.

Neither case is currently reachable with a bio that actually has an
encryption context.  However, it's fragile to rely on this.  Just make
bio_crypt_clone() able to fail, analogous to bio_integrity_clone().
Reported-by: NMiaohe Lin <linmiaohe@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Reviewed-by: NSatya Tangirala <satyat@google.com>
Cc: Satya Tangirala <satyat@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix stale references to functions that have been renamed and fix typo.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

dm_process_bio() is only called by dm_submit_bio(), there is no benefit
to keeping dm_process_bio() factored out, so fold it.

While at it, cleanup dm_submit_bio()'s DMF_BLOCK_IO_FOR_SUSPEND related
branching and expand scope of dm_get_live_table() rcu reference on map
via common 'out' label to dm_put_live_table().
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

If a DM device was suspended when bios were issued to it, those bios
would be deferred using queue_io(). Once the DM device was resumed
dm_process_bio() could be called by dm_wq_work() for original bio that
still needs splitting. dm_process_bio()'s check for current->bio_list
(meaning call chain is within ->submit_bio) as a prerequisite for
calling blk_queue_split() for "abnormal IO" would result in
dm_process_bio() never imposing corresponding queue_limits
(e.g. discard_granularity, discard_max_bytes, etc).

Fix this by always having dm_wq_work() resubmit deferred bios using
submit_bio_noacct().

Side-effect is blk_queue_split() is always called for "abnormal IO" from
->submit_bio, be it from application thread or dm_wq_work() workqueue,
so proper bio splitting and depth-first bio submission is performed.
For sake of clarity, remove current->bio_list check before call to
blk_queue_split().

Also, remove dm_wq_work()'s use of dm_{get,put}_live_table() -- no
longer needed since IO will be reissued in terms of ->submit_bio.
And rename bio variable from 'c' to 'bio'.

Fixes: cf9c3786 ("dm: fix comment in dm_process_bio()")
Reported-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Move 'struct dm_table' definition from dm-table.c to dm-core.h and
update DM core to access its members directly.

Helps optimize max_io_len() and other methods slightly.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Only call bio_op() once in switch statement.  Also remove the
excessive factoring out to one line functions.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Eliminates duplicate code, no functional change.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Saves redundant dm_target_offset() math.

Also, reverse argument order for max_io_len() to be consistent with
other similar functions.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Also, update associated stale comment in __bind().
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Using blk_max_size_offset() enables DM core's splitting to impose
ti->max_io_len (via q->limits.chunk_sectors) and also fallback to
respecting q->limits.max_sectors if chunk_sectors isn't set.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Add DM target feature flag DM_TARGET_NOWAIT which advertises that
target works with REQ_NOWAIT bios.

Add dm_table_supports_nowait() and update dm_table_set_restrictions()
to set/clear QUEUE_FLAG_NOWAIT accordingly.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Refer to the correct function (->submit_bio instead of ->queue_bio).
Also, add details about why using blk_queue_split() isn't needed for
dm_wq_work()'s call to dm_process_bio().

Fixes: c62b37d9 ("block: move ->make_request_fn to struct block_device_operations")
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

dm_queue_split() is removed because __split_and_process_bio() _must_
handle splitting bios to ensure proper bio submission and completion
ordering as a bio is split.

Otherwise, multiple recursive calls to ->submit_bio will cause multiple
split bios to be allocated from the same ->bio_split mempool at the same
time. This would result in deadlock in low memory conditions because no
progress could be made (only one bio is available in ->bio_split
mempool).

This fix has been verified to still fix the loss of performance, due
to excess splitting, that commit 120c9257 provided.

Fixes: 120c9257 ("Revert "dm: always call blk_queue_split() in dm_process_bio()"")
Cc: stable@vger.kernel.org # 5.0+, requires custom backport due to 5.9 changes
Reported-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>