Remove goto labels and use direct returns as error unwinding code only
needs to free t_page variable if we alloc_pages() call fails as having
two labels for one kfree() can be avoided easily.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220222152852.26043-3-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Only caller of null_alloc_page() is null_insert_page() unconditionally
sets only parameter to GFP_NOIO and that is statically hard-coded in
null_blk. There is no point in having statically hardcoded function
parameter.

Remove the unnecessary parameter gfp_flags and adjust the code, so it
can retain existing behavior null_alloc_page() with GFP_NOIO.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220222152852.26043-2-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Only caller of alloc_cmd() is null_submit_bio() unconditionally sets
second parameter to true and that is statically hard-coded in null_blk.
There is no point in having statically hardcoded function parameter.

Remove the unnecessary parameter can_wait and adjust the code so it
can retain existing behavior of waiting when we don't get valid
nullb_cmd from __alloc_cmd() in alloc_cmd().

The restructured code avoids multiple return statements, multiple
calls to __alloc_cmd() and resulting a fast path call to
prepare_to_wait() due to removal of first alloc_cmd() call.

Follow the pattern that we have in bio_alloc() to set the structure
members in the structure allocation function in alloc_cmd() and pass
bio to initialize newly allocated cmd->bio member.

Follow the pattern in copy_to_nullb() to use result of one function call
(null_cache_active()) to be used as a parameter to another function call
(null_insert_page()), use result of alloc_cmd() as a first parameter to
the null_handle_cmd() in null_submit_bio() function. This allow us to
remove the local variable cmd on stack in null_submit_bio() that is in
fast path.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220216172945.31124-2-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Instead of hardcoding queue depth allow user to set the hw queue depth
using module parameter. Set default value to 128 to retain the existing
behavior.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20220215213310.7264-5-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The local variable file is used to pass it to the vfs_fsync(). We can
get away with using lo->lo_backing_file instead of storing in a local
variable which is not used anywhere else.

No functional change in this patch.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20220215213310.7264-4-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The local variable q is used to pass it to the blk_queue_discard(). We
can get away with using lo->lo_queue instead of storing in a local
variable which is not used anywhere else.

No functional change in this patch.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20220215213310.7264-3-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.

Use a generic sysfs_emit function that knows the size of the
temporary buffer and ensures that no overrun is done for offset
attribute in
loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20220215213310.7264-2-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The function nullb_device_power_store() returns -ENOMEM when
null_add_dev() fails. null_add_dev() can fail with return value
other than -ENOMEM such as -EINVAL when Zoned Block Device option
is used, see :

nullb_device_power_store()
 null_add_dev()
  null_init_zoned_dev()
	return -EINVAL;

When trying to load the module having -ENOMEM value returned on the
command line creates confusion when pleanty of memory is free on the
machine.

Instead of hardcoding -ENOMEM return the value of null_add_dev()
function.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220215115951.15945-1-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The phrase "has still" should be "still has" to clean up the grammar.
Signed-off-by: NColin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220208114656.61629-1-colin.i.king@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

According to lib/idr.c,
   The IDA handles its own locking.  It is safe to call any of the IDA
   functions without synchronisation in your code.

so the 'ida_lock' mutex can just be removed.
It is here only to protect some ida_simple_get()/ida_simple_remove() calls.

While at it, switch to ida_alloc_XXX()/ida_free() instead to
ida_simple_get()/ida_simple_remove().
The latter is deprecated and more verbose.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: NJack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/7f9eccd8b1fce1bac45ac9b01a78cf72f54c0a61.1644266862.git.christophe.jaillet@wanadoo.frSigned-off-by: NJens Axboe <axboe@kernel.dk>

On client side, the device is a network device. There is no reason
to set rotational even-if the target device on server is rotational.
Signed-off-by: NGioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: NJack Wang <jinpu.wang@ionos.com>
Signed-off-by: NMd Haris Iqbal <haris.iqbal@ionos.com>
Link: https://lore.kernel.org/r/20220114155855.984144-3-haris.iqbal@ionos.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

This patch fix the "CHECK:BRACES: braces {} should be used on all
arms of this statement" warning from checkpatch
Signed-off-by: NGioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: NMd Haris Iqbal <haris.iqbal@ionos.com>
Link: https://lore.kernel.org/r/20220114155855.984144-2-haris.iqbal@ionos.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Implement the ->free_disk method to free the virtio_blk structure only
once the last gendisk reference goes away instead of keeping a local
refcount.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20220215094514.3828912-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Implement the ->free_disk method to free the msb_data structure only once
the last gendisk reference goes away instead of keeping a local
refcount.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220215094514.3828912-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use set_disk_ro to propagate the read-only state to the block layer
instead of checking for it in ->open and leaking a reference in case
of a read-only device.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220215094514.3828912-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Implement the ->free_disk method to free the msb_data structure only once
the last gendisk reference goes away instead of keeping a local refcount.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220215094514.3828912-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold dm_dispatch_clone_request into it's only caller, and use a switch
statement to single dispatch for the handling of the different return
values from blk_insert_cloned_request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220215100540.3892965-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Both ->start_time_ns and the RQF_IO_STAT are set when the request is
allocated using blk_mq_alloc_request by dm-mpath in blk_mq_rq_ctx_init.
The block layer also ensures ->start_time_ns is only set when actually
needed.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220215100540.3892965-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The request must be submitted to the queue it was allocated for, so
remove the extra request_queue argument.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220215100540.3892965-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The code to stack blk-mq drivers is only used by dm-multipath, and
will preferably stay that way.  Make it optional and only selected
by device mapper, so that the buildbots more easily catch abuses
like the one that slipped in in the ufs driver in the last merged
window.  Another positive side effects is that kernel builds without
device mapper shrink a little bit as well.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220215100540.3892965-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass a block_device to bio_clone_fast and __bio_clone_fast and give
the functions more suitable names.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers of __bio_clone_fast initialize the bio first.  Move that
initialization into __bio_clone_fast instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Replace open coded bio_clone_fast implementations with the actual helper.
Note that the bio allocated as part of the dm_io structure in alloc_io
will only actually be used later in alloc_tio, making this earlier
cloning of the information safe.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-12-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

__bio_clone_fast should also clone integrity and crypto data, as a clone
without those is incomplete.  Right now the only caller that can actually
support crypto and integrity data (dm) does it manually for the one
callchain that supports these, but we better do it properly in the core.

Note that all callers except for the above mentioned one also don't need
to handle failure at all, given that the integrity and crypto clones are
based on mempool allocations that won't fail for sleeping allocations.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold __remap_to_origin_clear_discard into the two callers to prepare
for bio cloning refactoring.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Most targets just need a single flush bio.  Open code that case in
__send_duplicate_bios without the need to add the bio to a list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-9-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Return the clone bio embedded into the tio as that is what the callers
actually want.  Similar for the free side.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-8-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

This simplifies the callers a bit.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-7-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Move the call to __bio_clone_fast and the assignment of ->len_ptr from
the callers into alloc_tio to prepare for changes to the bio clone API.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold __send_duplicate_bios into its only caller to prepare for
refactoring.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold clone_bio into its only caller to prepare for refactoring.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add a helper to stop open coding the container_of operations to get
from the clone bio to the tio structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Make sure the newly allocated bio has the correct bi_bdev set from the
start.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The new error message for such case looks like

[  172.809565] device offline error, dev sda, sector 3138208 ...

which will not be confused with regular I/O error (BLK_STS_IOERR).
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NSong Liu <song@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220203192827.1370270-4-song@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_reset to optimize the assigment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-20-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_init to optimize the assignment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_bioset to optimize the assigment.  NULL/0 can be passed, both
for the passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-16-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers need to set the block_device and operation, so lift that into
the common code.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-15-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Remove handling of NULL returns from sleeping bio_alloc calls given that
those can't fail.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>