The bio argument is entirely unused, and the request_queue can be passed
through the alloc_data, given that it needs to be filled out for the
low-level tag allocation anyway. Also rename the function to
__blk_mq_alloc_request as the switch between get and alloc in the call
chains is rather confusing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
None of the I/O schedulers actually needs it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use blk_mq_foce_complete_rq() to bypass fake timeout error injection so
that request reclaim may proceed.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Drivers may need to bypass error injection for error recovery. Rename
__blk_mq_complete_request() to blk_mq_force_complete_rq() and export
that function so drivers may skip potential fake timeouts after they've
reclaimed lost requests.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
disk_start_io_acct and disk_end_io_acct need at least a struct gendisk
forward declaration, but for weird historic reasons much of blkdev.h
is stubbed out for CONFIG_BLOCK=n. Fix this by stubbing more out for
now, but eventually this header will need a massive cleanup.
Fixes: 956d510ee7 ("block: add disk/bio-based accounting helpers")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The variable err is being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Satya Tangirala <satyat@google.com>
Addresses-Coverity: ("Unused value")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We only need the stats lock (aka preempt_disable()) for updating the
states, not for looking up or dropping the hd_struct reference.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Most architectures have fast path to access percpu for current cpu.
The required preempt_disable() is provided by part_stat_lock().
[hch: rebased]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The RCU lock is required only in disk_map_sector_rcu() to lookup the
partition. After that request holds reference to related hd_struct.
Replace get_cpu() with preempt_disable() - returned cpu index is unused.
[hch: rebased]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the non-"new_io" branch of blk_account_io_start() into separate
function. Fix merge accounting for discards (they were counted as write
merges).
The new blk_account_io_merge_bio() doesn't call update_io_ticks() unlike
blk_account_io_start(), as there is no reason for that.
[hch: rebased]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Also rename blk_account_io_merge() into blk_account_io_merge_request() to
distinguish it from merging request and bio.
[hch: rebased]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
percpu variables have a perfectly fine working stub implementation
for UP kernels, so use that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
All callers are in blk-core.c, so move update_io_ticks over.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove these now unused functions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch zram to use the nicer bio accounting helpers, and as part of that
ensure each bio is counted as a single I/O request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch dm to use the nicer bio accounting helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch dm to use the nicer bio accounting helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch bcache to use the nicer bio accounting helpers, and call the
routines where we also sample the start time to give coherent accounting
results.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch rsxx to use the nicer bio accounting helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch rsxx to use the nicer bio accounting helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch drbd to use the nicer bio accounting helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add two new helpers to simplify I/O accounting for bio based drivers.
Currently these drivers use the generic_start_io_acct and
generic_end_io_acct helpers which have very cumbersome calling
conventions, don't actually return the time they started accounting,
and try to deal with accounting for partitions, which can't happen
for bio based drivers. The new helpers will be used to subsequently
replace uses of the old helpers.
The main API is the bio based wrappes in blkdev.h, but for zram
which wants to account rw_page based I/O lower level routines are
provided as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The argument isn't used by any caller, and drivers don't fill out
bi_sector for flush requests either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The flush_queue_delayed was introdued to hold queue if flush is
running for non-queueable flush drive by commit 3ac0cc4508
("hold queue if flush is running for non-queueable flush drive"),
but the non mq parts of the flush code had been removed by
commit 7e992f847a ("block: remove non mq parts from the flush code"),
as well as removing the usage of the flush_queue_delayed flag.
Thus remove the unused flush_queue_delayed flag.
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch suppresses an uninteresting KMSAN complaint without affecting
performance of the null_blk driver if CONFIG_KMSAN is disabled.
Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Alexander Potapenko <glider@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since it is nontrivial that nth_page() does not have to be used for a
bio_vec, document this.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
CC: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This change makes it possible to pass 'const struct bio *' arguments to
these functions.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
part_inc_in_flight and part_dec_in_flight only have one caller each, and
those callers are purely for bio based drivers. Merge each function into
the only caller, and remove the superflous blk-mq checks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
part_inc_in_flight and part_dec_in_flight are no-ops for blk-mq queues,
so remove the calls in purely blk-mq callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Don't bother to call part_in_flight / part_in_flight_rw on blk-mq
devices, just call the blk-mq versions directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_make_request currently needs to grab an q_usage_counter
reference when allocating a request. This is because the block layer
grabs one before calling blk_mq_make_request, but also releases it as
soon as blk_mq_make_request returns. Remove the blk_queue_exit call
after blk_mq_make_request returns, and instead let it consume the
reference. This works perfectly fine for the block layer caller, just
device mapper needs an extra reference as the old problem still
persists there. Open code blk_queue_enter_live in device mapper,
as there should be no other callers and this allows better documenting
why we do a non-try get.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No need for two queue references.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No need for two queue references.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the blk_queue_enter_live calls into the callers, where they can
successively be cleaned up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently informational messages within block trace do not have PID
information of the process reporting the message included. With BFQ it
is sometimes useful to have the information and there's no good reason
to omit the information from the trace. So just fill in pid information
when generating note message.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Blk-crypto delegates crypto operations to inline encryption hardware
when available. The separately configurable blk-crypto-fallback contains
a software fallback to the kernel crypto API - when enabled, blk-crypto
will use this fallback for en/decryption when inline encryption hardware
is not available.
This lets upper layers not have to worry about whether or not the
underlying device has support for inline encryption before deciding to
specify an encryption context for a bio. It also allows for testing
without actual inline encryption hardware - in particular, it makes it
possible to test the inline encryption code in ext4 and f2fs simply by
running xfstests with the inlinecrypt mount option, which in turn allows
for things like the regular upstream regression testing of ext4 to cover
the inline encryption code paths.
For more details, refer to Documentation/block/inline-encryption.rst.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Whenever a device supports blk-integrity, make the kernel pretend that
the device doesn't support inline encryption (essentially by setting the
keyslot manager in the request queue to NULL).
There's no hardware currently that supports both integrity and inline
encryption. However, it seems possible that there will be such hardware
in the near future (like the NVMe key per I/O support that might support
both inline encryption and PI).
But properly integrating both features is not trivial, and without
real hardware that implements both, it is difficult to tell if it will
be done correctly by the majority of hardware that support both.
So it seems best not to support both features together right now, and
to decide what to do at probe time.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We must have some way of letting a storage device driver know what
encryption context it should use for en/decrypting a request. However,
it's the upper layers (like the filesystem/fscrypt) that know about and
manages encryption contexts. As such, when the upper layer submits a bio
to the block layer, and this bio eventually reaches a device driver with
support for inline encryption, the device driver will need to have been
told the encryption context for that bio.
We want to communicate the encryption context from the upper layer to the
storage device along with the bio, when the bio is submitted to the block
layer. To do this, we add a struct bio_crypt_ctx to struct bio, which can
represent an encryption context (note that we can't use the bi_private
field in struct bio to do this because that field does not function to pass
information across layers in the storage stack). We also introduce various
functions to manipulate the bio_crypt_ctx and make the bio/request merging
logic aware of the bio_crypt_ctx.
We also make changes to blk-mq to make it handle bios with encryption
contexts. blk-mq can merge many bios into the same request. These bios need
to have contiguous data unit numbers (the necessary changes to blk-merge
are also made to ensure this) - as such, it suffices to keep the data unit
number of just the first bio, since that's all a storage driver needs to
infer the data unit number to use for each data block in each bio in a
request. blk-mq keeps track of the encryption context to be used for all
the bios in a request with the request's rq_crypt_ctx. When the first bio
is added to an empty request, blk-mq will program the encryption context
of that bio into the request_queue's keyslot manager, and store the
returned keyslot in the request's rq_crypt_ctx. All the functions to
operate on encryption contexts are in blk-crypto.c.
Upper layers only need to call bio_crypt_set_ctx with the encryption key,
algorithm and data_unit_num; they don't have to worry about getting a
keyslot for each encryption context, as blk-mq/blk-crypto handles that.
Blk-crypto also makes it possible for request-based layered devices like
dm-rq to make use of inline encryption hardware by cloning the
rq_crypt_ctx and programming a keyslot in the new request_queue when
necessary.
Note that any user of the block layer can submit bios with an
encryption context, such as filesystems, device-mapper targets, etc.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Inline Encryption hardware allows software to specify an encryption context
(an encryption key, crypto algorithm, data unit num, data unit size) along
with a data transfer request to a storage device, and the inline encryption
hardware will use that context to en/decrypt the data. The inline
encryption hardware is part of the storage device, and it conceptually sits
on the data path between system memory and the storage device.
Inline Encryption hardware implementations often function around the
concept of "keyslots". These implementations often have a limited number
of "keyslots", each of which can hold a key (we say that a key can be
"programmed" into a keyslot). Requests made to the storage device may have
a keyslot and a data unit number associated with them, and the inline
encryption hardware will en/decrypt the data in the requests using the key
programmed into that associated keyslot and the data unit number specified
with the request.
As keyslots are limited, and programming keys may be expensive in many
implementations, and multiple requests may use exactly the same encryption
contexts, we introduce a Keyslot Manager to efficiently manage keyslots.
We also introduce a blk_crypto_key, which will represent the key that's
programmed into keyslots managed by keyslot managers. The keyslot manager
also functions as the interface that upper layers will use to program keys
into inline encryption hardware. For more information on the Keyslot
Manager, refer to documentation found in block/keyslot-manager.c and
linux/keyslot-manager.h.
Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The blk-crypto framework adds support for inline encryption. There are
numerous changes throughout the storage stack. This patch documents the
main design choices in the block layer, the API presented to users of
the block layer (like fscrypt or layered devices) and the API presented
to drivers for adding support for inline encryption.
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When the QoS targets are met and nothing is being throttled, there's
no way to tell how saturated the underlying device is - it could be
almost entirely idle, at the cusp of saturation or anywhere inbetween.
Given that there's no information, it's best to keep vrate as-is in
this state. Before 7cd806a9a9 ("iocost: improve nr_lagging
handling"), this was the case - if the device isn't missing QoS
targets and nothing is being throttled, busy_level was reset to zero.
While fixing nr_lagging handling, 7cd806a9a9 ("iocost: improve
nr_lagging handling") broke this. Now, while the device is hitting
QoS targets and nothing is being throttled, vrate keeps getting
adjusted according to the existing busy_level.
This led to vrate keeping climing till it hits max when there's an IO
issuer with limited request concurrency if the vrate started low.
vrate starts getting adjusted upwards until the issuer can issue IOs
w/o being throttled. From then on, QoS targets keeps getting met and
nothing on the system needs throttling and vrate keeps getting
increased due to the existing busy_level.
This patch makes the following changes to the busy_level logic.
* Reset busy_level if nr_shortages is zero to avoid the above
scenario.
* Make non-zero nr_lagging block lowering nr_level but still clear
positive busy_level if there's clear non-saturation signal - QoS
targets are met and nr_shortages is non-zero. nr_lagging's role is
preventing adjusting vrate upwards while there are long-running
commands and it shouldn't keep busy_level positive while there's
clear non-saturation signal.
* Restructure code for clarity and add comments.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Andy Newell <newella@fb.com>
Fixes: 7cd806a9a9 ("iocost: improve nr_lagging handling")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_io_schedule() isn't called from performance sensitive code path, and
it is easier to maintain by exporting it as symbol.
Also blk_io_schedule() is only called by CONFIG_BLOCK code, so it is safe
to do this way. Meantime fixes build failure when CONFIG_BLOCK is off.
Cc: Christoph Hellwig <hch@infradead.org>
Fixes: e6249cdd46 ("block: add blk_io_schedule() for avoiding task hung in sync dio")
Reported-by: Satya Tangirala <satyat@google.com>
Tested-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Synchronous direct I/O to a sequential write only zone can be issued using
the new REQ_OP_ZONE_APPEND request operation. As dispatching multiple
BIOs can potentially result in reordering, we cannot support asynchronous
IO via this interface.
We also can only dispatch up to queue_max_zone_append_sectors() via the
new zone-append method and have to return a short write back to user-space
in case an IO larger than queue_max_zone_append_sectors() has been issued.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Export bio_release_pages and bio_iov_iter_get_pages, so they can be used
from modular code.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Support REQ_OP_ZONE_APPEND requests for null_blk devices with zoned
mode enabled. Use the internally tracked zone write pointer position
as the actual write position and return it using the command request
__sector field in the case of an mq device and using the command BIO
sector in the case of a BIO device.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Emulate ZONE_APPEND for SCSI disks using a regular WRITE(16) command
with a start LBA set to the target zone write pointer position.
In order to always know the write pointer position of a sequential write
zone, the write pointer of all zones is tracked using an array of 32bits
zone write pointer offset attached to the scsi disk structure. Each
entry of the array indicate a zone write pointer position relative to
the zone start sector. The write pointer offsets are maintained in sync
with the device as follows:
1) the write pointer offset of a zone is reset to 0 when a
REQ_OP_ZONE_RESET command completes.
2) the write pointer offset of a zone is set to the zone size when a
REQ_OP_ZONE_FINISH command completes.
3) the write pointer offset of a zone is incremented by the number of
512B sectors written when a write, write same or a zone append
command completes.
4) the write pointer offset of all zones is reset to 0 when a
REQ_OP_ZONE_RESET_ALL command completes.
Since the block layer does not write lock zones for zone append
commands, to ensure a sequential ordering of the regular write commands
used for the emulation, the target zone of a zone append command is
locked when the function sd_zbc_prepare_zone_append() is called from
sd_setup_read_write_cmnd(). If the zone write lock cannot be obtained
(e.g. a zone append is in-flight or a regular write has already locked
the zone), the zone append command dispatching is delayed by returning
BLK_STS_ZONE_RESOURCE.
To avoid the need for write locking all zones for REQ_OP_ZONE_RESET_ALL
requests, use a spinlock to protect accesses and modifications of the
zone write pointer offsets. This spinlock is initialized from sd_probe()
using the new function sd_zbc_init().
Co-developed-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
