Pass 'ublk_thread *' to more common helpers, then we can avoid to store
this reference into 'struct ublk_io'.
Prepare for supporting to handle IO via different task context.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250713143415.2857561-14-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
'struct thread' is task local structure, and the related code will become
more readable if we pass it via parameter.
Meantime pass 'ublk_thread *' to ublk_io_alloc_sqes(), and this way is
natural since we use per-thread io_uring for handling IO.
More importantly it helps much for removing the current ubq_daemon or
per-io-task limit.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250713143415.2857561-13-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The `tag` parameter can be figured out from cqe->user_data, and that is
also the only way to get the info, so remove `tag` parameter, and
let target code retrieve it from cqe->user_data.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250713143415.2857561-12-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add support in kublk for decoupled ublk_queues and ublk server threads.
kublk now has two modes of operation:
- (preexisting mode) threads and queues are paired 1:1, and each thread
services all the I/Os of one queue
- (new mode) thread and queue counts are independently configurable.
threads service I/Os in a way that balances load across threads even
if load is not balanced over queues.
The default is the preexisting mode. The new mode is activated by
passing the --per_io_tasks flag.
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250529-ublk_task_per_io-v8-6-e9d3b119336a@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We currently have a helper ublk_queue_alloc_sqes which the ublk targets
use to allocate SQEs for their own operations. However, as we move
towards decoupled ublk_queues and ublk server threads, this helper does
not make sense anymore. SQEs are allocated from rings, and we will have
one ring per thread to avoid locking. Change the SQE allocation helper
to ublk_io_alloc_sqes. Currently this still allocates SQEs from the io's
queue's ring, but when we fully decouple threads and queues, it will
allocate from the io's thread's ring instead.
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250529-ublk_task_per_io-v8-3-e9d3b119336a@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, when we process CQEs, we know which ublk_queue we are working
on because we know which ring we are working on, and ublk_queues and
rings are in 1:1 correspondence. However, as we decouple ublk_queues
from ublk server threads, ublk_queues and rings will no longer be in 1:1
correspondence - each ublk server thread will have a ring, and each
thread may issue commands against more than one ublk_queue. So in order
to know which ublk_queue a CQE refers to, plumb that information in the
associated SQE's user_data.
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250529-ublk_task_per_io-v8-2-e9d3b119336a@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add test for covering UBLK_AUTO_BUF_REG_FALLBACK:
- pass '--auto_zc_fallback' to null target, which requires both F_AUTO_BUF_REG
and F_SUPPORT_ZERO_COPY for handling UBLK_AUTO_BUF_REG_FALLBACK
- add ->buf_index() method for returning invalid buffer index to trigger
UBLK_AUTO_BUF_REG_FALLBACK
- add generic_09 for running the test
- add --auto_zc_fallback test in stress_03/stress_04/stress_05
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-7-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Enable UBLK_F_AUTO_BUF_REG support for ublk utility by argument `--auto_zc`,
meantime support this feature in null, loop and stripe target code.
Add function test generic_08 for covering basic UBLK_F_AUTO_BUF_REG feature.
Also cover UBLK_F_AUTO_BUF_REG in stress_03, stress_04 and stress_05 test too.
'fio/t/io_uring -p0 /dev/ublkb0' shows that F_AUTO_BUF_REG can improve
IOPS by 50% compared with F_SUPPORT_ZERO_COPY in my test VM.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-6-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
- pass 'truct dev_ctx *ctx' to target init function
- add 'private_data' to 'struct ublk_dev' for storing target specific data
- add 'private_data' to 'struct ublk_io' for storing per-IO data
- add 'tgt_ios' to 'struct ublk_io' for counting how many io_uring ios
for handling the current io command
- add helper ublk_get_io() for supporting stripe target
- add two helpers for simplifying target io handling
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250322093218.431419-6-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move two functions for initializing & de-initializing backing file
into common.c.
Also move one common helper into kublk.h.
Prepare for supporting ublk-stripe.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250322093218.431419-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Unify the sqe allocator helper, and we will use it for supporting
more cases, such as ublk stripe, in which variable sqe allocation
is required.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250322093218.431419-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Firstly ublk char device node may not be created by udev yet, so wait
a while until it can be opened or timeout.
Secondly delete created ublk device in case of start failure, otherwise
the device becomes zombie.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250321135324.259677-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For loop target, write cache isn't enabled, and each write isn't be
marked as DSYNC too.
Fix it by enabling write cache, meantime fix FLUSH implementation
by not taking LBA range into account, and there isn't such info
for FLUSH command.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250321004758.152572-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Enable zero copy on file backed target, meantime add one fio test for
covering write verify, another test for mkfs/mount/umount.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250228161919.2869102-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add file backed ublk target code, meantime add one fio test for
covering write verify, another test for mkfs/mount/umount.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250228161919.2869102-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
