Ming Lei [Sat, 16 Jul 2022 09:53:44 +0000 (17:53 +0800)]
ublk_drv: fix build warning with -Wmaybe-uninitialized and one sparse warning
After applying -Wmaybe-uninitialized manually, two build warnings are
triggered:
drivers/block/ublk_drv.c:940:11: warning: ‘io’ may be used uninitialized [-Wmaybe-uninitialized]
940 | io->flags &= ~UBLK_IO_FLAG_ACTIVE;
drivers/block/ublk_drv.c: In function ‘ublk_ctrl_uring_cmd’:
drivers/block/ublk_drv.c:1531:9: warning: ‘ret’ may be used uninitialized [-Wmaybe-uninitialized]
Fix the 1st one by removing 'io->flags &= ~UBLK_IO_FLAG_ACTIVE;' which
isn't needed since the function always return successfully after setting
this flag.
Fix the 2nd one by always initializing 'ret'.
Also fix another sparse warning of 'sparse: sparse: incorrect type in return
expression' by changing return type of ublk_setup_iod().
blktrace: Fix the blk_fill_rwbs() kernel-doc header
Reflect recent changes in the blk_fill_rwbs() kernel-doc header.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Christoph Hellwig <hch@lst.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 0cf958806000 ("blktrace: Use the new blk_opf_t type") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220715184735.2326034-3-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/buffer: Fix the ll_rw_block() kernel-doc header
Bring the ll_rw_block() kernel-doc header again in sync with the
function prototype.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jan Kara <jack@suse.cz> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 05014528d766 ("fs/buffer: Combine two submit_bh() and ll_rw_block() arguments") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220715184735.2326034-2-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for the
combination of a request operation with request flags.
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the first two
hib_submit_io() arguments into a single argument.
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the last two
o2hb_setup_one_bio() arguments into a single argument.
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-61-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/nilfs2: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the 'mode' and
'mode_flags' arguments of nilfs_btnode_submit_block into a single
argument 'opf'.
Improve static type checking by using enum req_op for request operations.
Rename an 'rw' argument into 'op' since that name is typically used for
request operations. This patch does not change any functionality. Note:
REQ_OP_READ = READ = 0 and REQ_OP_WRITE = WRITE = 1.
Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-58-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/jbd2: Fix the documentation of the jbd2_write_superblock() callers
Commit 60445db98619 ("fs: have submit_bh users pass in op and flags
separately") renamed the jbd2_write_superblock() 'write_op' argument into
'write_flags'. Propagate this change to the jbd2_write_superblock()
callers. Additionally, change the type of 'write_flags' into blk_opf_t.
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
the combination of a request operation and request flags.
fs/hfsplus: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the last two
hfsplus_submit_bio() arguments into a single argument.
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the first two
gfs2_submit_bhs() arguments into a single argument.
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Reduce the size of struct dio by combining the 'op' and 'op_flags' into
the new 'opf' member. Use the new blk_opf_t type to improve static type
checking. This patch does not change any functionality.
Reviewed-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-49-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/buffer: Combine two submit_bh() and ll_rw_block() arguments
Both submit_bh() and ll_rw_block() accept a request operation type and
request flags as their first two arguments. Micro-optimize these two
functions by combining these first two arguments into a single argument.
This patch does not change the behavior of any of the modified code.
Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jan Kara <jack@suse.cz> Acked-by: Song Liu <song@kernel.org> (for the md changes) Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-48-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the new blk_opf_t type for block layer
request flags. Change WRITE into REQ_OP_WRITE. This patch does not change
any functionality since REQ_OP_WRITE == WRITE == 1.
Reviewed-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-47-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the new blk_opf_t type for block
layer request flags.
Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Stefan Roesch <shr@fb.com> Cc: NeilBrown <neilb@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-46-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use the new blk_opf_t type for arguments and variables that represent
request flags. Use the !! operator in scsi_noretry_cmd() to convert the
blk_opf_t type into a boolean. This patch does not change any functionality.
Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: John Garry <john.garry@huawei.com> Cc: Mike Christie <michael.christie@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-42-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
scsi/core: Change the return type of scsi_noretry_cmd() into bool
This patch prepares for introducing the new blk_opf_t type in the SCSI core.
Since the value returned by scsi_noretry_cmd() is only used in boolean
expressions, this patch does not change any functionality.
Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: John Garry <john.garry@huawei.com> Cc: Mike Christie <michael.christie@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-41-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the new blk_opf_t type for the
combination of a request operation and its flags.
Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: John Garry <john.garry@huawei.com> Cc: Mike Christie <michael.christie@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-40-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the new blk_opf_t type for variables
that represent a request operation combined with request flags. Rename
those variables from 'op' into 'opf'.
nvme/host: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Cc: Christoph Hellwig <hch@lst.de> Cc: Keith Busch <kbusch@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-38-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Use the enum req_op type for request operations instead of unsigned int.
This patch fixes a sparse warning that has been introduced by making
enum req_op __bitwise.
dm/dm-integrity: Combine request operation and flags
Combine the request operation type and request flags into a single
argument. Improve static type checking by using the enum req_op type for
variables that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Eric Biggers <ebiggers@google.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-27-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using type 'enum req_op' instead of 'int'.
Make the role of the 'rw' arguments more clear by renaming these into
'op' (operation). This patch does not change any functionality since
REQ_OP_READ = READ = 0 and REQ_OP_WRITE = WRITE = 1.
Improve kernel code uniformity by combining the request operation type and
flags into a single variable. Change 'int rw' into 'enum req_op op' because
the name 'op' is what is used in the block layer to hold a request type.
Use the blk_opf_t and enum req_op types where appropriate to improve static
type checking.
The member name 'rw' suggests that this member either has the value 'READ'
or 'WRITE' and no other values. Since that member also can have the value
REQ_OP_WRITE_ZEROES, rename 'rw' into 'op'. This patch does not change any
functionality since REQ_OP_READ = READ = 0 and REQ_OP_WRITE = WRITE = 1.
Combine the bi_op and bi_op_flags into the bi_opf member. Use the new
blk_opf_t type to improve static type checking. This patch does not
change any functionality.
Since the type of request.cmd_flags has been changed from u32 into
blk_opf_t, use the __force keyword when casting to an integer type to
prevent that sparse warns about this cast.
block/drbd: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-14-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve static type checking by using the new blk_opf_t type for a function
argument that represents a combination of a request operation and request
flags. Rename that argument from 'op' into 'opf' to make its role more
clear.
Cc: Christoph Hellwig <hch@lst.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-12-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Trace the remapped operation and its flags instead of only the data
direction of remapped operations. This issue was detected by analyzing
the warnings reported by sparse related to the new blk_opf_t type.
Reviewed-by: Jun'ichi Nomura <junichi.nomura@nec.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mike Christie <michael.christie@oracle.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Fixes: 9dbf0eab28ec ("blktrace: use op accessors") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-11-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use the new blk_opf_t type for arguments that represent a bitwise
combination of a request operation and request flags. Rename those
arguments from 'op' into 'opf'.
Use the new blk_opf_t type for an argument that represents a bitwise
combination of a request operation and request flags. Rename that
argument from 'op' into 'opf'.
Use the new blk_opf_t type for arguments and variables that represent
request flags or a bitwise combination of a request operation and
request flags. Rename those variables from 'op' into 'opf'.
Use the new blk_opf_t type for arguments and variables that represent
request flags or a bitwise combination of a request operation and
request flags. Rename the function arguments and also a structure member
that hold a request operation and flags from 'rw' into 'opf'.
This patch does not change any functionality.
Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-7-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Introduce the type blk_opf_t for the request operation and flags (REQ_OP_*
and REQ_*). This type will be used to improve documentation of the block
layer code and also to allow sparse to verify whether request flags are used
correctly.
Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-6-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: Change the type of req_op() and bio_op() into enum req_op
Improve static type checking by changing the type of the value returned by
req_op() and bio_op() from unsigned int into enum req_op. Insert
'default: break;' in switch statements on the enum req_op type to prevent
that the compiler warns about these switch statements.
Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Tim Waugh <tim@cyberelk.net> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-5-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: Change the type of the last .rw_page() argument
All .rw_page() callers pass an enum req_op value as last argument. Make
this explicit by changing the type of the last argument into enum req_op.
See also commit 874a19a45687 ("block: make bdev_ops->rw_page() take a
REQ_OP instead of bool").
Cc: Tejun Heo <tj@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-4-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Change the type of the arguments that are used to pass a REQ_OP_* value
from int or unsigned int into enum req_op to improve static type
checking.
Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-3-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
The type name enum req_opf is misleading since it suggests that values of
this type include both an operation type and flags. Since values of this
type represent an operation only, change the type name into enum req_op.
Convert the enum req_op documentation into kernel-doc format. Move a few
definitions such that the enum req_op documentation occurs just above
the enum req_op definition.
The name "req_opf" was introduced by commit 86207eb9fda1 ("block: better op
and flags encoding").
Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-2-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
mmp_bdevname is currently both initialized nested inside the kthread_run
call in ext4_multi_mount_protect and in the kmmpd thread started by it.
Lift the initiaization out of the kthread_run call in
ext4_multi_mount_protect, move the BUILD_BUG_ON next to it and remove
the duplicate assignment inside of kmmpd.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220713055317.1888500-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
rnbd-srv: remove the name field from struct rnbd_dev
Just print the block device name directly using the %pg format specifier.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jack Wang <jinpu.wang@ionos.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220713055317.1888500-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Thu, 14 Jul 2022 10:32:01 +0000 (18:32 +0800)]
ublk_drv: fix request queue leak
Call blk_cleanup_queue() in release code path for fixing request
queue leak.
Also for-5.20/block has cleaned up blk_cleanup_queue(), which is
basically merged to del_gendisk() if blk_mq_alloc_disk() is used
for allocating disk and queue.
However, ublk may not add disk in case of starting device failure, then
del_gendisk() won't be called when removing ublk device, so blk_mq_exit_queue
will not be callsed, and it can be bit hard to deal with this kind of
merge conflict.
Turns out ublk's queue/disk use model is very similar with scsi, so switch
to scsi's model by allocating disk and queue independently, then it can be
quite easy to handle v5.20 merge conflict by replacing blk_cleanup_queue
with blk_mq_destroy_queue.
Reported-by: Jens Axboe <axboe@kernel.dk> Fixes: 44155c24ce3c ("ublk_drv: add io_uring based userspace block driver") Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220714103201.131648-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Wed, 13 Jul 2022 14:07:11 +0000 (22:07 +0800)]
ublk_drv: support to complete io command via task_work_add
Use task_work_add if it is available, since task_work_add can bring
up better performance, especially batching signaling ->ubq_daemon can
be done.
It is observed that task_work_add() can boost iops by +4% on random
4k io test. Also except for completing io command, all other code
paths are same with completing io command via
io_uring_cmd_complete_in_task.
Meantime add one flag of UBLK_F_URING_CMD_COMP_IN_TASK for comparing
the mode easily.
Ming Lei [Wed, 13 Jul 2022 14:07:10 +0000 (22:07 +0800)]
ublk_drv: add io_uring based userspace block driver
This is the driver part of userspace block driver(ublk driver), the other
part is userspace daemon part(ublksrv)[1].
The two parts communicate by io_uring's IORING_OP_URING_CMD with one
shared cmd buffer for storing io command, and the buffer is read only for
ublksrv, each io command is indexed by io request tag directly, and is
written by ublk driver.
For example, when one READ io request is submitted to ublk block driver,
ublk driver stores the io command into cmd buffer first, then completes
one IORING_OP_URING_CMD for notifying ublksrv, and the URING_CMD is issued
to ublk driver beforehand by ublksrv for getting notification of any new
io request, and each URING_CMD is associated with one io request by tag.
After ublksrv gets the io command, it translates and handles the ublk io
request, such as, for the ublk-loop target, ublksrv translates the request
into same request on another file or disk, like the kernel loop block
driver. In ublksrv's implementation, the io is still handled by io_uring,
and share same ring with IORING_OP_URING_CMD command. When the target io
request is done, the same IORING_OP_URING_CMD is issued to ublk driver for
both committing io request result and getting future notification of new
io request.
Another thing done by ublk driver is to copy data between kernel io
request and ublksrv's io buffer:
1) before ubsrv handles WRITE request, copy the request's data into
ublksrv's userspace io buffer, so that ublksrv can handle the write
request
2) after ubsrv handles READ request, copy ublksrv's userspace io buffer
into this READ request, then ublk driver can complete the READ request
Zero copy may be switched if mm is ready to support it.
ublk driver doesn't handle any logic of the specific user space driver,
so it is small/simple enough.
Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old
in blkcg_unuse_delay, blkcg_set_delay and blkcg_clear_delay and
atomic64_try_cmpxchg in blkcg_scale_delay. x86 CMPXCHG instruction
returns success in ZF flag, so this change saves a compare after cmpxchg
(and related move instruction in front of cmpxchg).
Also, atomic_try_cmpxchg implicitly assigns old *ptr value to "old" when
cmpxchg fails, enabling further code simplifications.
Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old
in check_scale_change and atomic64_try_cmpxchg in blkcg_iolatency_done_bio.
x86 CMPXCHG instruction returns success in ZF flag, so this change saves a
compare after cmpxchg (and related move instruction in front of cmpxchg).
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
update_io_ticks. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related
move instruction in front of cmpxchg).
block/rq_qos: Use atomic_try_cmpxchg in atomic_inc_below
Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old in
atomic_inc_below. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move instruction
in front of cmpxchg).
Also, atomic_try_cmpxchg implicitly assigns old *ptr value to "old" when
cmpxchg fails, enabling further code simplifications.
Ming Lei [Mon, 11 Jul 2022 09:08:08 +0000 (17:08 +0800)]
blk-mq: don't create hctx debugfs dir until q->debugfs_dir is created
blk_mq_debugfs_register_hctx() can be called by blk_mq_update_nr_hw_queues
when gendisk isn't added yet, such as nvme tcp.
Fixes the warning of 'debugfs: Directory 'hctx0' with parent '/' already present!'
which can be observed reliably when running blktests nvme/005.
Fixes: 08a5d58dd943 ("blk-mq: no need to check return value of debugfs_create functions") Reported-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220711090808.259682-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the zone related fields that are currently stored in
struct request_queue to struct gendisk as these are part of the highlevel
block layer API and are only used for non-passthrough I/O that requires
the gendisk.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220706070350.1703384-17-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
nvmet:: use bdev based helpers in nvmet_bdev_zone_mgmt_emulate_all
Use the bdev based helpers instead of the queue based ones to clean up
the code a bit and prepare for storing all zone related fields in
struct gendisk.
block: use bdev based helpers in blkdev_zone_mgmt{,all}
Use the bdev based helpers instead of the queue based ones to clean up
the code a bit and prepare for storing all zone related fields in
struct gendisk.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220706070350.1703384-13-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass a block_device instead of a request_queue as that is what most
callers have at hand.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Link: https://lore.kernel.org/r/20220706070350.1703384-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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