Add two variants of helper functions that calculate the correct number
of queues to use. Two variants are needed because some drivers base
their maximum number of queues on the possible CPU mask, while others
use the online CPU mask.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20250617-isolcpus-queue-counters-v1-2-13923686b54b@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove the q argument from blk_rq_map_kern and the internal helpers
called by it as the queue can trivially be derived from the request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250507120451.4000627-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Both adding/deleting disk code are reader of `nr_hw_queues`, so we can't
allow them in-progress when updating nr_hw_queues, kernel panic and
kasan has been reported in [1].
Prevent adding/deleting disk during updating nr_hw_queues by adding
rw_semaphore to tagset, write lock is grabbed in blk_mq_update_nr_hw_queues(),
and read lock is acquired when adding/deleting disk.
Also mark GFP_NOIO allocation scope for adding/deleting disk because
blk_mq_update_nr_hw_queues() is part of some driver's error handler.
This way avoids lot of trouble.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Suggested-by: Nilay Shroff <nilay@linux.ibm.com>
Reported-by: Nilay Shroff <nilay@linux.ibm.com>
Closes: https://lore.kernel.org/linux-block/a5896cdb-a59a-4a37-9f99-20522f5d2987@linux.ibm.com/
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250505141805.2751237-9-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
request_queue param is no longer used by blk_rq_map_sg and
__blk_rq_map_sg. Remove it.
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250313035322.243239-1-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 1f47ed294a ("block: cleanup and fix batch completion adding
conditions") modified the evaluation criteria for the third argument,
'ioerror', in the blk_mq_add_to_batch() function. Initially, the
function had checked if 'ioerror' equals zero. Following the commit, it
started checking for negative error values, with the presumption that
such values, for instance -EIO, would be passed in.
However, blk_mq_add_to_batch() callers do not pass negative error
values. Instead, they pass status codes defined in various ways:
- NVMe PCI and Apple drivers pass NVMe status code
- virtio_blk driver passes the virtblk request header status byte
- null_blk driver passes blk_status_t
These codes are either zero or positive, therefore the revised check
fails to function as intended. Specifically, with the NVMe PCI driver,
this modification led to the failure of the blktests test case nvme/039.
In this test scenario, errors are artificially injected to the NVMe
driver, resulting in positive NVMe status codes passed to
blk_mq_add_to_batch(), which unexpectedly processes the failed I/O in a
batch. Hence the failure.
To correct the ioerror check within blk_mq_add_to_batch(), make all
callers to uniformly pass the argument as boolean. Modify the callers to
check their specific status codes and pass the boolean value 'is_error'.
Also describe the arguments of blK_mq_add_to_batch as kerneldoc.
Fixes: 1f47ed294a ("block: cleanup and fix batch completion adding conditions")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250311104359.1767728-3-shinichiro.kawasaki@wdc.com
[axboe: fold in documentation update]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 5f89154e8e ("block: Use enum to define RQF_x bit
indexes") converted the RQF flags to an anonymous enum, which was
a beneficial change. This patch goes one step further by naming the enum
as "rqf_flags".
This naming enables exporting these flags to BPF clients, eliminating
the need to duplicate these flags in BPF code. Instead, BPF clients can
now access the same kernel-side values through CO:RE (Compile Once, Run
Everywhere), as shown in this example:
rqf_stats = bpf_core_enum_value(enum rqf_flags, __RQF_STATS)
Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20250306-rqf_flags-v1-1-bbd64918b406@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The conditions for whether or not a request is allowed adding to a
completion batch are a bit hard to read, and they also have a few
issues. One is that ioerror may indeed be a random value on passthrough,
and it's being checked unconditionally of whether or not the given
request is a passthrough request or not.
Rewrite the conditions to be separate for easier reading, and only check
ioerror for non-passthrough requests. This fixes an issue with bio
unmapping on passthrough, where it fails getting added to a batch. This
both leads to suboptimal performance, and may trigger a potential
schedule-under-atomic condition for polled passthrough IO.
Fixes: f794f3351f ("block: add support for blk_mq_end_request_batch()")
Link: https://lore.kernel.org/r/20575f0a-656e-4bb3-9d82-dec6c7e3a35c@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When block drivers or the core block code perform allocations with a
frozen queue, this could try to recurse into the block device to
reclaim memory and deadlock. Thus all allocations done by a process
that froze a queue need to be done without __GFP_IO and __GFP_FS.
Instead of tying to track all of them down, force a noio scope as
part of freezing the queue.
Note that nvme is a bit of a mess here due to the non-owner freezes,
and they will be addressed separately.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250131120352.1315351-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use a plain BLK_MQ_F_* flag to select the round robin tag selection
instead of overlaying an enum with just two possible values into the
flags space.
Doing so allows adding a BLK_MQ_F_MAX sentinel for simplified overflow
checking in the messy debugfs helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250106083531.799976-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only queues that really can't support a scheduler are those that
do not have a gendisk associated with them, and thus can't be used for
non-passthrough commands. In addition to those null_blk can optionally
set the flag, which is a bad odd. Replace the null_blk usage with
BLK_MQ_F_NO_SCHED_BY_DEFAULT to keep the expected semantics and then
remove BLK_MQ_F_NO_SCHED as the non-disk queues never call into
elevator_init_mq or blk_register_queue which adds the sysfs attributes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250106083531.799976-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is not real point in a helper just to assign three values to four
fields, especially when the surrounding code is working on the
neighbor fields directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20250103073417.459715-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
BLK_MQ_F_SHOULD_MERGE is set for all tag_sets except those that purely
process passthrough commands (bsg-lib, ufs tmf, various nvme admin
queues) and thus don't even check the flag. Remove it to simplify the
driver interface.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241219060214.1928848-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_pci_map_queues and blk_mq_virtio_map_queues will create a CPU to
hardware queue mapping based on affinity information. These two function
share common code and only differ on how the affinity information is
retrieved. Also, those functions are located in the block subsystem
where it doesn't really fit in. They are virtio and pci subsystem
specific.
Thus introduce provide a generic mapping function which uses the
irq_get_affinity callback from bus_type.
Originally idea from Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Link: https://lore.kernel.org/r/20241202-refactor-blk-affinity-helpers-v6-4-27211e9c2cd5@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
LIFO ordering for batched completions is a bit unexpected and also
defeats some merging optimizations in e.g. the XFS buffered write
code. Now that we can easily add the request to the tail of the list
do that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241113152050.157179-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Replace the semi-open coded request list helpers with a proper rq_list
type that mirrors the bio_list and has head and tail pointers. Besides
better type safety this actually allows to insert at the tail of the
list, which will be useful soon.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241113152050.157179-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The request ioprio is only initialized from the first attached bio,
so requests without a bio already never set it. Directly use the
bio field instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20241112170050.1612998-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The write_hint is only used for read/write requests, which must have a
bio attached to them. Just use the bio field instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20241112170050.1612998-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add non_owner variant of start_freeze/unfreeze queue APIs, so that the
caller knows that what they are doing, and we can skip lockdep support
for non_owner variant in per-call level.
Prepare for supporting lockdep for freezing/unfreezing queue.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241025003722.3630252-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Simply checking the rq_flags is enough to determine if accounting is
being done for this request.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Always defining the field will make using it easier and less error prone
in future patches.
There shouldn't be any downside to this: the field fits in what would
otherwise be a 2-byte hole, so we're not saving space by conditionally
leaving it out.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240913182854.2445457-2-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a BUILD_BUG_ON() call to ensure that we are not missing entries in
rqf_name[].
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-16-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Similar to what we do for enum req_flag_bits, divide the definition of
RQF_x flags into an enum to declare the bits and an actual flag.
Tweak some comments to not spill onto new lines.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-14-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make BLK_TAG_ALLOC_x an enum and add a "max" entry.
Add a BUILD_BUG_ON() call to ensure that we are not missing entries in
hctx_flag_name[].
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-12-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Refresh values in BLK_MQ_F_x enum, and then re-arrange members in
hctx_flag_name[] to match that enum. Renumber
BLK_MQ_F_ALLOC_POLICY_START_BIT to match the value refresh.
Add a BUILD_BUG_ON() call to ensure that we are not missing entries in
hctx_flag_name[].
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-11-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a build-time assert that we are not missing entries from
hctx_state_name[]. For this, create a separate enum for state flags and add
a "max" entry for BLK_MQ_S_x flags.
The numbering for those enum values is as default, so don't explicitly
number.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-10-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
BLK_MQ_MAX_DEPTH is defined as an enumerated value, but has no real
relation to the other members in its enum, so just use #define to provide
the definition.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240719112912.3830443-7-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Zone write locking is now unused and replaced with zone write plugging.
Remove all code that was implementing zone write locking, that is, the
various helper functions controlling request zone write locking and
the gendisk attached zone bitmaps.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-27-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Zone write plugging implements a per-zone "plug" for write operations
to control the submission and execution order of write operations to
sequential write required zones of a zoned block device. Per-zone
plugging guarantees that at any time there is at most only one write
request per zone being executed. This mechanism is intended to replace
zone write locking which implements a similar per-zone write throttling
at the scheduler level, but is implemented only by mq-deadline.
Unlike zone write locking which operates on requests, zone write
plugging operates on BIOs. A zone write plug is simply a BIO list that
is atomically manipulated using a spinlock and a kblockd submission
work. A write BIO to a zone is "plugged" to delay its execution if a
write BIO for the same zone was already issued, that is, if a write
request for the same zone is being executed. The next plugged BIO is
unplugged and issued once the write request completes.
This mechanism allows to:
- Untangle zone write ordering from block IO schedulers. This allows
removing the restriction on using mq-deadline for writing to zoned
block devices. Any block IO scheduler, including "none" can be used.
- Zone write plugging operates on BIOs instead of requests. Plugged
BIOs waiting for execution thus do not hold scheduling tags and thus
are not preventing other BIOs from executing (reads or writes to
other zones). Depending on the workload, this can significantly
improve the device use (higher queue depth operation) and
performance.
- Both blk-mq (request based) zoned devices and BIO-based zoned devices
(e.g. device mapper) can use zone write plugging. It is mandatory
for the former but optional for the latter. BIO-based drivers can
use zone write plugging to implement write ordering guarantees, or
the drivers can implement their own if needed.
- The code is less invasive in the block layer and is mostly limited to
blk-zoned.c with some small changes in blk-mq.c, blk-merge.c and
bio.c.
Zone write plugging is implemented using struct blk_zone_wplug. This
structure includes a spinlock, a BIO list and a work structure to
handle the submission of plugged BIOs. Zone write plugs structures are
managed using a per-disk hash table.
Plugging of zone write BIOs is done using the function
blk_zone_write_plug_bio() which returns false if a BIO execution does
not need to be delayed and true otherwise. This function is called
from blk_mq_submit_bio() after a BIO is split to avoid large BIOs
spanning multiple zones which would cause mishandling of zone write
plugs. This ichange enables by default zone write plugging for any mq
request-based block device. BIO-based device drivers can also use zone
write plugging by expliclty calling blk_zone_write_plug_bio() in their
->submit_bio method. For such devices, the driver must ensure that a
BIO passed to blk_zone_write_plug_bio() is already split and not
straddling zone boundaries.
Only write and write zeroes BIOs are plugged. Zone write plugging does
not introduce any significant overhead for other operations. A BIO that
is being handled through zone write plugging is flagged using the new
BIO flag BIO_ZONE_WRITE_PLUGGING. A request handling a BIO flagged with
this new flag is flagged with the new RQF_ZONE_WRITE_PLUGGING flag.
The completion of BIOs and requests flagged trigger respectively calls
to the functions blk_zone_write_bio_endio() and
blk_zone_write_complete_request(). The latter function is used to
trigger submission of the next plugged BIO using the zone plug work.
blk_zone_write_bio_endio() does the same for BIO-based devices.
This ensures that at any time, at most one request (blk-mq devices) or
one BIO (BIO-based devices) is being executed for any zone. The
handling of zone write plugs using a per-zone plug spinlock maximizes
parallelism and device usage by allowing multiple zones to be writen
simultaneously without lock contention.
Zone write plugging ignores flush BIOs without data. Hovever, any flush
BIO that has data is always plugged so that the write part of the flush
sequence is serialized with other regular writes.
Given that any BIO handled through zone write plugging will be the only
BIO in flight for the target zone when it is executed, the unplugging
and submission of a BIO will have no chance of successfully merging with
plugged requests or requests in the scheduler. To overcome this
potential performance degradation, blk_mq_submit_bio() calls the
function blk_zone_write_plug_attempt_merge() to try to merge other
plugged BIOs with the one just unplugged and submitted. Successful
merging is signaled using blk_zone_write_plug_bio_merged(), called from
bio_attempt_back_merge(). Furthermore, to avoid recalculating the number
of segments of plugged BIOs to attempt merging, the number of segments
of a plugged BIO is saved using the new struct bio field
__bi_nr_segments. To avoid growing the size of struct bio, this field is
added as a union with the bio_cookie field. This is safe to do as
polling is always disabled for plugged BIOs.
When BIOs are plugged in a zone write plug, the device request queue
usage counter is always incremented. This reference is kept and reused
for blk-mq devices when the plugged BIO is unplugged and submitted
again using submit_bio_noacct_nocheck(). For this case, the unplugged
BIO is already flagged with BIO_ZONE_WRITE_PLUGGING and
blk_mq_submit_bio() proceeds directly to allocating a new request for
the BIO, re-using the usage reference count taken when the BIO was
plugged. This extra reference count is dropped in
blk_zone_write_plug_attempt_merge() for any plugged BIO that is
successfully merged. Given that BIO-based devices will not take this
path, the extra reference is dropped after a plugged BIO is unplugged
and submitted.
Zone write plugs are dynamically allocated and managed using a hash
table (an array of struct hlist_head) with RCU protection.
A zone write plug is allocated when a write BIO is received for the
zone and not freed until the zone is fully written, reset or finished.
To detect when a zone write plug can be freed, the write state of each
zone is tracked using a write pointer offset which corresponds to the
offset of a zone write pointer relative to the zone start. Write
operations always increment this write pointer offset. Zone reset
operations set it to 0 and zone finish operations set it to the zone
size.
If a write error happens, the wp_offset value of a zone write plug may
become incorrect and out of sync with the device managed write pointer.
This is handled using the zone write plug flag BLK_ZONE_WPLUG_ERROR.
The function blk_zone_wplug_handle_error() is called from the new disk
zone write plug work when this flag is set. This function executes a
report zone to update the zone write pointer offset to the current
value as indicated by the device. The disk zone write plug work is
scheduled whenever a BIO flagged with BIO_ZONE_WRITE_PLUGGING completes
with an error or when bio_zone_wplug_prepare_bio() detects an unaligned
write. Once scheduled, the disk zone write plugs work keeps running
until all zone errors are handled.
To match the new data structures used for zoned disks, the function
disk_free_zone_bitmaps() is renamed to the more generic
disk_free_zone_resources(). The function disk_init_zone_resources() is
also introduced to initialize zone write plugs resources when a gendisk
is allocated.
In order to guarantee that the user can simultaneously write up to a
number of zones equal to a device max active zone limit or max open zone
limit, zone write plugs are allocated using a mempool sized to the
maximum of these 2 device limits. For a device that does not have
active and open zone limits, 128 is used as the default mempool size.
If a change to the device active and open zone limits is detected, the
disk mempool is resized when blk_revalidate_disk_zones() is executed.
This commit contains contributions from Christoph Hellwig <hch@lst.de>.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240408014128.205141-8-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass a queue_limits to blk_mq_alloc_disk and apply it if non-NULL. This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass a queue_limits to blk_mq_init_queue and apply it if non-NULL. This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.
Also rename the function to blk_mq_alloc_queue as that is a much better
name for a function that allocates a queue and always pass the queuedata
argument instead of having a separate version for the extra argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Restore support for passing data lifetime information from filesystems to
block drivers. This patch reverts commit b179c98f76 ("block: Remove
request.write_hint") and commit c75e707fe1 ("block: remove the
per-bio/request write hint").
This patch does not modify the size of struct bio because the new
bi_write_hint member fills a hole in struct bio. pahole reports the
following for struct bio on an x86_64 system with this patch applied:
/* size: 112, cachelines: 2, members: 20 */
/* sum members: 110, holes: 1, sum holes: 2 */
/* last cacheline: 48 bytes */
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240202203926.2478590-7-bvanassche@acm.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Nobody uses the debugfs hctx 'run' attribute. Hence remove this
attribute and also the code that updates the corresponding member
variable.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Cc: Gabriel Ryan <gabe@cs.columbia.edu>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240117203609.4122520-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
commit 41fa722239 ("blk-mq: do not include passthrough requests in I/O
accounting")' disables I/O accounting for passthrough requests. Since tools
like 'iostat' do not show anything useful for passthrough I/O, it's
wasteful to do start/end time-stamping. So do away with that.
Avoiding the time-stamping improves the I/O performance by ~7%
Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20231222101707.6921-1-kundan.kumar@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since the previous patch change to only account active requests when
we really allocate the driver tag, the RQF_MQ_INFLIGHT can be removed
and no double account problem.
1. none elevator: flush request will use the first pending request's
driver tag, won't double account.
2. other elevator: flush request will be accounted when allocate driver
tag when issue, and will be unaccounted when it put the driver tag.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230913151616.3164338-3-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-----BEGIN PGP SIGNATURE-----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=p1bd
-----END PGP SIGNATURE-----
Merge tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
"Pretty quiet round for this release. This contains:
- Add support for zoned storage to ublk (Andreas, Ming)
- Series improving performance for drivers that mark themselves as
needing a blocking context for issue (Bart)
- Cleanup the flush logic (Chengming)
- sed opal keyring support (Greg)
- Fixes and improvements to the integrity support (Jinyoung)
- Add some exports for bcachefs that we can hopefully delete again in
the future (Kent)
- deadline throttling fix (Zhiguo)
- Series allowing building the kernel without buffer_head support
(Christoph)
- Sanitize the bio page adding flow (Christoph)
- Write back cache fixes (Christoph)
- MD updates via Song:
- Fix perf regression for raid0 large sequential writes (Jan)
- Fix split bio iostat for raid0 (David)
- Various raid1 fixes (Heinz, Xueshi)
- raid6test build fixes (WANG)
- Deprecate bitmap file support (Christoph)
- Fix deadlock with md sync thread (Yu)
- Refactor md io accounting (Yu)
- Various non-urgent fixes (Li, Yu, Jack)
- Various fixes and cleanups (Arnd, Azeem, Chengming, Damien, Li,
Ming, Nitesh, Ruan, Tejun, Thomas, Xu)"
* tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux: (113 commits)
block: use strscpy() to instead of strncpy()
block: sed-opal: keyring support for SED keys
block: sed-opal: Implement IOC_OPAL_REVERT_LSP
block: sed-opal: Implement IOC_OPAL_DISCOVERY
blk-mq: prealloc tags when increase tagset nr_hw_queues
blk-mq: delete redundant tagset map update when fallback
blk-mq: fix tags leak when shrink nr_hw_queues
ublk: zoned: support REQ_OP_ZONE_RESET_ALL
md: raid0: account for split bio in iostat accounting
md/raid0: Fix performance regression for large sequential writes
md/raid0: Factor out helper for mapping and submitting a bio
md raid1: allow writebehind to work on any leg device set WriteMostly
md/raid1: hold the barrier until handle_read_error() finishes
md/raid1: free the r1bio before waiting for blocked rdev
md/raid1: call free_r1bio() before allow_barrier() in raid_end_bio_io()
blk-cgroup: Fix NULL deref caused by blkg_policy_data being installed before init
drivers/rnbd: restore sysfs interface to rnbd-client
md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()
raid6: test: only check for Altivec if building on powerpc hosts
raid6: test: make sure all intermediate and artifact files are .gitignored
...
Since we don't need to maintain inflight flush_data requests list
anymore, we can reuse rq->queuelist for flush pending list.
Note in mq_flush_data_end_io(), we need to re-initialize rq->queuelist
before reusing it in the state machine when end, since the rq->rq_next
also reuse it, may have corrupted rq->queuelist by the driver.
This patch decrease the size of struct request by 16 bytes.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230717040058.3993930-5-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If request need to be completed remotely, we insert it into percpu llist,
and smp_call_function_single_async() if llist is empty previously.
We don't need to use per-rq csd, percpu csd is enough. And the size of
struct request is decreased by 24 bytes.
This way is cleaner, and looks correct, given block softirq is guaranteed
to be scheduled to consume the list if one new request is added to this
percpu list, either smp_call_function_single_async() returns -EBUSY or 0.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230717040058.3993930-2-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Provide a direct request polling will for drivers. The interface does
not require a bio, and can skip the overhead associated with polling
those. The biggest gain from skipping the relatively expensive xarray
lookup unnecessary when you already have the request.
With this, the simple rq/qc conversion functions have only one caller
each, so open code this and remove the helpers.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230612190343.2087040-2-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Request allocated from sched tags can't be issued via ->queue_rqs()
directly, since driver tag isn't allocated yet. This is the 1st misuse
of RQF_USE_SCHED for figuring out plug->has_elevator.
Request allocated from sched tags can't be ended by
blk_mq_end_request_batch() too, fix the 2nd RQF_USE_SCHED misuse
in blk_mq_add_to_batch().
Without this patch, NVMe uring cmd passthrough IO workload can run into
hang easily with real io scheduler.
Fixes: dd6216bb16 ("blk-mq: make sure elevator callbacks aren't called for passthrough request")
Reported-by: Guangwu Zhang <guazhang@redhat.com>
Closes: https://lore.kernel.org/linux-block/CAGS2=YrBjpLPOKa-gzcKuuOG60AGth5794PNCDwatdnnscB9ug@mail.gmail.com/
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230624130105.1443879-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In __blk_mq_tag_busy/idle(), updating 'active_queues' and calculating
'wake_batch' is not atomic:
t1: t2:
_blk_mq_tag_busy blk_mq_tag_busy
inc active_queues
// assume 1->2
inc active_queues
// 2 -> 3
blk_mq_update_wake_batch
// calculate based on 3
blk_mq_update_wake_batch
/* calculate based on 2, while active_queues is actually 3. */
Fix this problem by protecting them wih 'tags->lock', this is not a hot
path, so performance should not be concerned. And now that all writers
are inside the lock, switch 'actives_queues' from atomic to unsigned
int.
Fixes: 180dccb0db ("blk-mq: fix tag_get wait task can't be awakened")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230610023043.2559121-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
op &= REQ_OP_MASK in blk_op_is_passthrough() is exactly what req_op() do.
Therefore, it is redundant to call req_op() for blk_op_is_passthrough().
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230522085355.1740772-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently both requeues of commands that were already sent to the driver
and flush commands submitted from the flush state machine share the same
requeue_list struct request_queue, despite requeues doing head
insertions and flushes not. Switch to using two separate lists instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230519044050.107790-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Send write requests issued by the flush state machine through the normal
I/O submission path including the I/O scheduler (if present) so that I/O
scheduler policies are applied to writes with the FUA flag set.
Separate the I/O scheduler members from the flush members in struct
request since now a request may pass through both an I/O scheduler
and the flush machinery.
Note that the actual flush requests, which have no bio attached to the
request still bypass the I/O schedulers.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[hch: rebased]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230519044050.107790-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
