- Dec 16, 2021
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Jens Axboe authored
Pointless to maintain a head/tail for the list, as we never need to access the tail. Entries are always LIFO for cache hotness reasons. Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
The batched completions only deal with non-partial requests anyway, and it doesn't deal with any requests that have errors. Add a completion handler that assumes it's a full request and that it's all being ended successfully. Reviewed-by:
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- Dec 15, 2021
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Jens Axboe authored
kyber turns on IO statistics when it is loaded on a queue, which means that even if kyber is then later unloaded, we're still stuck with stats enabled on the queue. Change the account enabled from a bool to an int, and pair the enable call with the equivalent disable call. This ensures that stats gets turned off again appropriately. Reviewed-by:
Omar Sandoval <osandov@fb.com> Signed-off-by:
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- Dec 14, 2021
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Matthew Wilcox (Oracle) authored
Add a Context section and rewrite the rest to be clearer. Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Link: https://lore.kernel.org/r/20211213171113.3097631-1-willy@infradead.org Signed-off-by:
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- Dec 13, 2021
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Christoph Hellwig authored
mtdblock / mtdblock_ro set part_bits to 0 and thus nevever scanned partitions. Restore that behavior by setting the GENHD_FL_NO_PART flag. Fixes: 1ebe2e5f ("block: remove GENHD_FL_EXT_DEVT") Reported-by:
Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by:
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- Dec 07, 2021
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John Garry authored
Kashyap reports high CPU usage in blk_mq_queue_tag_busy_iter() and callees using megaraid SAS RAID card since moving to shared tags [0]. Previously, when shared tags was shared sbitmap, this function was less than optimum since we would iter through all tags for all hctx's, yet only ever match upto tagset depth number of rqs. Since the change to shared tags, things are even less efficient if we have parallel callers of blk_mq_queue_tag_busy_iter(). This is because in bt_iter() -> blk_mq_find_and_get_req() there would be more contention on accessing each request ref and tags->lock since they are now shared among all HW queues. Optimise by having separate calls to bt_for_each() for when we're using shared tags. In this case no longer pass a hctx, as it is no longer relevant, and teach bt_iter() about this. Ming suggested something along the lines of this change, apart from a different implementation. [0] https://lore.kernel.org/linux-block/e4e92abbe9d52bcba6b8cc6c91c442cc@mail.gmail.com/ Signed-off-by:
John Garry <john.garry@huawei.com> Reviewed-by:
Hannes Reinecke <hare@suse.de> Reviewed-by:
Ming Lei <ming.lei@redhat.com> Reported-and-tested-by:
Kashyap Desai <kashyap.desai@broadcom.com> Fixes: e155b0c2 ("blk-mq: Use shared tags for shared sbitmap support") Link: https://lore.kernel.org/r/1638794990-137490-4-git-send-email-john.garry@huawei.com Signed-off-by:
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John Garry authored
Typedefs busy_iter_fn and busy_tag_iter_fn are now identical, so delete busy_iter_fn to reduce duplication. It would be nicer to delete busy_tag_iter_fn, as the name busy_iter_fn is less specific. However busy_tag_iter_fn is used in many different parts of the tree, unlike busy_iter_fn which is just use in block/, so just take the straightforward path now, so that we could rename later treewide. Signed-off-by:
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John Garry authored
The only user of blk_mq_hw_ctx blk_mq_hw_ctx argument is blk_mq_rq_inflight(). Function blk_mq_rq_inflight() uses the hctx to find the associated request queue to match against the request. However this same check is already done in caller bt_iter(), so drop this check. With that change there are no more users of busy_iter_fn blk_mq_hw_ctx argument, so drop the argument. Reviewed-by Hannes Reinecke <hare@suse.de> Signed-off-by:
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Ming Lei authored
blk_mq_run_dispatch_ops() is defined as one macro, and plug->mq_list will be changed when running 'dispatch_ops', so add one local variable for holding request queue. Reported-and-tested-by:
Yi Zhang <yi.zhang@redhat.com> Fixes: 4cafe86c ("blk-mq: run dispatch lock once in case of issuing from list") Signed-off-by:
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Ming Lei authored
The operation protected via blk_mq_run_dispatch_ops() in blk_mq_run_hw_queue won't sleep, so don't run might_sleep() for it. Reported-and-tested-by:
Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by:
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- Dec 04, 2021
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Ming Lei authored
It isn't necessary to call blk_mq_run_dispatch_ops() once for issuing single request directly, and enough to do it one time when issuing from whole list. Signed-off-by:
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Ming Lei authored
We have switched to allocate srcu into request queue, so it is fine to pass request queue to blk_mq_run_dispatch_ops(). Signed-off-by:
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Ming Lei authored
In case of BLK_MQ_F_BLOCKING, per-hctx srcu is used to protect dispatch critical area. However, this srcu instance stays at the end of hctx, and it often takes standalone cacheline, often cold. Inside srcu_read_lock() and srcu_read_unlock(), WRITE is always done on the indirect percpu variable which is allocated from heap instead of being embedded, srcu->srcu_idx is read only in srcu_read_lock(). It doesn't matter if srcu structure stays in hctx or request queue. So switch to per-request-queue srcu for protecting dispatch, and this way simplifies quiesce a lot, not mention quiesce is always done on the request queue wide. Signed-off-by:
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Ming Lei authored
Remove hctx_lock and hctx_unlock, and add one helper of blk_mq_run_dispatch_ops() to run code block defined in dispatch_ops with rcu/srcu read held. Compared with hctx_lock()/hctx_unlock(): 1) remove 2 branch to 1, so we just need to check (hctx->flags & BLK_MQ_F_BLOCKING) once when running one dispatch_ops 2) srcu_idx needn't to be touched in case of non-blocking 3) might_sleep_if() can be moved to the blocking branch Also put the added blk_mq_run_dispatch_ops() in private header, so that the following patch can use it out of blk-mq.c. Signed-off-by:
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Jens Axboe authored
refcount_t is not as expensive as it used to be, but it's still more expensive than the io_uring method of using atomic_t and just checking for potential over/underflow. This borrows that same implementation, which in turn is based on the mm implementation from Linus. Reviewed-by:
Keith Busch <kbusch@kernel.org> Signed-off-by:
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Jens Axboe authored
Don't call into generic_file_read_iter() if we know it's O_DIRECT, just set it up ourselves and call our own handler. This avoids an indirect call for O_DIRECT. Fall back to filemap_read() if we fail. Signed-off-by: -
Jens Axboe authored
No functional changes in this patch, just in preparation for efficiently calling this light function from the block O_DIRECT handling. Reviewed-by:
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- Dec 03, 2021
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Jens Axboe authored
When we attempt to merge off the cached request path, we return NULL if successful. This makes the caller believe that it's should allocate a new request, and hence we end up with the bio both merged and associated with a new request. This, predictably, leads to all sorts of crashes. Pass in a pointer to the bio pointer, and clear it for the merge case. Then the caller knows that the bio is already queued, and no new requests need to get allocated. Fixes: 5b13bc8a ("blk-mq: cleanup request allocation") Reviewed-by:
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Jens Axboe authored
Expected case is returning a request, just check for success and return the request rather than having an error label. Signed-off-by:
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- Dec 02, 2021
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Ming Lei authored
Without checking q->poll_stat in queue_poll_stat_show(), kernel panic may be caused if q->poll_stat isn't allocated. Fixes: 48b5c1fb ("block: only allocate poll_stats if there's a user of them") Signed-off-by:
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- Nov 29, 2021
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Ye Bin authored
We do test with inject error fault base on v4.19, after test some time we found sync /dev/sda always failed. [root@localhost] sync /dev/sda sync: error syncing '/dev/sda': Input/output error scsi log as follows: [19069.812296] sd 0:0:0:0: [sda] tag#64 Send: scmd 0x00000000d03a0b6b [19069.812302] sd 0:0:0:0: [sda] tag#64 CDB: Synchronize Cache(10) 35 00 00 00 00 00 00 00 00 00 [19069.812533] sd 0:0:0:0: [sda] tag#64 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK [19069.812536] sd 0:0:0:0: [sda] tag#64 CDB: Synchronize Cache(10) 35 00 00 00 00 00 00 00 00 00 [19069.812539] sd 0:0:0:0: [sda] tag#64 scsi host busy 1 failed 0 [19069.812542] sd 0:0:0:0: Notifying upper driver of completion (result 0) [19069.812546] sd 0:0:0:0: [sda] tag#64 sd_done: completed 0 of 0 bytes [19069.812549] sd 0:0:0:0: [sda] tag#64 0 sectors total, 0 bytes done. [19069.812564] print_req_error: I/O error, dev sda, sector 0 ftrace log as follows: rep-306069 [007] .... 19654.923315: block_bio_queue: 8,0 FWS 0 + 0 [rep] rep-306069 [007] .... 19654.923333: block_getrq: 8,0 FWS 0 + 0 [rep] kworker/7:1H-250 [007] .... 19654.923352: block_rq_issue: 8,0 FF 0 () 0 + 0 [kworker/7:1H] <idle>-0 [007] ..s. 19654.923562: block_rq_complete: 8,0 FF () 18446744073709551615 + 0 [0] <idle>-0 [007] d.s. 19654.923576: block_rq_complete: 8,0 WS () 0 + 0 [-5] As 8d699663 introduce 'fq->rq_status', this data only update when 'flush_rq' reference count isn't zero. If flush request once failed and record error code in 'fq->rq_status'. If there is no chance to update 'fq->rq_status',then do fsync will always failed. To address this issue reset 'fq->rq_status' after return error code to upper layer. Fixes: 8d699663 ("block: fix null pointer dereference in blk_mq_rq_timed_out()") Signed-off-by:
Ye Bin <yebin10@huawei.com> Reviewed-by:
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Christoph Hellwig authored
Now that blk_execute_rq does not take a gendisk argument there is no need to pass it through the scsi_ioctl callchain either. Signed-off-by:
Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by:
Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20211126121802.2090656-6-hch@lst.de Signed-off-by:
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Christoph Hellwig authored
Remove the gendisk aregument to blk_execute_rq and blk_execute_rq_nowait given that it is unused now. Also convert the boolean at_head parameter to actually use the bool type while touching the prototype. Signed-off-by:
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Christoph Hellwig authored
Just use the disk attached to the request_queue instead. Signed-off-by:
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Christoph Hellwig authored
There is a 1:1 relationship between request_queues and gendisks now, so no need for these extra checks. Signed-off-by:
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Christoph Hellwig authored
The block layer already performs this check, no need to duplicate it in the driver. Signed-off-by:
Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by:
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Colin Ian King authored
The variable ret is being initialized with a value that is never read, it is being updated later on. The assignment is redundant and can be removed. Signed-off-by:
Colin Ian King <colin.i.king@gmail.com> Link: https://lore.kernel.org/r/20211126230652.1175636-1-colin.i.king@gmail.com Signed-off-by:
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Christoph Hellwig authored
Remove the ioc argument as it always points to current->io_context. Signed-off-by:
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Christoph Hellwig authored
Remove the ioc and gfp_mask argument, which are hard coded by the caller. Signed-off-by:
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Christoph Hellwig authored
Grab a reference to the newly allocated or existing io_context in create_task_io_context and return it. This simplifies the callers and removes the need for double lookups. Signed-off-by:
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Christoph Hellwig authored
In __copy_io we know that the newly allocate task_struct does not have an I/O context yet and is not exiting. So just allocate the I/O context struct and install it directly. There is no need to lock the task either as it is just being created. Signed-off-by:
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Christoph Hellwig authored
Factor out a helper that just allocate an I/O context. Signed-off-by:
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Christoph Hellwig authored
Fold it into it's only caller, and remove a lof of the debug checks that are not needed. Signed-off-by:
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Christoph Hellwig authored
After the prepare side has been moved to the only I/O scheduler that cares, do the same for the cleanup and the NULL initialization. Signed-off-by:
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Christoph Hellwig authored
Move blk_mq_sched_assign_ioc so that many interfaces from the file can be marked static. Rename the function to ioc_find_get_icq as well and return the icq to simplify the interface. Signed-off-by:
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Christoph Hellwig authored
Signed-off-by:
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Christoph Hellwig authored
This reverts commit 4896c4e64ba5d5d5acdbcf68c5910dd4f6d8fa62. The helper is not needed any more. Signed-off-by:
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Christoph Hellwig authored
No need to create a new I/O context if there is none present yet in ->limit_depth. Signed-off-by:
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Christoph Hellwig authored
Remove the unused bfqd argument, and hardcode ioc to current->io_context. Signed-off-by:
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Christoph Hellwig authored
Move the copying of the I/O context to the block layer as that is where we can use the proper low-level interfaces. Signed-off-by:
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