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* lightnvm: fix cleanup order of disk on init errorJavier González2017-04-161-7/+7
| | | | | | | | | Reorder disk allocation such that the disk structure can be put safely. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: double-clear of dev->lun_map on target init errorJavier González2017-04-161-7/+10
| | | | | | | | | | | | | | | The dev->lun_map bits are cleared twice if an target init error occurs. First in the target clean routine, and then next in the nvm_tgt_create error function. Make sure that it is only cleared once by extending nvm_remove_tgt_devi() with a clear bit, such that clearing of bits can ignored when cleaning up a successful initialized target. Signed-off-by: Javier González <javier@cnexlabs.com> Fix style. Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: don't check for failure from mempool_alloc()NeilBrown2017-04-161-9/+0
| | | | | | | | | | | | mempool_alloc() cannot fail if the gfp flags allow it to sleep, and both GFP_KERNEL and GFP_NOIO allows for sleeping. So rrpc_move_valid_pages() and rrpc_make_rq() don't need to test the return value. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: enable nvme size compile assertsMatias Bjørling2017-04-161-2/+4
| | | | | | | | | | | The asserts in _nvme_nvm_check_size are not compiled due to the function not begin called. Make sure that it is called, and also fix the wrong sizes of asserts for nvme_nvm_addr_format, and nvme_nvm_bb_tbl, which checked for number of bits instead of bytes. Reported-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: free reverse device mapJavier González2017-04-161-1/+13
| | | | | | | | Free the reverse mapping table correctly on target tear down Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: rename scrambler controller hintJavier González2017-04-161-1/+1
| | | | | | | | | | | According to the OCSSD 1.2 specification, the 0x200 hint enables the media scrambler for the read/write opcode, providing that the controller has been correctly configured by the firmware. Rename the macro to represent this meaning. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: submit erases using the I/O pathJavier González2017-04-164-50/+47
| | | | | | | | | | | | | | | Until now erases have been submitted as synchronous commands through a dedicated erase function. In order to enable targets implementing asynchronous erases, refactor the erase path so that it uses the normal async I/O submission functions. If a target requires sync I/O, it can implement it internally. Also, adapt rrpc to use the new erase path. Signed-off-by: Javier González <javier@cnexlabs.com> Fixed spelling error. Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* nvme/lightnvm: Prevent small buffer overflow in nvme_nvm_identifyScott Bauer2017-04-161-1/+1
| | | | | | | | | | | | | | | | | | | | There are two closely named structs in lightnvm: struct nvme_nvm_addr_format and struct nvme_addr_format. The first struct has 4 reserved bytes at the end, the second does not. (gdb) p sizeof(struct nvme_nvm_addr_format) $1 = 16 (gdb) p sizeof(struct nvm_addr_format) $2 = 12 In the nvme_nvm_identify function we memcpy from the larger struct to the smaller struct. We incorrectly pass the length of the larger struct and overflow by 4 bytes, lets not do that. Signed-off-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* lightnvm: Fix error handlingChristophe JAILLET2017-04-161-2/+4
| | | | | | | | | According to error handling in this function, it is likely that going to 'out' was expected here. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* net: off by one in inet6_pton()Dan Carpenter2017-04-141-1/+1
| | | | | | | | | If "scope_len" is sizeof(scope_id) then we would put the NUL terminator one space beyond the end of the buffer. Fixes: b1a951fe469e ("net/utils: generic inet_pton_with_scope helper") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: introduce Kyber multiqueue I/O schedulerOmar Sandoval2017-04-144-0/+743
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Kyber I/O scheduler is an I/O scheduler for fast devices designed to scale to multiple queues. Users configure only two knobs, the target read and synchronous write latencies, and the scheduler tunes itself to achieve that latency goal. The implementation is based on "tokens", built on top of the scalable bitmap library. Tokens serve as a mechanism for limiting requests. There are two tiers of tokens: queueing tokens and dispatch tokens. A queueing token is required to allocate a request. In fact, these tokens are actually the blk-mq internal scheduler tags, but the scheduler manages the allocation directly in order to implement its policy. Dispatch tokens are device-wide and split up into two scheduling domains: reads vs. writes. Each hardware queue dispatches batches round-robin between the scheduling domains as long as tokens are available for that domain. These tokens can be used as the mechanism to enable various policies. The policy Kyber uses is inspired by active queue management techniques for network routing, similar to blk-wbt. The scheduler monitors latencies and scales the number of dispatch tokens accordingly. Queueing tokens are used to prevent starvation of synchronous requests by asynchronous requests. Various extensions are possible, including better heuristics and ionice support. The new scheduler isn't set as the default yet. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq-sched: make completed_request() callback more usefulOmar Sandoval2017-04-143-10/+8
| | | | | | | | | | | Currently, this callback is called right after put_request() and has no distinguishable purpose. Instead, let's call it before put_request() as soon as I/O has completed on the request, before we account it in blk-stat. With this, Kyber can enable stats when it sees a latency outlier and make sure the outlier gets accounted. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: export helpersOmar Sandoval2017-04-142-0/+3
| | | | | | | | | blk_mq_finish_request() is required for schedulers that define their own put_request(). blk_mq_run_hw_queue() is required for schedulers that hold back requests to be run later. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: add shallow depth option for blk_mq_get_tag()Omar Sandoval2017-04-142-1/+5
| | | | | | | | Wire up the sbitmap_get_shallow() operation to the tag code so that a caller can limit the number of tags available to it. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* sbitmap: add sbitmap_get_shallow() operationOmar Sandoval2017-04-142-7/+123
| | | | | | | | | | | | This operation supports the use case of limiting the number of bits that can be allocated for a given operation. Rather than setting aside some bits at the end of the bitmap, we can set aside bits in each word of the bitmap. This means we can keep the allocation hints spread out and support sbitmap_resize() nicely at the cost of lower granularity for the allowed depth. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* remove the mg_disk driverChristoph Hellwig2017-04-145-1257/+0
| | | | | | | | | | | | This drivers was added in 2008, but as far as a I can tell we never had a single platform that actually registered resources for the platform driver. It's also been unmaintained for a long time and apparently has a ATA mode that can be driven using the IDE/libata subsystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Fix list corruption of blk stats callback listJan Kara2017-04-111-8/+4
| | | | | | | | | | | | | | | When CFQ calls wbt_disable_default(), it will call blk_stat_remove_callback() to stop gathering IO statistics for the purposes of writeback throttling. Later, when request_queue is unregistered, wbt_exit() will call blk_stat_remove_callback() again which will try to delete callback from the list again and possibly cause list corruption. Fix the problem by making wbt_disable_default() called wbt_exit() which is properly guarded against being called multiple times. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: Show symbolic names for hctx state and flagsBart Van Assche2017-04-101-3/+34
| | | | | | | | | | Instead of showing the hctx state and flags as numbers, show the names of the flags. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: Export queue state through /sys/kernel/debug/block/*/stateBart Van Assche2017-04-101-0/+106
| | | | | | | | | | | Make it possible to check whether or not a block layer queue has been stopped. Make it possible to start and to run a blk-mq queue from user space. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* scsi: sd: Remove LBPRZ dependency for discardsMartin K. Petersen2017-04-081-19/+6
| | | | | | | | | | | | | | Separating discards and zeroout operations allows us to remove the LBPRZ block zeroing constraints from discards and honor the device preferences for UNMAP commands. If supported by the device, we'll also choose UNMAP over one of the WRITE SAME variants for discards. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* scsi: sd: Separate zeroout and discard command choicesMartin K. Petersen2017-04-082-3/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that zeroout and discards are distinct operations we need to separate the policy of choosing the appropriate command. Create a zeroing_mode which can be one of: write: Zeroout assist not present, use regular WRITE writesame: Allow WRITE SAME(10/16) with a zeroed payload writesame_16_unmap: Allow WRITE SAME(16) with UNMAP writesame_10_unmap: Allow WRITE SAME(10) with UNMAP The last two are conditional on the device being thin provisioned with LBPRZ=1 and LBPWS=1 or LBPWS10=1 respectively. Whether to set the UNMAP bit or not depends on the REQ_NOUNMAP flag. And if none of the _unmap variants are supported, regular WRITE SAME will be used if the device supports it. The zeroout_mode is exported in sysfs and the detected mode for a given device can be overridden using the string constants above. With this change in place we can now issue WRITE SAME(16) with UNMAP set for block zeroing applications that require hard guarantees and logical_block_size granularity. And at the same time use the UNMAP command with the device's preferred granulary and alignment for discard operations. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: remove the discard_zeroes_data flagChristoph Hellwig2017-04-0823-124/+27
| | | | | | | | | | Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can kill this hack. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: implement REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-085-7/+15
| | | | | | | | | It seems like DRBD assumes its on the wire TRIM request always zeroes data. Use that fact to implement REQ_OP_WRITE_ZEROES. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* drbd: make intelligent use of blkdev_issue_zerooutChristoph Hellwig2017-04-084-110/+7
| | | | | | | | | | drbd always wants its discard wire operations to zero the blocks, so use blkdev_issue_zeroout with the BLKDEV_ZERO_UNMAP flag instead of reinventing it poorly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: stop using discards for zeroingChristoph Hellwig2017-04-081-6/+6
| | | | | | | | | | | | Now that we have REQ_OP_WRITE_ZEROES implemented for all devices that support efficient zeroing, we can remove the call to blkdev_issue_discard. This means we only have two ways of zeroing left and can simplify the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* mmc: remove the discard_zeroes_data flagChristoph Hellwig2017-04-081-2/+0
| | | | | | | | | mmc only supports discarding on large alignments, so the zeroing code would always fall back to explicit writings of zeroes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* rsxx: remove the discard_zeroes_data flagChristoph Hellwig2017-04-081-1/+0
| | | | | | | | | rsxx only supports discarding on large alignments, so the zeroing code would always fall back to explicit writings of zeroes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* rbd: remove the discard_zeroes_data flagChristoph Hellwig2017-04-081-1/+0
| | | | | | | | | rbd only supports discarding on large alignments, so the zeroing code would always fall back to explicit writings of zeroes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* brd: remove discard supportChristoph Hellwig2017-04-081-54/+0
| | | | | | | | | It's just a in-driver reimplementation of writing zeroes to the pages, which fails if the discards aren't page aligned. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* loop: implement REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-081-0/+4
| | | | | | | | | It's identical to discard as hole punches will always leave us with zeroes on reads. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* zram: implement REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-081-5/+8
| | | | | | | | Just the same as discard if the block size equals the system page size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* nvme: implement REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-083-11/+11
| | | | | | | | | | | But now for the real NVMe Write Zeroes yet, just to get rid of the discard abuse for zeroing. Also rename the quirk flag to be a bit more self-explanatory. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* sd: implement unmapping Write ZeroesChristoph Hellwig2017-04-081-0/+9
| | | | | | | | | | Try to use a write same with unmap bit variant if the device supports it and the caller allows for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block_dev: use blkdev_issue_zerout for hole punchesChristoph Hellwig2017-04-081-8/+2
| | | | | | | | | | | | | | This gets us support for non-discard efficient write of zeroes (e.g. NVMe) and prepares for removing the discard_zeroes_data flag. Also remove a pointless discard support check, which is done in blkdev_issue_discard already. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: add a new BLKDEV_ZERO_NOFALLBACK flagChristoph Hellwig2017-04-082-1/+5
| | | | | | | | | | | | | This avoids fallbacks to explicit zeroing in (__)blkdev_issue_zeroout if the caller doesn't want them. Also clean up the convoluted check for the return condition that this new flag is added to. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: add a REQ_NOUNMAP flag for REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-082-14/+11
| | | | | | | | | | | | | | If this flag is set logical provisioning capable device should release space for the zeroed blocks if possible, if it is not set devices should keep the blocks anchored. Also remove an out of sync kerneldoc comment for a static function that would have become even more out of data with this change. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: add a flags argument to (__)blkdev_issue_zerooutChristoph Hellwig2017-04-088-31/+35
| | | | | | | | | | Turn the existing discard flag into a new BLKDEV_ZERO_UNMAP flag with similar semantics, but without referring to diѕcard. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: stop using blkdev_issue_write_same for zeroingChristoph Hellwig2017-04-081-4/+0
| | | | | | | | | We'll always use the WRITE ZEROES code for zeroing now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* dm kcopyd: switch to use REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-081-3/+3
| | | | | | | | | | | | | It seems like the code currently passes whatever it was using for writes to WRITE SAME. Just switch it to WRITE ZEROES, although that doesn't need any payload. Untested, and confused by the code, maybe someone who understands it better than me can help.. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* dm: support REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-089-8/+83
| | | | | | | | Copy & paste from the REQ_OP_WRITE_SAME code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* dm io: discards don't take a payloadChristoph Hellwig2017-04-081-2/+8
| | | | | | | | | | | | Fix up do_region to not allocate a bio_vec for discards. We've got rid of the discard payload allocated by the caller years ago. Obviously this wasn't actually harmful given how long it's been there, but it's still good to avoid the pointless allocation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* md: support REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-087-1/+16
| | | | | | | | Copy & paste from the REQ_OP_WRITE_SAME code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* sd: implement REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-082-5/+27
| | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: implement splitting of REQ_OP_WRITE_ZEROES biosChristoph Hellwig2017-04-081-2/+15
| | | | | | | | | | Copy and past the REQ_OP_WRITE_SAME code to prepare to implementations that limit the write zeroes size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: renumber REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-081-1/+1
| | | | | | | | | | Make life easy for implementations that needs to send a data buffer to the device (e.g. SCSI) by numbering it as a data out command. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* sd: split sd_setup_discard_cmndChristoph Hellwig2017-04-081-69/+84
| | | | | | | | | | | | | Split sd_setup_discard_cmnd into one function per provisioning type. While this creates some very slight duplication of boilerplate code it keeps the code modular for additions of new provisioning types, and for reusing the write same functions for the upcoming scsi implementation of the Write Zeroes operation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: sed-opal: Tone down all the pr_* to debugsScott Bauer2017-04-071-79/+74
| | | | | | | | Lets not flood the kernel log with messages unless the user requests so. Signed-off-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: Clarify comments in blk_mq_dispatch_rq_list()Bart Van Assche2017-04-071-10/+18
| | | | | | | | | | | | | The blk_mq_dispatch_rq_list() implementation got modified several times but the comments in that function were not updated every time. Since it is nontrivial what is going on, update the comments in blk_mq_dispatch_rq_list(). Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_listBart Van Assche2017-04-071-2/+9
| | | | | | | | | | | | | Since the next patch in this series will use RCU to iterate over tag_list, make this safe. Add lockdep_assert_held() statements in functions that iterate over tag_list to make clear that using list_for_each_entry() instead of list_for_each_entry_rcu() is fine in these functions. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: use true instead of 1 for blk_mq_queue_data.lastOmar Sandoval2017-04-071-1/+1
| | | | | | | Trivial cleanup. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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