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path: root/drivers/scsi/scsi.c
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2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27scsi: kill command serial numberHannes Reinecke
No users left, kill it. Signed-off-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-07scsi: kill off the legacy IO pathJens Axboe
This removes the legacy (non-mq) IO path for SCSI. Cc: linux-scsi@vger.kernel.org Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-26scsi: read host_busy via scsi_host_busy()Ming Lei
No functional change. Just introduce scsi_host_busy() and replace the direct read of scsi_host->host_busy with this new API. Cc: Omar Sandoval <osandov@fb.com>, Cc: "Martin K. Petersen" <martin.petersen@oracle.com>, Cc: James Bottomley <james.bottomley@hansenpartnership.com>, Cc: Christoph Hellwig <hch@lst.de>, Cc: Don Brace <don.brace@microsemi.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Laurence Oberman <loberman@redhat.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-06-26scsi: core: check for equality of result byte valuesJohannes Thumshirn
When evaluating a SCSI command's result using the field access macros, check for equality of the fields and not if a specific bit is set. This is a preparation patch, for reworking the results field in the SCSI command. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-02-27scsi: core: fix two wrong indentation casesJianchao Wang
No functional changes. Just fix two wrong indentation cases in scsi_finish_command and scsi_decide_disposition. Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-09-07Merge branch 'fixes' into miscJames Bottomley
2017-08-29scsi: Rework handling of scsi_device.vpd_pg8[03]Bart Van Assche
Introduce struct scsi_vpd for the VPD page length, data and the RCU head that will be used to free the VPD data. Use kfree_rcu() instead of kfree() to free VPD data. Move the VPD buffer pointer check inside the RCU read lock in the sysfs code. Only annotate pointers that are shared across threads with __rcu. Use rcu_dereference() when dereferencing an RCU pointer. This patch suppresses about twenty sparse complaints about the vpd_pg8[03] pointers. This patch also fixes a race condition, namely that updating of the VPD pointers and length variables in struct scsi_device was not atomic with reference to the code reading these variables. See also "Does the update code tolerate concurrent accesses?" in Documentation/RCU/checklist.txt. Fixes: commit 09e2b0b14690 ("scsi: rescan VPD attributes") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Shane Seymour <shane.seymour@hpe.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Shane Seymour <shane.seymour@hpe.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-08-29scsi: Rework the code for caching Vital Product Data (VPD)Bart Van Assche
Introduce the scsi_get_vpd_buf() and scsi_update_vpd_page() functions. The only functional change in this patch is that if updating page 0x80 fails that it is attempted to update page 0x83. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Shane Seymour <shane.seymour@hpe.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Shane M Seymour <shane.seymour@hpe.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-08-16Revert "scsi: default to scsi-mq"Christoph Hellwig
Defaulting to scsi-mq in 4.13-rc has shown various regressions on setups that we didn't previously consider. Fixes for them are in progress, but too invasive to make it in this cycle. So for now revert the commit that defaults to blk-mq for SCSI. For 4.14 we'll plan to try again with these fixes. This reverts commit 5c279bd9e40624f4ab6e688671026d6005b066fa. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-06-27scsi: default to scsi-mqChristoph Hellwig
Remove the SCSI_MQ_DEFAULT config option and default to the blk-mq I/O path now that we had plenty of testing, and have I/O schedulers for blk-mq. The module option to disable the blk-mq path is kept around for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-06-12scsi: Only add commands to the device command list if required by the LLDBart Van Assche
Just like for the scsi-mq code path, in the single queue SCSI code path only add commands to the per-device command list if required by the SCSI LLD. This patch will make it easier to merge the single-queue and multiqueue command initialization code. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-05-08scsi: Skip deleted devices in __scsi_device_lookupZhou Zhengping
When a device is unplugged from a SCSI controller, if the scsi_device is still in use by application layer, it won't get released until users close it. In this case, scsi_device_remove just set the scsi_device's state to be SDEV_DEL. But if you plug the disk just before the old scsi_device is released, then there will be two scsi_device structures in scsi_host->__devices. When the next unplug event happens, some low-level drivers will check whether the scsi_device has been added to host (for example the MegaRAID SAS series controller) by calling scsi_device_lookup(call __scsi_device_lookup) in function megasas_aen_polling. __scsi_device_lookup will return the first scsi_device. Because its state is SDEV_DEL, the scsi_device_lookup will return NULL, making the low-level driver assume that the scsi_device has been removed, and won't call scsi_device_remove which will lead to hot swap failure. Signed-off-by: Zhou Zhengping <johnzzpcrystal@gmail.com> Tested-by: Zeng Rujia <ZengRujia@sangfor.com.cn> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195607 Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-01-31block: introduce blk_rq_is_passthroughChristoph Hellwig
This can be used to check for fs vs non-fs requests and basically removes all knowledge of BLOCK_PC specific from the block layer, as well as preparing for removing the cmd_type field in struct request. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27scsi: allocate scsi_cmnd structures as part of struct requestChristoph Hellwig
Rely on the new block layer functionality to allocate additional driver specific data behind struct request instead of implementing it in SCSI itѕelf. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27scsi: remove scsi_cmd_dma_poolChristoph Hellwig
There is no need for GFP_DMA allocations of the scsi_cmnd structures themselves, all that might be DMAed to or from is the actual payload, or the sense buffers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27scsi: respect unchecked_isa_dma for blk-mqChristoph Hellwig
Currently blk-mq always allocates the sense buffer using normal GFP_KERNEL allocation. Refactor the cmd pool code to split the cmd and sense allocation and share the code to allocate the sense buffers as well as the sense buffer slab caches between the legacy and blk-mq path. Note that this switches to lazy allocation of the sense slab caches - the slab caches (not the actual allocations) won't be destroy until the scsi module is unloaded instead of keeping track of hosts using them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27scsi: remove gfp_flags member in scsi_host_cmd_poolChristoph Hellwig
When using the slab allocator we already decide at cache creation time if an allocation comes from a GFP_DMA pool using the SLAB_CACHE_DMA flag, and there is no point passing the kmalloc-family only GFP_DMA flag to kmem_cache_alloc. Drop all the infrastructure for doing so. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-05block: add code to track actual device queue depthJens Axboe
For blk-mq, ->nr_requests does track queue depth, at least at init time. But for the older queue paths, it's simply a soft setting. On top of that, it's generally larger than the hardware setting on purpose, to allow backup of requests for merging. Fill a hole in struct request with a 'queue_depth' member, that drivers can call to more closely inform the block layer of the real queue depth. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Jan Kara <jack@suse.cz>
2016-09-26scsi: Avoid that toggling use_blk_mq triggers a memory leakBart Van Assche
This patch avoids that the following memory leak is triggered if use_blk_mq is disabled after a SCSI host has been allocated by the ib_srp driver and before the same SCSI host is freed: unreferenced object 0xffff8803a168c568 (size 256): backtrace: [<ffffffff81620c95>] kmemleak_alloc+0x45/0xa0 [<ffffffff811bb104>] __kmalloc_node+0x1e4/0x400 [<ffffffff81309fe4>] blk_mq_alloc_tag_set+0xb4/0x230 [<ffffffff814731b7>] scsi_mq_setup_tags+0xc7/0xd0 [<ffffffff81469c26>] scsi_add_host_with_dma+0x216/0x2d0 [<ffffffffa064bef5>] srp_create_target+0xe55/0x13d0 [ib_srp] [<ffffffff8143ce23>] dev_attr_store+0x13/0x20 [<ffffffff8125f030>] sysfs_kf_write+0x40/0x50 [<ffffffff8125e397>] kernfs_fop_write+0x137/0x1c0 [<ffffffff811d8c13>] __vfs_write+0x23/0x140 [<ffffffff811d92e0>] vfs_write+0xb0/0x190 [<ffffffff811da5b4>] SyS_write+0x44/0xa0 [<ffffffff8162c8a5>] entry_SYSCALL_64_fastpath+0x18/0xa8 Fixes: 9aa9cc4221f5 ("scsi: remove the disable_blk_mq host flag") Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: <stable@vger.kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-07-15scsi: remove the disable_blk_mq host flagChristoph Hellwig
We've had scsi-mq for 2.5 years now, so we can remove the unused flag to disable the code on a per-host basis that was put in for unexpected emergencies during bringup. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-05scsi: Do not attach VPD to devices that don't support itHannes Reinecke
The patch "scsi: rescan VPD attributes" introduced a regression in which devices that don't support VPD were being scanned for VPD attributes anyway. This could cause issues for some devices and should be avoided so the check for scsi_level has been moved out of scsi_add_lun and into scsi_attach_vpd so that all callers will not scan VPD for devices that don't support it. [mkp: Merge fix] Fixes: 09e2b0b14690 ("scsi: rescan VPD attributes") Cc: <stable@vger.kernel.org> #v4.5+ Suggested-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-11-30scsi: rescan VPD attributesHannes Reinecke
The VPD page information might change, so we need to be able to update it. This patch implements a VPD page rescan whenever the 'rescan' sysfs attribute is triggered. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Shane Seymour <shane.seymour@hpe.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-11-09scsi: use host wide tags by defaultChristoph Hellwig
This patch changes the !blk-mq path to the same defaults as the blk-mq I/O path by always enabling block tagging, and always using host wide tags. We've had blk-mq available for a few releases so bugs with this mode should have been ironed out, and this ensures we get better coverage of over tagging setup over different configs. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-06-01Move code that is used both by initiator and target driversBart Van Assche
Move the functions that are used by both the initiator and target subsystems into scsi_common.c/.h. This change will allow to remove the initiator SCSI header include directives from most SCSI target source files in a later patch. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-03-19scsi: proper state checking and module refcount handling in scsi_device_getChristoph Hellwig
This effectively reverts commits 85b6c7 ("[SCSI] sd: fix cache flushing on module removal (and individual device removal)" and dc4515ea ("scsi: always increment reference count"). We now never call scsi_device_get from the shutdown path, and the fact that we started grabbing reference there in commit 85b6c7 turned out turned out to create more problems than it solves, and required workarounds for workarounds for workarounds. Move back to properly checking the device state and carefully handle module refcounting. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2015-02-11Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull first round of SCSI updates from James Bottomley: "This is the usual grab bag of driver updates (hpsa, storvsc, mp2sas, megaraid_sas, ses) plus an assortment of minor updates. There's also an update to ufs which adds new phy drivers and finally a new logging infrastructure for SCSI" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (114 commits) scsi_logging: return void for dev_printk() functions scsi: print single-character strings with seq_putc scsi: merge consecutive seq_puts calls scsi: replace seq_printf with seq_puts aha152x: replace seq_printf with seq_puts advansys: replace seq_printf with seq_puts scsi: remove SPRINTF macro sg: remove an unused variable hpsa: Use local workqueues instead of system workqueues hpsa: add in P840ar controller model name hpsa: add in gen9 controller model names hpsa: detect and report failures changing controller transport modes hpsa: shorten the wait for the CISS doorbell mode change ack hpsa: refactor duplicated scan completion code into a new routine hpsa: move SG descriptor set-up out of hpsa_scatter_gather() hpsa: do not use function pointers in fast path command submission hpsa: print CDBs instead of kernel virtual addresses for uncommon errors hpsa: do not use a void pointer for scsi_cmd field of struct CommandList hpsa: return failed from device reset/abort handlers hpsa: check for ctlr lockup after command allocation in main io path ...
2015-01-23scsi: always increment reference countRusty Russell
James reported: > After e513cc1 module: Remove stop_machine from module unloading, > module_refcount() is returning (unsigned long)-1 when called from within > a routine that runs in module_exit. This is confusing the scsi device > put code which is coded to detect a module_refcount() of zero for > running within a module exit routine and not try to do another > module_put. The fix is to restore the original behaviour of > module_refcount() and return zero if we're running inside an exit > routine. The correct fix is to turn try_module_get() into __module_get(), and always do the module_put(). Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-09scsi: Do not display buffer pointers in scsi_log_send()Hannes Reinecke
scsi_log_send() would display buffer pointer for higher logging levels. This is not only of questionable value but also exposes kernel pointer to userspace, which is discouraged in some setups. So drop this message altogether. Tested-by: Robert Elliott <elliott@hp.com> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-01-09scsi: use per-cpu buffer for formatting scsi_print_result()Hannes Reinecke
Convert scsi_print_result() to use the per-cpu buffer for decoding the command result and disposition. Tested-by: Robert Elliott <elliott@hp.com> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-12-18Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley
2014-12-08Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley
Conflicts: drivers/scsi/scsi_debug.c Agreed and tested resolution to a merge problem between a fix in scsi_debug and a driver update Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-12-04scsi: never drop to untagged mode during queue ramp downChristoph Hellwig
Dropping to untagged mode when ramping down a queue due to QUEUE FULL events has two problems: - nothing in the midlayer or drivers ever moves back to tagged mode during queue ramp up. - cmd_per_lun isn't the untagged queue depth for many modern drivers that can handle multiple untagged commands, and this is the only place in the midlayer assuming that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-12-04scsi: remove ->change_queue_type methodChristoph Hellwig
Since we got rid of ordered tag support in 2010 the prime use case of switching on and off ordered tags has been obsolete. The other function of enabling/disabling tagging entirely has only been correctly implemented by the 53c700 driver and isn't generally useful. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24scsi: move scsi_dispatch_cmd to scsi_lib.cChristoph Hellwig
scsi_lib.c is where the rest of the I/O submission path lives, so move scsi_dispatch_cmd there and mark it static. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24scsi: drop reason argument from ->change_queue_depthChristoph Hellwig
Drop the now unused reason argument from the ->change_queue_depth method. Also add a return value to scsi_adjust_queue_depth, and rename it to scsi_change_queue_depth now that it can be used as the default ->change_queue_depth implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12scsi: don't set tagging state from scsi_adjust_queue_depthChristoph Hellwig
Remove the tagged argument from scsi_adjust_queue_depth, and just let it handle the queue depth. For most drivers those two are fairly separate, given that most modern drivers don't care about the SCSI "tagged" status of a command at all, and many old drivers allow queuing of multiple untagged commands in the driver. Instead we start out with the ->simple_tags flag set before calling ->slave_configure, which is how all drivers actually looking at ->simple_tags except for one worke anyway. The one other case looks broken, but I've kept the behavior as-is for now. Except for that we only change ->simple_tags from the ->change_queue_type, and when rejecting a tag message in a single driver, so keeping this churn out of scsi_adjust_queue_depth is a clear win. Now that the usage of scsi_adjust_queue_depth is more obvious we can also remove all the trivial instances in ->slave_alloc or ->slave_configure that just set it to the cmd_per_lun default. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-11-12scsi: always assign block layer tags if enabledChristoph Hellwig
Allow a driver to ask for block layer tags by setting .use_blk_tags in the host template, in which case it will always see a valid value in request->tag, similar to the behavior when using blk-mq. This means even SCSI "untagged" commands will now have a tag, which is especially useful when using a host-wide tag map. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12scsi: remove ordered_tags scsi_device fieldChristoph Hellwig
Remove the ordered_tags field, we haven't been issuing ordered tags based on it since the big barrier rework in 2010. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-11-12scsi: provide a generic change_queue_type methodChristoph Hellwig
Most drivers use exactly the same implementation, so provide it as a library function. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12scsi: simplify scsi_log_(send|completion)Hannes Reinecke
Simplify scsi_log_(send|completion) by externalizing scsi_mlreturn_string() and always print the command address. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12scsi: use sdev as argument for sense code printingHannes Reinecke
We should be using the standard dev_printk() variants for sense code printing. [hch: remove __scsi_print_sense call in xen-scsiback, Acked by Juergen] [hch: folded bracing fix from Dan Carpenter] Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-10-01scsi: add a CONFIG_SCSI_MQ_DEFAULT optionChristoph Hellwig
Add a Kconfig option to enable the blk-mq path for SCSI by default to ease testing and deployment in setups that know they benefit from blk-mq. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Robert Elliott <elliott@hp.com> Tested-by: Robert Elliott <elliott@hp.com>
2014-09-15scsi: don't store LUN bits in CDB[1] for USB mass-storage devicesAlan Stern
The SCSI specification requires that the second Command Data Byte should contain the LUN value in its high-order bits if the recipient device reports SCSI level 2 or below. Nevertheless, some USB mass-storage devices use those bits for other purposes in vendor-specific commands. Currently Linux has no way to send such commands, because the SCSI stack always overwrites the LUN bits. Testing shows that Windows 7 and XP do not store the LUN bits in the CDB when sending commands to a USB device. This doesn't matter if the device uses the Bulk-Only or UAS transports (which virtually all modern USB mass-storage devices do), as these have a separate mechanism for sending the LUN value. Therefore this patch introduces a flag in the Scsi_Host structure to inform the SCSI midlayer that a transport does not require the LUN bits to be stored in the CDB, and it makes usb-storage set this flag for all devices using the Bulk-Only transport. (UAS is handled by a separate driver, but it doesn't really matter because no SCSI-2 or lower device is at all likely to use UAS.) The patch also cleans up the code responsible for storing the LUN value by adding a bitflag to the scsi_device structure. The test for whether to stick the LUN value in the CDB can be made when the device is probed, and stored for future use rather than being made over and over in the fast path. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Tiziano Bacocco <tiziano.bacocco@gmail.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-08-15[SCSI] save command pool address of Scsi_HostJuergen Gross
If a scsi host driver specifies .cmd_len in it's scsi_host_template, a driver's private command pool is needed. scsi_find_host_cmd_pool() will locate it, but scsi_alloc_host_cmd_pool() isn't saving the pool address in the host template. This will result in an access error when the host is removed. Avoid the problem by saving the address of a new allocated command pool where it is expected. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Fixes: 89d9a567952baec13e26ada3e438f1b642d66b6e Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-07-29scsi: use short driver name for per-driver cmd slab cachesJames Bottomley
hostt->name might contain space, so use the ->proc_name short name instead when creating per-driver command slabs. Signed-off-by: James Bottomley <JBottomley@Parallels.com> Reported-by: poma <pomidorabelisima@gmail.com> Tested-by: poma <pomidorabelisima@gmail.com> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-25scsi: update scsi_device_typesChristoph Hellwig
Add two new device types, most importantly the zoned block device one. Split from an earlier patch by Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-07-25scsi: add support for a blk-mq based I/O path.Christoph Hellwig
This patch adds support for an alternate I/O path in the scsi midlayer which uses the blk-mq infrastructure instead of the legacy request code. Use of blk-mq is fully transparent to drivers, although for now a host template field is provided to opt out of blk-mq usage in case any unforseen incompatibilities arise. In general replacing the legacy request code with blk-mq is a simple and mostly mechanical transformation. The biggest exception is the new code that deals with the fact the I/O submissions in blk-mq must happen from process context, which slightly complicates the I/O completion handler. The second biggest differences is that blk-mq is build around the concept of preallocated requests that also include driver specific data, which in SCSI context means the scsi_cmnd structure. This completely avoids dynamic memory allocations for the fast path through I/O submission. Due the preallocated requests the MQ code path exclusively uses the host-wide shared tag allocator instead of a per-LUN one. This only affects drivers actually using the block layer provided tag allocator instead of their own. Unlike the old path blk-mq always provides a tag, although drivers don't have to use it. For now the blk-mq path is disable by defauly and must be enabled using the "use_blk_mq" module parameter. Once the remaining work in the block layer to make blk-mq more suitable for slow devices is complete I hope to make it the default and eventually even remove the old code path. Based on the earlier scsi-mq prototype by Nicholas Bellinger. Thanks to Bart Van Assche and Robert Elliot for testing, benchmarking and various sugestions and code contributions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25scsi: fix the {host,target,device}_blocked counter messChristoph Hellwig
Seems like these counters are missing any sort of synchronization for updates, as a over 10 year old comment from me noted. Fix this by using atomic counters, and while we're at it also make sure they are in the same cacheline as the _busy counters and not needlessly stored to in every I/O completion. With the new model the _busy counters can temporarily go negative, so all the readers are updated to check for > 0 values. Longer term every successful I/O completion will reset the counters to zero, so the temporarily negative values will not cause any harm. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25scsi: convert host_busy to atomic_tChristoph Hellwig
Avoid taking the host-wide host_lock to check the per-host queue limit. Instead we do an atomic_inc_return early on to grab our slot in the queue, and if necessary decrement it after finishing all checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>