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* scsi: default to scsi-mqChristoph Hellwig2017-06-271-4/+0
| | | | | | | | | | 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>
* scsi: Only add commands to the device command list if required by the LLDBart Van Assche2017-06-121-8/+1
| | | | | | | | | | | | | 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>
* scsi: Skip deleted devices in __scsi_device_lookupZhou Zhengping2017-05-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* block: introduce blk_rq_is_passthroughChristoph Hellwig2017-01-311-1/+1
| | | | | | | | | 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>
* scsi: allocate scsi_cmnd structures as part of struct requestChristoph Hellwig2017-01-271-319/+0
| | | | | | | | | | | 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>
* scsi: remove scsi_cmd_dma_poolChristoph Hellwig2017-01-271-14/+1
| | | | | | | | | | | 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>
* scsi: respect unchecked_isa_dma for blk-mqChristoph Hellwig2017-01-271-19/+5
| | | | | | | | | | | | | | | | 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>
* scsi: remove gfp_flags member in scsi_host_cmd_poolChristoph Hellwig2017-01-271-10/+4
| | | | | | | | | | | | 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>
* block: add code to track actual device queue depthJens Axboe2016-11-051-0/+3
| | | | | | | | | | | | | | 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>
* scsi: Avoid that toggling use_blk_mq triggers a memory leakBart Van Assche2016-09-261-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* scsi: remove the disable_blk_mq host flagChristoph Hellwig2016-07-151-0/+1
| | | | | | | | | | 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>
* scsi: Do not attach VPD to devices that don't support itHannes Reinecke2016-04-051-1/+2
| | | | | | | | | | | | | | | | | | 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>
* scsi: rescan VPD attributesHannes Reinecke2015-11-301-3/+17
| | | | | | | | | | | 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>
* scsi: use host wide tags by defaultChristoph Hellwig2015-11-091-24/+3
| | | | | | | | | | | | | 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>
* Move code that is used both by initiator and target driversBart Van Assche2015-06-011-46/+0
| | | | | | | | | | | | 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>
* scsi: proper state checking and module refcount handling in scsi_device_getChristoph Hellwig2015-03-191-7/+13
| | | | | | | | | | | | | | | | | 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>
* Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds2015-02-111-9/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * scsi: Do not display buffer pointers in scsi_log_send()Hannes Reinecke2015-01-091-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * scsi: use per-cpu buffer for formatting scsi_print_result()Hannes Reinecke2015-01-091-1/+1
| | | | | | | | | | | | | | | | | | | | 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>
* | scsi: always increment reference countRusty Russell2015-01-231-10/+3
|/ | | | | | | | | | | | | | | | | | 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>
* Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley2014-12-181-22/+0
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| * scsi: never drop to untagged mode during queue ramp downChristoph Hellwig2014-12-041-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * scsi: remove ->change_queue_type methodChristoph Hellwig2014-12-041-16/+0
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley2014-12-081-26/+15
|\ \ | |/ | | | | | | | | | | | | | | | | 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>
| * scsi: drop reason argument from ->change_queue_depthChristoph Hellwig2014-11-241-26/+15
| | | | | | | | | | | | | | | | | | | | | | 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>
* | scsi: move scsi_dispatch_cmd to scsi_lib.cChristoph Hellwig2014-11-241-81/+0
|/ | | | | | | | | 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>
* scsi: don't set tagging state from scsi_adjust_queue_depthChristoph Hellwig2014-11-121-20/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* scsi: always assign block layer tags if enabledChristoph Hellwig2014-11-121-8/+4
| | | | | | | | | | | | | 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>
* scsi: remove ordered_tags scsi_device fieldChristoph Hellwig2014-11-121-11/+2
| | | | | | | | | | 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>
* scsi: provide a generic change_queue_type methodChristoph Hellwig2014-11-121-0/+20
| | | | | | | | | | | 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>
* scsi: simplify scsi_log_(send|completion)Hannes Reinecke2014-11-121-37/+6
| | | | | | | | | 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>
* scsi: use sdev as argument for sense code printingHannes Reinecke2014-11-121-1/+1
| | | | | | | | | | | 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>
* scsi: add a CONFIG_SCSI_MQ_DEFAULT optionChristoph Hellwig2014-10-011-0/+4
| | | | | | | | | | | 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>
* scsi: don't store LUN bits in CDB[1] for USB mass-storage devicesAlan Stern2014-09-151-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [SCSI] save command pool address of Scsi_HostJuergen Gross2014-08-151-2/+10
| | | | | | | | | | | | | | | | | | 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>
* scsi: use short driver name for per-driver cmd slab cachesJames Bottomley2014-07-291-2/+2
| | | | | | | | | | | | | 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>
* scsi: update scsi_device_typesChristoph Hellwig2014-07-251-0/+2
| | | | | | | | | | | 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>
* scsi: add support for a blk-mq based I/O path.Christoph Hellwig2014-07-251-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* scsi: fix the {host,target,device}_blocked counter messChristoph Hellwig2014-07-251-11/+10
| | | | | | | | | | | | | | | | | | | | 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>
* scsi: convert host_busy to atomic_tChristoph Hellwig2014-07-251-1/+1
| | | | | | | | | | | | | | 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>
* scsi: set ->scsi_done before calling scsi_dispatch_cmdChristoph Hellwig2014-07-251-22/+1
| | | | | | | | | | | | | The blk-mq code path will set this to a different function, so make the code simpler by setting it up in a legacy-request specific place. 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>
* scsi: centralize command re-queueing in scsi_dispatch_fnChristoph Hellwig2014-07-251-23/+12
| | | | | | | | | | | | Make sure we only have the logic for requeing commands in one place. 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>
* scsi: cleanup switch in scsi_adjust_queue_depthDouglas Gilbert2014-07-171-4/+6
| | | | | | | | | | | | | | While checking what scsi_adjust_queue_depth() did I thought its switch statement could be clearer: - remove redundant assignment (to sdev->queue_depth) - re-order cases (thus removing the fall-through) Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Robert Elliott <elliott@hp.com> Tested-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* scsi: remove various exports that were only used by scsi_tgtChristoph Hellwig2014-07-171-7/+3
| | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
* scsi: use dev_printk variants where possibleHannes Reinecke2014-07-171-9/+9
| | | | | | | | | | Using dev_printk variants prefixes the logging message with the originating device, which makes debugging easier. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
* scsi: use 64-bit LUNsHannes Reinecke2014-07-171-4/+4
| | | | | | | | | | | | | The SCSI standard defines 64-bit values for LUNs, and large arrays employing large or hierarchical LUN numbers become more and more common. So update the linux SCSI stack to use 64-bit LUN numbers. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Ewan Milne <emilne@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* scsi: remove two cancel_delayed_work() calls from the mid-layerBart Van Assche2014-07-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | scsi_put_command() is either invoked before blk_start_request() or after block layer processing has completed. scsi_cmnd.abort_work is scheduled from inside the SCSI timeout handler. The block layer guarantees that either the regular completion handler (softirq_done_fn()) or the timeout handler (rq_timed_out_fn()) is invoked but not both. This means that scsi_put_command() is never invoked while abort_work is scheduled. Hence remove the cancel_delayed_work() call from scsi_put_command(). Similarly, scsi_abort_command() is only invoked from the SCSI timeout handler. If scsi_abort_command() is invoked for a SCSI command with the SCSI_EH_ABORT_SCHEDULED flag set this means that scmd_eh_abort_handler() has already invoked scsi_queue_insert() and hence that scsi_cmnd.abort_work is no longer pending. Hence also remove the cancel_delayed_work() call from scsi_abort_command(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
* Merge branch 'async-scsi-resume' of ↵Linus Torvalds2014-04-111-0/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci Pull async SCSI resume support from Dan Williams: "Allow disks and other devices to resume in parallel. This provides a tangible speed up for a non-esoteric use case (laptop resume): https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach" * 'async-scsi-resume' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci: scsi: async sd resume
| * scsi: async sd resumeDan Williams2014-04-101-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | async_schedule() sd resume work to allow disks and other devices to resume in parallel. This moves the entirety of scsi_device resume to an async context to ensure that scsi_device_resume() remains ordered with respect to the completion of the start/stop command. For the duration of the resume, new command submissions (that do not originate from the scsi-core) will be deferred (BLKPREP_DEFER). It adds a new ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain) as a container of these operations. Like scsi_sd_probe_domain it is flushed at sd_remove() time to ensure async ops do not continue past the end-of-life of the sdev. The implementation explicitly refrains from reusing scsi_sd_probe_domain directly for this purpose as it is flushed at the end of dpm_resume(), potentially defeating some of the benefit. Given sdevs are quiesced it is permissible for these resume operations to bleed past the async_synchronize_full() calls made by the driver core. We defer the resolution of which pm callback to call until scsi_dev_type_{suspend|resume} time and guarantee that the callback parameter is never NULL. With this in place the type of resume operation is encoded in the async function identifier. There is a concern that async resume could trigger PSU overload. In the enterprise, storage enclosures enforce staggered spin-up regardless of what the kernel does making async scanning safe by default. Outside of that context a user can disable asynchronous scanning via a kernel command line or CONFIG_SCSI_SCAN_ASYNC. Honor that setting when deciding whether to do resume asynchronously. Inspired by Todd's analysis and initial proposal [2]: https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach Cc: Len Brown <len.brown@intel.com> Cc: Phillip Susi <psusi@ubuntu.com> [alan: bug fix and clean up suggestion] Acked-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Todd Brandt <todd.e.brandt@linux.intel.com> [djbw: kick all resume work to the async queue] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | [SCSI] add support for per-host cmd poolsChristoph Hellwig2014-03-271-19/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows drivers to specify the size of their per-command private data in the host template and then get extra memory allocated for each command instead of needing another allocation in ->queuecommand. With the current SCSI code that already does multiple allocations for each command this probably doesn't make a big performance impact, but it allows to clean up the drivers, and prepare them for using the blk-mq infrastructure where the common allocation will make a difference. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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