lwn.git/drivers/scsi/scsi_lib.c, branch docs-4.16

scsi: use dma_get_cache_alignment() as minimum DMA alignment

2017-11-22T04:05:57+00:00

In non-coherent DMA mode, kernel uses cache flushing operations to maintain I/O coherency, so scsi's block queue should be aligned to the value returned by dma_get_cache_alignment(). Otherwise, If a DMA buffer and a kernel structure share a same cache line, and if the kernel structure has dirty data, cache_invalidate (no writeback) will cause data corruption. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen [hch: rebased and updated the comment and changelog] Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2017-11-15T00:23:44+00:00

Pull SCSI updates from James Bottomley: "This is mostly updates of the usual suspects: lpfc, qla2xxx, hisi_sas, megaraid_sas, pm80xx, mpt3sas, be2iscsi, hpsa. and a host of minor updates. There's no major behaviour change or additions to the core in all of this, so the potential for regressions should be small (biggest potential being in the scsi error handler changes)" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (203 commits) scsi: lpfc: Fix hard lock up NMI in els timeout handling. scsi: mpt3sas: remove a stray KERN_INFO scsi: mpt3sas: cleanup _scsih_pcie_enumeration_event() scsi: aacraid: use timespec64 instead of timeval scsi: scsi_transport_fc: add 64GBIT and 128GBIT port speed definitions scsi: qla2xxx: Suppress a kernel complaint in qla_init_base_qpair() scsi: mpt3sas: fix dma_addr_t casts scsi: be2iscsi: Use kasprintf scsi: storvsc: Avoid excessive host scan on controller change scsi: lpfc: fix kzalloc-simple.cocci warnings scsi: mpt3sas: Update mpt3sas driver version. scsi: mpt3sas: Fix sparse warnings scsi: mpt3sas: Fix nvme drives checking for tlr. scsi: mpt3sas: NVMe drive support for BTDHMAPPING ioctl command and log info scsi: mpt3sas: Add-Task-management-debug-info-for-NVMe-drives. scsi: mpt3sas: scan and add nvme device after controller reset scsi: mpt3sas: Set NVMe device queue depth as 128 scsi: mpt3sas: Handle NVMe PCIe device related events generated from firmware. scsi: mpt3sas: API's to remove nvme drive from sml scsi: mpt3sas: API 's to support NVMe drive addition to SML ...

Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block

2017-11-14T23:32:19+00:00

Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...

block, scsi: Make SCSI quiesce and resume work reliably

2017-11-11T02:53:25+00:00

The contexts from which a SCSI device can be quiesced or resumed are: * Writing into /sys/class/scsi_device/*/device/state. * SCSI parallel (SPI) domain validation. * The SCSI device power management methods. See also scsi_bus_pm_ops. It is essential during suspend and resume that neither the filesystem state nor the filesystem metadata in RAM changes. This is why while the hibernation image is being written or restored that SCSI devices are quiesced. The SCSI core quiesces devices through scsi_device_quiesce() and scsi_device_resume(). In the SDEV_QUIESCE state execution of non-preempt requests is deferred. This is realized by returning BLKPREP_DEFER from inside scsi_prep_state_check() for quiesced SCSI devices. Avoid that a full queue prevents power management requests to be submitted by deferring allocation of non-preempt requests for devices in the quiesced state. This patch has been tested by running the following commands and by verifying that after each resume the fio job was still running: for ((i=0; i<10; i++)); do ( cd /sys/block/md0/md && while true; do [ "$( sync_action sleep 1 done ) & pids=($!) for d in /sys/class/block/sd*[a-z]; do bdev=${d#/sys/class/block/} hcil=$(readlink "$d/device") hcil=${hcil#../../../} echo 4 > "$d/queue/nr_requests" echo 1 > "/sys/class/scsi_device/$hcil/device/queue_depth" fio --name="$bdev" --filename="/dev/$bdev" --buffered=0 --bs=512 \ --rw=randread --ioengine=libaio --numjobs=4 --iodepth=16 \ --iodepth_batch=1 --thread --loops=$((2**31)) & pids+=($!) done sleep 1 echo "$(date) Hibernating ..." >>hibernate-test-log.txt systemctl hibernate sleep 10 kill "${pids[@]}" echo idle > /sys/block/md0/md/sync_action wait echo "$(date) Done." >>hibernate-test-log.txt done Reported-by: Oleksandr Natalenko References: "I/O hangs after resuming from suspend-to-ram" (https://marc.info/?l=linux-block&m=150340235201348). Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Martin Steigerwald Tested-by: Oleksandr Natalenko Cc: Martin K. Petersen Cc: Ming Lei Cc: Christoph Hellwig Cc: Johannes Thumshirn Signed-off-by: Jens Axboe

ide, scsi: Tell the block layer at request allocation time about preempt requests

2017-11-11T02:53:25+00:00

Convert blk_get_request(q, op, __GFP_RECLAIM) into blk_get_request_flags(q, op, BLK_MQ_PREEMPT). This patch does not change any functionality. Signed-off-by: Bart Van Assche Tested-by: Martin Steigerwald Acked-by: David S. Miller [ for IDE ] Acked-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Tested-by: Oleksandr Natalenko Cc: Ming Lei Cc: Christoph Hellwig Cc: Johannes Thumshirn Signed-off-by: Jens Axboe

Revert "scsi: make 'state' device attribute pollable"

2017-11-07T17:04:32+00:00

This reverts commit 8a97712e5314aefe16b3ffb4583a34deaa49de04. This commit added a call to sysfs_notify() from within scsi_device_set_state(), which in turn turns out to make libata very unhappy, because ata_eh_detach_dev() does spin_lock_irqsave(ap->lock, flags); .. if (ata_scsi_offline_dev(dev)) { dev->flags |= ATA_DFLAG_DETACHED; ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG; } and ata_scsi_offline_dev() then does that scsi_device_set_state() to set it offline. So now we called sysfs_notify() from within a spinlocked region, which really doesn't work. The 0day robot reported this as: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:238 because sysfs_notify() ends up calling kernfs_find_and_get_ns() which then does mutex_lock(&kernfs_mutex).. The pollability of the device state isn't critical, so revert this all for now, and maybe we'll do it differently in the future. Reported-by: Fengguang Wu Acked-by: Tejun Heo Acked-by: Martin K. Petersen Acked-by: Hannes Reinecke Signed-off-by: Linus Torvalds

blk-mq: don't handle failure in .get_budget

2017-11-04T18:31:08+00:00

It is enough to just check if we can get the budget via .get_budget(). And we don't need to deal with device state change in .get_budget(). For SCSI, one issue to be fixed is that we have to call scsi_mq_uninit_cmd() to free allocated ressources if SCSI device fails to handle the request. And it isn't enough to simply call blk_mq_end_request() to do that if this request is marked as RQF_DONTPREP. Fixes: 0df21c86bdbf(scsi: implement .get_budget and .put_budget for blk-mq) Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

SCSI: don't get target/host busy_count in scsi_mq_get_budget()

2017-11-04T14:19:25+00:00

It is very expensive to atomic_inc/atomic_dec the host wide counter of host->busy_count, and it should have been avoided via blk-mq's mechanism of getting driver tag, which uses the more efficient way of sbitmap queue. Also we don't check atomic_read(&sdev->device_busy) in scsi_mq_get_budget() and don't run queue if the counter becomes zero, so IO hang may be caused if all requests are completed just before the current SCSI device is added to shost->starved_list. Fixes: 0df21c86bdbf(scsi: implement .get_budget and .put_budget for blk-mq) Reported-by: Bart Van Assche Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

scsi: implement .get_budget and .put_budget for blk-mq

2017-11-01T14:20:02+00:00

We need to tell blk-mq to reserve resources before queuing one request, so implement these two callbacks. Then blk-mq can avoid to dequeue request too early, and IO merging can be improved a lot. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

scsi: allow passing in null rq to scsi_prep_state_check()

2017-11-01T14:20:02+00:00

In the following patch, we will implement scsi_get_budget() which need to call scsi_prep_state_check() when rq isn't dequeued yet. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe