summaryrefslogtreecommitdiffstats
path: root/drivers/infiniband/ulp/srp
AgeCommit message (Collapse)Author
2014-08-14IB/srp: Fix return value check in srp_init_module()Wei Yongjun
In case of error, the function create_workqueue() returns NULL pointer not ERR_PTR(). The IS_ERR() test in the return value check should be replaced with NULL test. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-08-01IB/srp: Fix residual handlingBart Van Assche
From Documentation/scsi/scsi_mid_low_api.txt: "resid - an LLD should set this signed integer to the requested transfer length (i.e. 'request_bufflen') less the number of bytes that are actually transferred." This means that resid > 0 in case of an underrun and also that resid < 0 in case of an overrun. Modify the SRP initiator code such that it matches this requirement. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: David Dillow <dave@thedillows.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-08-01IB/srp: Fix deadlock between host removal and multipathdBart Van Assche
If scsi_remove_host() is invoked after a SCSI device has been blocked, if the fast_io_fail_tmo or dev_loss_tmo work gets scheduled on the workqueue executing srp_remove_work() and if an I/O request is scheduled after the SCSI device had been blocked by e.g. multipathd then the following deadlock can occur: kworker/6:1 D ffff880831f3c460 0 195 2 0x00000000 Call Trace: [<ffffffff814aafd9>] schedule+0x29/0x70 [<ffffffff814aa0ef>] schedule_timeout+0x10f/0x2a0 [<ffffffff8105af6f>] msleep+0x2f/0x40 [<ffffffff8123b0ae>] __blk_drain_queue+0x4e/0x180 [<ffffffff8123d2d5>] blk_cleanup_queue+0x225/0x230 [<ffffffffa0010732>] __scsi_remove_device+0x62/0xe0 [scsi_mod] [<ffffffffa000ed2f>] scsi_forget_host+0x6f/0x80 [scsi_mod] [<ffffffffa0002eba>] scsi_remove_host+0x7a/0x130 [scsi_mod] [<ffffffffa07cf5c5>] srp_remove_work+0x95/0x180 [ib_srp] [<ffffffff8106d7aa>] process_one_work+0x1ea/0x6c0 [<ffffffff8106dd9b>] worker_thread+0x11b/0x3a0 [<ffffffff810758bd>] kthread+0xed/0x110 [<ffffffff814b972c>] ret_from_fork+0x7c/0xb0 multipathd D ffff880096acc460 0 5340 1 0x00000000 Call Trace: [<ffffffff814aafd9>] schedule+0x29/0x70 [<ffffffff814aa0ef>] schedule_timeout+0x10f/0x2a0 [<ffffffff814ab79b>] io_schedule_timeout+0x9b/0xf0 [<ffffffff814abe1c>] wait_for_completion_io_timeout+0xdc/0x110 [<ffffffff81244b9b>] blk_execute_rq+0x9b/0x100 [<ffffffff8124f665>] sg_io+0x1a5/0x450 [<ffffffff8124fd21>] scsi_cmd_ioctl+0x2a1/0x430 [<ffffffff8124fef2>] scsi_cmd_blk_ioctl+0x42/0x50 [<ffffffffa00ec97e>] sd_ioctl+0xbe/0x140 [sd_mod] [<ffffffff8124bd04>] blkdev_ioctl+0x234/0x840 [<ffffffff811cb491>] block_ioctl+0x41/0x50 [<ffffffff811a0df0>] do_vfs_ioctl+0x300/0x520 [<ffffffff811a1051>] SyS_ioctl+0x41/0x80 [<ffffffff814b9962>] tracesys+0xd0/0xd5 Fix this by scheduling removal work on another workqueue than the transport layer timers. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: David Dillow <dave@thedillows.org> Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-29IB/srp: Avoid problems if a header uses pr_fmtJoe Perches
SRP defines pr_fmt(fmt) to be "PFX fmt", and then includes a bunch of header files before it gets around to defining PFX. This causes problems if any of the header files do a pr_... and use pr_fmt(). Fix this by using KBUILD_MODNAME instead of the private PFX. Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Add fast registration supportBart Van Assche
Certain HCA types (e.g. Connect-IB) and certain configurations (e.g. ConnectX VF) support fast registration but not FMR. Hence add fast registration support. In function srp_rport_reconnect(), move the the srp_finish_req() loop from after to before the srp_create_target_ib() call. This is needed to avoid that srp_finish_req() tries to queue any invalidation requests for rkeys associated with the old queue pair on the newly allocated queue pair. Invoking srp_finish_req() before the queue pair has been reallocated is safe since srp_claim_req() handles completions correctly that arrive after srp_finish_req() has been invoked. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Rename FMR-related variablesBart Van Assche
The next patch will cause the renamed variables to be shared between the code for FMR and for FR memory registration. Make the names of these variables independent of the memory registration mode. This patch does not change any functionality. The start of this patch was the changes applied via the following shell command: sed -i.orig 's/SRP_FMR_SIZE/SRP_MAX_PAGES_PER_MR/g; \ s/fmr_page_mask/mr_page_mask/g;s/fmr_page_size/mr_page_size/g; \ s/fmr_page_shift/mr_page_shift/g;s/fmr_max_size/mr_max_size/g; \ s/max_pages_per_fmr/max_pages_per_mr/g;s/nfmr/nmdesc/g; \ s/fmr_len/dma_len/g' drivers/infiniband/ulp/srp/ib_srp.[ch] Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: One FMR pool per SRP connectionBart Van Assche
Allocate one FMR pool per SRP connection instead of one SRP pool per HCA. This improves scalability of the SRP initiator. Only request the SCSI mid-layer to retry a SCSI command after a temporary mapping failure (-ENOMEM) but not after a permanent mapping failure. This avoids that SCSI commands are retried indefinitely if a permanent memory mapping failure occurs. Tell the SCSI mid-layer to reduce queue depth temporarily in the unlikely case where an application is queuing many requests with more than max_pages_per_fmr sg-list elements. For FMR pool allocation, base the max_pages_per_fmr parameter on the HCA memory registration limit. Only try to allocate an FMR pool if FMR is supported. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Introduce the 'register_always' kernel module parameterBart Van Assche
Add a kernel module parameter that enables memory registration also for SG-lists that can be processed without memory registration. This makes it easier for kernel developers to test the memory registration code. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Introduce srp_finish_mapping()Bart Van Assche
This patch does not change any functionality. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Introduce srp_map_fmr()Bart Van Assche
This patch does not change any functionality. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Introduce an additional local variableBart Van Assche
This patch does not change any functionality. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Fix kernel-doc warningsBart Van Assche
Avoid that the kernel-doc tool warns about missing argument descriptions for the ib_srp.[ch] source files. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-20IB/srp: Fix a sporadic crash triggered by cable pullingBart Van Assche
Avoid that the loops that iterate over the request ring can encounter a pointer to a SCSI command in req->scmnd that is no longer associated with that request. If the function srp_unmap_data() is invoked twice for a SCSI command that is not in flight then that would cause ib_fmr_pool_unmap() to be invoked with an invalid pointer as argument, resulting in a kernel oops. Reported-by: Sagi Grimberg <sagig@mellanox.com> Reference: http://thread.gmane.org/gmane.linux.drivers.rdma/19068/focus=19069 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24IB/srp: Fix a race condition between failing I/O and I/O completionBart Van Assche
Avoid that srp_terminate_io() can access req->scmnd after it has been cleared by the I/O completion code. Do this by protecting req->scmnd accesses from srp_terminate_io() via locking Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24IB/srp: Avoid that writing into "add_target" hangs due to a cable pullBart Van Assche
If a cable is pulled while srp_connect_target() is in progress that can result in that function never to return. That makes the process, e.g. srp_daemon, that invoked this function unkillable. Avoid this by letting srp_connect_target() finish if the event IB_CM_TIMEWAIT_EXIT is received. This patch fixes a hang with the following call trace: [<ffffffff814eae85>] schedule_timeout+0x215/0x2e0 [<ffffffff814eab03>] wait_for_common+0x123/0x180 [<ffffffff814eac1d>] wait_for_completion+0x1d/0x20 [<ffffffffa03b398c>] srp_connect_target+0x1dc/0x410 [ib_srp] [<ffffffffa03b5809>] srp_create_target+0xba9/0xe70 [ib_srp] [<ffffffff8133e590>] dev_attr_store+0x20/0x30 [<ffffffff811eb8f5>] sysfs_write_file+0xe5/0x170 [<ffffffff811767c8>] vfs_write+0xb8/0x1a0 [<ffffffff811770c1>] sys_write+0x51/0x90 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24IB/srp: Make writing into the "add_target" sysfs attribute interruptibleBart Van Assche
Avoid that stopping srp_daemon takes unusually long due to a cable pull by making writing into the "add_target" sysfs attribute interruptible. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24IB/srp: Avoid duplicate connectionsBart Van Assche
The connection uniqueness check is performed before a new connection is added to the target list. This patch protects both actions by a mutex such that simultaneous writes from two different threads into the "add_target" variable do not result in duplicate connections. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24IB/srp: Add more loggingBart Van Assche
Log sgid and dgid when reporting that a login has been rejected or when a host has been added. This makes it easy to figure out which initiator and target ports these messages apply to. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24IB/srp: Check ib_query_gid return valueSagi Grimberg
Detected by Coverity. Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-01-21scsi_transport_srp: Fix a race conditionBart Van Assche
The rport timers must be stopped before the SRP initiator destroys the resources associated with the SCSI host. This is necessary because otherwise the callback functions invoked from the SRP transport layer could trigger a use-after-free. Stopping the rport timers before invoking scsi_remove_host() can trigger long delays in the SCSI error handler if a transport layer failure occurs while scsi_remove_host() is in progress. Hence move the code for stopping the rport timers from srp_rport_release() into a new function and invoke that function after scsi_remove_host() has finished. This patch fixes the following sporadic kernel crash: kernel BUG at include/asm-generic/dma-mapping-common.h:64! invalid opcode: 0000 [#1] SMP RIP: 0010:[<ffffffffa03b20b1>] [<ffffffffa03b20b1>] srp_unmap_data+0x121/0x130 [ib_srp] Call Trace: [<ffffffffa03b20fc>] srp_free_req+0x3c/0x80 [ib_srp] [<ffffffffa03b2188>] srp_finish_req+0x48/0x70 [ib_srp] [<ffffffffa03b21fb>] srp_terminate_io+0x4b/0x60 [ib_srp] [<ffffffffa03a6fb5>] __rport_fail_io_fast+0x75/0x80 [scsi_transport_srp] [<ffffffffa03a7438>] rport_fast_io_fail_timedout+0x88/0xc0 [scsi_transport_srp] [<ffffffff8108b370>] worker_thread+0x170/0x2a0 [<ffffffff81090876>] kthread+0x96/0xa0 [<ffffffff8100c0ca>] child_rip+0xa/0x20 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Report receive errors correctlyBart Van Assche
The IB spec does not guarantee that the opcode is available in error completions. Hence do not rely on it. See also commit 948d1e889e5b ("IB/srp: Introduce srp_handle_qp_err()"). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: <stable@vger.kernel.org> # v3.8 Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Avoid offlining operational SCSI devicesBart Van Assche
If SCSI commands are submitted with a SCSI request timeout that is lower than the the IB RC timeout, it can happen that the SCSI error handler has already started device recovery before transport layer error handling starts. So it can happen that the SCSI error handler tries to abort a SCSI command after it has been reset by srp_rport_reconnect(). Tell the SCSI error handler that such commands have finished and that it is not necessary to continue its recovery strategy for commands that have been reset by srp_rport_reconnect(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Remove target from list before freeing Scsi_Host structureVu Pham
Remove an SRP target from the SRP target list before invoking the last scsi_host_put() call. This change is necessary because that last put frees the memory that holds the srp_target_port structure. This patch prevents the following kernel oops: RIP: 0010:[<ffffffff810b00d0>] __lock_acquire+0x500/0x1570 Call Trace: [<ffffffff810b11e4>] lock_acquire+0xa4/0x120 [<ffffffff81531206>] _spin_lock+0x36/0x70 [<ffffffffa01b6d8f>] srp_remove_work+0xef/0x180 [ib_srp] [<ffffffff8109125c>] worker_thread+0x21c/0x3d0 [<ffffffff81096e86>] kthread+0x96/0xa0 [<ffffffff8100c20a>] child_rip+0xa/0x20 Signed-off-by: Vu Pham <vuhuong@mellanox.com> [ bvanassche - Modified path description and CC'ed stable. ] Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Add change_queue_depth and change_queue_type supportJack Wang
Currently, it's not possible to change queue depth for a device behind SRP host. Sometimes, we need to adjust queue_depth for performance reason (eg storage busy, we need lower queue_depth to avoid running into SCSI error handler), so this patch add support for SRP driver. Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com> Tested-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Make queue size configurableBart Van Assche
Certain storage configurations, e.g. a sufficiently large array of hard disks in a RAID configuration, need a queue depth above 64 to achieve optimal performance. Hence make the queue depth configurable. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Tested-by: Jack Wang <xjtuwjp@gmail.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Introduce srp_alloc_req_data()Bart Van Assche
This patch does not change any functionality. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Cc: Roland Dreier <roland@purestorage.com> Cc: Vu Pham <vu@mellanox.com> Cc: Sebastian Riemer <sebastian.riemer@profitbricks.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Export sgid to sysfsBart Van Assche
On an initiator system with multiple IB ports it is not yet possible to figure out what the originating port of an SRP connection is. Hence make the source GID available in sysfs. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Add periodic reconnect functionalityBart Van Assche
After a transport layer occurred, periodically try to reconnect to the target until the dev_loss timer expires. Protect the callback functions that can be invoked from inside the SCSI EH against concurrent invocation with srp_reconnect_rport() via the rport mutex. Change the default dev_loss_tmo from 60s into 600s to give the reconnect mechanism a chance to kick in. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08scsi_transport_srp: Add periodic reconnect supportBart Van Assche
Add support for periodically reconnecting to an SRP target until the dev_loss timer expires. After the tenth reconnection attempt, gradually slow down subsequent reconnect attempts. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Start timers if a transport layer error occursBart Van Assche
Start the reconnect timer, fast_io_fail timer and dev_loss timers if a transport layer error occurs. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Use SRP transport layer error recoveryBart Van Assche
Enable fast_io_fail_tmo and dev_loss_tmo functionality for the IB SRP initiator. Add kernel module parameters that allow to specify default values for these parameters. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Keep rport as long as the IB transport layerBart Van Assche
Keep the rport data structure around after srp_remove_host() has finished until cleanup of the IB transport layer has finished completely. This is necessary because later patches use the rport pointer inside the queuecommand callback. Without this patch accessing the rport from inside a queuecommand callback is racy because srp_remove_host() must be invoked before scsi_remove_host() and because the queuecommand callback could get invoked after srp_remove_host() has finished. In other words, without this patch the queuecommand callback can get invoked after the rport data structure has been freed. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Make transport layer retry count configurableVu Pham
Allow the InfiniBand RC retry count to be configured by the user as an option in the target login string. Reducing this retry count allows to reduce the path failover time. Signed-off-by: Vu Pham <vu@mellanox.com> [ bvanassche: Rewrote patch description / changed default retry count ] Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-07-11IB/srp: Let srp_abort() return FAST_IO_FAIL if TL offlineBart Van Assche
If the transport layer is offline it is more appropriate to let srp_abort() return FAST_IO_FAIL instead of SUCCESS. Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-07-01IB/srp: Bump driver version and release dateVu Pham
Signed-off-by: Vu Pham <vu@mellanox.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-07-01IB/srp: Make HCA completion vector configurableBart Van Assche
Several InfiniBand HCAs allow configuring the completion vector per CQ. This allows spreading the workload created by IB completion interrupts over multiple MSI-X vectors and hence over multiple CPU cores. In other words, configuring the completion vector properly not only allows reducing latency on an initiator connected to multiple SRP targets but also allows improving throughput. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-07-01IB/srp: Maintain a single connection per I_T nexusBart Van Assche
An SRP target is required to maintain a single connection between initiator and target. This means that if the 'add_target' attribute is used to create a second connection to a target, the first connection will be logged out and that the SCSI error handler will kick in. The SCSI error handler will cause the SRP initiator to reconnect, which will cause I/O over the second connection to fail. Avoid such ping-pong behavior by disabling relogins. If reconnecting manually is necessary, that is possible by deleting and recreating an rport via sysfs. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Sebastian Riemer <sebastian.riemer@profitbricks.com> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-07-01IB/srp: Fail I/O fast if target offlineBart Van Assche
If reconnecting failed we know that no command completion will be received anymore. Hence let the SCSI error handler fail such commands immediately. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-06-27IB/srp: Skip host settle delayBart Van Assche
The SRP initiator implements host reset by reconnecting to the SRP target. That means that communication with the target is possible as soon as host reset finished. Hence skip the host settle delay. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sebastian Riemer <sebastian.riemer@profitbricks.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-06-27IB/srp: Avoid skipping srp_reset_host() after a transport errorBart Van Assche
The SCSI error handler assumes that the transport layer is operational if an eh_abort_handler() returns SUCCESS. Hence srp_abort() only should return SUCCESS if sending the ABORT TASK task management function succeeded. This patch avoids the SCSI error handler skipping the srp_reset_host() call after a transport layer error. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-06-27IB/srp: Fix remove_one crash due to resource exhaustionDotan Barak
If the add_one callback fails during driver load no resources are allocated so there isn't a need to release any resources. Trying to clean the resource may lead to the following kernel panic: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffffa0132331>] srp_remove_one+0x31/0x240 [ib_srp] RIP: 0010:[<ffffffffa0132331>] [<ffffffffa0132331>] srp_remove_one+0x31/0x240 [ib_srp] Process rmmod (pid: 4562, threadinfo ffff8800dd738000, task ffff8801167e60c0) Call Trace: [<ffffffffa024500e>] ib_unregister_client+0x4e/0x120 [ib_core] [<ffffffffa01361bd>] srp_cleanup_module+0x15/0x71 [ib_srp] [<ffffffff810ac6a4>] sys_delete_module+0x194/0x260 [<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il> Reviewed-by: Eli Cohen <eli@mellanox.co.il> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: Sebastian Riemer <sebastian.riemer@profitbricks.com> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-02-25IB/srp: Fail I/O requests if the transport is offlineBart Van Assche
If an SRP target is no longer reachable and srp_reset_host() fails to reconnect then ib_srp will invoke scsi_remove_host(). That function will invoke __scsi_remove_device() for each LUN. And that last function will change the device state from SDEV_TRANSPORT_OFFLINE into SDEV_CANCEL. Certain user space software, e.g. older versions of multipathd, continue queueing I/O to SCSI devices that are in the SDEV_CANCEL state. If these I/O requests are submitted as SG_IO that means that the REQ_PREEMPT flag will be set and hence that these requests will be passed to srp_queuecommand(). These requests will time out. If new requests are queued fast enough from user space these active requests will prevent __scsi_remove_device() to finish. Avoid this by failing I/O requests in the SDEV_CANCEL state if the transport is offline. Introduce a new variable to keep track of the transport state instead of failing requests if (!target->connected || target->qp_in_error), so that the SCSI error handler has a chance to retry commands after a transport layer failure occurred. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: <stable@vger.kernel.org> # 3.8 Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-02-25IB/srp: Avoid endless SCSI error handling loopBart Van Assche
If a SCSI command times out it is passed to the SCSI error handler. The SCSI error handler will try to abort the commands that timed out. If aborting fails, a device reset will be attempted. If the device reset also fails a host reset will be attempted. If the host reset also fails the whole procedure will be repeated. srp_abort() and srp_reset_device() fail for a QP in the error state. srp_reset_host() fails after host removal has started. Hence if the SCSI error handler gets invoked after host removal has started and with the QP in the error state an endless loop will be triggered. Modify the SCSI error handling functions in ib_srp as follows: - Abort SCSI commands properly even if the QP is in the error state. - Make srp_reset_host() reset SCSI requests even after host removal has already started or if reconnecting fails. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dave@thedillows.org> Cc: <stable@vger.kernel.org> # 3.8 Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-02-25IB/srp: Avoid sending a task management function needlesslyBart Van Assche
Do not send a task management function if sending will fail anyway because either there is no RDMA/RC connection or the QP is in the error state. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dave@thedillows.org> Cc: <stable@vger.kernel.org> # 3.8 Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-02-25IB/srp: Track connection state properlyBart Van Assche
Remove an assignment that incorrectly overwrites the connection state update by srp_connect_target(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dave@thedillows.org> Cc: <stable@vger.kernel.org> # 3.8 Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-11-30IB/srp: Allow SRP disconnect through sysfsBart Van Assche
Make it possible to disconnect the IB RC connection used by the SRP protocol to communicate with a target. Have the SRP transport layer create a sysfs "delete" attribute for initiator drivers that support this functionality. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-11-30IB/srp: send disconnect request without waiting for CM timewait exitVu Pham
Now that SRP recreates the CM ID, QP, and CQ for each connection, there is no need to wait for the timewait state to complete. Signed-off-by: Vu Pham <vu@mellanox.com> Signed-off-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-11-30IB/srp: destroy and recreate QP and CQs when reconnectingIshai Rabinovitz
HW QP FATAL errors persist over a reset operation, but we can recover from that by recreating the QP and associated CQs for each connection. Creating a new QP/CQ also completely forecloses any possibility of getting stale completions or packets on the new connection. Signed-off-by: Ishai Rabinovitz <ishai@mellanox.co.il> Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il> [ updated to current code from OFED, cleaned up commit message ] Signed-off-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-11-30IB/srp: Eliminate state SRP_TARGET_DEADBart Van Assche
Only queue removal work after having changed the target state into SRP_TARGET_REMOVED and not if that state was already equal to SRP_TARGET_REMOVED. That allows us to remove the state SRP_TARGET_DEAD. Add a call to srp_disconnect_target() in srp_remove_target() -- due to previous changes it is now safe to invoke that function even if the IB connection has already been disconnected. This change allows us to replace the target removal code in srp_remove_one() by an (indirect) call to srp_remove_target(). Rename srp_target_port.work into srp_target_port.remove_work to reflect its usage. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-11-30IB/srp: Introduce the helper function srp_remove_target()Bart Van Assche
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>