If a cable is pulled during LUN scanning it can happen that the
SRP rport and the SCSI host have been created but no LUNs have been
added to the SCSI host. Since multipathd only sends SCSI commands
to a SCSI target if one or more SCSI devices are present and since
there is no keepalive mechanism for IB queue pairs this means that
after a LUN scan failed and after a reconnect has succeeded no
data will be sent over the QP and hence that a subsequent cable
pull will not be detected. Avoid this by not creating an rport or
SCSI host if a cable is pulled during a SCSI LUN scan.
Note: so far the above behavior has only been observed with the
kernel module parameter ch_count set to a value >= 2.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Attempting to connect three times may be insufficient after an
initiator system tries to relogin, especially if the relogin
attempt occurs before the SRP target service ID has been
registered. Since the srp_daemon retries a failed login attempt
anyway, remove the stale connection retry mechanism.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The patch that adds multichannel support into the SRP initiator
driver introduces an additional call to srp_free_ch_ib(). This
patch helps to keep that later patch simple.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
The IB spec does not guarantee that the opcode is available in error
completions. Hence do not rely on it. See also commit 948d1e889e
("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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
