Commit Graph

187 Commits

Author SHA1 Message Date
Bart Van Assche 56b5390caf IB/srp: Use P_Key cache for P_Key lookups
This change slightly reduces the time needed to log in.

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>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-04-15 16:06:54 -04:00
Linus Torvalds cdce6ac277 SCSI for-linus on 20141220
This is a much shorter set of patches that were on the go but didn't make it
 in to the early pull request for the merge window.  It's really a set of bug
 fixes plus some final cleanup work on the new tag queue API.
 
 Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Merge tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI update from James Bottomley:
 "This is a much shorter set of patches that were on the go but didn't
  make it in to the early pull request for the merge window.  It's
  really a set of bug fixes plus some final cleanup work on the new tag
  queue API"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  storvsc: ring buffer failures may result in I/O freeze
  ipr: set scsi_level correctly for disk arrays
  ipr: add support for async scanning to speed up boot
  scsi_debug: fix missing "break;" in SDEBUG_UA_CAPACITY_CHANGED case
  scsi_debug: take sdebug_host_list_lock when changing capacity
  scsi_debug: improve driver description in Kconfig
  scsi_debug: fix compare and write errors
  qla2xxx: fix race in handling rport deletion during recovery causes panic
  scsi: blacklist RSOC for Microsoft iSCSI target devices
  scsi: fix random memory corruption with scsi-mq + T10 PI
  Revert "[SCSI] mpt3sas: Remove phys on topology change"
  Revert "[SCSI] mpt2sas: Remove phys on topology change."
  esas2r: Correct typos of "validate" in a comment
  fc: FCP_PTA_SIMPLE is 0
  ibmvfc: remove unused tag variable
  scsi: remove MSG_*_TAG defines
  scsi: remove scsi_set_tag_type
  scsi: remove scsi_get_tag_type
  scsi: never drop to untagged mode during queue ramp down
  scsi: remove ->change_queue_type method
2014-12-20 13:42:57 -08:00
Sagi Grimberg 7dcf9c193b IB/srp: Allow newline separator for connection string
In case the last argument of the connection string is processed as a
string (destination GID for example).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15 18:15:23 -08:00
Christoph Hellwig efc3c1df5f scsi: remove ->change_queue_type method
Since we got rid of ordered tag support in 2010 the prime use case of
switching on and off ordered tags has been obsolete.  The other function
of enabling/disabling tagging entirely has only been correctly implemented
by the 53c700 driver and isn't generally useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-12-04 09:55:45 +01:00
Christoph Hellwig db5ed4dfd5 scsi: drop reason argument from ->change_queue_depth
Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24 14:45:27 +01:00
Christoph Hellwig 1e6f241604 scsi: don't allow setting of queue_depth bigger than can_queue
We won't ever queue more commands than the host allows.  Instead of
letting drivers either reject or ignore this case handle it in
common code.  Note that various driver use internal constant or
variables that are assigned to both shost->can_queue and checked
in ->change_queue_depth - I did remove those checks as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24 14:45:26 +01:00
Christoph Hellwig c40ecc12cf scsi: avoid ->change_queue_depth indirection for queue full tracking
All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

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: Venkatesh Srinivas <venkateshs@google.com>
2014-11-24 14:45:12 +01:00
Bart Van Assche 7dad6b2e44 IB/srp: Fix a race condition triggered by destroying a queue pair
At least LID reassignment can trigger a race condition in the SRP
initiator driver, namely the receive completion handler trying to
post a request on a QP during or after QP destruction and before
the CQ's have been destroyed. Avoid this race by modifying a QP
into the error state and by waiting until all receive completions
have been processed before destroying a QP.

Reported-by: Max Gurtuvoy <maxg@mellanox.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12 12:05:24 +01:00
Bart Van Assche d92c0da71a IB/srp: Add multichannel support
Improve performance by using multiple RDMA/RC channels per SCSI
host for communication with an SRP target. About the
implementation:
- Introduce a loop over all channels in the code that uses
  target->ch.
- Set the SRP_MULTICHAN_MULTI flag during login for the creation
  of the second and subsequent channels.
- RDMA completion vectors are chosen such that RDMA completion
  interrupts are handled by the CPU socket that submitted the I/O
  request. As one can see in this patch it has been assumed if a
  system contains n CPU sockets and m RDMA completion vectors
  have been assigned to an RDMA HCA that IRQ affinity has been
  configured such that completion vectors [i*m/n..(i+1)*m/n) are
  bound to CPU socket i with 0 <= i < n.
- Modify srp_free_ch_ib() and srp_free_req_data() such that it
  becomes safe to invoke these functions after the corresponding
  allocation function failed.
- Add a ch_count sysfs attribute per target port.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12 12:05:24 +01:00
Bart Van Assche 77f2c1a40e IB/srp: Use block layer tags
Since the block layer already contains functionality to assign
a tag to each request, use that functionality instead of
reimplementing that functionality in the SRP initiator driver.
This change makes the free_reqs list superfluous. Hence remove
that list.

[hch: updated to use .use_blk_tags instead scsi_activate_tcq]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12 12:05:23 +01:00
Bart Van Assche 509c07bc18 IB/srp: Separate target and channel variables
Changes in this patch:
- Move channel variables into a new structure (struct srp_rdma_ch).
- Add an srp_target_port pointer, 'lock' and 'comp_vector' members
  in struct srp_rdma_ch.
- Add code to initialize these three new member variables.
- Many boring "target->" into "ch->" changes.
- The cm_id and completion handler context pointers are now of type
  srp_rdma_ch * instead of srp_target_port *.
- Three kzalloc(a * b, f) calls have been changed into kcalloc(a, b, f)
  to avoid that this patch would trigger a checkpatch warning.
- Two casts from u64 into unsigned long long have been left out
  because these are superfluous. Since considerable time u64 is
  defined as unsigned long long for all architectures supported by
  the Linux kernel.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12 11:32:03 +01:00
Bart Van Assche 747fe000ef IB/srp: Introduce two new srp_target_port member variables
Introduce the srp_target_port member variables 'sgid' and 'pkey'.
Change the type of 'orig_dgid' from __be16[8] into union ib_gid.
This patch does not change any functionality but makes the
"Separate target and channel variables" patch easier to verify.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12 11:32:03 +01:00
Bart Van Assche 34aa654ecb IB/srp: Avoid that I/O hangs due to a cable pull during LUN scanning
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>
2014-11-12 11:32:02 +01:00
Bart Van Assche 205619f2f8 IB/srp: Remove stale connection retry mechanism
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>
2014-11-12 11:32:02 +01:00
Bart Van Assche 394c595ee8 IB/srp: Move ib_destroy_cm_id() call into srp_free_ch_ib()
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>
2014-11-12 11:32:01 +01:00
Christoph Hellwig c8b09f6fb6 scsi: don't set tagging state from scsi_adjust_queue_depth
Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-11-12 11:19:43 +01:00
Christoph Hellwig a62182f338 scsi: provide a generic change_queue_type method
Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12 11:19:39 +01:00
Wei Yongjun da05be290f IB/srp: Fix return value check in srp_init_module()
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>
2014-08-14 08:57:54 -07:00
Bart Van Assche e714531a34 IB/srp: Fix residual handling
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>
2014-08-01 15:21:51 -07:00
Bart Van Assche bcc0591035 IB/srp: Fix deadlock between host removal and multipathd
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>
2014-08-01 15:21:51 -07:00
Joe Perches d236cd0e20 IB/srp: Avoid problems if a header uses pr_fmt
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>
2014-05-29 21:32:54 -07:00
Bart Van Assche 5cfb17828d IB/srp: Add fast registration support
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>
2014-05-20 09:20:52 -07:00
Bart Van Assche 52ede08f00 IB/srp: Rename FMR-related variables
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>
2014-05-20 09:20:52 -07:00
Bart Van Assche d1b4289e16 IB/srp: One FMR pool per SRP connection
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>
2014-05-20 09:20:52 -07:00
Bart Van Assche b1b8854d16 IB/srp: Introduce the 'register_always' kernel module parameter
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>
2014-05-20 09:20:52 -07:00
Bart Van Assche 539dde6fc5 IB/srp: Introduce srp_finish_mapping()
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>
2014-05-20 09:20:52 -07:00
Bart Van Assche 76bc1e1ddd IB/srp: Introduce srp_map_fmr()
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>
2014-05-20 09:20:51 -07:00
Bart Van Assche 62154b2e89 IB/srp: Introduce an additional local variable
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>
2014-05-20 09:20:51 -07:00
Bart Van Assche af24663bc8 IB/srp: Fix kernel-doc warnings
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>
2014-05-20 09:20:51 -07:00
Bart Van Assche 024ca90151 IB/srp: Fix a sporadic crash triggered by cable pulling
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>
2014-05-20 09:20:51 -07:00
Bart Van Assche b3fe628da2 IB/srp: Fix a race condition between failing I/O and I/O completion
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>
2014-03-24 10:05:31 -07:00
Bart Van Assche ac72d766a8 IB/srp: Avoid that writing into "add_target" hangs due to a cable pull
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>
2014-03-24 10:05:31 -07:00
Bart Van Assche a702adceec IB/srp: Make writing into the "add_target" sysfs attribute interruptible
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>
2014-03-24 10:05:31 -07:00
Bart Van Assche 2d7091bcf6 IB/srp: Avoid duplicate connections
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>
2014-03-24 10:05:31 -07:00
Bart Van Assche e7ffde0164 IB/srp: Add more logging
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>
2014-03-24 10:05:30 -07:00
Sagi Grimberg 2088ca66f5 IB/srp: Check ib_query_gid return value
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>
2014-03-24 10:05:30 -07:00
Bart Van Assche 93079162bf scsi_transport_srp: Fix a race condition
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>
2014-01-21 10:46:17 -08:00
Bart Van Assche cd4e38542a IB/srp: Report receive errors correctly
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>
2013-11-08 14:43:18 -08:00
Bart Van Assche 99b6697a50 IB/srp: Avoid offlining operational SCSI devices
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>
2013-11-08 14:43:18 -08:00
Vu Pham 65d7dd2f34 IB/srp: Remove target from list before freeing Scsi_Host structure
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>
2013-11-08 14:43:17 -08:00
Jack Wang 71444b9781 IB/srp: Add change_queue_depth and change_queue_type support
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>
2013-11-08 14:43:17 -08:00
Bart Van Assche 4d73f95f70 IB/srp: Make queue size configurable
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>
2013-11-08 14:43:17 -08:00
Bart Van Assche b81d00bddf IB/srp: Introduce srp_alloc_req_data()
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>
2013-11-08 14:43:17 -08:00
Bart Van Assche 848b3082db IB/srp: Export sgid to sysfs
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>
2013-11-08 14:43:16 -08:00
Bart Van Assche a95cadb9da IB/srp: Add periodic reconnect functionality
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>
2013-11-08 14:43:16 -08:00
Bart Van Assche 8c64e4531c scsi_transport_srp: Add periodic reconnect support
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>
2013-11-08 14:43:16 -08:00
Bart Van Assche c1120f8981 IB/srp: Start timers if a transport layer error occurs
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>
2013-11-08 14:43:15 -08:00
Bart Van Assche ed9b2264fb IB/srp: Use SRP transport layer error recovery
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>
2013-11-08 14:43:15 -08:00
Bart Van Assche 9dd69a600a IB/srp: Keep rport as long as the IB transport layer
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>
2013-11-08 14:43:15 -08:00
Vu Pham 7bb312e4a2 IB/srp: Make transport layer retry count configurable
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>
2013-11-08 14:43:15 -08:00