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path: root/drivers/infiniband/ulp/srp/ib_srp.c
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2015-02-13Reset to 3.12.37Scott Wood
2013-12-04IB/srp: Report receive errors correctlyBart Van Assche
commit cd4e38542a5c2cab94e5410fb17c1cc004a60792 upstream. 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> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-04IB/srp: Avoid offlining operational SCSI devicesBart Van Assche
commit 99b6697a50c2acbe3ca2772d359fc9a28835dc84 upstream. 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> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-04IB/srp: Remove target from list before freeing Scsi_Host structureVu Pham
commit 65d7dd2f3479ef5aec1d9ddd1481cb7851c11af6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [ bvanassche - Modified path description and CC'ed stable. ] Signed-off-by: Bart Van Assche <bvanassche@acm.org> 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>
2012-12-01IB/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>
2012-12-01IB/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>
2012-12-01IB/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>
2012-12-01IB/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>
2012-12-01IB/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>
2012-12-01IB/srp: Suppress superfluous error messagesBart Van Assche
Keep track of the connection state. Only report QP errors while connected. Only invoke ib_send_cm_dreq() when connected so that invoking srp_disconnect_target() after having received a DREQ does not cause an error message to be printed. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-12-01IB/srp: Process all error completionsBart Van Assche
If the RDMA RC connection is closed, tell the SCSI mid-layer to terminate all pending commands instead of only the first. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-12-01IB/srp: Introduce srp_handle_qp_err()Bart Van Assche
Introduce the function srp_handle_qp_err(), change the type of qp_in_error from int into bool and move the initialization of that variable from srp_reconnect_target() to srp_connect_target(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-12-01IB/srp: Simplify SCSI error handlingBart Van Assche
Since scsi_remove_host() has been modified so that SCSI error handling functions will no longer be invoked after scsi_remove_host() returns, the test at the start of srp_send_tsk_mgmt() is now superfluous. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-12-01IB/srp: Keep processing commands during host removalBart Van Assche
Some SCSI upper layer drivers, e.g. sd, issue SCSI commands from inside scsi_remove_host() (see the sd_shutdown() call in sd_remove()). Make sure that these commands have a chance to reach the SCSI device. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-12-01IB/srp: Eliminate state SRP_TARGET_CONNECTINGBart Van Assche
Block the SCSI host while reconnecting instead of representing the reconnection activity as a distinct SRP target state. This allows us to eliminate the target state SRP_TARGET_CONNECTING. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-12-01IB/srp: Increase block layer timeoutBart Van Assche
Increase the block layer timeout for disks so that it is above the InfiniBand transport layer timeout. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-10-01IB/srp: Avoid having aborted requests hangBart Van Assche
We need to call scsi_done() for commands after we abort them. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-10-01IB/srp: Fix use-after-free in srp_reset_req()Bart Van Assche
srp_free_req() uses the scsi_cmnd structure contents to unmap buffers, so we must invoke srp_free_req() before we release ownership of that structure. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-08-15IB/srp: Fix a race conditionBart Van Assche
Avoid a crash caused by the scmnd->scsi_done(scmnd) call in srp_process_rsp() being invoked with scsi_done == NULL. This can happen if a reply is received during or after a command abort. Reported-by: Joseph Glanville <joseph.glanville@orionvm.com.au> Reference: http://marc.info/?l=linux-rdma&m=134314367801595 Cc: <stable@vger.kernel.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-02-27IB/srp: Consolidate repetitive sysfs codeBart Van Assche
Remove sysfs attributes before removing a target instead of testing the target state in every sysfs attribute callback method. Note: it is safe to invoke a sysfs attribute removal method like device_remove_file() twice on the same attribute. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-02-27IB/srp: Use pr_fmt() and pr_err()/pr_warn()Bart Van Assche
Use pr_fmt() and pr_xxx() instead of more verbose printk() equivalents. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-13IB/srp: Avoid duplicate devices from LUN scanBart Van Assche
SCSI scanning of a channel:id:lun triplet in Linux works as follows (function scsi_scan_target() in drivers/scsi/scsi_scan.c): - If lun == SCAN_WILD_CARD, send a REPORT LUNS command to the target and process the result. - If lun != SCAN_WILD_CARD, send an INQUIRY command to the LUN corresponding to the specified channel:id:lun triplet to verify whether the LUN exists. So a SCSI driver must either take the channel and target id values in account in its quecommand() function or it should declare that it only supports one channel and one target id. Currently the ib_srp driver does neither. As a result scanning the SCSI bus via e.g. rescan-scsi-bus.sh causes many duplicate SCSI devices to be created. For each 0:0:L device, several duplicates are created with the same LUN number and with (C:I) != (0:0). Fix this by declaring that the ib_srp driver only supports one channel and one target id. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: <stable@kernel.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-05-23IB/srp: Fix integer -> pointer cast warningsRoland Dreier
Fix drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_handle_recv': drivers/infiniband/ulp/srp/ib_srp.c:1150: warning: cast to pointer from integer of different size drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_send_completion': drivers/infiniband/ulp/srp/ib_srp.c:1234: warning: cast to pointer from integer of different size by adding an intermediate cast to uintptr_t. Signed-off-by: Roland Dreier <roland@purestorage.com> Acked-by: David Dillow <dillowda@ornl.gov>
2011-03-15IB/srp: try to use larger FMR sizes to cover our mappingsDavid Dillow
Now that we can get larger SG lists, we can take advantage of HCAs that allow us to use larger FMR sizes. In many cases, we can use up to 512 entries, so start there and work our way down. Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-03-15IB/srp: add support for indirect tables that don't fit in SRP_CMDDavid Dillow
This allows us to guarantee the ability to submit up to 8 MB requests based on the current value of SCSI_MAX_SG_CHAIN_SEGMENTS. While FMR will usually condense the requests into 8 SG entries, it is imperative that the target support external tables in case the FMR mapping fails or is not supported. We add a safety valve to allow targets without the needed support to reap the benefits of the large tables, but fail in a manner that lets the user know that the data didn't make it to the device. The user must add "allow_ext_sg=1" to the target parameters to indicate that the target has the needed support. If indirect_sg_entries is not specified in the modules options, then the sg_tablesize for the target will default to cmd_sg_entries unless overridden by the target options. Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-03-15IB/srp: rework mapping engine to use multiple FMR entriesDavid Dillow
Instead of forcing all of the S/G entries to fit in one FMR, and falling back to indirect descriptors if that fails, allow the use of as many FMRs as needed to map the request. This lays the groundwork for allowing indirect descriptor tables that are larger than can fit in the command IU, but should marginally improve performance now by reducing the number of indirect descriptors needed. We increase the minimum page size for the FMR pool to 4K, as larger pages help increase the coverage of each FMR, and it is rare that the kernel would send down a request with scattered 512 byte fragments. This patch also move some of the target initialization code afte the parsing of options, to keep it together with the new code that needs to allocate memory based on the options given. Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-03-15IB/srp: allow sg_tablesize to be set for each targetDavid Dillow
Different configurations of target software allow differing max sizes of the command IU. Allowing this to be changed per-target allows all targets on an initiator to get an optimal setting. We deprecate srp_sg_tablesize and replace it with cmd_sg_entries in preparation for allowing more indirect descriptors than can fit in the IU. Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-03-15IB/srp: move IB CM setup completion into its own functionDavid Dillow
This is to clean up prior to further changes. Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-03-15IB/srp: always avoid non-zero offsets into an FMRDavid Dillow
It is unclear exactly how this code works around Mellanox SRP targets, or if the problem is on the target side or in the HCA itself. In an abundance of caution, we should always enable the workaround. Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-01-17Merge branches 'misc', 'mlx4', 'mthca', 'nes' and 'srp' into for-nextRoland Dreier
2011-01-17RDMA: Update workqueue usageTejun Heo
* ib_wq is added, which is used as the common workqueue for infiniband instead of the system workqueue. All system workqueue usages including flush_scheduled_work() callers are converted to use and flush ib_wq. * cancel_delayed_work() + flush_scheduled_work() converted to cancel_delayed_work_sync(). * qib_wq is removed and ib_wq is used instead. This is to prepare for deprecation of flush_scheduled_work(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2011-01-13IB/srp: Test only once whether iu allocation succeededBart Van Assche
Merge the two tests in srp_queuecommand() of whether information unit allocation succeeded into one. An intended side effect of this change is that we fix the warning: drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_queuecommand': drivers/infiniband/ulp/srp/ib_srp.c:1116: warning: 'req' may be used uninitialized in this function (seen with CONFIG_CC_OPTIMIZE_FOR_SIZE=y at least with gcc 4.4.4) Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2011-01-10IB/srp: consolidate hot-path variables into cache linesDavid Dillow
Put the variables accessed together in the hot-path into common cachelines, and separate them by RW vs RO to avoid false dirtying. We keep a local copy of the lkey and rkey in the target to avoid traversing pointers (and associated cache lines) to find them. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-01-10IB/srp: stop sharing the host lock with SCSIBart Van Assche
We don't need protection against the SCSI stack, so use our own lock to allow parallel progress on separate CPUs. Signed-off-by: Bart Van Assche <bvanassche@acm.org> [ broken out and small cleanups by David Dillow ] Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-01-10IB/srp: reduce lock coverage of command completionBart Van Assche
We only need the lock to cover list and credit manipulations, so push those into srp_remove_req() and update the call chains. We reorder the request removal and command completion in srp_process_rsp() to avoid the SCSI mid-layer sending another command before we've released our request and added any credits returned by the target. This prevents us from returning HOST_BUSY unneccesarily. Signed-off-by: Bart Van Assche <bvanassche@acm.org> [ broken out, small cleanups, and modified to avoid potential extraneous HOST_BUSY returns by David Dillow ] Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-01-10IB/srp: reduce local coverage for command submission and EHBart Van Assche
We only need locks to protect our lists and number of credits available. By pre-consuming the credit for the request, we can reduce our lock coverage to just those areas. If we don't actually send the request, we'll need to put the credit back into the pool. Signed-off-by: Bart Van Assche <bvanassche@acm.org> [ broken out and small cleanups by David Dillow ] Signed-off-by: David Dillow <dillowda@ornl.gov>
2011-01-10IB/srp: don't move active requests to their own listBart Van Assche
We use req->scmnd != NULL to indicate an active request, so there's no need to keep a separate list for them. We can afford the array iteration during error handling, and dropping it gives us one less item that needs lock protection. Signed-off-by: Bart Van Assche <bvanassche@acm.org> [ broken out and small cleanups by David Dillow ] Signed-off-by: David Dillow <dillowda@ornl.gov>