diff options
author | Bart Van Assche <bvanassche@acm.org> | 2013-02-21 12:20:00 -0500 |
---|---|---|
committer | Roland Dreier <roland@purestorage.com> | 2013-02-25 12:31:14 -0500 |
commit | 2ce19e72f4d570c87e025ee6fca4eae699a8b712 (patch) | |
tree | f9055b2a0390954b222450ea93dffdab0316c674 /drivers/infiniband/ulp | |
parent | c7c4e7ff8047e43c45628b85ac200582e9404c39 (diff) |
IB/srp: Fail I/O requests if the transport is offline
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>
Diffstat (limited to 'drivers/infiniband/ulp')
-rw-r--r-- | drivers/infiniband/ulp/srp/ib_srp.c | 7 | ||||
-rw-r--r-- | drivers/infiniband/ulp/srp/ib_srp.h | 1 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 8a7eb9f98a0c..7ccf3284dda3 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c | |||
@@ -734,6 +734,7 @@ static int srp_reconnect_target(struct srp_target_port *target) | |||
734 | 734 | ||
735 | scsi_target_unblock(&shost->shost_gendev, ret == 0 ? SDEV_RUNNING : | 735 | scsi_target_unblock(&shost->shost_gendev, ret == 0 ? SDEV_RUNNING : |
736 | SDEV_TRANSPORT_OFFLINE); | 736 | SDEV_TRANSPORT_OFFLINE); |
737 | target->transport_offline = !!ret; | ||
737 | 738 | ||
738 | if (ret) | 739 | if (ret) |
739 | goto err; | 740 | goto err; |
@@ -1353,6 +1354,12 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) | |||
1353 | unsigned long flags; | 1354 | unsigned long flags; |
1354 | int len; | 1355 | int len; |
1355 | 1356 | ||
1357 | if (unlikely(target->transport_offline)) { | ||
1358 | scmnd->result = DID_NO_CONNECT << 16; | ||
1359 | scmnd->scsi_done(scmnd); | ||
1360 | return 0; | ||
1361 | } | ||
1362 | |||
1356 | spin_lock_irqsave(&target->lock, flags); | 1363 | spin_lock_irqsave(&target->lock, flags); |
1357 | iu = __srp_get_tx_iu(target, SRP_IU_CMD); | 1364 | iu = __srp_get_tx_iu(target, SRP_IU_CMD); |
1358 | if (!iu) | 1365 | if (!iu) |
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h index de2d0b3c0bfe..66fbedda4571 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.h +++ b/drivers/infiniband/ulp/srp/ib_srp.h | |||
@@ -140,6 +140,7 @@ struct srp_target_port { | |||
140 | unsigned int cmd_sg_cnt; | 140 | unsigned int cmd_sg_cnt; |
141 | unsigned int indirect_size; | 141 | unsigned int indirect_size; |
142 | bool allow_ext_sg; | 142 | bool allow_ext_sg; |
143 | bool transport_offline; | ||
143 | 144 | ||
144 | /* Everything above this point is used in the hot path of | 145 | /* Everything above this point is used in the hot path of |
145 | * command processing. Try to keep them packed into cachelines. | 146 | * command processing. Try to keep them packed into cachelines. |