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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 11:23:28 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 11:23:28 -0800
commit28bc6fb9596fe1e577d09fc17ee6e1bb051c6ba3 (patch)
tree6293b282a960720fc5008e3e5fa4d096d974b2f1 /drivers/scsi/scsi_lib.c
parent0be600a5add76e8e8b9e1119f2a7426ff849aca8 (diff)
parenta2390348c19d0819d525d375414a7cfdacb51a68 (diff)
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI updates from James Bottomley: "This is mostly updates of the usual driver suspects: arcmsr, scsi_debug, mpt3sas, lpfc, cxlflash, qla2xxx, aacraid, megaraid_sas, hisi_sas. We also have a rework of the libsas hotplug handling to make it more robust, a slew of 32 bit time conversions and fixes, and a host of the usual minor updates and style changes. The biggest potential for regressions is the libsas hotplug changes, but so far they seem stable under testing" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (313 commits) scsi: qla2xxx: Fix logo flag for qlt_free_session_done() scsi: arcmsr: avoid do_gettimeofday scsi: core: Add VENDOR_SPECIFIC sense code definitions scsi: qedi: Drop cqe response during connection recovery scsi: fas216: fix sense buffer initialization scsi: ibmvfc: Remove unneeded semicolons scsi: hisi_sas: fix a bug in hisi_sas_dev_gone() scsi: hisi_sas: directly attached disk LED feature for v2 hw scsi: hisi_sas: devicetree: bindings: add LED feature for v2 hw scsi: megaraid_sas: NVMe passthrough command support scsi: megaraid: use ktime_get_real for firmware time scsi: fnic: use 64-bit timestamps scsi: qedf: Fix error return code in __qedf_probe() scsi: devinfo: fix format of the device list scsi: qla2xxx: Update driver version to 10.00.00.05-k scsi: qla2xxx: Add XCB counters to debugfs scsi: qla2xxx: Fix queue ID for async abort with Multiqueue scsi: qla2xxx: Fix warning for code intentation in __qla24xx_handle_gpdb_event() scsi: qla2xxx: Fix warning during port_name debug print scsi: qla2xxx: Fix warning in qla2x00_async_iocb_timeout() ...
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c50
1 files changed, 33 insertions, 17 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d9ca1dfab154..976c936029cb 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -164,7 +164,7 @@ static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
* for a requeue after completion, which should only occur in this
* file.
*/
-static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
+static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
{
struct scsi_device *device = cmd->device;
struct request_queue *q = device->request_queue;
@@ -220,7 +220,7 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
*/
void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
{
- __scsi_queue_insert(cmd, reason, 1);
+ __scsi_queue_insert(cmd, reason, true);
}
@@ -318,22 +318,39 @@ static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
cmd->cmd_len = scsi_command_size(cmd->cmnd);
}
-void scsi_device_unbusy(struct scsi_device *sdev)
+/*
+ * Decrement the host_busy counter and wake up the error handler if necessary.
+ * Avoid as follows that the error handler is not woken up if shost->host_busy
+ * == shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
+ * with an RCU read lock in this function to ensure that this function in its
+ * entirety either finishes before scsi_eh_scmd_add() increases the
+ * host_failed counter or that it notices the shost state change made by
+ * scsi_eh_scmd_add().
+ */
+static void scsi_dec_host_busy(struct Scsi_Host *shost)
{
- struct Scsi_Host *shost = sdev->host;
- struct scsi_target *starget = scsi_target(sdev);
unsigned long flags;
+ rcu_read_lock();
atomic_dec(&shost->host_busy);
- if (starget->can_queue > 0)
- atomic_dec(&starget->target_busy);
-
- if (unlikely(scsi_host_in_recovery(shost) &&
- (shost->host_failed || shost->host_eh_scheduled))) {
+ if (unlikely(scsi_host_in_recovery(shost))) {
spin_lock_irqsave(shost->host_lock, flags);
- scsi_eh_wakeup(shost);
+ if (shost->host_failed || shost->host_eh_scheduled)
+ scsi_eh_wakeup(shost);
spin_unlock_irqrestore(shost->host_lock, flags);
}
+ rcu_read_unlock();
+}
+
+void scsi_device_unbusy(struct scsi_device *sdev)
+{
+ struct Scsi_Host *shost = sdev->host;
+ struct scsi_target *starget = scsi_target(sdev);
+
+ scsi_dec_host_busy(shost);
+
+ if (starget->can_queue > 0)
+ atomic_dec(&starget->target_busy);
atomic_dec(&sdev->device_busy);
}
@@ -998,11 +1015,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
break;
case ACTION_RETRY:
/* Retry the same command immediately */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
+ __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);
break;
case ACTION_DELAYED_RETRY:
/* Retry the same command after a delay */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
+ __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);
break;
}
}
@@ -1128,7 +1145,7 @@ EXPORT_SYMBOL(scsi_init_io);
* Called from inside blk_get_request() for pass-through requests and from
* inside scsi_init_command() for filesystem requests.
*/
-void scsi_initialize_rq(struct request *rq)
+static void scsi_initialize_rq(struct request *rq)
{
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
@@ -1136,7 +1153,6 @@ void scsi_initialize_rq(struct request *rq)
cmd->jiffies_at_alloc = jiffies;
cmd->retries = 0;
}
-EXPORT_SYMBOL(scsi_initialize_rq);
/* Add a command to the list used by the aacraid and dpt_i2o drivers */
void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
@@ -1532,7 +1548,7 @@ starved:
list_add_tail(&sdev->starved_entry, &shost->starved_list);
spin_unlock_irq(shost->host_lock);
out_dec:
- atomic_dec(&shost->host_busy);
+ scsi_dec_host_busy(shost);
return 0;
}
@@ -2020,7 +2036,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
return BLK_STS_OK;
out_dec_host_busy:
- atomic_dec(&shost->host_busy);
+ scsi_dec_host_busy(shost);
out_dec_target_busy:
if (scsi_target(sdev)->can_queue > 0)
atomic_dec(&scsi_target(sdev)->target_busy);

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