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authorBrian King <brking@linux.vnet.ibm.com>2014-10-30 17:27:10 -0500
committerChristoph Hellwig <hch@lst.de>2015-01-19 10:46:20 +0100
commit6cdb08172bc89f0a39e1643c5e7eab362692fd1b (patch)
tree455a246fb286c335b737d14d03b3f50ef629d3c7 /drivers/scsi
parent70a0f2c1898c6abf53670e55642b6e840b003892 (diff)
ipr: wait for aborted command responses
Fixes a race condition in abort handling that was injected when multiple interrupt support was added. When only a single interrupt is present, the adapter guarantees it will send responses for aborted commands prior to the response for the abort command itself. With multiple interrupts, these responses generally come back on different interrupts, so we need to ensure the abort thread waits until the aborted command is complete so we don't perform a double completion. This race condition was being hit frequently in environments which were triggering command timeouts, which was resulting in a double completion causing a kernel oops. Cc: <stable@vger.kernel.org> Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Wendy Xiong <wenxiong@linux.vnet.ibm.com> Tested-by: Wendy Xiong <wenxiong@linux.vnet.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/ipr.c92
-rw-r--r--drivers/scsi/ipr.h1
2 files changed, 93 insertions, 0 deletions
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index df4e27cd996a..9219953ee949 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -683,6 +683,7 @@ static void ipr_init_ipr_cmnd(struct ipr_cmnd *ipr_cmd,
ipr_reinit_ipr_cmnd(ipr_cmd);
ipr_cmd->u.scratch = 0;
ipr_cmd->sibling = NULL;
+ ipr_cmd->eh_comp = NULL;
ipr_cmd->fast_done = fast_done;
init_timer(&ipr_cmd->timer);
}
@@ -848,6 +849,8 @@ static void ipr_scsi_eh_done(struct ipr_cmnd *ipr_cmd)
scsi_dma_unmap(ipr_cmd->scsi_cmd);
scsi_cmd->scsi_done(scsi_cmd);
+ if (ipr_cmd->eh_comp)
+ complete(ipr_cmd->eh_comp);
list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q);
}
@@ -4811,6 +4814,84 @@ static int ipr_slave_alloc(struct scsi_device *sdev)
return rc;
}
+/**
+ * ipr_match_lun - Match function for specified LUN
+ * @ipr_cmd: ipr command struct
+ * @device: device to match (sdev)
+ *
+ * Returns:
+ * 1 if command matches sdev / 0 if command does not match sdev
+ **/
+static int ipr_match_lun(struct ipr_cmnd *ipr_cmd, void *device)
+{
+ if (ipr_cmd->scsi_cmd && ipr_cmd->scsi_cmd->device == device)
+ return 1;
+ return 0;
+}
+
+/**
+ * ipr_wait_for_ops - Wait for matching commands to complete
+ * @ipr_cmd: ipr command struct
+ * @device: device to match (sdev)
+ * @match: match function to use
+ *
+ * Returns:
+ * SUCCESS / FAILED
+ **/
+static int ipr_wait_for_ops(struct ipr_ioa_cfg *ioa_cfg, void *device,
+ int (*match)(struct ipr_cmnd *, void *))
+{
+ struct ipr_cmnd *ipr_cmd;
+ int wait;
+ unsigned long flags;
+ struct ipr_hrr_queue *hrrq;
+ signed long timeout = IPR_ABORT_TASK_TIMEOUT;
+ DECLARE_COMPLETION_ONSTACK(comp);
+
+ ENTER;
+ do {
+ wait = 0;
+
+ for_each_hrrq(hrrq, ioa_cfg) {
+ spin_lock_irqsave(hrrq->lock, flags);
+ list_for_each_entry(ipr_cmd, &hrrq->hrrq_pending_q, queue) {
+ if (match(ipr_cmd, device)) {
+ ipr_cmd->eh_comp = &comp;
+ wait++;
+ }
+ }
+ spin_unlock_irqrestore(hrrq->lock, flags);
+ }
+
+ if (wait) {
+ timeout = wait_for_completion_timeout(&comp, timeout);
+
+ if (!timeout) {
+ wait = 0;
+
+ for_each_hrrq(hrrq, ioa_cfg) {
+ spin_lock_irqsave(hrrq->lock, flags);
+ list_for_each_entry(ipr_cmd, &hrrq->hrrq_pending_q, queue) {
+ if (match(ipr_cmd, device)) {
+ ipr_cmd->eh_comp = NULL;
+ wait++;
+ }
+ }
+ spin_unlock_irqrestore(hrrq->lock, flags);
+ }
+
+ if (wait)
+ dev_err(&ioa_cfg->pdev->dev, "Timed out waiting for aborted commands\n");
+ LEAVE;
+ return wait ? FAILED : SUCCESS;
+ }
+ }
+ } while (wait);
+
+ LEAVE;
+ return SUCCESS;
+}
+
static int ipr_eh_host_reset(struct scsi_cmnd *cmd)
{
struct ipr_ioa_cfg *ioa_cfg;
@@ -5030,11 +5111,17 @@ static int __ipr_eh_dev_reset(struct scsi_cmnd *scsi_cmd)
static int ipr_eh_dev_reset(struct scsi_cmnd *cmd)
{
int rc;
+ struct ipr_ioa_cfg *ioa_cfg;
+
+ ioa_cfg = (struct ipr_ioa_cfg *) cmd->device->host->hostdata;
spin_lock_irq(cmd->device->host->host_lock);
rc = __ipr_eh_dev_reset(cmd);
spin_unlock_irq(cmd->device->host->host_lock);
+ if (rc == SUCCESS)
+ rc = ipr_wait_for_ops(ioa_cfg, cmd->device, ipr_match_lun);
+
return rc;
}
@@ -5234,13 +5321,18 @@ static int ipr_eh_abort(struct scsi_cmnd *scsi_cmd)
{
unsigned long flags;
int rc;
+ struct ipr_ioa_cfg *ioa_cfg;
ENTER;
+ ioa_cfg = (struct ipr_ioa_cfg *) scsi_cmd->device->host->hostdata;
+
spin_lock_irqsave(scsi_cmd->device->host->host_lock, flags);
rc = ipr_cancel_op(scsi_cmd);
spin_unlock_irqrestore(scsi_cmd->device->host->host_lock, flags);
+ if (rc == SUCCESS)
+ rc = ipr_wait_for_ops(ioa_cfg, scsi_cmd->device, ipr_match_lun);
LEAVE;
return rc;
}
diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h
index b4f3eec51bc9..ec03b42fa2b9 100644
--- a/drivers/scsi/ipr.h
+++ b/drivers/scsi/ipr.h
@@ -1606,6 +1606,7 @@ struct ipr_cmnd {
struct scsi_device *sdev;
} u;
+ struct completion *eh_comp;
struct ipr_hrr_queue *hrrq;
struct ipr_ioa_cfg *ioa_cfg;
};