From: Stephen M. Cameron <scame...@beardog.cce.hp.com>
Cap CCISS_BIG_PASSTHRU as well. If an attempt is made
to exceed this, ioctl() will return -1 with errno == EAGAIN.
This is to prevent a userland program from exhausting all of
pci_alloc_consistent memory. I've only seen this problem when
running a special test program designed to provoke it. 20
concurrent commands via the passthru ioctls (not counting SG_IO)
should be more than enough.
Signed-off-by: Stephen M. Cameron <scame...@beardog.cce.hp.com>
---
drivers/scsi/hpsa.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
drivers/scsi/hpsa.h | 5 +++++
2 files changed, 47 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index fdc2228..ebb7144 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -3218,6 +3218,36 @@ static void check_ioctl_unit_attention(struct ctlr_info
*h,
c->err_info->ScsiStatus != SAM_STAT_CHECK_CONDITION)
(void) check_for_unit_attention(h, c);
}
+
+static int increment_passthru_count(struct ctlr_info *h)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&h->passthru_count_lock, flags);
+ if (h->passthru_count >= HPSA_MAX_CONCURRENT_PASSTHRUS) {
+ spin_unlock_irqrestore(&h->passthru_count_lock, flags);
+ return -1;
+ }
+ h->passthru_count++;
+ spin_unlock_irqrestore(&h->passthru_count_lock, flags);
+ return 0;
+}
+
+static void decrement_passthru_count(struct ctlr_info *h)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&h->passthru_count_lock, flags);
+ if (h->passthru_count <= 0) {
+ spin_unlock_irqrestore(&h->passthru_count_lock, flags);
+ /* not expecting to get here. */
+ dev_warn(&h->pdev->dev, "Bug detected, passthru_count seems to
be incorrect.\n");
+ return;
+ }
+ h->passthru_count--;
+ spin_unlock_irqrestore(&h->passthru_count_lock, flags);
+}
+
/*
* ioctl
*/
@@ -3225,6 +3255,7 @@ static int hpsa_ioctl(struct scsi_device *dev, int cmd,
void *arg)
{
struct ctlr_info *h;
void __user *argp = (void __user *)arg;
+ int rc;
h = sdev_to_hba(dev);
@@ -3239,9 +3270,17 @@ static int hpsa_ioctl(struct scsi_device *dev, int cmd,
void *arg)
case CCISS_GETDRIVVER:
return hpsa_getdrivver_ioctl(h, argp);
case CCISS_PASSTHRU:
- return hpsa_passthru_ioctl(h, argp);
+ if (increment_passthru_count(h))
+ return -EAGAIN;
+ rc = hpsa_passthru_ioctl(h, argp);
+ decrement_passthru_count(h);
+ return rc;
case CCISS_BIG_PASSTHRU:
- return hpsa_big_passthru_ioctl(h, argp);
+ if (increment_passthru_count(h))
+ return -EAGAIN;
+ rc = hpsa_big_passthru_ioctl(h, argp);
+ decrement_passthru_count(h);
+ return rc;
default:
return -ENOTTY;
}
@@ -4772,6 +4811,7 @@ reinit_after_soft_reset:
INIT_LIST_HEAD(&h->reqQ);
spin_lock_init(&h->lock);
spin_lock_init(&h->scan_lock);
+ spin_lock_init(&h->passthru_count_lock);
rc = hpsa_pci_init(h);
if (rc != 0)
goto clean1;
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index b48f1de..fd9910a 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -114,6 +114,11 @@ struct ctlr_info {
struct TransTable_struct *transtable;
unsigned long transMethod;
+ /* cap concurrent passthrus at some reasonable maximum */
+#define HPSA_MAX_CONCURRENT_PASSTHRUS (20)
+ spinlock_t passthru_count_lock; /* protects passthru_count */
+ int passthru_count;
+
/*
* Performant mode completion buffers
*/
--
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