[SCSI] qla2xxx: fix to honor ignored parameters in sysfs attributes

This is a patch to fix 'segmentation fault' issue which was initiated
by Richard Lary <rlary@us.ibm.com>.  Thanks again Richard.

- on following sysfs attritute function, changes have made so that both
  count and offset input parameters are honored by the functions.
    = qla2x00_sysfs_read_nvram()
    = qla2x00_sysfs_read_vpd()
- made changes so that NVRAM data to be cached to minimize H/W accesses
  during agent querying of the driver's.

Signed-off-by: Seokmann Ju <seokmann.ju@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 23 insertions, 16 deletions

diff --git a/drivers/scsi/qla2xxx/qla_attr.c b/drivers/scsi/qla2xxx/qla_attr.c
index 1612f9200a5..0f2a9f5d801 100644
--- a/drivers/scsi/qla2xxx/qla_attr.c
+++ b/drivers/scsi/qla2xxx/qla_attr.c
@@ -91,18 +91,20 @@ qla2x00_sysfs_read_nvram(struct kobject *kobj,
 {
 	struct scsi_qla_host *ha = to_qla_host(dev_to_shost(container_of(kobj,
 	    struct device, kobj)));
-	unsigned long	flags;
+	int		size = ha->nvram_size;
+	char		*nvram_cache = ha->nvram;
 
-	if (!capable(CAP_SYS_ADMIN) || off != 0)
+	if (!capable(CAP_SYS_ADMIN) || off > size || count == 0)
 		return 0;
+	if (off + count > size) {
+		size -= off;
+		count = size;
+	}
 
-	/* Read NVRAM. */
-	spin_lock_irqsave(&ha->hardware_lock, flags);
-	ha->isp_ops->read_nvram(ha, (uint8_t *)buf, ha->nvram_base,
-	    ha->nvram_size);
-	spin_unlock_irqrestore(&ha->hardware_lock, flags);
+	/* Read NVRAM data from cache. */
+	memcpy(buf, &nvram_cache[off], count);
 
-	return ha->nvram_size;
+	return count;
 }
 
 static ssize_t
@@ -144,6 +146,8 @@ qla2x00_sysfs_write_nvram(struct kobject *kobj,
 	/* Write NVRAM. */
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	ha->isp_ops->write_nvram(ha, (uint8_t *)buf, ha->nvram_base, count);
+	ha->isp_ops->read_nvram(ha, (uint8_t *)&ha->nvram, ha->nvram_base,
+	    count);
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
 	set_bit(ISP_ABORT_NEEDED, &ha->dpc_flags);
@@ -298,18 +302,20 @@ qla2x00_sysfs_read_vpd(struct kobject *kobj,
 {
 	struct scsi_qla_host *ha = to_qla_host(dev_to_shost(container_of(kobj,
 	    struct device, kobj)));
-	unsigned long flags;
+	int           size = ha->vpd_size;
+	char          *vpd_cache = ha->vpd;
 
-	if (!capable(CAP_SYS_ADMIN) || off != 0)
+	if (!capable(CAP_SYS_ADMIN) || off > size || count == 0)
 		return 0;
+	if (off + count > size) {
+		size -= off;
+		count = size;
+	}
 
-	/* Read NVRAM. */
-	spin_lock_irqsave(&ha->hardware_lock, flags);
-	ha->isp_ops->read_nvram(ha, (uint8_t *)buf, ha->vpd_base,
-	    ha->vpd_size);
-	spin_unlock_irqrestore(&ha->hardware_lock, flags);
+	/* Read NVRAM data from cache. */
+	memcpy(buf, &vpd_cache[off], count);
 
-	return ha->vpd_size;
+	return count;
 }
 
 static ssize_t
@@ -327,6 +333,7 @@ qla2x00_sysfs_write_vpd(struct kobject *kobj,
 	/* Write NVRAM. */
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	ha->isp_ops->write_nvram(ha, (uint8_t *)buf, ha->vpd_base, count);
+	ha->isp_ops->read_nvram(ha, (uint8_t *)ha->vpd, ha->vpd_base, count);
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
 	return count;