scsi: Rework the code for caching Vital Product Data (VPD)
Introduce the scsi_get_vpd_buf() and scsi_update_vpd_page()
functions. The only functional change in this patch is that if updating
page 0x80 fails that it is attempted to update page 0x83.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Shane M Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 3d38c6d..f3f4926 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -412,6 +412,63 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
/**
+ * scsi_get_vpd_buf - Get Vital Product Data from a SCSI device
+ * @sdev: The device to ask
+ * @page: Which Vital Product Data to return
+ * @len: Upon success, the VPD length will be stored in *@len.
+ *
+ * Returns %NULL upon failure.
+ */
+static unsigned char *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page,
+ int *len)
+{
+ unsigned char *vpd_buf;
+ int vpd_len = SCSI_VPD_PG_LEN, result;
+
+retry_pg:
+ vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+ if (!vpd_buf)
+ return NULL;
+
+ result = scsi_vpd_inquiry(sdev, vpd_buf, page, vpd_len);
+ if (result < 0) {
+ kfree(vpd_buf);
+ return NULL;
+ }
+ if (result > vpd_len) {
+ vpd_len = result;
+ kfree(vpd_buf);
+ goto retry_pg;
+ }
+
+ *len = result;
+
+ return vpd_buf;
+}
+
+static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page,
+ unsigned char __rcu **sdev_vpd_buf,
+ int *sdev_vpd_len)
+{
+ unsigned char *vpd_buf;
+ int len;
+
+ vpd_buf = scsi_get_vpd_buf(sdev, page, &len);
+ if (!vpd_buf)
+ return;
+
+ mutex_lock(&sdev->inquiry_mutex);
+ rcu_swap_protected(*sdev_vpd_buf, vpd_buf,
+ lockdep_is_held(&sdev->inquiry_mutex));
+ *sdev_vpd_len = len;
+ mutex_unlock(&sdev->inquiry_mutex);
+
+ synchronize_rcu();
+
+ kfree(vpd_buf);
+}
+
+/**
* scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
* @sdev: The device to ask
*
@@ -422,95 +479,26 @@ EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
*/
void scsi_attach_vpd(struct scsi_device *sdev)
{
- int result, i;
- int vpd_len = SCSI_VPD_PG_LEN;
- int pg80_supported = 0;
- int pg83_supported = 0;
- unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL;
+ int i, vpd_len;
+ unsigned char *vpd_buf;
if (!scsi_device_supports_vpd(sdev))
return;
-retry_pg0:
- vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
+ /* Ask for all the pages supported by this device */
+ vpd_buf = scsi_get_vpd_buf(sdev, 0, &vpd_len);
if (!vpd_buf)
return;
- /* Ask for all the pages supported by this device */
- result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
- if (result < 0) {
- kfree(vpd_buf);
- return;
- }
- if (result > vpd_len) {
- vpd_len = result;
- kfree(vpd_buf);
- goto retry_pg0;
- }
-
- for (i = 4; i < result; i++) {
+ for (i = 4; i < vpd_len; i++) {
if (vpd_buf[i] == 0x80)
- pg80_supported = 1;
+ scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80,
+ &sdev->vpd_pg80_len);
if (vpd_buf[i] == 0x83)
- pg83_supported = 1;
+ scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83,
+ &sdev->vpd_pg83_len);
}
kfree(vpd_buf);
- vpd_len = SCSI_VPD_PG_LEN;
-
- if (pg80_supported) {
-retry_pg80:
- vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
- if (!vpd_buf)
- return;
-
- result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
- if (result < 0) {
- kfree(vpd_buf);
- return;
- }
- if (result > vpd_len) {
- vpd_len = result;
- kfree(vpd_buf);
- goto retry_pg80;
- }
- mutex_lock(&sdev->inquiry_mutex);
- orig_vpd_buf = sdev->vpd_pg80;
- sdev->vpd_pg80_len = result;
- rcu_assign_pointer(sdev->vpd_pg80, vpd_buf);
- mutex_unlock(&sdev->inquiry_mutex);
- synchronize_rcu();
- if (orig_vpd_buf) {
- kfree(orig_vpd_buf);
- orig_vpd_buf = NULL;
- }
- vpd_len = SCSI_VPD_PG_LEN;
- }
-
- if (pg83_supported) {
-retry_pg83:
- vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
- if (!vpd_buf)
- return;
-
- result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
- if (result < 0) {
- kfree(vpd_buf);
- return;
- }
- if (result > vpd_len) {
- vpd_len = result;
- kfree(vpd_buf);
- goto retry_pg83;
- }
- mutex_lock(&sdev->inquiry_mutex);
- orig_vpd_buf = sdev->vpd_pg83;
- sdev->vpd_pg83_len = result;
- rcu_assign_pointer(sdev->vpd_pg83, vpd_buf);
- mutex_unlock(&sdev->inquiry_mutex);
- synchronize_rcu();
- if (orig_vpd_buf)
- kfree(orig_vpd_buf);
- }
}
/**