[SCSI] Return VPD page length in scsi_vpd_inquiry()
We should be returning the number of bytes of the
requested VPD page in scsi_vpd_inquiry.
This makes it easier for the caller to verify the
required space.
[jejb: fix up mm warning spotted by Sergey]
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 2b12983..b2526ad 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -942,7 +942,7 @@
* This is an internal helper function. You probably want to use
* scsi_get_vpd_page instead.
*
- * Returns 0 on success or a negative error number.
+ * Returns size of the vpd page on success or a negative error number.
*/
static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
u8 page, unsigned len)
@@ -950,6 +950,9 @@
int result;
unsigned char cmd[16];
+ if (len < 4)
+ return -EINVAL;
+
cmd[0] = INQUIRY;
cmd[1] = 1; /* EVPD */
cmd[2] = page;
@@ -964,13 +967,13 @@
result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
len, NULL, 30 * HZ, 3, NULL);
if (result)
- return result;
+ return -EIO;
/* Sanity check that we got the page back that we asked for */
if (buffer[1] != page)
return -EIO;
- return 0;
+ return get_unaligned_be16(&buffer[2]) + 4;
}
/**
@@ -997,18 +1000,18 @@
/* Ask for all the pages supported by this device */
result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
- if (result)
+ if (result < 4)
goto fail;
/* If the user actually wanted this page, we can skip the rest */
if (page == 0)
return 0;
- for (i = 0; i < min((int)buf[3], buf_len - 4); i++)
- if (buf[i + 4] == page)
+ for (i = 4; i < min(result, buf_len); i++)
+ if (buf[i] == page)
goto found;
- if (i < buf[3] && i >= buf_len - 4)
+ if (i < result && i >= buf_len)
/* ran off the end of the buffer, give us benefit of doubt */
goto found;
/* The device claims it doesn't support the requested page */
@@ -1016,7 +1019,7 @@
found:
result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
- if (result)
+ if (result < 0)
goto fail;
return 0;