[PATCH v4] usb-storage: Check whether the media is initialized successfully

[Shichao Lai <shichaorai@gmail.com>]

The member "uzonesize" of struct alauda_info will remain 0
if alauda_init_media() fails, potentially causing divide errors
in alauda_read_data() and alauda_write_lba().
- Add a member "initialized" to struct alauda_info as a symbol
  for media initialization.
- Change a condition in alauda_check_media() to ensure the
  first initialization.
- Add an error check for the return value of alauda_init_media().

Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Suggested-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Shichao Lai <shichaorai@gmail.com>
---
Changes since v1:
- Check the initialization of alauda_check_media() 
  which is the root cause.

 drivers/usb/storage/alauda.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
index 115f05a6201a..ddf0da203481 100644
--- a/drivers/usb/storage/alauda.c
+++ b/drivers/usb/storage/alauda.c
@@ -105,6 +105,8 @@ struct alauda_info {
 	unsigned char sense_key;
 	unsigned long sense_asc;	/* additional sense code */
 	unsigned long sense_ascq;	/* additional sense code qualifier */
+
+	bool initialized;           /* true if the media is initialized */
 };
 
 #define short_pack(lsb,msb) ( ((u16)(lsb)) | ( ((u16)(msb))<<8 ) )
@@ -476,11 +478,12 @@ static int alauda_check_media(struct us_data *us)
 	}
 
 	/* Check for media change */
-	if (status[0] & 0x08) {
+	if (status[0] & 0x08 || !info->initialized) {
 		usb_stor_dbg(us, "Media change detected\n");
 		alauda_free_maps(&MEDIA_INFO(us));
-		alauda_init_media(us);
-
+		rc = alauda_init_media(us);
+		if (rc == USB_STOR_TRANSPORT_GOOD)
+			info->initialized = true;
 		info->sense_key = UNIT_ATTENTION;
 		info->sense_asc = 0x28;
 		info->sense_ascq = 0x00;
@@ -1120,6 +1123,7 @@ static int init_alauda(struct us_data *us)
 	info->wr_ep = usb_sndbulkpipe(us->pusb_dev,
 		altsetting->endpoint[0].desc.bEndpointAddress
 		& USB_ENDPOINT_NUMBER_MASK);
+	info->initialized = false;
 
 	return 0;
 }
-- 
2.34.1