[PATCH v6] usb-storage: alauda: Check whether the media is initialized

[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 "media_initialized" to struct alauda_info.
- Change a condition in alauda_check_media() to ensure the
  first initialization.
- Add an error check for the return value of alauda_init_media().

Fixes: e80b0fade09e ("[PATCH] USB Storage: add alauda support")
Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Shichao Lai <shichaorai@gmail.com>
---
Changes since v5:
- Check the initialization of alauda_check_media()
  which is the root cause.

 drivers/usb/storage/alauda.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
index 115f05a6201a..40d34cc28344 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 media_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->media_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->media_initialized = true;
 		info->sense_key = UNIT_ATTENTION;
 		info->sense_asc = 0x28;
 		info->sense_ascq = 0x00;
-- 
2.34.1