[PATCH] USB Storage: more sddr09 cleanups

This is the third of three patches to prepare the sddr09 subdriver for
conversion to the Sim-SCSI framework.  This patch (as596) moves the
computation of the LBA to the start of the read/write routines, so that
addresses completely beyond the end of the device can be detected and
reported differently from transfers that are partially within the
device's capacity.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andries Brouwer <Andries.Brouwer@cwi.nl>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 23 insertions, 10 deletions

diff --git a/drivers/usb/storage/sddr09.c b/drivers/usb/storage/sddr09.c
index 760fe9362b6d..b8e7802c871d 100644
--- a/drivers/usb/storage/sddr09.c
+++ b/drivers/usb/storage/sddr09.c
@@ -711,6 +711,13 @@ sddr09_read_data(struct us_data *us,
         unsigned int len, index, offset;
         int result;
 
+        // Figure out the initial LBA and page
+        lba = address >> info->blockshift;
+        page = (address & info->blockmask);
+        maxlba = info->capacity >> (info->pageshift + info->blockshift);
+        if (lba >= maxlba)
+                return -EIO;
+
         // Since we only read in one block at a time, we have to create
         // a bounce buffer and move the data a piece at a time between the
         // bounce buffer and the actual transfer buffer.
@@ -722,11 +729,6 @@ sddr09_read_data(struct us_data *us,
                 return -ENOMEM;
         }
 
-        // Figure out the initial LBA and page
-        lba = address >> info->blockshift;
-        page = (address & info->blockmask);
-        maxlba = info->capacity >> (info->pageshift + info->blockshift);
-
         // This could be made much more efficient by checking for
         // contiguous LBA's. Another exercise left to the student.
 
@@ -928,13 +930,20 @@ sddr09_write_data(struct us_data *us,
                   unsigned int sectors) {
 
         struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
-        unsigned int lba, page, pages;
+        unsigned int lba, maxlba, page, pages;
         unsigned int pagelen, blocklen;
         unsigned char *blockbuffer;
         unsigned char *buffer;
         unsigned int len, index, offset;
         int result;
 
+        // Figure out the initial LBA and page
+        lba = address >> info->blockshift;
+        page = (address & info->blockmask);
+        maxlba = info->capacity >> (info->pageshift + info->blockshift);
+        if (lba >= maxlba)
+                return -EIO;
+
         // blockbuffer is used for reading in the old data, overwriting
         // with the new data, and performing ECC calculations
 
@@ -961,10 +970,6 @@ sddr09_write_data(struct us_data *us,
                 return -ENOMEM;
         }
 
-        // Figure out the initial LBA and page
-        lba = address >> info->blockshift;
-        page = (address & info->blockmask);
-
         result = 0;
         index = offset = 0;
 
@@ -975,6 +980,14 @@ sddr09_write_data(struct us_data *us,
                 pages = min(sectors, info->blocksize - page);
                 len = (pages << info->pageshift);
 
+                /* Not overflowing capacity? */
+                if (lba >= maxlba) {
+                        US_DEBUGP("Error: Requested lba %u exceeds "
+                                  "maximum %u\n", lba, maxlba);
+                        result = -EIO;
+                        break;
+                }
+
                 // Get the data from the transfer buffer
                 usb_stor_access_xfer_buf(buffer, len, us->srb,
                                 &index, &offset, FROM_XFER_BUF);