scsi: simplify scsi_bios_ptable

Use read_mapping_page and kmemdup instead of the odd read_dev_sector and
put_dev_sector helpers from the partitioning code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/scsi/scsicam.c b/drivers/scsi/scsicam.c
index e969138051c7fc47eadbae68d1690a5d3c8abbfa..91a9530a4dcbe4617603d5ad7f2e5636d61b9722 100644 (file)
--- a/drivers/scsi/scsicam.c
+++ b/drivers/scsi/scsicam.c
@@ -35,19 +35,17 @@ static int setsize(unsigned long capacity, unsigned int *cyls, unsigned int *hds
  */
 unsigned char *scsi_bios_ptable(struct block_device *dev)
 {
-       unsigned char *res = kmalloc(66, GFP_KERNEL);
-       if (res) {
-               struct block_device *bdev = dev->bd_contains;
-               Sector sect;
-               void *data = read_dev_sector(bdev, 0, &sect);
-               if (data) {
-                       memcpy(res, data + 0x1be, 66);
-                       put_dev_sector(sect);
-               } else {
-                       kfree(res);
-                       res = NULL;
-               }
-       }
+       struct address_space *mapping = dev->bd_contains->bd_inode->i_mapping;
+       unsigned char *res = NULL;
+       struct page *page;
+
+       page = read_mapping_page(mapping, 0, NULL);
+       if (IS_ERR(page))
+               return NULL;
+
+       if (!PageError(page))
+               res = kmemdup(page_address(page) + 0x1be, 66, GFP_KERNEL);
+       put_page(page);
        return res;
 }
 EXPORT_SYMBOL(scsi_bios_ptable);