qemu-img: Change check_empty_sectors() to byte-based

Continue on the quest to make more things byte-based instead of
sector-based.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qemu-img.c

@@ -1203,30 +1203,29 @@ static int64_t sectors_to_bytes(int64_t sectors)
  * an error message.
  *
  * @param blk:  BlockBackend for the image
- * @param sect_num: Number of first sector to check
- * @param sect_count: Number of sectors to check
+ * @param offset: Starting offset to check
+ * @param bytes: Number of bytes to check
  * @param filename: Name of disk file we are checking (logging purpose)
  * @param buffer: Allocated buffer for storing read data
  * @param quiet: Flag for quiet mode
  */
-static int check_empty_sectors(BlockBackend *blk, int64_t sect_num,
-                               int sect_count, const char *filename,
+static int check_empty_sectors(BlockBackend *blk, int64_t offset,
+                               int64_t bytes, const char *filename,
                                uint8_t *buffer, bool quiet)
 {
     int ret = 0;
     int64_t idx;
 
-    ret = blk_pread(blk, sect_num << BDRV_SECTOR_BITS, buffer,
-                    sect_count << BDRV_SECTOR_BITS);
+    ret = blk_pread(blk, offset, buffer, bytes);
     if (ret < 0) {
         error_report("Error while reading offset %" PRId64 " of %s: %s",
-                     sectors_to_bytes(sect_num), filename, strerror(-ret));
+                     offset, filename, strerror(-ret));
         return 4;
     }
-    idx = find_nonzero(buffer, sect_count * BDRV_SECTOR_SIZE);
+    idx = find_nonzero(buffer, bytes);
     if (idx >= 0) {
         qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
-                sectors_to_bytes(sect_num) + idx);
+                offset + idx);
         return 1;
     }
 
@@ -1471,10 +1470,12 @@ static int img_compare(int argc, char **argv)
         } else {
             nb_sectors = MIN(nb_sectors, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
             if (allocated1) {
-                ret = check_empty_sectors(blk1, sector_num, nb_sectors,
+                ret = check_empty_sectors(blk1, sector_num * BDRV_SECTOR_SIZE,
+                                          nb_sectors * BDRV_SECTOR_SIZE,
                                           filename1, buf1, quiet);
             } else {
-                ret = check_empty_sectors(blk2, sector_num, nb_sectors,
+                ret = check_empty_sectors(blk2, sector_num * BDRV_SECTOR_SIZE,
+                                          nb_sectors * BDRV_SECTOR_SIZE,
                                           filename2, buf1, quiet);
             }
             if (ret) {
@@ -1519,7 +1520,9 @@ static int img_compare(int argc, char **argv)
             nb_sectors = count >> BDRV_SECTOR_BITS;
             if (ret & BDRV_BLOCK_ALLOCATED && !(ret & BDRV_BLOCK_ZERO)) {
                 nb_sectors = MIN(nb_sectors, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
-                ret = check_empty_sectors(blk_over, sector_num, nb_sectors,
+                ret = check_empty_sectors(blk_over,
+                                          sector_num * BDRV_SECTOR_SIZE,
+                                          nb_sectors * BDRV_SECTOR_SIZE,
                                           filename_over, buf1, quiet);
                 if (ret) {
                     goto out;