raw-posix: raw_co_get_block_status() return value

Instead of generating the full return value thrice in try_fiemap(),
try_seek_hole() and as a fall-back in raw_co_get_block_status() itself,
generate the value only in raw_co_get_block_status().

While at it, also remove the pnum parameter from try_fiemap() and
try_seek_hole().
Suggested-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Message-id: 1414148280-17949-3-git-send-email-mreitz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

block/raw-posix.c

@@ -1481,12 +1481,12 @@ out:
     return result;
 }
 
-static int64_t try_fiemap(BlockDriverState *bs, off_t start, off_t *data,
-                          off_t *hole, int nb_sectors, int *pnum)
+static int try_fiemap(BlockDriverState *bs, off_t start, off_t *data,
+                      off_t *hole, int nb_sectors)
 {
 #ifdef CONFIG_FIEMAP
     BDRVRawState *s = bs->opaque;
-    int64_t ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+    int ret = 0;
     struct {
         struct fiemap fm;
         struct fiemap_extent fe;
@@ -1527,8 +1527,8 @@ static int64_t try_fiemap(BlockDriverState *bs, off_t start, off_t *data,
 #endif
 }
 
-static int64_t try_seek_hole(BlockDriverState *bs, off_t start, off_t *data,
-                             off_t *hole, int *pnum)
+static int try_seek_hole(BlockDriverState *bs, off_t start, off_t *data,
+                         off_t *hole)
 {
 #if defined SEEK_HOLE && defined SEEK_DATA
     BDRVRawState *s = bs->opaque;
@@ -1548,7 +1548,7 @@ static int64_t try_seek_hole(BlockDriverState *bs, off_t start, off_t *data,
         }
     }
 
-    return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+    return 0;
 #else
     return -ENOTSUP;
 #endif
@@ -1575,7 +1575,7 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
 {
     off_t start, data = 0, hole = 0;
     int64_t total_size;
-    int64_t ret;
+    int ret;
 
     ret = fd_open(bs);
     if (ret < 0) {
@@ -1593,28 +1593,28 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
         nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
     }
 
-    ret = try_seek_hole(bs, start, &data, &hole, pnum);
+    ret = try_seek_hole(bs, start, &data, &hole);
     if (ret < 0) {
-        ret = try_fiemap(bs, start, &data, &hole, nb_sectors, pnum);
+        ret = try_fiemap(bs, start, &data, &hole, nb_sectors);
         if (ret < 0) {
             /* Assume everything is allocated. */
             data = 0;
             hole = start + nb_sectors * BDRV_SECTOR_SIZE;
-            ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+            ret = 0;
         }
     }
 
+    assert(ret >= 0);
+
     if (data <= start) {
         /* On a data extent, compute sectors to the end of the extent.  */
         *pnum = MIN(nb_sectors, (hole - start) / BDRV_SECTOR_SIZE);
+        return ret | BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
     } else {
         /* On a hole, compute sectors to the beginning of the next extent.  */
         *pnum = MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE);
-        ret &= ~BDRV_BLOCK_DATA;
-        ret |= BDRV_BLOCK_ZERO;
+        return ret | BDRV_BLOCK_ZERO | BDRV_BLOCK_OFFSET_VALID | start;
     }
-
-    return ret;
 }
 
 static coroutine_fn BlockAIOCB *raw_aio_discard(BlockDriverState *bs,