block: Add PreallocMode to bdrv_truncate()

For block drivers that just pass a truncate request to the underlying
protocol, we can now pass the preallocation mode instead of aborting if
it is not PREALLOC_MODE_OFF.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

block.c

@@ -3411,7 +3411,8 @@ exit:
 /**
  * Truncate file to 'offset' bytes (needed only for file protocols)
  */
-int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp)
+int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
+                  Error **errp)
 {
     BlockDriverState *bs = child->bs;
     BlockDriver *drv = bs->drv;
@@ -3434,7 +3435,7 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp)
 
     assert(!(bs->open_flags & BDRV_O_INACTIVE));
 
-    ret = drv->bdrv_truncate(bs, offset, PREALLOC_MODE_OFF, errp);
+    ret = drv->bdrv_truncate(bs, offset, prealloc, errp);
     if (ret == 0) {
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
         bdrv_dirty_bitmap_truncate(bs);

block/blkdebug.c

@@ -824,13 +824,7 @@ static int64_t blkdebug_getlength(BlockDriverState *bs)
 static int blkdebug_truncate(BlockDriverState *bs, int64_t offset,
                              PreallocMode prealloc, Error **errp)
 {
-    if (prealloc != PREALLOC_MODE_OFF) {
+    return bdrv_truncate(bs->file, offset, prealloc, errp);
-        error_setg(errp, "Unsupported preallocation mode '%s'",
-                   PreallocMode_lookup[prealloc]);
-        return -ENOTSUP;
-    }
-
-    return bdrv_truncate(bs->file, offset, errp);
 }
 
 static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)

block/block-backend.c

@@ -1780,7 +1780,7 @@ int blk_truncate(BlockBackend *blk, int64_t offset, Error **errp)
         return -ENOMEDIUM;
     }
 
-    return bdrv_truncate(blk->root, offset, errp);
+    return bdrv_truncate(blk->root, offset, PREALLOC_MODE_OFF, errp);
 }
 
 static void blk_pdiscard_entry(void *opaque)

block/crypto.c

@@ -367,15 +367,9 @@ static int block_crypto_truncate(BlockDriverState *bs, int64_t offset,
     size_t payload_offset =
         qcrypto_block_get_payload_offset(crypto->block);
 
-    if (prealloc != PREALLOC_MODE_OFF) {
-        error_setg(errp, "Unsupported preallocation mode '%s'",
-                   PreallocMode_lookup[prealloc]);
-        return -ENOTSUP;
-    }
-
     offset += payload_offset;
 
-    return bdrv_truncate(bs->file, offset, errp);
+    return bdrv_truncate(bs->file, offset, prealloc, errp);
 }
 
 static void block_crypto_close(BlockDriverState *bs)

block/parallels.c

@@ -224,7 +224,7 @@ static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
         } else {
             ret = bdrv_truncate(bs->file,
                                 (s->data_end + space) << BDRV_SECTOR_BITS,
-                                NULL);
+                                PREALLOC_MODE_OFF, NULL);
         }
         if (ret < 0) {
             return ret;
@@ -458,7 +458,8 @@ static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
         res->leaks += count;
         if (fix & BDRV_FIX_LEAKS) {
             Error *local_err = NULL;
-            ret = bdrv_truncate(bs->file, res->image_end_offset, &local_err);
+            ret = bdrv_truncate(bs->file, res->image_end_offset,
+                                PREALLOC_MODE_OFF, &local_err);
             if (ret < 0) {
                 error_report_err(local_err);
                 res->check_errors++;
@@ -699,7 +700,8 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     if (!(flags & BDRV_O_RESIZE) || !bdrv_has_zero_init(bs->file->bs) ||
-            bdrv_truncate(bs->file, bdrv_getlength(bs->file->bs), NULL) != 0) {
+            bdrv_truncate(bs->file, bdrv_getlength(bs->file->bs),
+                          PREALLOC_MODE_OFF, NULL) != 0) {
         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
     }
 
@@ -742,7 +744,8 @@ static void parallels_close(BlockDriverState *bs)
     }
 
     if (bs->open_flags & BDRV_O_RDWR) {
-        bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, NULL);
+        bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
+                      PREALLOC_MODE_OFF, NULL);
     }
 
     g_free(s->bat_dirty_bmap);

block/qcow.c

@@ -443,7 +443,8 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
                 /* round to cluster size */
                 cluster_offset = (cluster_offset + s->cluster_size - 1) &
                     ~(s->cluster_size - 1);
-                bdrv_truncate(bs->file, cluster_offset + s->cluster_size, NULL);
+                bdrv_truncate(bs->file, cluster_offset + s->cluster_size,
+                              PREALLOC_MODE_OFF, NULL);
                 /* if encrypted, we must initialize the cluster
                    content which won't be written */
                 if (bs->encrypted &&
@@ -923,7 +924,8 @@ static int qcow_make_empty(BlockDriverState *bs)
     if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
             l1_length) < 0)
         return -1;
-    ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length, NULL);
+    ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length,
+                        PREALLOC_MODE_OFF, NULL);
     if (ret < 0)
         return ret;
 

block/qcow2-refcount.c

@@ -1732,7 +1732,7 @@ static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res,
                 }
 
                 ret = bdrv_truncate(bs->file, offset + s->cluster_size,
-                                    &local_err);
+                                    PREALLOC_MODE_OFF, &local_err);
                 if (ret < 0) {
                     error_report_err(local_err);
                     goto resize_fail;

block/qcow2.c

@@ -3133,7 +3133,7 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
         /* align end of file to a sector boundary to ease reading with
            sector based I/Os */
         cluster_offset = bdrv_getlength(bs->file->bs);
-        return bdrv_truncate(bs->file, cluster_offset, NULL);
+        return bdrv_truncate(bs->file, cluster_offset, PREALLOC_MODE_OFF, NULL);
     }
 
     buf = qemu_blockalign(bs, s->cluster_size);
@@ -3349,7 +3349,7 @@ static int make_completely_empty(BlockDriverState *bs)
     }
 
     ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size,
-                        &local_err);
+                        PREALLOC_MODE_OFF, &local_err);
     if (ret < 0) {
         error_report_err(local_err);
         goto fail;

block/raw-format.c

@@ -357,12 +357,6 @@ static int raw_truncate(BlockDriverState *bs, int64_t offset,
 {
     BDRVRawState *s = bs->opaque;
 
-    if (prealloc != PREALLOC_MODE_OFF) {
-        error_setg(errp, "Unsupported preallocation mode '%s'",
-                   PreallocMode_lookup[prealloc]);
-        return -ENOTSUP;
-    }
-
     if (s->has_size) {
         error_setg(errp, "Cannot resize fixed-size raw disks");
         return -ENOTSUP;
@@ -375,7 +369,7 @@ static int raw_truncate(BlockDriverState *bs, int64_t offset,
 
     s->size = offset;
     offset += s->offset;
-    return bdrv_truncate(bs->file, offset, errp);
+    return bdrv_truncate(bs->file, offset, prealloc, errp);
 }
 
 static int raw_media_changed(BlockDriverState *bs)

block/vhdx-log.c

@@ -548,7 +548,7 @@ static int vhdx_log_flush(BlockDriverState *bs, BDRVVHDXState *s,
             if (new_file_size % (1024*1024)) {
                 /* round up to nearest 1MB boundary */
                 new_file_size = ((new_file_size >> 20) + 1) << 20;
-                bdrv_truncate(bs->file, new_file_size, NULL);
+                bdrv_truncate(bs->file, new_file_size, PREALLOC_MODE_OFF, NULL);
             }
         }
         qemu_vfree(desc_entries);

block/vhdx.c

@@ -1171,7 +1171,8 @@ static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s,
     /* per the spec, the address for a block is in units of 1MB */
     *new_offset = ROUND_UP(*new_offset, 1024 * 1024);
 
-    return bdrv_truncate(bs->file, *new_offset + s->block_size, NULL);
+    return bdrv_truncate(bs->file, *new_offset + s->block_size,
+                         PREALLOC_MODE_OFF, NULL);
 }
 
 /*

include/block/block.h

@@ -302,7 +302,8 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
     const char *backing_file);
 int bdrv_get_backing_file_depth(BlockDriverState *bs);
 void bdrv_refresh_filename(BlockDriverState *bs);
-int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp);
+int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
+                  Error **errp);
 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 int64_t bdrv_getlength(BlockDriverState *bs);
 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);