block: Add PreallocMode to blk_truncate()

blk_truncate() itself will pass that value to bdrv_truncate(), and all
callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF
for now.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

block/block-backend.c

@@ -1773,14 +1773,15 @@ int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
                    BDRV_REQ_WRITE_COMPRESSED);
 }
 
-int blk_truncate(BlockBackend *blk, int64_t offset, Error **errp)
+int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc,
+                 Error **errp)
 {
     if (!blk_is_available(blk)) {
         error_setg(errp, "No medium inserted");
         return -ENOMEDIUM;
     }
 
-    return bdrv_truncate(blk->root, offset, PREALLOC_MODE_OFF, errp);
+    return bdrv_truncate(blk->root, offset, prealloc, errp);
 }
 
 static void blk_pdiscard_entry(void *opaque)

block/commit.c

@@ -163,7 +163,7 @@ static void coroutine_fn commit_run(void *opaque)
     }
 
     if (base_len < s->common.len) {
-        ret = blk_truncate(s->base, s->common.len, NULL);
+        ret = blk_truncate(s->base, s->common.len, PREALLOC_MODE_OFF, NULL);
         if (ret) {
             goto out;
         }
@@ -521,7 +521,7 @@ int bdrv_commit(BlockDriverState *bs)
      * grow the backing file image if possible.  If not possible,
      * we must return an error */
     if (length > backing_length) {
-        ret = blk_truncate(backing, length, &local_err);
+        ret = blk_truncate(backing, length, PREALLOC_MODE_OFF, &local_err);
         if (ret < 0) {
             error_report_err(local_err);
             goto ro_cleanup;

block/mirror.c

@@ -739,7 +739,8 @@ static void coroutine_fn mirror_run(void *opaque)
         }
 
         if (s->bdev_length > base_length) {
-            ret = blk_truncate(s->target, s->bdev_length, NULL);
+            ret = blk_truncate(s->target, s->bdev_length, PREALLOC_MODE_OFF,
+                               NULL);
             if (ret < 0) {
                 goto immediate_exit;
             }

block/parallels.c

@@ -508,7 +508,7 @@ static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
 
     blk_set_allow_write_beyond_eof(file, true);
 
-    ret = blk_truncate(file, 0, errp);
+    ret = blk_truncate(file, 0, PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         goto exit;
     }

block/qcow.c

@@ -813,7 +813,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
 
     blk_set_allow_write_beyond_eof(qcow_blk, true);
 
-    ret = blk_truncate(qcow_blk, 0, errp);
+    ret = blk_truncate(qcow_blk, 0, PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         goto exit;
     }

block/qcow2.c

@@ -2802,7 +2802,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     }
 
     /* Okay, now that we have a valid image, let's give it the right size */
-    ret = blk_truncate(blk, total_size, errp);
+    ret = blk_truncate(blk, total_size, PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         error_prepend(errp, "Could not resize image: ");
         goto out;
@@ -3995,7 +3995,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
             return ret;
         }
 
-        ret = blk_truncate(blk, new_size, &local_err);
+        ret = blk_truncate(blk, new_size, PREALLOC_MODE_OFF, &local_err);
         blk_unref(blk);
         if (ret < 0) {
             error_report_err(local_err);

block/qed.c

@@ -583,7 +583,7 @@ static int qed_create(const char *filename, uint32_t cluster_size,
     blk_set_allow_write_beyond_eof(blk, true);
 
     /* File must start empty and grow, check truncate is supported */
-    ret = blk_truncate(blk, 0, errp);
+    ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         goto out;
     }

block/vdi.c

@@ -832,7 +832,8 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     if (image_type == VDI_TYPE_STATIC) {
-        ret = blk_truncate(blk, offset + blocks * block_size, errp);
+        ret = blk_truncate(blk, offset + blocks * block_size,
+                           PREALLOC_MODE_OFF, errp);
         if (ret < 0) {
             error_prepend(errp, "Failed to statically allocate %s", filename);
             goto exit;

block/vhdx.c

@@ -1608,12 +1608,13 @@ static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s,
     if (type == VHDX_TYPE_DYNAMIC) {
         /* All zeroes, so we can just extend the file - the end of the BAT
          * is the furthest thing we have written yet */
-        ret = blk_truncate(blk, data_file_offset, errp);
+        ret = blk_truncate(blk, data_file_offset, PREALLOC_MODE_OFF, errp);
         if (ret < 0) {
             goto exit;
         }
     } else if (type == VHDX_TYPE_FIXED) {
-        ret = blk_truncate(blk, data_file_offset + image_size, errp);
+        ret = blk_truncate(blk, data_file_offset + image_size,
+                           PREALLOC_MODE_OFF, errp);
         if (ret < 0) {
             goto exit;
         }

block/vmdk.c

@@ -1714,7 +1714,7 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
     blk_set_allow_write_beyond_eof(blk, true);
 
     if (flat) {
-        ret = blk_truncate(blk, filesize, errp);
+        ret = blk_truncate(blk, filesize, PREALLOC_MODE_OFF, errp);
         goto exit;
     }
     magic = cpu_to_be32(VMDK4_MAGIC);
@@ -1777,7 +1777,8 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
         goto exit;
     }
 
-    ret = blk_truncate(blk, le64_to_cpu(header.grain_offset) << 9, errp);
+    ret = blk_truncate(blk, le64_to_cpu(header.grain_offset) << 9,
+                       PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         goto exit;
     }
@@ -2086,7 +2087,7 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp)
     /* bdrv_pwrite write padding zeros to align to sector, we don't need that
      * for description file */
     if (desc_offset == 0) {
-        ret = blk_truncate(new_blk, desc_len, errp);
+        ret = blk_truncate(new_blk, desc_len, PREALLOC_MODE_OFF, errp);
     }
 exit:
     if (new_blk) {

block/vpc.c

@@ -858,7 +858,7 @@ static int create_fixed_disk(BlockBackend *blk, uint8_t *buf,
     /* Add footer to total size */
     total_size += HEADER_SIZE;
 
-    ret = blk_truncate(blk, total_size, errp);
+    ret = blk_truncate(blk, total_size, PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         return ret;
     }

blockdev.c

@@ -2958,7 +2958,7 @@ void qmp_block_resize(bool has_device, const char *device,
     }
 
     bdrv_drained_begin(bs);
-    ret = blk_truncate(blk, size, errp);
+    ret = blk_truncate(blk, size, PREALLOC_MODE_OFF, errp);
     bdrv_drained_end(bs);
 
 out:

include/sysemu/block-backend.h

@@ -223,7 +223,8 @@ int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
                                       int bytes, BdrvRequestFlags flags);
 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
                           int bytes);
-int blk_truncate(BlockBackend *blk, int64_t offset, Error **errp);
+int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc,
+                 Error **errp);
 int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
                      int64_t pos, int size);

qemu-img.c

@@ -3537,7 +3537,7 @@ static int img_resize(int argc, char **argv)
         goto out;
     }
 
-    ret = blk_truncate(blk, total_size, &err);
+    ret = blk_truncate(blk, total_size, PREALLOC_MODE_OFF, &err);
     if (!ret) {
         qprintf(quiet, "Image resized.\n");
     } else {

qemu-io-cmds.c

@@ -1577,7 +1577,7 @@ static int truncate_f(BlockBackend *blk, int argc, char **argv)
         return 0;
     }
 
-    ret = blk_truncate(blk, offset, &local_err);
+    ret = blk_truncate(blk, offset, PREALLOC_MODE_OFF, &local_err);
     if (ret < 0) {
         error_report_err(local_err);
         return 0;