gwj / at91sam9263 · Commits

Commit 5eb456396d20554a6b9637b23519579f083aa992

Authored by aliguori
1 parent 9b80ddf3

block: support known backing format for image create and open (Uri Lublin) 

Added a backing_format field to BlockDriverState.
Added bdrv_create2 and drv->bdrv_create2 to create an image with
a known backing file format.
Upon bdrv_open2 if backing format is known use it, instead of
probing the (backing) image.

Signed-off-by: Uri Lublin <uril@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6908 c046a42c-6fe2-441c-8c8c-71466251a162
Inline Side-by-side
Showing 3 changed files with 35 additions and 4 deletions
... ... @@ -181,6 +181,20 @@ BlockDriver *bdrv_find_format(const char *format_name)
181 181 return NULL;
182 182 }
183 183  
  184 +int bdrv_create2(BlockDriver *drv,
  185 + const char *filename, int64_t size_in_sectors,
  186 + const char *backing_file, const char *backing_format,
  187 + int flags)
  188 +{
  189 + if (drv->bdrv_create2)
  190 + return drv->bdrv_create2(filename, size_in_sectors, backing_file,
  191 + backing_format, flags);
  192 + if (drv->bdrv_create)
  193 + return drv->bdrv_create(filename, size_in_sectors, backing_file,
  194 + flags);
  195 + return -ENOTSUP;
  196 +}
  197 +
184 198 int bdrv_create(BlockDriver *drv,
185 199 const char *filename, int64_t size_in_sectors,
186 200 const char *backing_file, int flags)
... ... @@ -357,7 +371,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
357 371  
358 372 /* if there is a backing file, use it */
359 373 bs1 = bdrv_new("");
360   - ret = bdrv_open(bs1, filename, 0);
  374 + ret = bdrv_open2(bs1, filename, 0, drv);
361 375 if (ret < 0) {
362 376 bdrv_delete(bs1);
363 377 return ret;
... ... @@ -378,12 +392,14 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
378 392 else
379 393 realpath(filename, backing_filename);
380 394  
381   - ret = bdrv_create(&bdrv_qcow2, tmp_filename,
382   - total_size, backing_filename, 0);
  395 + ret = bdrv_create2(&bdrv_qcow2, tmp_filename,
  396 + total_size, backing_filename,
  397 + (drv ? drv->format_name : NULL), 0);
383 398 if (ret < 0) {
384 399 return ret;
385 400 }
386 401 filename = tmp_filename;
  402 + drv = &bdrv_qcow2;
387 403 bs->is_temporary = 1;
388 404 }
389 405  
... ... @@ -429,10 +445,14 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
429 445 #endif
430 446 if (bs->backing_file[0] != '\0') {
431 447 /* if there is a backing file, use it */
  448 + BlockDriver *back_drv = NULL;
432 449 bs->backing_hd = bdrv_new("");
433 450 path_combine(backing_filename, sizeof(backing_filename),
434 451 filename, bs->backing_file);
435   - ret = bdrv_open(bs->backing_hd, backing_filename, open_flags);
  452 + if (bs->backing_format[0] != '\0')
  453 + back_drv = bdrv_find_format(bs->backing_format);
  454 + ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
  455 + back_drv);
436 456 if (ret < 0) {
437 457 bdrv_close(bs);
438 458 return ret;
... ...
... ... @@ -62,6 +62,10 @@ BlockDriver *bdrv_find_format(const char *format_name);
62 62 int bdrv_create(BlockDriver *drv,
63 63 const char *filename, int64_t size_in_sectors,
64 64 const char *backing_file, int flags);
  65 +int bdrv_create2(BlockDriver *drv,
  66 + const char *filename, int64_t size_in_sectors,
  67 + const char *backing_file, const char *backing_format,
  68 + int flags);
65 69 BlockDriverState *bdrv_new(const char *device_name);
66 70 void bdrv_delete(BlockDriverState *bs);
67 71 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags);
... ...
block_int.h
  View file @5eb4563
... ... @@ -91,6 +91,12 @@ struct BlockDriver {
91 91 BlockDriverCompletionFunc *cb, void *opaque);
92 92  
93 93 AIOPool aio_pool;
  94 +
  95 + /* new create with backing file format */
  96 + int (*bdrv_create2)(const char *filename, int64_t total_sectors,
  97 + const char *backing_file, const char *backing_format,
  98 + int flags);
  99 +
94 100 struct BlockDriver *next;
95 101 };
96 102  
... ... @@ -113,6 +119,7 @@ struct BlockDriverState {
113 119 char filename[1024];
114 120 char backing_file[1024]; /* if non zero, the image is a diff of
115 121 this file image */
  122 + char backing_format[16]; /* if non-zero and backing_file exists */
116 123 int is_temporary;
117 124 int media_changed;
118 125  
... ...