Revision 15dc2697
| b/block.c | ||
|---|---|---|
| 451 | 451 |
bs->enable_write_cache = 1; |
| 452 | 452 |
|
| 453 | 453 |
bs->read_only = (flags & BDRV_O_RDWR) == 0; |
| 454 |
if (!(flags & BDRV_O_FILE)) {
|
|
| 455 |
open_flags = (flags & (BDRV_O_RDWR | BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO)); |
|
| 456 |
if (bs->is_temporary) { /* snapshot should be writeable */
|
|
| 457 |
open_flags |= BDRV_O_RDWR; |
|
| 458 |
} |
|
| 459 |
} else {
|
|
| 460 |
open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT); |
|
| 454 |
|
|
| 455 |
/* |
|
| 456 |
* Clear flags that are internal to the block layer before opening the |
|
| 457 |
* image. |
|
| 458 |
*/ |
|
| 459 |
open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
|
| 460 |
|
|
| 461 |
/* |
|
| 462 |
* Snapshots should be writeable. |
|
| 463 |
* |
|
| 464 |
* XXX(hch): and what is the point of a snapshot during a read-only open? |
|
| 465 |
*/ |
|
| 466 |
if (!(flags & BDRV_O_FILE) && bs->is_temporary) {
|
|
| 467 |
open_flags |= BDRV_O_RDWR; |
|
| 461 | 468 |
} |
| 462 | 469 |
|
| 463 | 470 |
ret = drv->bdrv_open(bs, filename, open_flags); |
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