block: Fix bdrv_is_allocated() for short backing files

bdrv_is_allocated() shouldn't return true for sectors that are
unallocated, but after the end of a short backing file, even though
such sectors are (correctly) marked as containing zeros.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2014-05-06 15:25:36 +02:00
parent 1a381811b4
commit e88ae2264d
2 changed files with 13 additions and 8 deletions

10
block.c
View File

@ -3864,7 +3864,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
if (!bs->drv->bdrv_co_get_block_status) {
*pnum = nb_sectors;
ret = BDRV_BLOCK_DATA;
ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
if (bs->drv->protocol_name) {
ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
}
@ -3883,6 +3883,10 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
*pnum, pnum);
}
if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
ret |= BDRV_BLOCK_ALLOCATED;
}
if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
if (bdrv_unallocated_blocks_are_zero(bs)) {
ret |= BDRV_BLOCK_ZERO;
@ -3959,9 +3963,7 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
if (ret < 0) {
return ret;
}
return
(ret & BDRV_BLOCK_DATA) ||
((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs));
return (ret & BDRV_BLOCK_ALLOCATED);
}
/*

View File

@ -120,6 +120,8 @@ typedef enum {
/* BDRV_BLOCK_DATA: data is read from bs->file or another file
* BDRV_BLOCK_ZERO: sectors read as zero
* BDRV_BLOCK_OFFSET_VALID: sector stored in bs->file as raw data
* BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
* layer (as opposed to the backing file)
* BDRV_BLOCK_RAW: used internally to indicate that the request
* was answered by the raw driver and that one
* should look in bs->file directly.
@ -141,10 +143,11 @@ typedef enum {
* f t f not allocated or unknown offset, read as zero
* f f f not allocated or unknown offset, read from backing_hd
*/
#define BDRV_BLOCK_DATA 1
#define BDRV_BLOCK_ZERO 2
#define BDRV_BLOCK_OFFSET_VALID 4
#define BDRV_BLOCK_RAW 8
#define BDRV_BLOCK_DATA 0x01
#define BDRV_BLOCK_ZERO 0x02
#define BDRV_BLOCK_OFFSET_VALID 0x04
#define BDRV_BLOCK_RAW 0x08
#define BDRV_BLOCK_ALLOCATED 0x10
#define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
typedef enum {