Commit 59c9a95f authored by Max Reitz's avatar Max Reitz Committed by Kevin Wolf

block: Respect underlying file's EOF

When falling through to the underlying file in
bdrv_co_get_block_status(), if it returns that the query offset is
beyond the file end (by setting *pnum to 0), return the range to be
zero and do not let the number of sectors for which information could be
obtained be overwritten.
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 7f75a07d
......@@ -3954,13 +3954,24 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
if (bs->file &&
(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
(ret & BDRV_BLOCK_OFFSET_VALID)) {
int file_pnum;
ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
*pnum, pnum);
*pnum, &file_pnum);
if (ret2 >= 0) {
/* Ignore errors. This is just providing extra information, it
* is useful but not necessary.
*/
ret |= (ret2 & BDRV_BLOCK_ZERO);
if (!file_pnum) {
/* !file_pnum indicates an offset at or beyond the EOF; it is
* perfectly valid for the format block driver to point to such
* offsets, so catch it and mark everything as zero */
ret |= BDRV_BLOCK_ZERO;
} else {
/* Limit request to the range reported by the protocol driver */
*pnum = file_pnum;
ret |= (ret2 & BDRV_BLOCK_ZERO);
}
}
}
......
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