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author | Eric Blake <eblake@redhat.com> | 2017-10-11 22:47:08 -0500 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2017-10-26 14:45:57 +0200 |
commit | 3182664220571d11d4fe03ecdc10fcc1e842ed32 (patch) | |
tree | a156b5da4a97164b0620bf8067130088a4cfe2f1 /include/block | |
parent | 5b648c67e3acea3e0136d0bb1bd47341996e0e4e (diff) | |
download | qemu-3182664220571d11d4fe03ecdc10fcc1e842ed32.zip qemu-3182664220571d11d4fe03ecdc10fcc1e842ed32.tar.gz qemu-3182664220571d11d4fe03ecdc10fcc1e842ed32.tar.bz2 |
block: Convert bdrv_get_block_status_above() to bytes
We are gradually moving away from sector-based interfaces, towards
byte-based. In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.
Changing the name of the function from bdrv_get_block_status_above()
to bdrv_block_status_above() ensures that the compiler enforces that
all callers are updated. Likewise, since it a byte interface allows
an offset mapping that might not be sector aligned, split the mapping
out of the return value and into a pass-by-reference parameter. For
now, the io.c layer still assert()s that all uses are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status in the drivers.
For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_block_status(), plus
updates for the new split return interface. But some code,
particularly bdrv_block_status(), gets a lot simpler because it no
longer has to mess with sectors. Likewise, mirror code no longer
computes s->granularity >> BDRV_SECTOR_BITS, and can therefore drop
an assertion about alignment because the loop no longer depends on
alignment (never mind that we don't really have a driver that
reports sub-sector alignments, so it's not really possible to test
the effect of sub-sector mirroring). Fix a neighboring assertion to
use is_power_of_2 while there.
For ease of review, bdrv_get_block_status() was tackled separately.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'include/block')
-rw-r--r-- | include/block/block.h | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/include/block/block.h b/include/block/block.h index 7ac851f..fbc21da 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -425,11 +425,9 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs); int bdrv_block_status(BlockDriverState *bs, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file); -int64_t bdrv_get_block_status_above(BlockDriverState *bs, - BlockDriverState *base, - int64_t sector_num, - int nb_sectors, int *pnum, - BlockDriverState **file); +int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, + int64_t offset, int64_t bytes, int64_t *pnum, + int64_t *map, BlockDriverState **file); int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, int64_t *pnum); int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, |