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block: Switch bdrv_co_get_block_status_above() to byte-based 

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Convert another internal
type (no semantic change), and rename it to match the corresponding
public function rename.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2017-10-11 22:47:07 -05:00 committed by Kevin Wolf
parent 7ddb99b9dc
commit 5b648c67e3
1 changed files with 24 additions and 44 deletions
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68
block/io.c
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@ -1976,33 +1976,26 @@ early_out:
return ret;
}
static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs,
BlockDriverState *base,
bool want_zero,
int64_t sector_num,
int nb_sectors,
int *pnum,
BlockDriverState **file)
static int coroutine_fn bdrv_co_block_status_above(BlockDriverState *bs,
BlockDriverState *base,
bool want_zero,
int64_t offset,
int64_t bytes,
int64_t *pnum,
int64_t *map,
BlockDriverState **file)
{
BlockDriverState *p;
int64_t ret = 0;
int ret = 0;
bool first = true;
int64_t map = 0;
assert(bs != base);
for (p = bs; p != base; p = backing_bs(p)) {
int64_t count;
ret = bdrv_co_block_status(p, want_zero,
sector_num * BDRV_SECTOR_SIZE,
nb_sectors * BDRV_SECTOR_SIZE, &count,
&map, file);
ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map,
file);
if (ret < 0) {
break;
}
assert(QEMU_IS_ALIGNED(count | map, BDRV_SECTOR_SIZE));
ret |= map;
*pnum = count >> BDRV_SECTOR_BITS;
if (ret & BDRV_BLOCK_ZERO && ret & BDRV_BLOCK_EOF && !first) {
/*
* Reading beyond the end of the file continues to read
@ -2010,47 +2003,35 @@ static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs,
* unallocated length we learned from an earlier
* iteration.
*/
*pnum = nb_sectors;
*pnum = bytes;
}
if (ret & (BDRV_BLOCK_ZERO | BDRV_BLOCK_DATA)) {
break;
}
/* [sector_num, pnum] unallocated on this layer, which could be only
* the first part of [sector_num, nb_sectors]. */
nb_sectors = MIN(nb_sectors, *pnum);
/* [offset, pnum] unallocated on this layer, which could be only
* the first part of [offset, bytes]. */
bytes = MIN(bytes, *pnum);
first = false;
}
return ret;
}
/* Coroutine wrapper for bdrv_get_block_status_above() */
static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque)
static void coroutine_fn bdrv_block_status_above_co_entry(void *opaque)
{
BdrvCoBlockStatusData *data = opaque;
int n = 0;
int64_t ret;
ret = bdrv_co_get_block_status_above(data->bs, data->base,
data->want_zero,
data->offset >> BDRV_SECTOR_BITS,
data->bytes >> BDRV_SECTOR_BITS,
&n,
data->file);
if (ret < 0) {
assert(INT_MIN <= ret);
data->ret = ret;
} else {
*data->pnum = n * BDRV_SECTOR_SIZE;
*data->map = ret & BDRV_BLOCK_OFFSET_MASK;
data->ret = ret & ~BDRV_BLOCK_OFFSET_MASK;
}
data->ret = bdrv_co_block_status_above(data->bs, data->base,
data->want_zero,
data->offset, data->bytes,
data->pnum, data->map, data->file);
data->done = true;
}
/*
* Synchronous wrapper around bdrv_co_get_block_status_above().
* Synchronous wrapper around bdrv_co_block_status_above().
*
* See bdrv_co_get_block_status_above() for details.
* See bdrv_co_block_status_above() for details.
*/
static int bdrv_common_block_status_above(BlockDriverState *bs,
BlockDriverState *base,
@ -2074,10 +2055,9 @@ static int bdrv_common_block_status_above(BlockDriverState *bs,
if (qemu_in_coroutine()) {
/* Fast-path if already in coroutine context */
bdrv_get_block_status_above_co_entry(&data);
bdrv_block_status_above_co_entry(&data);
} else {
co = qemu_coroutine_create(bdrv_get_block_status_above_co_entry,
&data);
co = qemu_coroutine_create(bdrv_block_status_above_co_entry, &data);
bdrv_coroutine_enter(bs, co);
BDRV_POLL_WHILE(bs, !data.done);
}