haraldwolff/qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

qcow2: use byte-based read in qcow2_decompress_cluster

Browse source 
We are gradually moving away from sector-based interfaces, towards
byte-based.  Get rid of it here too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2018-11-01 21:27:36 +03:00 committed by Kevin Wolf
parent 341926ab83
commit c068a1cd52
1 changed files with 12 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

19
block/qcow2.c
View file

@ -3957,17 +3957,19 @@ fail:
return ret;
}
int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
int coroutine_fn
qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
{
BDRVQcow2State *s = bs->opaque;
int ret, csize, nb_csectors, sector_offset;
int ret, csize, nb_csectors;
uint64_t coffset;
struct iovec iov;
QEMUIOVector local_qiov;
coffset = cluster_offset & s->cluster_offset_mask;
if (s->cluster_cache_offset != coffset) {
nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
sector_offset = coffset & 511;
csize = nb_csectors * 512 - sector_offset;
csize = nb_csectors * 512 - (coffset & 511);
/* Allocate buffers on first decompress operation, most images are
* uncompressed and the memory overhead can be avoided. The buffers
@ -3985,14 +3987,17 @@ int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
s->cluster_cache = g_malloc(s->cluster_size);
}
iov.iov_base = s->cluster_data;
iov.iov_len = csize;
qemu_iovec_init_external(&local_qiov, &iov, 1);
BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data,
nb_csectors);
ret = bdrv_co_preadv(bs->file, coffset, csize, &local_qiov, 0);
if (ret < 0) {
return ret;
}
if (qcow2_decompress(s->cluster_cache, s->cluster_size,
s->cluster_data + sector_offset, csize) < 0) {
s->cluster_data, csize) < 0) {
return -EIO;
}
s->cluster_cache_offset = coffset;