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[Qemu-devel] [PATCH 5/7] qcow2: use byte-based read in qcow2_decompress_
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-devel] [PATCH 5/7] qcow2: use byte-based read in qcow2_decompress_cluster |
Date: |
Thu, 1 Nov 2018 21:27:36 +0300 |
We are gradually moving away from sector-based interfaces, towards
byte-based. Get rid of it here too.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/qcow2.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index e9d24b801e..950b9f7ec6 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3956,14 +3956,15 @@ fail:
int 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
@@ -3981,14 +3982,17 @@ 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;
--
2.18.0