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qcow2: Make Qcow2AioTask store the full host offset

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The file_cluster_offset field of Qcow2AioTask stores a cluster-aligned
host offset. In practice this is not very useful because all users(*)
of this structure need the final host offset into the cluster, which
they calculate using

   host_offset = file_cluster_offset + offset_into_cluster(s, offset)

There is no reason why Qcow2AioTask cannot store host_offset directly
and that is what this patch does.

(*) compressed clusters are the exception: in this case what
    file_cluster_offset was storing was the full compressed cluster
    descriptor (offset + size). This does not change with this patch
    but it is documented now.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <07c4b15c644dcf06c9459f98846ac1c4ea96e26f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Alberto Garcia 2020-07-10 18:12:43 +02:00 committed by Max Reitz
parent 30aa19446d
commit 9c4269d54b
2 changed files with 34 additions and 37 deletions
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69
block/qcow2.c
View File

@ -74,7 +74,7 @@ typedef struct {
static int coroutine_fn
qcow2_co_preadv_compressed(BlockDriverState *bs,
uint64_t file_cluster_offset,
uint64_t cluster_descriptor,
uint64_t offset,
uint64_t bytes,
QEMUIOVector *qiov,
@ -2113,7 +2113,7 @@ out:
static coroutine_fn int
qcow2_co_preadv_encrypted(BlockDriverState *bs,
uint64_t file_cluster_offset,
uint64_t host_offset,
uint64_t offset,
uint64_t bytes,
QEMUIOVector *qiov,
@ -2140,16 +2140,12 @@ qcow2_co_preadv_encrypted(BlockDriverState *bs,
}
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
ret = bdrv_co_pread(s->data_file,
file_cluster_offset + offset_into_cluster(s, offset),
bytes, buf, 0);
ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0);
if (ret < 0) {
goto fail;
}
if (qcow2_co_decrypt(bs,
file_cluster_offset + offset_into_cluster(s, offset),
offset, buf, bytes) < 0)
if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0)
{
ret = -EIO;
goto fail;
@ -2167,7 +2163,7 @@ typedef struct Qcow2AioTask {
BlockDriverState *bs;
QCow2ClusterType cluster_type; /* only for read */
uint64_t file_cluster_offset;
uint64_t host_offset; /* or full descriptor in compressed clusters */
uint64_t offset;
uint64_t bytes;
QEMUIOVector *qiov;
@ -2180,7 +2176,7 @@ static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
AioTaskPool *pool,
AioTaskFunc func,
QCow2ClusterType cluster_type,
uint64_t file_cluster_offset,
uint64_t host_offset,
uint64_t offset,
uint64_t bytes,
QEMUIOVector *qiov,
@ -2195,7 +2191,7 @@ static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
.bs = bs,
.cluster_type = cluster_type,
.qiov = qiov,
.file_cluster_offset = file_cluster_offset,
.host_offset = host_offset,
.offset = offset,
.bytes = bytes,
.qiov_offset = qiov_offset,
@ -2204,7 +2200,7 @@ static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
trace_qcow2_add_task(qemu_coroutine_self(), bs, pool,
func == qcow2_co_preadv_task_entry ? "read" : "write",
cluster_type, file_cluster_offset, offset, bytes,
cluster_type, host_offset, offset, bytes,
qiov, qiov_offset);
if (!pool) {
@ -2218,13 +2214,12 @@ static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
static coroutine_fn int qcow2_co_preadv_task(BlockDriverState *bs,
QCow2ClusterType cluster_type,
uint64_t file_cluster_offset,
uint64_t host_offset,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov,
size_t qiov_offset)
{
BDRVQcow2State *s = bs->opaque;
int offset_in_cluster = offset_into_cluster(s, offset);
switch (cluster_type) {
case QCOW2_CLUSTER_ZERO_PLAIN:
@ -2240,19 +2235,17 @@ static coroutine_fn int qcow2_co_preadv_task(BlockDriverState *bs,
qiov, qiov_offset, 0);
case QCOW2_CLUSTER_COMPRESSED:
return qcow2_co_preadv_compressed(bs, file_cluster_offset,
return qcow2_co_preadv_compressed(bs, host_offset,
offset, bytes, qiov, qiov_offset);
case QCOW2_CLUSTER_NORMAL:
assert(offset_into_cluster(s, file_cluster_offset) == 0);
if (bs->encrypted) {
return qcow2_co_preadv_encrypted(bs, file_cluster_offset,
return qcow2_co_preadv_encrypted(bs, host_offset,
offset, bytes, qiov, qiov_offset);
}
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
return bdrv_co_preadv_part(s->data_file,
file_cluster_offset + offset_in_cluster,
return bdrv_co_preadv_part(s->data_file, host_offset,
bytes, qiov, qiov_offset, 0);
default:
@ -2268,7 +2261,7 @@ static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task)
assert(!t->l2meta);
return qcow2_co_preadv_task(t->bs, t->cluster_type, t->file_cluster_offset,
return qcow2_co_preadv_task(t->bs, t->cluster_type, t->host_offset,
t->offset, t->bytes, t->qiov, t->qiov_offset);
}
@ -2304,11 +2297,20 @@ static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
{
qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
} else {
/*
* For compressed clusters the variable cluster_offset
* does not actually store the offset but the full
* descriptor. We need to leave it unchanged because
* that's what qcow2_co_preadv_compressed() expects.
*/
uint64_t host_offset = (ret == QCOW2_CLUSTER_COMPRESSED) ?
cluster_offset :
cluster_offset + offset_into_cluster(s, offset);
if (!aio && cur_bytes != bytes) {
aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
}
ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, ret,
cluster_offset, offset, cur_bytes,
host_offset, offset, cur_bytes,
qiov, qiov_offset, NULL);
if (ret < 0) {
goto out;
@ -2459,7 +2461,7 @@ static int handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta)
* not use it somehow after qcow2_co_pwritev_task() call
*/
static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs,
uint64_t file_cluster_offset,
uint64_t host_offset,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov,
uint64_t qiov_offset,
@ -2468,7 +2470,6 @@ static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs,
int ret;
BDRVQcow2State *s = bs->opaque;
void *crypt_buf = NULL;
int offset_in_cluster = offset_into_cluster(s, offset);
QEMUIOVector encrypted_qiov;
if (bs->encrypted) {
@ -2481,9 +2482,7 @@ static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs,
}
qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes);
if (qcow2_co_encrypt(bs, file_cluster_offset + offset_in_cluster,
offset, crypt_buf, bytes) < 0)
{
if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) {
ret = -EIO;
goto out_unlocked;
}
@ -2507,10 +2506,8 @@ static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs,
*/
if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) {
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
trace_qcow2_writev_data(qemu_coroutine_self(),
file_cluster_offset + offset_in_cluster);
ret = bdrv_co_pwritev_part(s->data_file,
file_cluster_offset + offset_in_cluster,
trace_qcow2_writev_data(qemu_coroutine_self(), host_offset);
ret = bdrv_co_pwritev_part(s->data_file, host_offset,
bytes, qiov, qiov_offset, 0);
if (ret < 0) {
goto out_unlocked;
@ -2540,7 +2537,7 @@ static coroutine_fn int qcow2_co_pwritev_task_entry(AioTask *task)
assert(!t->cluster_type);
return qcow2_co_pwritev_task(t->bs, t->file_cluster_offset,
return qcow2_co_pwritev_task(t->bs, t->host_offset,
t->offset, t->bytes, t->qiov, t->qiov_offset,
t->l2meta);
}
@ -2595,8 +2592,8 @@ static coroutine_fn int qcow2_co_pwritev_part(
aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
}
ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0,
cluster_offset, offset, cur_bytes,
qiov, qiov_offset, l2meta);
cluster_offset + offset_in_cluster, offset,
cur_bytes, qiov, qiov_offset, l2meta);
l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */
if (ret < 0) {
goto fail_nometa;
@ -4562,7 +4559,7 @@ qcow2_co_pwritev_compressed_part(BlockDriverState *bs,
static int coroutine_fn
qcow2_co_preadv_compressed(BlockDriverState *bs,
uint64_t file_cluster_offset,
uint64_t cluster_descriptor,
uint64_t offset,
uint64_t bytes,
QEMUIOVector *qiov,
@ -4574,8 +4571,8 @@ qcow2_co_preadv_compressed(BlockDriverState *bs,
uint8_t *buf, *out_buf;
int offset_in_cluster = offset_into_cluster(s, offset);
coffset = file_cluster_offset & s->cluster_offset_mask;
nb_csectors = ((file_cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
coffset = cluster_descriptor & s->cluster_offset_mask;
nb_csectors = ((cluster_descriptor >> s->csize_shift) & s->csize_mask) + 1;
csize = nb_csectors * QCOW2_COMPRESSED_SECTOR_SIZE -
(coffset & ~QCOW2_COMPRESSED_SECTOR_MASK);

2
block/trace-events
View File

@ -77,7 +77,7 @@ luring_io_uring_submit(void *s, int ret) "LuringState %p ret %d"
luring_resubmit_short_read(void *s, void *luringcb, int nread) "LuringState %p luringcb %p nread %d"
# qcow2.c
qcow2_add_task(void *co, void *bs, void *pool, const char *action, int cluster_type, uint64_t file_cluster_offset, uint64_t offset, uint64_t bytes, void *qiov, size_t qiov_offset) "co %p bs %p pool %p: %s: cluster_type %d file_cluster_offset %" PRIu64 " offset %" PRIu64 " bytes %" PRIu64 " qiov %p qiov_offset %zu"
qcow2_add_task(void *co, void *bs, void *pool, const char *action, int cluster_type, uint64_t host_offset, uint64_t offset, uint64_t bytes, void *qiov, size_t qiov_offset) "co %p bs %p pool %p: %s: cluster_type %d file_cluster_offset %" PRIu64 " offset %" PRIu64 " bytes %" PRIu64 " qiov %p qiov_offset %zu"
qcow2_writev_start_req(void *co, int64_t offset, int bytes) "co %p offset 0x%" PRIx64 " bytes %d"
qcow2_writev_done_req(void *co, int ret) "co %p ret %d"
qcow2_writev_start_part(void *co) "co %p"