Similarly to previous commit, prepare for parallelizing write-loop
iterations.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
block/qcow2.c | 150 +++++++++++++++++++++++++++++---------------------
1 file changed, 88 insertions(+), 62 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 7fa71968b2..37766b8b7c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2235,6 +2235,87 @@ static int handle_alloc_space(BlockDriverState *bs,
QCowL2Meta *l2meta)
return 0;
}
+/*
+ * qcow2_co_pwritev_task
+ * Called with s->lock unlocked
+ * l2meta - if not NULL, qcow2_co_do_pwritev() will consume it. Caller must
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 offset, uint64_t bytes,
+ QEMUIOVector *qiov,
+ uint64_t qiov_offset,
+ QCowL2Meta *l2meta)
+{
+ 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) {
+ assert(s->crypto);
+ assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+ crypt_buf = qemu_try_blockalign(bs->file->bs, bytes);
+ if (crypt_buf == NULL) {
+ ret = -ENOMEM;
+ goto out_unlocked;
+ }
+ qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes);
+
+ if (qcow2_co_encrypt(bs, file_cluster_offset, offset,
+ crypt_buf, bytes) < 0) {
+ ret = -EIO;
+ goto out_unlocked;
+ }
+
+ qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes);
+ qiov = &encrypted_qiov;
+ qiov_offset = 0;
+ }
+
+ /* Try to efficiently initialize the physical space with zeroes */
+ ret = handle_alloc_space(bs, l2meta);
+ if (ret < 0) {
+ goto out_unlocked;
+ }
+
+ /*
+ * If we need to do COW, check if it's possible to merge the
+ * writing of the guest data together with that of the COW regions.
+ * If it's not possible (or not necessary) then write the
+ * guest data now.
+ */
+ 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,
+ bytes, qiov, qiov_offset, 0);
+ if (ret < 0) {
+ goto out_unlocked;
+ }
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+
+ ret = qcow2_handle_l2meta(bs, &l2meta, true);
+ goto out_locked;
+
+out_unlocked:
+ qemu_co_mutex_lock(&s->lock);
+
+out_locked:
+ qcow2_handle_l2meta(bs, &l2meta, false);
+ qemu_co_mutex_unlock(&s->lock);
+
+ qemu_vfree(crypt_buf);
+
+ return ret;
+}
+
static coroutine_fn int qcow2_co_pwritev_part(
BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, size_t qiov_offset, int flags)
@@ -2244,15 +2325,11 @@ static coroutine_fn int qcow2_co_pwritev_part(
int ret;
unsigned int cur_bytes; /* number of sectors in current iteration */
uint64_t cluster_offset;
- QEMUIOVector encrypted_qiov;
uint64_t bytes_done = 0;
- uint8_t *cluster_data = NULL;
QCowL2Meta *l2meta = NULL;
trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes);
- qemu_co_mutex_lock(&s->lock);
-
while (bytes != 0) {
l2meta = NULL;
@@ -2266,6 +2343,8 @@ static coroutine_fn int qcow2_co_pwritev_part(
- offset_in_cluster);
}
+ qemu_co_mutex_lock(&s->lock);
+
ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes,
&cluster_offset, &l2meta);
if (ret < 0) {
@@ -2283,62 +2362,11 @@ static coroutine_fn int qcow2_co_pwritev_part(
qemu_co_mutex_unlock(&s->lock);
- if (bs->encrypted) {
- assert(s->crypto);
- if (!cluster_data) {
- cluster_data = qemu_try_blockalign(bs->file->bs,
- QCOW_MAX_CRYPT_CLUSTERS
- * s->cluster_size);
- if (cluster_data == NULL) {
- ret = -ENOMEM;
- goto out_unlocked;
- }
- }
-
- assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
- qemu_iovec_to_buf(qiov, qiov_offset + bytes_done,
- cluster_data, cur_bytes);
-
- if (qcow2_co_encrypt(bs, cluster_offset, offset,
- cluster_data, cur_bytes) < 0) {
- ret = -EIO;
- goto out_unlocked;
- }
-
- qemu_iovec_init_buf(&encrypted_qiov, cluster_data, cur_bytes);
- }
-
- /* Try to efficiently initialize the physical space with zeroes */
- ret = handle_alloc_space(bs, l2meta);
+ ret = qcow2_co_pwritev_task(bs, cluster_offset, offset, cur_bytes,
+ qiov, bytes_done, l2meta);
+ l2meta = NULL; /* l2meta is consumed by qcow2_co_do_pwritev() */
if (ret < 0) {
- goto out_unlocked;
- }
-
- /* If we need to do COW, check if it's possible to merge the
- * writing of the guest data together with that of the COW regions.
- * If it's not possible (or not necessary) then write the
- * guest data now. */
- if (!merge_cow(offset, cur_bytes,
- bs->encrypted ? &encrypted_qiov : qiov,
- bs->encrypted ? 0 : qiov_offset + bytes_done, l2meta))
- {
- BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
- trace_qcow2_writev_data(qemu_coroutine_self(),
- cluster_offset + offset_in_cluster);
- ret = bdrv_co_pwritev_part(
- s->data_file, cluster_offset + offset_in_cluster,
cur_bytes,
- bs->encrypted ? &encrypted_qiov : qiov,
- bs->encrypted ? 0 : qiov_offset + bytes_done, 0);
- if (ret < 0) {
- goto out_unlocked;
- }
- }
-
- qemu_co_mutex_lock(&s->lock);
-
- ret = qcow2_handle_l2meta(bs, &l2meta, true);
- if (ret) {
- goto out_locked;
+ goto fail_nometa;
}
bytes -= cur_bytes;
@@ -2347,9 +2375,7 @@ static coroutine_fn int qcow2_co_pwritev_part(
trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes);
}
ret = 0;
- goto out_locked;
-out_unlocked:
qemu_co_mutex_lock(&s->lock);
out_locked:
@@ -2357,7 +2383,7 @@ out_locked:
qemu_co_mutex_unlock(&s->lock);
- qemu_vfree(cluster_data);
+fail_nometa:
trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
return ret;
--
2.18.0
