From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-devel@nongnu.org, qemu-block@nongnu.org
Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, armbru@redhat.com,
mreitz@redhat.com, stefanha@redhat.com, den@openvz.org
Subject: [Qemu-devel] [PATCH v2 2/4] block/qcow2: refactor qcow2_co_preadv_part
Date: Tue, 30 Jul 2019 17:18:24 +0300 [thread overview]
Message-ID: <20190730141826.709849-3-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20190730141826.709849-1-vsementsov@virtuozzo.com>
Further patch will run partial requests of iterations of
qcow2_co_preadv in parallel for performance reasons. To prepare for
this, separate part which may be parallelized into separate function
(qcow2_co_preadv_task).
While being here, also separate encrypted clusters reading to own
function, like it is done for compressed reading.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
qapi/block-core.json | 2 +-
block/qcow2.c | 206 +++++++++++++++++++++++--------------------
2 files changed, 112 insertions(+), 96 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 0d43d4f37c..dd80aa11db 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -3266,7 +3266,7 @@
'pwritev_rmw_tail', 'pwritev_rmw_after_tail', 'pwritev',
'pwritev_zero', 'pwritev_done', 'empty_image_prepare',
'l1_shrink_write_table', 'l1_shrink_free_l2_clusters',
- 'cor_write', 'cluster_alloc_space', 'none'] }
+ 'cor_write', 'cluster_alloc_space', 'none', 'read_encrypted'] }
##
# @BlkdebugIOType:
diff --git a/block/qcow2.c b/block/qcow2.c
index 93ab7edcea..7fa71968b2 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1967,17 +1967,115 @@ out:
return ret;
}
+static coroutine_fn int
+qcow2_co_preadv_encrypted(BlockDriverState *bs,
+ uint64_t file_cluster_offset,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov,
+ uint64_t qiov_offset)
+{
+ int ret;
+ BDRVQcow2State *s = bs->opaque;
+ uint8_t *buf;
+
+ assert(bs->encrypted && s->crypto);
+ assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+
+ /*
+ * For encrypted images, read everything into a temporary
+ * contiguous buffer on which the AES functions can work.
+ * Note, that we can implement enctyption, working on qiov,
+ * but we must not do decryption in guest buffers for security
+ * reasons.
+ */
+
+ buf = qemu_try_blockalign(s->data_file->bs, bytes);
+ if (buf == NULL) {
+ return -ENOMEM;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_ENCRYPTED);
+ ret = bdrv_co_pread(s->data_file,
+ file_cluster_offset + offset_into_cluster(s, offset),
+ bytes, buf, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ if (qcow2_co_decrypt(bs, file_cluster_offset, offset, buf, bytes) < 0) {
+ ret = -EIO;
+ goto fail;
+ }
+ qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes);
+
+fail:
+ qemu_vfree(buf);
+
+ return ret;
+}
+
+static coroutine_fn int qcow2_co_preadv_task(BlockDriverState *bs,
+ QCow2ClusterType cluster_type,
+ uint64_t file_cluster_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_UNALLOCATED:
+ assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
+ return bdrv_co_preadv_part(bs->backing, offset, bytes,
+ qiov, qiov_offset, 0);
+
+ case QCOW2_CLUSTER_COMPRESSED:
+ return qcow2_co_preadv_compressed(bs, file_cluster_offset,
+ offset, bytes, qiov, qiov_offset);
+
+ case QCOW2_CLUSTER_NORMAL:
+ if ((file_cluster_offset & 511) != 0) {
+ return -EIO;
+ }
+
+ if (bs->encrypted) {
+ return qcow2_co_preadv_encrypted(bs, file_cluster_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,
+ bytes, qiov, qiov_offset, 0);
+
+ default:
+ g_assert_not_reached();
+ /*
+ * QCOW2_CLUSTER_ZERO_PLAIN and QCOW2_CLUSTER_ZERO_ALLOC handled
+ * in qcow2_co_preadv_part
+ */
+ }
+
+ g_assert_not_reached();
+
+ return -EIO;
+}
+
static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov,
size_t qiov_offset, int flags)
{
BDRVQcow2State *s = bs->opaque;
- int offset_in_cluster;
int ret;
unsigned int cur_bytes; /* number of bytes in current iteration */
uint64_t cluster_offset = 0;
- uint8_t *cluster_data = NULL;
while (bytes != 0) {
@@ -1992,111 +2090,29 @@ static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset);
qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
- goto fail;
+ return ret;
}
- offset_in_cluster = offset_into_cluster(s, offset);
-
- switch (ret) {
- case QCOW2_CLUSTER_UNALLOCATED:
-
- if (bs->backing) {
- BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
- ret = bdrv_co_preadv_part(bs->backing, offset, cur_bytes,
- qiov, qiov_offset, 0);
- if (ret < 0) {
- goto fail;
- }
- } else {
- /* Note: in this case, no need to wait */
- qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
- }
- break;
-
- case QCOW2_CLUSTER_ZERO_PLAIN:
- case QCOW2_CLUSTER_ZERO_ALLOC:
+ if (ret == QCOW2_CLUSTER_ZERO_PLAIN ||
+ ret == QCOW2_CLUSTER_ZERO_ALLOC ||
+ (ret == QCOW2_CLUSTER_UNALLOCATED && !bs->backing))
+ {
qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
- break;
-
- case QCOW2_CLUSTER_COMPRESSED:
- ret = qcow2_co_preadv_compressed(bs, cluster_offset,
- offset, cur_bytes,
- qiov, qiov_offset);
+ } else {
+ ret = qcow2_co_preadv_task(bs, ret,
+ cluster_offset, offset, cur_bytes,
+ qiov, qiov_offset);
if (ret < 0) {
- goto fail;
- }
-
- break;
-
- case QCOW2_CLUSTER_NORMAL:
- if ((cluster_offset & 511) != 0) {
- ret = -EIO;
- goto fail;
- }
-
- if (bs->encrypted) {
- assert(s->crypto);
-
- /*
- * For encrypted images, read everything into a temporary
- * contiguous buffer on which the AES functions can work.
- */
- if (!cluster_data) {
- cluster_data =
- qemu_try_blockalign(s->data_file->bs,
- QCOW_MAX_CRYPT_CLUSTERS
- * s->cluster_size);
- if (cluster_data == NULL) {
- ret = -ENOMEM;
- goto fail;
- }
- }
-
- assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
-
- BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
- ret = bdrv_co_pread(s->data_file,
- cluster_offset + offset_in_cluster,
- cur_bytes, cluster_data, 0);
- if (ret < 0) {
- goto fail;
- }
-
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- if (qcow2_co_decrypt(bs, cluster_offset, offset,
- cluster_data, cur_bytes) < 0) {
- ret = -EIO;
- goto fail;
- }
- qemu_iovec_from_buf(qiov, qiov_offset, cluster_data, cur_bytes);
- } else {
- BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
- ret = bdrv_co_preadv_part(s->data_file,
- cluster_offset + offset_in_cluster,
- cur_bytes, qiov, qiov_offset, 0);
- if (ret < 0) {
- goto fail;
- }
+ return ret;
}
- break;
-
- default:
- g_assert_not_reached();
- ret = -EIO;
- goto fail;
}
bytes -= cur_bytes;
offset += cur_bytes;
qiov_offset += cur_bytes;
}
- ret = 0;
-
-fail:
- qemu_vfree(cluster_data);
- return ret;
+ return 0;
}
/* Check if it's possible to merge a write request with the writing of
--
2.18.0
next prev parent reply other threads:[~2019-07-30 14:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-30 14:18 [Qemu-devel] [PATCH v2 0/4] qcow2: async handling of fragmented io Vladimir Sementsov-Ogievskiy
2019-07-30 14:18 ` [Qemu-devel] [PATCH v2 1/4] block: introduce aio task pool Vladimir Sementsov-Ogievskiy
2019-08-13 20:47 ` Max Reitz
2019-08-14 8:18 ` Vladimir Sementsov-Ogievskiy
2019-07-30 14:18 ` Vladimir Sementsov-Ogievskiy [this message]
2019-08-13 21:31 ` [Qemu-devel] [PATCH v2 2/4] block/qcow2: refactor qcow2_co_preadv_part Max Reitz
2019-08-14 9:11 ` Vladimir Sementsov-Ogievskiy
2019-08-14 15:03 ` Max Reitz
2019-08-14 15:15 ` Eric Blake
2019-08-14 15:58 ` Max Reitz
2019-07-30 14:18 ` [Qemu-devel] [PATCH v2 3/4] block/qcow2: refactor qcow2_co_pwritev_part Vladimir Sementsov-Ogievskiy
2019-08-14 15:55 ` Max Reitz
2019-08-14 16:23 ` Max Reitz
2019-07-30 14:18 ` [Qemu-devel] [PATCH v2 4/4] block/qcow2: introduce parallel subrequest handling in read and write Vladimir Sementsov-Ogievskiy
2019-08-14 16:24 ` Max Reitz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190730141826.709849-3-vsementsov@virtuozzo.com \
--to=vsementsov@virtuozzo.com \
--cc=armbru@redhat.com \
--cc=den@openvz.org \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).