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[Qemu-block] [PATCH 3/7] qcow2: split out reading normal clusters from q
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-block] [PATCH 3/7] qcow2: split out reading normal clusters from qcow2_co_preadv |
Date: |
Tue, 7 Aug 2018 20:43:07 +0300 |
Memory allocation may become less efficient for encrypted case. It's a
payment for further asynchronous scheme.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/qcow2.c | 114 ++++++++++++++++++++++++++++++++--------------------------
1 file changed, 64 insertions(+), 50 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 65e3ca00e2..5e7f2ee318 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1808,6 +1808,67 @@ out:
return ret;
}
+static coroutine_fn int qcow2_co_preadv_normal(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;
+ void *crypt_buf = NULL;
+ QEMUIOVector hd_qiov;
+ int offset_in_cluster = offset_into_cluster(s, offset);
+
+ if ((file_cluster_offset & 511) != 0) {
+ return -EIO;
+ }
+
+ qemu_iovec_init(&hd_qiov, qiov->niov);
+
+ if (bs->encrypted) {
+ assert(s->crypto);
+ assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+
+ crypt_buf = qemu_try_blockalign(bs->file->bs, bytes);
+ qemu_iovec_add(&hd_qiov, crypt_buf, bytes);
+ } else {
+ qemu_iovec_concat(&hd_qiov, qiov, qiov_offset, bytes);
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ ret = bdrv_co_preadv(bs->file,
+ file_cluster_offset + offset_in_cluster,
+ bytes, &hd_qiov, 0);
+ if (ret < 0) {
+ goto out;
+ }
+
+ if (bs->encrypted) {
+ assert(s->crypto);
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ if (qcrypto_block_decrypt(s->crypto,
+ (s->crypt_physical_offset ?
+ file_cluster_offset + offset_in_cluster :
+ offset),
+ crypt_buf,
+ bytes,
+ NULL) < 0) {
+ ret = -EIO;
+ goto out;
+ }
+ qemu_iovec_from_buf(qiov, qiov_offset, crypt_buf, bytes);
+ }
+
+out:
+ qemu_vfree(crypt_buf);
+ qemu_iovec_destroy(&hd_qiov);
+
+ return ret;
+}
+
static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov,
int flags)
@@ -1819,7 +1880,6 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState
*bs, uint64_t offset,
uint64_t cluster_offset = 0;
uint64_t bytes_done = 0;
QEMUIOVector hd_qiov;
- uint8_t *cluster_data = NULL;
qemu_iovec_init(&hd_qiov, qiov->niov);
@@ -1882,57 +1942,12 @@ static coroutine_fn int
qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
case QCOW2_CLUSTER_NORMAL:
qemu_co_mutex_unlock(&s->lock);
- if ((cluster_offset & 511) != 0) {
- ret = -EIO;
- goto fail_nolock;
- }
-
- 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(bs->file->bs,
- QCOW_MAX_CRYPT_CLUSTERS
- * s->cluster_size);
- if (cluster_data == NULL) {
- ret = -ENOMEM;
- goto fail_nolock;
- }
- }
-
- assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
- qemu_iovec_reset(&hd_qiov);
- qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes);
- }
-
- BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
- ret = bdrv_co_preadv(bs->file,
- cluster_offset + offset_in_cluster,
- cur_bytes, &hd_qiov, 0);
+ ret = qcow2_co_preadv_normal(bs, cluster_offset,
+ offset, cur_bytes, qiov, bytes_done);
if (ret < 0) {
goto fail_nolock;
}
- if (bs->encrypted) {
- assert(s->crypto);
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- if (qcrypto_block_decrypt(s->crypto,
- (s->crypt_physical_offset ?
- cluster_offset + offset_in_cluster :
- offset),
- cluster_data,
- cur_bytes,
- NULL) < 0) {
- ret = -EIO;
- goto fail_nolock;
- }
- qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes);
- }
+
qemu_co_mutex_lock(&s->lock);
break;
@@ -1953,7 +1968,6 @@ fail:
fail_nolock:
qemu_iovec_destroy(&hd_qiov);
- qemu_vfree(cluster_data);
return ret;
}
--
2.11.1
- [Qemu-block] [PATCH 0/7] qcow2: async handling of fragmented io, Vladimir Sementsov-Ogievskiy, 2018/08/07
- [Qemu-block] [PATCH 1/7] qcow2: move qemu_co_mutex_lock below decryption procedure, Vladimir Sementsov-Ogievskiy, 2018/08/07
- [Qemu-block] [PATCH 2/7] qcow2: bdrv_co_pwritev: move encryption code out of lock, Vladimir Sementsov-Ogievskiy, 2018/08/07
- [Qemu-block] [PATCH 6/7] qcow2: refactor qcow2_co_pwritev locals scope, Vladimir Sementsov-Ogievskiy, 2018/08/07
- [Qemu-block] [PATCH 3/7] qcow2: split out reading normal clusters from qcow2_co_preadv,
Vladimir Sementsov-Ogievskiy <=
- [Qemu-block] [PATCH 7/7] qcow2: async scheme for qcow2_co_pwritev, Vladimir Sementsov-Ogievskiy, 2018/08/07
- [Qemu-block] [PATCH 4/7] qcow2: async scheme for qcow2_co_preadv, Vladimir Sementsov-Ogievskiy, 2018/08/07
- [Qemu-block] [PATCH 5/7] qcow2: refactor qcow2_co_pwritev: split out qcow2_co_do_pwritev, Vladimir Sementsov-Ogievskiy, 2018/08/07
- Re: [Qemu-block] [PATCH 0/7] qcow2: async handling of fragmented io, Max Reitz, 2018/08/15