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Diffstat (limited to 'block/qcow2.c')
-rw-r--r--block/qcow2.c86
1 files changed, 59 insertions, 27 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index a53014dbda..4a688b4863 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -311,8 +311,8 @@ static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
}
/* handle reading after the end of the backing file */
-int qcow2_backing_read1(BlockDriverState *bs,
- int64_t sector_num, uint8_t *buf, int nb_sectors)
+int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
+ int64_t sector_num, int nb_sectors)
{
int n1;
if ((sector_num + nb_sectors) <= bs->total_sectors)
@@ -321,7 +321,9 @@ int qcow2_backing_read1(BlockDriverState *bs,
n1 = 0;
else
n1 = bs->total_sectors - sector_num;
- memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
+
+ qemu_iovec_memset(qiov, 0, 512 * (nb_sectors - n1));
+
return n1;
}
@@ -333,6 +335,7 @@ typedef struct QCowAIOCB {
void *orig_buf;
int remaining_sectors;
int cur_nr_sectors; /* number of sectors in current iteration */
+ uint64_t bytes_done;
uint64_t cluster_offset;
uint8_t *cluster_data;
BlockDriverAIOCB *hd_aiocb;
@@ -397,15 +400,19 @@ static void qcow_aio_read_cb(void *opaque, int ret)
/* nothing to do */
} else {
if (s->crypt_method) {
- qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
- acb->cur_nr_sectors, 0,
- &s->aes_decrypt_key);
+ qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data,
+ acb->cluster_data, acb->cur_nr_sectors, 0, &s->aes_decrypt_key);
+ qemu_iovec_reset(&acb->hd_qiov);
+ qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done,
+ acb->cur_nr_sectors * 512);
+ qemu_iovec_from_buffer(&acb->hd_qiov, acb->cluster_data,
+ 512 * acb->cur_nr_sectors);
}
}
acb->remaining_sectors -= acb->cur_nr_sectors;
acb->sector_num += acb->cur_nr_sectors;
- acb->buf += acb->cur_nr_sectors * 512;
+ acb->bytes_done += acb->cur_nr_sectors * 512;
if (acb->remaining_sectors == 0) {
/* request completed */
@@ -415,6 +422,11 @@ static void qcow_aio_read_cb(void *opaque, int ret)
/* prepare next AIO request */
acb->cur_nr_sectors = acb->remaining_sectors;
+ if (s->crypt_method) {
+ acb->cur_nr_sectors = MIN(acb->cur_nr_sectors,
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
+ }
+
ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
&acb->cur_nr_sectors, &acb->cluster_offset);
if (ret < 0) {
@@ -423,15 +435,17 @@ static void qcow_aio_read_cb(void *opaque, int ret)
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
+ qemu_iovec_reset(&acb->hd_qiov);
+ qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done,
+ acb->cur_nr_sectors * 512);
+
if (!acb->cluster_offset) {
+
if (bs->backing_hd) {
/* read from the base image */
- n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num,
- acb->buf, acb->cur_nr_sectors);
+ n1 = qcow2_backing_read1(bs->backing_hd, &acb->hd_qiov,
+ acb->sector_num, acb->cur_nr_sectors);
if (n1 > 0) {
- acb->hd_iov.iov_base = (void *)acb->buf;
- acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
- qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
&acb->hd_qiov, acb->cur_nr_sectors,
@@ -445,7 +459,7 @@ static void qcow_aio_read_cb(void *opaque, int ret)
}
} else {
/* Note: in this case, no need to wait */
- memset(acb->buf, 0, 512 * acb->cur_nr_sectors);
+ qemu_iovec_memset(&acb->hd_qiov, 0, 512 * acb->cur_nr_sectors);
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
if (ret < 0)
goto done;
@@ -454,8 +468,11 @@ static void qcow_aio_read_cb(void *opaque, int ret)
/* add AIO support for compressed blocks ? */
if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0)
goto done;
- memcpy(acb->buf, s->cluster_cache + index_in_cluster * 512,
- 512 * acb->cur_nr_sectors);
+
+ qemu_iovec_from_buffer(&acb->hd_qiov,
+ s->cluster_cache + index_in_cluster * 512,
+ 512 * acb->cur_nr_sectors);
+
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
if (ret < 0)
goto done;
@@ -465,9 +482,23 @@ static void qcow_aio_read_cb(void *opaque, int ret)
goto done;
}
- acb->hd_iov.iov_base = (void *)acb->buf;
- acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
- qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ if (s->crypt_method) {
+ /*
+ * For encrypted images, read everything into a temporary
+ * contiguous buffer on which the AES functions can work.
+ */
+ if (!acb->cluster_data) {
+ acb->cluster_data =
+ qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+ }
+
+ assert(acb->cur_nr_sectors <=
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
+ qemu_iovec_reset(&acb->hd_qiov);
+ qemu_iovec_add(&acb->hd_qiov, acb->cluster_data,
+ 512 * acb->cur_nr_sectors);
+ }
+
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
acb->hd_aiocb = bdrv_aio_readv(bs->file,
(acb->cluster_offset >> 9) + index_in_cluster,
@@ -481,11 +512,8 @@ static void qcow_aio_read_cb(void *opaque, int ret)
return;
done:
- if (acb->qiov->niov > 1) {
- qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
- qemu_vfree(acb->orig_buf);
- }
acb->common.cb(acb->common.opaque, ret);
+ qemu_iovec_destroy(&acb->hd_qiov);
qemu_aio_release(acb);
}
@@ -501,13 +529,17 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
acb->hd_aiocb = NULL;
acb->sector_num = sector_num;
acb->qiov = qiov;
- if (qiov->niov > 1) {
- acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
- if (is_write)
- qemu_iovec_to_buffer(qiov, acb->buf);
- } else {
+
+ if (!is_write) {
+ qemu_iovec_init(&acb->hd_qiov, qiov->niov);
+ } else if (qiov->niov == 1) {
acb->buf = (uint8_t *)qiov->iov->iov_base;
+ } else {
+ acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
+ qemu_iovec_to_buffer(qiov, acb->buf);
}
+
+ acb->bytes_done = 0;
acb->remaining_sectors = nb_sectors;
acb->cur_nr_sectors = 0;
acb->cluster_offset = 0;
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-29 13:39:00 +0000