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-rw-r--r--block/qcow2-cluster.c27
-rw-r--r--block/qcow2.c108
-rw-r--r--block/qcow2.h2
3 files changed, 72 insertions, 65 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index a59fb34..277764f 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -424,7 +424,8 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs,
* interface. This avoids double I/O throttling and request tracking,
* which can lead to deadlock when block layer copy-on-read is enabled.
*/
- ret = bs->drv->bdrv_co_readv(bs, start_sect + n_start, n, &qiov);
+ ret = bs->drv->bdrv_co_preadv(bs, (start_sect + n_start) * BDRV_SECTOR_SIZE,
+ n * BDRV_SECTOR_SIZE, &qiov, 0);
if (ret < 0) {
goto out;
}
@@ -464,19 +465,21 @@ out:
/*
* get_cluster_offset
*
- * For a given offset of the disk image, find the cluster offset in
- * qcow2 file. The offset is stored in *cluster_offset.
+ * For a given offset of the virtual disk, find the cluster type and offset in
+ * the qcow2 file. The offset is stored in *cluster_offset.
*
- * on entry, *num is the number of contiguous sectors we'd like to
- * access following offset.
+ * On entry, *bytes is the maximum number of contiguous bytes starting at
+ * offset that we are interested in.
*
- * on exit, *num is the number of contiguous sectors we can read.
+ * On exit, *bytes is the number of bytes starting at offset that have the same
+ * cluster type and (if applicable) are stored contiguously in the image file.
+ * Compressed clusters are always returned one by one.
*
* Returns the cluster type (QCOW2_CLUSTER_*) on success, -errno in error
* cases.
*/
int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int *num, uint64_t *cluster_offset)
+ unsigned int *bytes, uint64_t *cluster_offset)
{
BDRVQcow2State *s = bs->opaque;
unsigned int l2_index;
@@ -485,13 +488,9 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
unsigned int offset_in_cluster, nb_clusters;
uint64_t bytes_available, bytes_needed;
int ret;
- unsigned int bytes;
-
- assert(*num <= BDRV_REQUEST_MAX_SECTORS);
- bytes = *num * BDRV_SECTOR_SIZE;
offset_in_cluster = offset_into_cluster(s, offset);
- bytes_needed = (uint64_t) bytes + offset_in_cluster;
+ bytes_needed = (uint64_t) *bytes + offset_in_cluster;
l1_bits = s->l2_bits + s->cluster_bits;
@@ -595,9 +594,7 @@ out:
bytes_available = bytes_needed;
}
- bytes = bytes_available - offset_in_cluster;
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- *num = bytes >> BDRV_SECTOR_BITS;
+ *bytes = bytes_available - offset_in_cluster;
return ret;
diff --git a/block/qcow2.c b/block/qcow2.c
index 6f5fb81..545dea0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -975,6 +975,9 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
}
bs->encrypted = 1;
+
+ /* Encryption works on a sector granularity */
+ bs->request_alignment = BDRV_SECTOR_SIZE;
}
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
@@ -1331,16 +1334,20 @@ static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
BDRVQcow2State *s = bs->opaque;
uint64_t cluster_offset;
int index_in_cluster, ret;
+ unsigned int bytes;
int64_t status = 0;
- *pnum = nb_sectors;
+ bytes = MIN(INT_MAX, nb_sectors * BDRV_SECTOR_SIZE);
qemu_co_mutex_lock(&s->lock);
- ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
+ ret = qcow2_get_cluster_offset(bs, sector_num << 9, &bytes,
+ &cluster_offset);
qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
return ret;
}
+ *pnum = bytes >> BDRV_SECTOR_BITS;
+
if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED &&
!s->cipher) {
index_in_cluster = sector_num & (s->cluster_sectors - 1);
@@ -1358,28 +1365,34 @@ static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
/* handle reading after the end of the backing file */
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
- int64_t sector_num, int nb_sectors)
+ int64_t offset, int bytes)
{
+ uint64_t bs_size = bs->total_sectors * BDRV_SECTOR_SIZE;
int n1;
- if ((sector_num + nb_sectors) <= bs->total_sectors)
- return nb_sectors;
- if (sector_num >= bs->total_sectors)
+
+ if ((offset + bytes) <= bs_size) {
+ return bytes;
+ }
+
+ if (offset >= bs_size) {
n1 = 0;
- else
- n1 = bs->total_sectors - sector_num;
+ } else {
+ n1 = bs_size - offset;
+ }
- qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1));
+ qemu_iovec_memset(qiov, n1, 0, bytes - n1);
return n1;
}
-static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
- int remaining_sectors, QEMUIOVector *qiov)
+static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov,
+ int flags)
{
BDRVQcow2State *s = bs->opaque;
- int index_in_cluster, n1;
+ int offset_in_cluster, n1;
int ret;
- int cur_nr_sectors; /* number of sectors in current iteration */
+ unsigned int cur_bytes; /* number of bytes in current iteration */
uint64_t cluster_offset = 0;
uint64_t bytes_done = 0;
QEMUIOVector hd_qiov;
@@ -1389,26 +1402,24 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
qemu_co_mutex_lock(&s->lock);
- while (remaining_sectors != 0) {
+ while (bytes != 0) {
/* prepare next request */
- cur_nr_sectors = remaining_sectors;
+ cur_bytes = MIN(bytes, INT_MAX);
if (s->cipher) {
- cur_nr_sectors = MIN(cur_nr_sectors,
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
+ cur_bytes = MIN(cur_bytes,
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
}
- ret = qcow2_get_cluster_offset(bs, sector_num << 9,
- &cur_nr_sectors, &cluster_offset);
+ ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset);
if (ret < 0) {
goto fail;
}
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
+ offset_in_cluster = offset_into_cluster(s, offset);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
- cur_nr_sectors * 512);
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes);
switch (ret) {
case QCOW2_CLUSTER_UNALLOCATED:
@@ -1416,18 +1427,17 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
if (bs->backing) {
/* read from the base image */
n1 = qcow2_backing_read1(bs->backing->bs, &hd_qiov,
- sector_num, cur_nr_sectors);
+ offset, cur_bytes);
if (n1 > 0) {
QEMUIOVector local_qiov;
qemu_iovec_init(&local_qiov, hd_qiov.niov);
- qemu_iovec_concat(&local_qiov, &hd_qiov, 0,
- n1 * BDRV_SECTOR_SIZE);
+ qemu_iovec_concat(&local_qiov, &hd_qiov, 0, n1);
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
qemu_co_mutex_unlock(&s->lock);
- ret = bdrv_co_readv(bs->backing->bs, sector_num,
- n1, &local_qiov);
+ ret = bdrv_co_preadv(bs->backing->bs, offset, n1,
+ &local_qiov, 0);
qemu_co_mutex_lock(&s->lock);
qemu_iovec_destroy(&local_qiov);
@@ -1438,12 +1448,12 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
}
} else {
/* Note: in this case, no need to wait */
- qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
+ qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes);
}
break;
case QCOW2_CLUSTER_ZERO:
- qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
+ qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes);
break;
case QCOW2_CLUSTER_COMPRESSED:
@@ -1454,8 +1464,8 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
}
qemu_iovec_from_buf(&hd_qiov, 0,
- s->cluster_cache + index_in_cluster * 512,
- 512 * cur_nr_sectors);
+ s->cluster_cache + offset_in_cluster,
+ cur_bytes);
break;
case QCOW2_CLUSTER_NORMAL:
@@ -1482,34 +1492,34 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
}
}
- assert(cur_nr_sectors <=
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
+ assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_add(&hd_qiov, cluster_data,
- 512 * cur_nr_sectors);
+ qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes);
}
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
qemu_co_mutex_unlock(&s->lock);
- ret = bdrv_co_readv(bs->file->bs,
- (cluster_offset >> 9) + index_in_cluster,
- cur_nr_sectors, &hd_qiov);
+ ret = bdrv_co_preadv(bs->file->bs,
+ cluster_offset + offset_in_cluster,
+ cur_bytes, &hd_qiov, 0);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
if (bs->encrypted) {
assert(s->cipher);
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
Error *err = NULL;
- if (qcow2_encrypt_sectors(s, sector_num, cluster_data,
- cluster_data, cur_nr_sectors, false,
- &err) < 0) {
+ if (qcow2_encrypt_sectors(s, offset >> BDRV_SECTOR_BITS,
+ cluster_data, cluster_data,
+ cur_bytes >> BDRV_SECTOR_BITS,
+ false, &err) < 0) {
error_free(err);
ret = -EIO;
goto fail;
}
- qemu_iovec_from_buf(qiov, bytes_done,
- cluster_data, 512 * cur_nr_sectors);
+ qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes);
}
break;
@@ -1519,9 +1529,9 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
goto fail;
}
- remaining_sectors -= cur_nr_sectors;
- sector_num += cur_nr_sectors;
- bytes_done += cur_nr_sectors * 512;
+ bytes -= cur_bytes;
+ offset += cur_bytes;
+ bytes_done += cur_bytes;
}
ret = 0;
@@ -2435,7 +2445,7 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
if (head || tail) {
int64_t cl_start = (offset - head) >> BDRV_SECTOR_BITS;
uint64_t off;
- int nr;
+ unsigned int nr;
assert(head + count <= s->cluster_size);
@@ -2452,7 +2462,7 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
/* We can have new write after previous check */
offset = cl_start << BDRV_SECTOR_BITS;
count = s->cluster_size;
- nr = s->cluster_sectors;
+ nr = s->cluster_size;
ret = qcow2_get_cluster_offset(bs, offset, &nr, &off);
if (ret != QCOW2_CLUSTER_UNALLOCATED && ret != QCOW2_CLUSTER_ZERO) {
qemu_co_mutex_unlock(&s->lock);
@@ -3368,7 +3378,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_co_get_block_status = qcow2_co_get_block_status,
.bdrv_set_key = qcow2_set_key,
- .bdrv_co_readv = qcow2_co_readv,
+ .bdrv_co_preadv = qcow2_co_preadv,
.bdrv_co_writev = qcow2_co_writev,
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
diff --git a/block/qcow2.h b/block/qcow2.h
index 7db9795..e2c42d5 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -544,7 +544,7 @@ int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
int nb_sectors, bool enc, Error **errp);
int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int *num, uint64_t *cluster_offset);
+ unsigned int *bytes, uint64_t *cluster_offset);
int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
int *num, uint64_t *host_offset, QCowL2Meta **m);
uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
generated by cgit v1.1 at 2024-12-29 10:42:41 +0000