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qed: Make qed_copy_from_backing_file() synchronous

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Note that this code is generally not running in coroutine context, so
this is an actual blocking synchronous operation. We'll fix this in a
moment.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2016-11-14 14:56:32 +01:00
parent e85c528142
commit 0f7aa24d2c
1 changed files with 29 additions and 49 deletions
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78
block/qed.c
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@ -854,44 +854,6 @@ static int qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
return 0;
}
typedef struct {
GenericCB gencb;
BDRVQEDState *s;
QEMUIOVector qiov;
QEMUIOVector *backing_qiov;
struct iovec iov;
uint64_t offset;
} CopyFromBackingFileCB;
static void qed_copy_from_backing_file_cb(void *opaque, int ret)
{
CopyFromBackingFileCB *copy_cb = opaque;
qemu_vfree(copy_cb->iov.iov_base);
gencb_complete(&copy_cb->gencb, ret);
}
static void qed_copy_from_backing_file_write(void *opaque, int ret)
{
CopyFromBackingFileCB *copy_cb = opaque;
BDRVQEDState *s = copy_cb->s;
if (copy_cb->backing_qiov) {
qemu_iovec_destroy(copy_cb->backing_qiov);
g_free(copy_cb->backing_qiov);
copy_cb->backing_qiov = NULL;
}
if (ret) {
qed_copy_from_backing_file_cb(copy_cb, ret);
return;
}
BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE,
&copy_cb->qiov, copy_cb->qiov.size / BDRV_SECTOR_SIZE,
qed_copy_from_backing_file_cb, copy_cb);
}
/**
* Copy data from backing file into the image
*
@ -907,7 +869,9 @@ static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos,
BlockCompletionFunc *cb,
void *opaque)
{
CopyFromBackingFileCB *copy_cb;
QEMUIOVector qiov;
QEMUIOVector *backing_qiov = NULL;
struct iovec iov;
int ret;
/* Skip copy entirely if there is no work to do */
@ -916,17 +880,33 @@ static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos,
return;
}
copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque);
copy_cb->s = s;
copy_cb->offset = offset;
copy_cb->backing_qiov = NULL;
copy_cb->iov.iov_base = qemu_blockalign(s->bs, len);
copy_cb->iov.iov_len = len;
qemu_iovec_init_external(&copy_cb->qiov, &copy_cb->iov, 1);
iov = (struct iovec) {
.iov_base = qemu_blockalign(s->bs, len),
.iov_len = len,
};
qemu_iovec_init_external(&qiov, &iov, 1);
ret = qed_read_backing_file(s, pos, &copy_cb->qiov,
&copy_cb->backing_qiov);
qed_copy_from_backing_file_write(copy_cb, ret);
ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov);
if (backing_qiov) {
qemu_iovec_destroy(backing_qiov);
g_free(backing_qiov);
backing_qiov = NULL;
}
if (ret) {
goto out;
}
BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
ret = bdrv_pwritev(s->bs->file, offset, &qiov);
if (ret < 0) {
goto out;
}
ret = 0;
out:
qemu_vfree(iov.iov_base);
cb(opaque, ret);
}
/**