[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-block] [PATCH 2/3] qcow2: Always execute preallocate() in a co
From: |
Jeff Cody |
Subject: |
Re: [Qemu-block] [PATCH 2/3] qcow2: Always execute preallocate() in a coroutine |
Date: |
Mon, 9 Oct 2017 19:30:26 -0400 |
User-agent: |
Mutt/1.5.24 (2015-08-30) |
On Mon, Oct 09, 2017 at 11:55:32PM +0200, Max Reitz wrote:
> Some qcow2 functions (at least perform_cow()) expect s->lock to be
> taken. Therefore, if we want to make use of them, we should execute
> preallocate() (as "preallocate_co") in a coroutine so that we can use
> the qemu_co_mutex_* functions.
>
> Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Jeff Cody <address@hidden>
> ---
> block/qcow2.c | 41 ++++++++++++++++++++++++++++++++++-------
> 1 file changed, 34 insertions(+), 7 deletions(-)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index c3b312cdef..cc75a5167f 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -2460,6 +2460,14 @@ static int qcow2_set_up_encryption(BlockDriverState
> *bs, const char *encryptfmt,
> }
>
>
> +typedef struct PreallocCo {
> + BlockDriverState *bs;
> + uint64_t offset;
> + uint64_t new_length;
> +
> + int ret;
> +} PreallocCo;
> +
> /**
> * Preallocates metadata structures for data clusters between @offset (in the
> * guest disk) and @new_length (which is thus generally the new guest disk
> @@ -2467,9 +2475,12 @@ static int qcow2_set_up_encryption(BlockDriverState
> *bs, const char *encryptfmt,
> *
> * Returns: 0 on success, -errno on failure.
> */
> -static int preallocate(BlockDriverState *bs,
> - uint64_t offset, uint64_t new_length)
> +static void coroutine_fn preallocate_co(void *opaque)
> {
> + struct PreallocCo *params = opaque;
> + BlockDriverState *bs = params->bs;
> + uint64_t offset = params->offset;
> + uint64_t new_length = params->new_length;
> BDRVQcow2State *s = bs->opaque;
> uint64_t bytes;
> uint64_t host_offset = 0;
> @@ -2477,9 +2488,7 @@ static int preallocate(BlockDriverState *bs,
> int ret;
> QCowL2Meta *meta;
>
> - if (qemu_in_coroutine()) {
> - qemu_co_mutex_lock(&s->lock);
> - }
> + qemu_co_mutex_lock(&s->lock);
>
> assert(offset <= new_length);
> bytes = new_length - offset;
> @@ -2533,10 +2542,28 @@ static int preallocate(BlockDriverState *bs,
> ret = 0;
>
> done:
> + qemu_co_mutex_unlock(&s->lock);
> + params->ret = ret;
> +}
> +
> +static int preallocate(BlockDriverState *bs,
> + uint64_t offset, uint64_t new_length)
> +{
> + PreallocCo params = {
> + .bs = bs,
> + .offset = offset,
> + .new_length = new_length,
> + .ret = -EINPROGRESS,
> + };
> +
> if (qemu_in_coroutine()) {
> - qemu_co_mutex_unlock(&s->lock);
> + preallocate_co(¶ms);
> + } else {
> + Coroutine *co = qemu_coroutine_create(preallocate_co, ¶ms);
> + bdrv_coroutine_enter(bs, co);
> + BDRV_POLL_WHILE(bs, params.ret == -EINPROGRESS);
> }
> - return ret;
> + return params.ret;
> }
>
> /* qcow2_refcount_metadata_size:
> --
> 2.13.6
>
>
- [Qemu-block] [PATCH 0/3] qcow2: Fix preallocated truncation, Max Reitz, 2017/10/09
- [Qemu-block] [PATCH 1/3] qcow2: Fix unaligned preallocated truncation, Max Reitz, 2017/10/09
- [Qemu-block] [PATCH 2/3] qcow2: Always execute preallocate() in a coroutine, Max Reitz, 2017/10/09
- [Qemu-block] [PATCH 3/3] iotests: Add cluster_size=64k to 125, Max Reitz, 2017/10/09
- Re: [Qemu-block] [PATCH 0/3] qcow2: Fix preallocated truncation, Max Reitz, 2017/10/11
- Re: [Qemu-block] [PATCH 0/3] qcow2: Fix preallocated truncation, Stefan Hajnoczi, 2017/10/11