From 572b07bea1d1a0f7726fd95c2613c76002a379bc Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 9 Oct 2017 23:55:32 +0200 Subject: qcow2: Always execute preallocate() in a coroutine 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 Message-id: 20171009215533.12530-3-mreitz@redhat.com Cc: qemu-stable@nongnu.org Reviewed-by: Eric Blake Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Signed-off-by: Max Reitz --- block/qcow2.c | 41 ++++++++++++++++++++++++++++++++++------- 1 file changed, 34 insertions(+), 7 deletions(-) (limited to 'block/qcow2.c') diff --git a/block/qcow2.c b/block/qcow2.c index 1ea763126d..92cb9f9bfa 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) { + 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: -- cgit v1.2.1