diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-05-15 12:00:54 +0200 |
|---|---|---|
| committer | Jeff Cody <jcody@redhat.com> | 2017-05-16 10:34:17 -0400 |
| commit | 34db05e7ffe8d61ca7288b9532ad6e8300853318 (patch) | |
| tree | c62780f726cfa639dbdbaee15c64169628dee9c1 | |
| parent | 675a775633e68bf8b426a896fea5b93a4f4ff1cc (diff) | |
| download | qemu-34db05e7ffe8d61ca7288b9532ad6e8300853318.zip | |
curl: never invoke callbacks with s->mutex held
All curl callbacks go through curl_multi_do, and hence are called with
s->mutex held. Note that with comments, and make curl_read_cb drop the
lock before invoking the callback.
Likewise for curl_find_buf, where the callback can be invoked by the
caller.
Cc: qemu-stable@nongnu.org
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170515100059.15795-3-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
| -rw-r--r-- | block/curl.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/block/curl.c b/block/curl.c index 562340f436..18b82bc107 100644 --- a/block/curl.c +++ b/block/curl.c @@ -148,6 +148,7 @@ static void curl_multi_do(void *arg); static void curl_multi_read(void *arg); #ifdef NEED_CURL_TIMER_CALLBACK +/* Called from curl_multi_do_locked, with s->mutex held. */ static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque) { BDRVCURLState *s = opaque; @@ -164,6 +165,7 @@ static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque) } #endif +/* Called from curl_multi_do_locked, with s->mutex held. */ static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action, void *userp, void *sp) { @@ -213,6 +215,7 @@ static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action, return 0; } +/* Called from curl_multi_do_locked, with s->mutex held. */ static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque) { BDRVCURLState *s = opaque; @@ -227,6 +230,7 @@ static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque) return realsize; } +/* Called from curl_multi_do_locked, with s->mutex held. */ static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque) { CURLState *s = ((CURLState*)opaque); @@ -265,7 +269,9 @@ static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque) request_length - offset); } + qemu_mutex_unlock(&s->s->mutex); acb->common.cb(acb->common.opaque, 0); + qemu_mutex_lock(&s->s->mutex); qemu_aio_unref(acb); s->acb[i] = NULL; } @@ -306,8 +312,6 @@ static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len, if (clamped_len < len) { qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len); } - acb->common.cb(acb->common.opaque, 0); - return FIND_RET_OK; } @@ -854,8 +858,8 @@ static void curl_readv_bh_cb(void *p) // we can just call the callback and be done. switch (curl_find_buf(s, start, acb->nb_sectors * BDRV_SECTOR_SIZE, acb)) { case FIND_RET_OK: - qemu_aio_unref(acb); - // fall through + ret = 0; + goto out; case FIND_RET_WAIT: goto out; default: |