haraldwolff
/
qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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>
(cherry picked from commit 34db05e7ff)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
stable-2.9
Paolo Bonzini 2017-05-15 12:00:54 +02:00 committed by Michael Roth
parent f00c08cbac
commit 4b519b9fd7
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
block/curl.c
View File

@ -147,6 +147,7 @@ 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;
@ -163,6 +164,7 @@ 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)
{
@ -212,6 +214,7 @@ 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;
@ -226,6 +229,7 @@ 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);
@ -264,7 +268,9 @@ 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;
}
@ -305,8 +311,6 @@ 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;
}
@ -832,8 +836,8 @@ 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: