Commit ba3186c4 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Stefan Hajnoczi
Browse files

curl: do not use aio_context_acquire/release 



Now that all bottom halves and callbacks take care of taking the
AioContext lock, we can migrate some users away from it and to a
specific QemuMutex or CoMutex.

Protect BDRVCURLState access with a QemuMutex.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-id: 20170222180725.28611-2-pbonzini@redhat.com
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent d992f2f1

block/curl.c

+15 −9
Original line number Diff line number Diff line
@@ -135,6 +135,7 @@ typedef struct BDRVCURLState { 
    char *cookie;

    bool accept_range;

    AioContext *aio_context;

    QemuMutex mutex;

    char *username;

    char *password;

    char *proxyusername;
@@ -333,6 +334,7 @@ static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len, 
    return FIND_RET_NONE;

}



/* Called with s->mutex held.  */

static void curl_multi_check_completion(BDRVCURLState *s)

{

    int msgs_in_queue;
@@ -374,7 +376,9 @@ static void curl_multi_check_completion(BDRVCURLState *s) 
                        continue;

                    }



                    qemu_mutex_unlock(&s->mutex);

                    acb->common.cb(acb->common.opaque, -EPROTO);

                    qemu_mutex_lock(&s->mutex);

                    qemu_aio_unref(acb);

                    state->acb[i] = NULL;

                }
@@ -386,6 +390,7 @@ static void curl_multi_check_completion(BDRVCURLState *s) 
    }

}



/* Called with s->mutex held.  */

static void curl_multi_do_locked(CURLState *s)

{

    CURLSocket *socket, *next_socket;
@@ -409,19 +414,19 @@ static void curl_multi_do(void *arg) 
{

    CURLState *s = (CURLState *)arg;



    aio_context_acquire(s->s->aio_context);

    qemu_mutex_lock(&s->s->mutex);

    curl_multi_do_locked(s);

    aio_context_release(s->s->aio_context);

    qemu_mutex_unlock(&s->s->mutex);

}



static void curl_multi_read(void *arg)

{

    CURLState *s = (CURLState *)arg;



    aio_context_acquire(s->s->aio_context);

    qemu_mutex_lock(&s->s->mutex);

    curl_multi_do_locked(s);

    curl_multi_check_completion(s->s);

    aio_context_release(s->s->aio_context);

    qemu_mutex_unlock(&s->s->mutex);

}



static void curl_multi_timeout_do(void *arg)
@@ -434,11 +439,11 @@ static void curl_multi_timeout_do(void *arg) 
        return;

    }



    aio_context_acquire(s->aio_context);

    qemu_mutex_lock(&s->mutex);

    curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);



    curl_multi_check_completion(s);

    aio_context_release(s->aio_context);

    qemu_mutex_unlock(&s->mutex);

#else

    abort();

#endif
@@ -771,6 +776,7 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags, 
    curl_easy_cleanup(state->curl);

    state->curl = NULL;



    qemu_mutex_init(&s->mutex);

    curl_attach_aio_context(bs, bdrv_get_aio_context(bs));



    qemu_opts_del(opts);
@@ -801,12 +807,11 @@ static void curl_readv_bh_cb(void *p) 
    CURLAIOCB *acb = p;

    BlockDriverState *bs = acb->common.bs;

    BDRVCURLState *s = bs->opaque;

    AioContext *ctx = bdrv_get_aio_context(bs);



    size_t start = acb->sector_num * BDRV_SECTOR_SIZE;

    size_t end;



    aio_context_acquire(ctx);

    qemu_mutex_lock(&s->mutex);



    // In case we have the requested data already (e.g. read-ahead),

    // we can just call the callback and be done.
@@ -854,7 +859,7 @@ static void curl_readv_bh_cb(void *p) 
    curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);



out:

    aio_context_release(ctx);

    qemu_mutex_unlock(&s->mutex);

    if (ret != -EINPROGRESS) {

        acb->common.cb(acb->common.opaque, ret);

        qemu_aio_unref(acb);
@@ -883,6 +888,7 @@ static void curl_close(BlockDriverState *bs) 


    DPRINTF("CURL: Close\n");

    curl_detach_aio_context(bs);

    qemu_mutex_destroy(&s->mutex);



    g_free(s->cookie);

    g_free(s->url);