Commit 471799d1 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi
Browse files

nfs: implement .bdrv_detach/attach_aio_context() 



Drop the assumption that we're using the main AioContext.  The following
functions need to be converted:
 * qemu_bh_new() -> aio_bh_new()
 * qemu_aio_set_fd_handler() -> aio_set_fd_handler()
 * qemu_aio_wait() -> aio_poll()

The .bdrv_detach/attach_aio_context() interfaces also need to be
implemented to move the fd handler from the old to the new AioContext.

Cc: Peter Lieven <pl@kamp.de>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarPeter Lieven <pl@kamp.de>
parent 69447cd8

block/nfs.c

+57 −24
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ typedef struct NFSClient { 
    struct nfsfh *fh;

    int events;

    bool has_zero_init;

    AioContext *aio_context;

} NFSClient;



typedef struct NFSRPC {
@@ -49,6 +50,7 @@ typedef struct NFSRPC { 
    struct stat *st;

    Coroutine *co;

    QEMUBH *bh;

    NFSClient *client;

} NFSRPC;



static void nfs_process_read(void *arg);
@@ -58,7 +60,8 @@ static void nfs_set_events(NFSClient *client) 
{

    int ev = nfs_which_events(client->context);

    if (ev != client->events) {

        qemu_aio_set_fd_handler(nfs_get_fd(client->context),

        aio_set_fd_handler(client->aio_context,

                           nfs_get_fd(client->context),

                           (ev & POLLIN) ? nfs_process_read : NULL,

                           (ev & POLLOUT) ? nfs_process_write : NULL,

                           client);
@@ -85,6 +88,7 @@ static void nfs_co_init_task(NFSClient *client, NFSRPC *task) 
{

    *task = (NFSRPC) {

        .co             = qemu_coroutine_self(),

        .client         = client,

    };

}
@@ -116,7 +120,8 @@ nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data, 
        error_report("NFS Error: %s", nfs_get_error(nfs));

    }

    if (task->co) {

        task->bh = qemu_bh_new(nfs_co_generic_bh_cb, task);

        task->bh = aio_bh_new(task->client->aio_context,

                              nfs_co_generic_bh_cb, task);

        qemu_bh_schedule(task->bh);

    }

}
@@ -224,13 +229,34 @@ static QemuOptsList runtime_opts = { 
    },

};



static void nfs_detach_aio_context(BlockDriverState *bs)

{

    NFSClient *client = bs->opaque;



    aio_set_fd_handler(client->aio_context,

                       nfs_get_fd(client->context),

                       NULL, NULL, NULL);

    client->events = 0;

}



static void nfs_attach_aio_context(BlockDriverState *bs,

                                   AioContext *new_context)

{

    NFSClient *client = bs->opaque;



    client->aio_context = new_context;

    nfs_set_events(client);

}



static void nfs_client_close(NFSClient *client)

{

    if (client->context) {

        if (client->fh) {

            nfs_close(client->context, client->fh);

        }

        qemu_aio_set_fd_handler(nfs_get_fd(client->context), NULL, NULL, NULL);

        aio_set_fd_handler(client->aio_context,

                           nfs_get_fd(client->context),

                           NULL, NULL, NULL);

        nfs_destroy_context(client->context);

    }

    memset(client, 0, sizeof(NFSClient));
@@ -345,6 +371,8 @@ static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags, 
    QemuOpts *opts;

    Error *local_err = NULL;



    client->aio_context = bdrv_get_aio_context(bs);



    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);

    qemu_opts_absorb_qdict(opts, options, &local_err);

    if (local_err) {
@@ -368,6 +396,8 @@ static int nfs_file_create(const char *url, QEMUOptionParameter *options, 
    int64_t total_size = 0;

    NFSClient *client = g_malloc0(sizeof(NFSClient));



    client->aio_context = qemu_get_aio_context();



    /* Read out options */

    while (options && options->name) {

        if (!strcmp(options->name, "size")) {
@@ -407,7 +437,7 @@ static int64_t nfs_get_allocated_file_size(BlockDriverState *bs) 


    while (!task.complete) {

        nfs_set_events(client);

        qemu_aio_wait();

        aio_poll(client->aio_context, true);

    }



    return (task.ret < 0 ? task.ret : st.st_blocks * st.st_blksize);
@@ -436,6 +466,9 @@ static BlockDriver bdrv_nfs = { 
    .bdrv_co_readv                  = nfs_co_readv,

    .bdrv_co_writev                 = nfs_co_writev,

    .bdrv_co_flush_to_disk          = nfs_co_flush,



    .bdrv_detach_aio_context        = nfs_detach_aio_context,

    .bdrv_attach_aio_context        = nfs_attach_aio_context,

};



static void nfs_block_init(void)