fuse_mt.c

Linux下fuse用户文件系统的的源代码

/*
    FUSE: Filesystem in Userspace
    Copyright (C) 2001-2006  Miklos Szeredi <[e-mail]>

    This program can be distributed under the terms of the GNU LGPL.
    See the file COPYING.LIB.
*/

#include "fuse_i.h"
#include "fuse_lowlevel.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <assert.h>

struct procdata {
    struct fuse *f;
    struct fuse_chan *prevch;
    struct fuse_session *prevse;
    fuse_processor_t proc;
    void *data;
};

static void mt_session_proc(void *data, const char *buf, size_t len,
                            struct fuse_chan *ch)
{
    struct procdata *pd = (struct procdata *) data;
    struct fuse_cmd *cmd = *(struct fuse_cmd **) buf;

    (void) len;
    cmd->ch = ch;
    pd->proc(pd->f, cmd, pd->data);
}

static void mt_session_exit(void *data, int val)
{
    struct procdata *pd = (struct procdata *) data;
    if (val)
        fuse_session_exit(pd->prevse);
    else
        fuse_session_reset(pd->prevse);
}

static int mt_session_exited(void *data)
{
    struct procdata *pd = (struct procdata *) data;
    return fuse_session_exited(pd->prevse);
}

static int mt_chan_receive(struct fuse_chan **chp, char *buf, size_t size)
{
    struct fuse_cmd *cmd;
    struct procdata *pd = (struct procdata *) fuse_chan_data(*chp);

    assert(size >= sizeof(cmd));

    cmd = fuse_read_cmd(pd->f);
    if (cmd == NULL)
        return 0;

    *(struct fuse_cmd **) buf = cmd;

    return sizeof(cmd);
}

static int mt_chan_send(struct fuse_chan *ch, const struct iovec iov[],
                        size_t count)
{
    struct procdata *pd = (struct procdata *) fuse_chan_data(ch);
    return fuse_chan_send(pd->prevch, iov, count);
}

int fuse_loop_mt_proc(struct fuse *f, fuse_processor_t proc, void *data)
{
    int res;
    struct procdata pd;
    struct fuse_session *prevse = fuse_get_session(f);
    struct fuse_session *se;
    struct fuse_chan *prevch = fuse_session_next_chan(prevse, NULL);
    struct fuse_chan *ch;
    struct fuse_session_ops sop = {
        .exit = mt_session_exit,
        .exited = mt_session_exited,
        .process = mt_session_proc,
    };
    struct fuse_chan_ops cop = {
        .receive = mt_chan_receive,
        .send = mt_chan_send,
    };

    pd.f = f;
    pd.prevch = prevch;
    pd.prevse = prevse;
    pd.proc = proc;
    pd.data = data;

    se = fuse_session_new(&sop, &pd);
    if (se == NULL)
        return -1;

    ch = fuse_chan_new(&cop, fuse_chan_fd(prevch), sizeof(struct fuse_cmd *),
                       &pd);
    if (ch == NULL) {
        fuse_session_destroy(se);
        return -1;
    }
    fuse_session_add_chan(se, ch);
    res = fuse_session_loop_mt(se);
    fuse_session_destroy(se);
    return res;
}

int fuse_loop_mt(struct fuse *f)
{
    if (f == NULL)
        return -1;

    return fuse_session_loop_mt(fuse_get_session(f));
}

__asm__(".symver fuse_loop_mt_proc,__fuse_loop_mt@");