1 

     2 #include <errno.h>

     3 #include <string.h>

     4 #include <stdlib.h>

     5 

     6 #include "evfuse.h"

     7 #include "lib/log.h"

     8 

     9 struct evfuse {

    10     // our mountpoint

    11     char *mountpoint;

    12 

    13     // the /dev/fuse fd/channel that we get from fuse_mount

    14     struct fuse_chan *chan;

    15 

    16     // the session that we use to process the fuse stuff

    17     struct fuse_session *session;

    18 

    19     // the event that we use to receive requests

    20     struct event *ev;

    21     

    22     // what our receive-message length is

    23     size_t recv_size;

    24 

    25     // the buffer that we use to receive events

    26     char *recv_buf;

    27 };

    28 

    29 // prototypes

    30 void evfuse_close (struct evfuse *ctx);

    31 

    32 static void _evfuse_ev_read (evutil_socket_t fd, short what, void *arg) {

    33     struct evfuse *ctx = arg;

    34     struct fuse_chan *ch = ctx->chan;

    35     int res;

    36     

    37     // loop until we complete a recv

    38     do {

    39         // a new fuse_req is available

    40         res = fuse_chan_recv(&ch, ctx->recv_buf, ctx->recv_size);

    41     } while (res == -EINTR);

    42 

    43     if (res == 0)

    44         ERROR("fuse_chan_recv gave EOF");

    45 

    46     if (res < 0 && res != -EAGAIN)

    47         ERROR("fuse_chan_recv failed: %s", strerror(-res));

    48     

    49     if (res > 0) {

    50         DEBUG("got %d bytes from /dev/fuse", res);

    51 

    52         // received a fuse_req, so process it

    53         fuse_session_process(ctx->session, ctx->recv_buf, res, ch);

    54     }

    55     

    56     // reschedule

    57     if (event_add(ctx->ev, NULL))

    58         PERROR("event_add");

    59 

    60     // ok, wait for the next event

    61     return;

    62 

    63 error:

    64     // close, but don't free

    65     evfuse_close(ctx);

    66 }

    67 

    68 struct evfuse *evfuse_new (struct event_base *evbase, struct fuse_args *args, struct fuse_lowlevel_ops *llops, void *cb_data) {

    69     struct evfuse *ctx = NULL;

    70     int multithreaded, foreground;

    71     

    72     // allocate our context

    73     if ((ctx = calloc(1, sizeof(*ctx))) == NULL)

    74         ERROR("calloc");

    75 

    76     // parse the commandline for the mountpoint

    77     if (fuse_parse_cmdline(args, &ctx->mountpoint, &multithreaded, &foreground) == -1)

    78         ERROR("fuse_parse_cmdline");

    79 

    80     // mount it

    81     if ((ctx->chan = fuse_mount(ctx->mountpoint, args)) == NULL)

    82         PERROR("fuse_mount_common");

    83 

    84     // the receive buffer stufff

    85     ctx->recv_size = fuse_chan_bufsize(ctx->chan);

    86 

    87     // allocate the recv buffer

    88     if ((ctx->recv_buf = malloc(ctx->recv_size)) == NULL)

    89         ERROR("malloc");

    90     

    91     // allocate a low-level session

    92     if ((ctx->session = fuse_lowlevel_new(args, llops, sizeof(*llops), cb_data)) == NULL)

    93         PERROR("fuse_lowlevel_new");

    94     

    95     // add the channel to the session

    96     // this isn't strictly necessary, but let's do it anyways

    97     fuse_session_add_chan(ctx->session, ctx->chan);

    98     

    99     // now, we can start listening for events on the channel

   100     if ((ctx->ev = event_new(evbase, fuse_chan_fd(ctx->chan), EV_READ, &_evfuse_ev_read, ctx)) == NULL)

   101         ERROR("event_new");

   102 

   103     if (event_add(ctx->ev, NULL))

   104         PERROR("event_add");

   105 

   106     // and then we wait

   107     return ctx;

   108 

   109 error:

   110     evfuse_free(ctx);

   111 

   112     return NULL;

   113 }

   114 

   115 void evfuse_close (struct evfuse *ctx) {

   116     if (ctx->ev) {

   117         // remove our event

   118         if (event_del(ctx->ev))

   119             PWARNING("event_del");

   120 

   121         ctx->ev = NULL;

   122     }

   123 

   124     if (ctx->session) {

   125         // remove the chan

   126         fuse_session_remove_chan(ctx->chan);

   127 

   128         // destroy the session

   129         fuse_session_destroy(ctx->session);

   130 

   131         ctx->session = NULL;

   132     }

   133 

   134     if (ctx->chan) {

   135         // unmount

   136         fuse_unmount(ctx->mountpoint, ctx->chan);

   137 

   138         ctx->chan = NULL;

   139     }

   140 

   141     // free

   142     free(ctx->recv_buf); ctx->recv_buf = NULL;

   143     free(ctx->mountpoint); ctx->mountpoint = NULL;

   144 }

   145 

   146 void evfuse_free (struct evfuse *ctx) {

   147     if (ctx) {

   148         evfuse_close(ctx);

   149 

   150         free(ctx);

   151     }

   152 }

   153