blob: e9963b5d9ca5dbaeffc6b33c4afe2dbc15219fe8
1 | /* |
2 | FUSE: Filesystem in Userspace |
3 | Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu> |
4 | |
5 | This program can be distributed under the terms of the GNU LGPLv2. |
6 | See the file COPYING.LIB |
7 | */ |
8 | |
9 | #include "config.h" |
10 | #include "fuse_lowlevel.h" |
11 | #include "fuse_kernel.h" |
12 | #include "fuse_i.h" |
13 | |
14 | #include <stdio.h> |
15 | #include <errno.h> |
16 | #include <unistd.h> |
17 | #include <assert.h> |
18 | |
19 | static int fuse_kern_chan_receive(struct fuse_chan **chp, char *buf, |
20 | size_t size) |
21 | { |
22 | struct fuse_chan *ch = *chp; |
23 | int err; |
24 | ssize_t res; |
25 | struct fuse_session *se = fuse_chan_session(ch); |
26 | assert(se != NULL); |
27 | |
28 | restart: |
29 | res = read(fuse_chan_fd(ch), buf, size); |
30 | err = errno; |
31 | |
32 | if (fuse_session_exited(se)) |
33 | return 0; |
34 | if (res == -1) { |
35 | /* ENOENT means the operation was interrupted, it's safe |
36 | to restart */ |
37 | if (err == ENOENT) |
38 | goto restart; |
39 | |
40 | if (err == ENODEV) { |
41 | fuse_session_exit(se); |
42 | return 0; |
43 | } |
44 | /* Errors occuring during normal operation: EINTR (read |
45 | interrupted), EAGAIN (nonblocking I/O), ENODEV (filesystem |
46 | umounted) */ |
47 | if (err != EINTR && err != EAGAIN) |
48 | perror("fuse: reading device"); |
49 | return -err; |
50 | } |
51 | if ((size_t) res < sizeof(struct fuse_in_header)) { |
52 | fprintf(stderr, "short read on fuse device\n"); |
53 | return -EIO; |
54 | } |
55 | return res; |
56 | } |
57 | |
58 | static int fuse_kern_chan_send(struct fuse_chan *ch, const struct iovec iov[], |
59 | size_t count) |
60 | { |
61 | if (iov) { |
62 | ssize_t res = writev(fuse_chan_fd(ch), iov, count); |
63 | int err = errno; |
64 | |
65 | if (res == -1) { |
66 | struct fuse_session *se = fuse_chan_session(ch); |
67 | |
68 | assert(se != NULL); |
69 | |
70 | /* ENOENT means the operation was interrupted */ |
71 | if (!fuse_session_exited(se) && err != ENOENT) |
72 | perror("fuse: writing device"); |
73 | return -err; |
74 | } |
75 | } |
76 | return 0; |
77 | } |
78 | |
79 | static void fuse_kern_chan_destroy(struct fuse_chan *ch) |
80 | { |
81 | close(fuse_chan_fd(ch)); |
82 | } |
83 | |
84 | #define MIN_BUFSIZE 0x21000 |
85 | |
86 | struct fuse_chan *fuse_kern_chan_new(int fd) |
87 | { |
88 | struct fuse_chan_ops op = { |
89 | .receive = fuse_kern_chan_receive, |
90 | .send = fuse_kern_chan_send, |
91 | .destroy = fuse_kern_chan_destroy, |
92 | }; |
93 | size_t bufsize = getpagesize() + 0x1000; |
94 | bufsize = bufsize < MIN_BUFSIZE ? MIN_BUFSIZE : bufsize; |
95 | return fuse_chan_new(&op, fd, bufsize, NULL); |
96 | } |
97 |