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authorAl Viro <viro@zeniv.linux.org.uk>2013-03-12 09:46:27 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2013-04-09 14:12:58 -0400
commitf776c738883bc949e654568a565aee5a7d3fe133 (patch)
treeb83f74a02ebcb8341d689f63c65899da17ef0b39 /fs/fifo.c
parent2dd8c9ad376ccc5d2980b38e96372a8e252ae8d0 (diff)
fold fifo.c into pipe.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/fifo.c')
-rw-r--r--fs/fifo.c153
1 files changed, 0 insertions, 153 deletions
diff --git a/fs/fifo.c b/fs/fifo.c
deleted file mode 100644
index cf6f4345ceb0..000000000000
--- a/fs/fifo.c
+++ /dev/null
@@ -1,153 +0,0 @@
1/*
2 * linux/fs/fifo.c
3 *
4 * written by Paul H. Hargrove
5 *
6 * Fixes:
7 * 10-06-1999, AV: fixed OOM handling in fifo_open(), moved
8 * initialization there, switched to external
9 * allocation of pipe_inode_info.
10 */
11
12#include <linux/mm.h>
13#include <linux/fs.h>
14#include <linux/sched.h>
15#include <linux/pipe_fs_i.h>
16
17static int wait_for_partner(struct inode* inode, unsigned int *cnt)
18{
19 int cur = *cnt;
20
21 while (cur == *cnt) {
22 pipe_wait(inode->i_pipe);
23 if (signal_pending(current))
24 break;
25 }
26 return cur == *cnt ? -ERESTARTSYS : 0;
27}
28
29static void wake_up_partner(struct inode* inode)
30{
31 wake_up_interruptible(&inode->i_pipe->wait);
32}
33
34static int fifo_open(struct inode *inode, struct file *filp)
35{
36 struct pipe_inode_info *pipe;
37 int ret;
38
39 mutex_lock(&inode->i_mutex);
40 pipe = inode->i_pipe;
41 if (!pipe) {
42 ret = -ENOMEM;
43 pipe = alloc_pipe_info(inode);
44 if (!pipe)
45 goto err_nocleanup;
46 inode->i_pipe = pipe;
47 }
48 filp->f_version = 0;
49
50 /* We can only do regular read/write on fifos */
51 filp->f_mode &= (FMODE_READ | FMODE_WRITE);
52
53 switch (filp->f_mode) {
54 case FMODE_READ:
55 /*
56 * O_RDONLY
57 * POSIX.1 says that O_NONBLOCK means return with the FIFO
58 * opened, even when there is no process writing the FIFO.
59 */
60 filp->f_op = &read_pipefifo_fops;
61 pipe->r_counter++;
62 if (pipe->readers++ == 0)
63 wake_up_partner(inode);
64
65 if (!pipe->writers) {
66 if ((filp->f_flags & O_NONBLOCK)) {
67 /* suppress POLLHUP until we have
68 * seen a writer */
69 filp->f_version = pipe->w_counter;
70 } else {
71 if (wait_for_partner(inode, &pipe->w_counter))
72 goto err_rd;
73 }
74 }
75 break;
76
77 case FMODE_WRITE:
78 /*
79 * O_WRONLY
80 * POSIX.1 says that O_NONBLOCK means return -1 with
81 * errno=ENXIO when there is no process reading the FIFO.
82 */
83 ret = -ENXIO;
84 if ((filp->f_flags & O_NONBLOCK) && !pipe->readers)
85 goto err;
86
87 filp->f_op = &write_pipefifo_fops;
88 pipe->w_counter++;
89 if (!pipe->writers++)
90 wake_up_partner(inode);
91
92 if (!pipe->readers) {
93 if (wait_for_partner(inode, &pipe->r_counter))
94 goto err_wr;
95 }
96 break;
97
98 case FMODE_READ | FMODE_WRITE:
99 /*
100 * O_RDWR
101 * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set.
102 * This implementation will NEVER block on a O_RDWR open, since
103 * the process can at least talk to itself.
104 */
105 filp->f_op = &rdwr_pipefifo_fops;
106
107 pipe->readers++;
108 pipe->writers++;
109 pipe->r_counter++;
110 pipe->w_counter++;
111 if (pipe->readers == 1 || pipe->writers == 1)
112 wake_up_partner(inode);
113 break;
114
115 default:
116 ret = -EINVAL;
117 goto err;
118 }
119
120 /* Ok! */
121 mutex_unlock(&inode->i_mutex);
122 return 0;
123
124err_rd:
125 if (!--pipe->readers)
126 wake_up_interruptible(&pipe->wait);
127 ret = -ERESTARTSYS;
128 goto err;
129
130err_wr:
131 if (!--pipe->writers)
132 wake_up_interruptible(&pipe->wait);
133 ret = -ERESTARTSYS;
134 goto err;
135
136err:
137 if (!pipe->readers && !pipe->writers)
138 free_pipe_info(inode);
139
140err_nocleanup:
141 mutex_unlock(&inode->i_mutex);
142 return ret;
143}
144
145/*
146 * Dummy default file-operations: the only thing this does
147 * is contain the open that then fills in the correct operations
148 * depending on the access mode of the file...
149 */
150const struct file_operations def_fifo_fops = {
151 .open = fifo_open, /* will set read_ or write_pipefifo_fops */
152 .llseek = noop_llseek,
153};
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-17 16:31:49 -0500