aboutsummaryrefslogtreecommitdiffstats
path: root/fs/relayfs/buffers.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/relayfs/buffers.c')
-rw-r--r--fs/relayfs/buffers.c190
1 files changed, 0 insertions, 190 deletions
diff --git a/fs/relayfs/buffers.c b/fs/relayfs/buffers.c
deleted file mode 100644
index 10187812771e..000000000000
--- a/fs/relayfs/buffers.c
+++ /dev/null
@@ -1,190 +0,0 @@
1/*
2 * RelayFS buffer management code.
3 *
4 * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
5 * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
6 *
7 * This file is released under the GPL.
8 */
9
10#include <linux/module.h>
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/relayfs_fs.h>
14#include "relay.h"
15#include "buffers.h"
16
17/*
18 * close() vm_op implementation for relayfs file mapping.
19 */
20static void relay_file_mmap_close(struct vm_area_struct *vma)
21{
22 struct rchan_buf *buf = vma->vm_private_data;
23 buf->chan->cb->buf_unmapped(buf, vma->vm_file);
24}
25
26/*
27 * nopage() vm_op implementation for relayfs file mapping.
28 */
29static struct page *relay_buf_nopage(struct vm_area_struct *vma,
30 unsigned long address,
31 int *type)
32{
33 struct page *page;
34 struct rchan_buf *buf = vma->vm_private_data;
35 unsigned long offset = address - vma->vm_start;
36
37 if (address > vma->vm_end)
38 return NOPAGE_SIGBUS; /* Disallow mremap */
39 if (!buf)
40 return NOPAGE_OOM;
41
42 page = vmalloc_to_page(buf->start + offset);
43 if (!page)
44 return NOPAGE_OOM;
45 get_page(page);
46
47 if (type)
48 *type = VM_FAULT_MINOR;
49
50 return page;
51}
52
53/*
54 * vm_ops for relay file mappings.
55 */
56static struct vm_operations_struct relay_file_mmap_ops = {
57 .nopage = relay_buf_nopage,
58 .close = relay_file_mmap_close,
59};
60
61/**
62 * relay_mmap_buf: - mmap channel buffer to process address space
63 * @buf: relay channel buffer
64 * @vma: vm_area_struct describing memory to be mapped
65 *
66 * Returns 0 if ok, negative on error
67 *
68 * Caller should already have grabbed mmap_sem.
69 */
70int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
71{
72 unsigned long length = vma->vm_end - vma->vm_start;
73 struct file *filp = vma->vm_file;
74
75 if (!buf)
76 return -EBADF;
77
78 if (length != (unsigned long)buf->chan->alloc_size)
79 return -EINVAL;
80
81 vma->vm_ops = &relay_file_mmap_ops;
82 vma->vm_private_data = buf;
83 buf->chan->cb->buf_mapped(buf, filp);
84
85 return 0;
86}
87
88/**
89 * relay_alloc_buf - allocate a channel buffer
90 * @buf: the buffer struct
91 * @size: total size of the buffer
92 *
93 * Returns a pointer to the resulting buffer, NULL if unsuccessful
94 */
95static void *relay_alloc_buf(struct rchan_buf *buf, unsigned long size)
96{
97 void *mem;
98 unsigned int i, j, n_pages;
99
100 size = PAGE_ALIGN(size);
101 n_pages = size >> PAGE_SHIFT;
102
103 buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL);
104 if (!buf->page_array)
105 return NULL;
106
107 for (i = 0; i < n_pages; i++) {
108 buf->page_array[i] = alloc_page(GFP_KERNEL);
109 if (unlikely(!buf->page_array[i]))
110 goto depopulate;
111 }
112 mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL);
113 if (!mem)
114 goto depopulate;
115
116 memset(mem, 0, size);
117 buf->page_count = n_pages;
118 return mem;
119
120depopulate:
121 for (j = 0; j < i; j++)
122 __free_page(buf->page_array[j]);
123 kfree(buf->page_array);
124 return NULL;
125}
126
127/**
128 * relay_create_buf - allocate and initialize a channel buffer
129 * @alloc_size: size of the buffer to allocate
130 * @n_subbufs: number of sub-buffers in the channel
131 *
132 * Returns channel buffer if successful, NULL otherwise
133 */
134struct rchan_buf *relay_create_buf(struct rchan *chan)
135{
136 struct rchan_buf *buf = kcalloc(1, sizeof(struct rchan_buf), GFP_KERNEL);
137 if (!buf)
138 return NULL;
139
140 buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);
141 if (!buf->padding)
142 goto free_buf;
143
144 buf->start = relay_alloc_buf(buf, chan->alloc_size);
145 if (!buf->start)
146 goto free_buf;
147
148 buf->chan = chan;
149 kref_get(&buf->chan->kref);
150 return buf;
151
152free_buf:
153 kfree(buf->padding);
154 kfree(buf);
155 return NULL;
156}
157
158/**
159 * relay_destroy_buf - destroy an rchan_buf struct and associated buffer
160 * @buf: the buffer struct
161 */
162void relay_destroy_buf(struct rchan_buf *buf)
163{
164 struct rchan *chan = buf->chan;
165 unsigned int i;
166
167 if (likely(buf->start)) {
168 vunmap(buf->start);
169 for (i = 0; i < buf->page_count; i++)
170 __free_page(buf->page_array[i]);
171 kfree(buf->page_array);
172 }
173 kfree(buf->padding);
174 kfree(buf);
175 kref_put(&chan->kref, relay_destroy_channel);
176}
177
178/**
179 * relay_remove_buf - remove a channel buffer
180 *
181 * Removes the file from the relayfs fileystem, which also frees the
182 * rchan_buf_struct and the channel buffer. Should only be called from
183 * kref_put().
184 */
185void relay_remove_buf(struct kref *kref)
186{
187 struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
188 buf->chan->cb->remove_buf_file(buf->dentry);
189 relay_destroy_buf(buf);
190}
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-24 04:28:02 -0400