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33#include <linux/percpu.h>
34#include <linux/seq_file.h>
35#include <linux/proc_fs.h>
36
37#include "rds.h"
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62struct rds_info_iterator {
63 struct page **pages;
64 void *addr;
65 unsigned long offset;
66};
67
68static DEFINE_SPINLOCK(rds_info_lock);
69static rds_info_func rds_info_funcs[RDS_INFO_LAST - RDS_INFO_FIRST + 1];
70
71void rds_info_register_func(int optname, rds_info_func func)
72{
73 int offset = optname - RDS_INFO_FIRST;
74
75 BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
76
77 spin_lock(&rds_info_lock);
78 BUG_ON(rds_info_funcs[offset] != NULL);
79 rds_info_funcs[offset] = func;
80 spin_unlock(&rds_info_lock);
81}
82EXPORT_SYMBOL_GPL(rds_info_register_func);
83
84void rds_info_deregister_func(int optname, rds_info_func func)
85{
86 int offset = optname - RDS_INFO_FIRST;
87
88 BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
89
90 spin_lock(&rds_info_lock);
91 BUG_ON(rds_info_funcs[offset] != func);
92 rds_info_funcs[offset] = NULL;
93 spin_unlock(&rds_info_lock);
94}
95EXPORT_SYMBOL_GPL(rds_info_deregister_func);
96
97
98
99
100
101
102void rds_info_iter_unmap(struct rds_info_iterator *iter)
103{
104 if (iter->addr != NULL) {
105 kunmap_atomic(iter->addr, KM_USER0);
106 iter->addr = NULL;
107 }
108}
109
110
111
112
113void rds_info_copy(struct rds_info_iterator *iter, void *data,
114 unsigned long bytes)
115{
116 unsigned long this;
117
118 while (bytes) {
119 if (iter->addr == NULL)
120 iter->addr = kmap_atomic(*iter->pages, KM_USER0);
121
122 this = min(bytes, PAGE_SIZE - iter->offset);
123
124 rdsdebug("page %p addr %p offset %lu this %lu data %p "
125 "bytes %lu\n", *iter->pages, iter->addr,
126 iter->offset, this, data, bytes);
127
128 memcpy(iter->addr + iter->offset, data, this);
129
130 data += this;
131 bytes -= this;
132 iter->offset += this;
133
134 if (iter->offset == PAGE_SIZE) {
135 kunmap_atomic(iter->addr, KM_USER0);
136 iter->addr = NULL;
137 iter->offset = 0;
138 iter->pages++;
139 }
140 }
141}
142EXPORT_SYMBOL_GPL(rds_info_copy);
143
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154
155
156int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval,
157 int __user *optlen)
158{
159 struct rds_info_iterator iter;
160 struct rds_info_lengths lens;
161 unsigned long nr_pages = 0;
162 unsigned long start;
163 unsigned long i;
164 rds_info_func func;
165 struct page **pages = NULL;
166 int ret;
167 int len;
168 int total;
169
170 if (get_user(len, optlen)) {
171 ret = -EFAULT;
172 goto out;
173 }
174
175
176 start = (unsigned long)optval;
177 if (len < 0 || len + PAGE_SIZE - 1 < len || start + len < start) {
178 ret = -EINVAL;
179 goto out;
180 }
181
182
183 if (len == 0)
184 goto call_func;
185
186 nr_pages = (PAGE_ALIGN(start + len) - (start & PAGE_MASK))
187 >> PAGE_SHIFT;
188
189 pages = kmalloc(nr_pages * sizeof(struct page *), GFP_KERNEL);
190 if (pages == NULL) {
191 ret = -ENOMEM;
192 goto out;
193 }
194 ret = get_user_pages_fast(start, nr_pages, 1, pages);
195 if (ret != nr_pages) {
196 if (ret > 0)
197 nr_pages = ret;
198 else
199 nr_pages = 0;
200 ret = -EAGAIN;
201 goto out;
202 }
203
204 rdsdebug("len %d nr_pages %lu\n", len, nr_pages);
205
206call_func:
207 func = rds_info_funcs[optname - RDS_INFO_FIRST];
208 if (func == NULL) {
209 ret = -ENOPROTOOPT;
210 goto out;
211 }
212
213 iter.pages = pages;
214 iter.addr = NULL;
215 iter.offset = start & (PAGE_SIZE - 1);
216
217 func(sock, len, &iter, &lens);
218 BUG_ON(lens.each == 0);
219
220 total = lens.nr * lens.each;
221
222 rds_info_iter_unmap(&iter);
223
224 if (total > len) {
225 len = total;
226 ret = -ENOSPC;
227 } else {
228 len = total;
229 ret = lens.each;
230 }
231
232 if (put_user(len, optlen))
233 ret = -EFAULT;
234
235out:
236 for (i = 0; pages != NULL && i < nr_pages; i++)
237 put_page(pages[i]);
238 kfree(pages);
239
240 return ret;
241}
242