Root/
1 | /* |
2 | FUSE: Filesystem in Userspace |
3 | Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> |
4 | |
5 | This program can be distributed under the terms of the GNU GPL. |
6 | See the file COPYING. |
7 | */ |
8 | |
9 | #include "fuse_i.h" |
10 | |
11 | #include <linux/init.h> |
12 | #include <linux/module.h> |
13 | |
14 | #define FUSE_CTL_SUPER_MAGIC 0x65735543 |
15 | |
16 | /* |
17 | * This is non-NULL when the single instance of the control filesystem |
18 | * exists. Protected by fuse_mutex |
19 | */ |
20 | static struct super_block *fuse_control_sb; |
21 | |
22 | static struct fuse_conn *fuse_ctl_file_conn_get(struct file *file) |
23 | { |
24 | struct fuse_conn *fc; |
25 | mutex_lock(&fuse_mutex); |
26 | fc = file->f_path.dentry->d_inode->i_private; |
27 | if (fc) |
28 | fc = fuse_conn_get(fc); |
29 | mutex_unlock(&fuse_mutex); |
30 | return fc; |
31 | } |
32 | |
33 | static ssize_t fuse_conn_abort_write(struct file *file, const char __user *buf, |
34 | size_t count, loff_t *ppos) |
35 | { |
36 | struct fuse_conn *fc = fuse_ctl_file_conn_get(file); |
37 | if (fc) { |
38 | fuse_abort_conn(fc); |
39 | fuse_conn_put(fc); |
40 | } |
41 | return count; |
42 | } |
43 | |
44 | static ssize_t fuse_conn_waiting_read(struct file *file, char __user *buf, |
45 | size_t len, loff_t *ppos) |
46 | { |
47 | char tmp[32]; |
48 | size_t size; |
49 | |
50 | if (!*ppos) { |
51 | long value; |
52 | struct fuse_conn *fc = fuse_ctl_file_conn_get(file); |
53 | if (!fc) |
54 | return 0; |
55 | |
56 | value = atomic_read(&fc->num_waiting); |
57 | file->private_data = (void *)value; |
58 | fuse_conn_put(fc); |
59 | } |
60 | size = sprintf(tmp, "%ld\n", (long)file->private_data); |
61 | return simple_read_from_buffer(buf, len, ppos, tmp, size); |
62 | } |
63 | |
64 | static ssize_t fuse_conn_limit_read(struct file *file, char __user *buf, |
65 | size_t len, loff_t *ppos, unsigned val) |
66 | { |
67 | char tmp[32]; |
68 | size_t size = sprintf(tmp, "%u\n", val); |
69 | |
70 | return simple_read_from_buffer(buf, len, ppos, tmp, size); |
71 | } |
72 | |
73 | static ssize_t fuse_conn_limit_write(struct file *file, const char __user *buf, |
74 | size_t count, loff_t *ppos, unsigned *val, |
75 | unsigned global_limit) |
76 | { |
77 | unsigned long t; |
78 | char tmp[32]; |
79 | unsigned limit = (1 << 16) - 1; |
80 | int err; |
81 | |
82 | if (*ppos || count >= sizeof(tmp) - 1) |
83 | return -EINVAL; |
84 | |
85 | if (copy_from_user(tmp, buf, count)) |
86 | return -EINVAL; |
87 | |
88 | tmp[count] = '\0'; |
89 | |
90 | err = strict_strtoul(tmp, 0, &t); |
91 | if (err) |
92 | return err; |
93 | |
94 | if (!capable(CAP_SYS_ADMIN)) |
95 | limit = min(limit, global_limit); |
96 | |
97 | if (t > limit) |
98 | return -EINVAL; |
99 | |
100 | *val = t; |
101 | |
102 | return count; |
103 | } |
104 | |
105 | static ssize_t fuse_conn_max_background_read(struct file *file, |
106 | char __user *buf, size_t len, |
107 | loff_t *ppos) |
108 | { |
109 | struct fuse_conn *fc; |
110 | unsigned val; |
111 | |
112 | fc = fuse_ctl_file_conn_get(file); |
113 | if (!fc) |
114 | return 0; |
115 | |
116 | val = fc->max_background; |
117 | fuse_conn_put(fc); |
118 | |
119 | return fuse_conn_limit_read(file, buf, len, ppos, val); |
120 | } |
121 | |
122 | static ssize_t fuse_conn_max_background_write(struct file *file, |
123 | const char __user *buf, |
124 | size_t count, loff_t *ppos) |
125 | { |
126 | unsigned val; |
127 | ssize_t ret; |
128 | |
129 | ret = fuse_conn_limit_write(file, buf, count, ppos, &val, |
130 | max_user_bgreq); |
131 | if (ret > 0) { |
132 | struct fuse_conn *fc = fuse_ctl_file_conn_get(file); |
133 | if (fc) { |
134 | fc->max_background = val; |
135 | fuse_conn_put(fc); |
136 | } |
137 | } |
138 | |
139 | return ret; |
140 | } |
141 | |
142 | static ssize_t fuse_conn_congestion_threshold_read(struct file *file, |
143 | char __user *buf, size_t len, |
144 | loff_t *ppos) |
145 | { |
146 | struct fuse_conn *fc; |
147 | unsigned val; |
148 | |
149 | fc = fuse_ctl_file_conn_get(file); |
150 | if (!fc) |
151 | return 0; |
152 | |
153 | val = fc->congestion_threshold; |
154 | fuse_conn_put(fc); |
155 | |
156 | return fuse_conn_limit_read(file, buf, len, ppos, val); |
157 | } |
158 | |
159 | static ssize_t fuse_conn_congestion_threshold_write(struct file *file, |
160 | const char __user *buf, |
161 | size_t count, loff_t *ppos) |
162 | { |
163 | unsigned val; |
164 | ssize_t ret; |
165 | |
166 | ret = fuse_conn_limit_write(file, buf, count, ppos, &val, |
167 | max_user_congthresh); |
168 | if (ret > 0) { |
169 | struct fuse_conn *fc = fuse_ctl_file_conn_get(file); |
170 | if (fc) { |
171 | fc->congestion_threshold = val; |
172 | fuse_conn_put(fc); |
173 | } |
174 | } |
175 | |
176 | return ret; |
177 | } |
178 | |
179 | static const struct file_operations fuse_ctl_abort_ops = { |
180 | .open = nonseekable_open, |
181 | .write = fuse_conn_abort_write, |
182 | }; |
183 | |
184 | static const struct file_operations fuse_ctl_waiting_ops = { |
185 | .open = nonseekable_open, |
186 | .read = fuse_conn_waiting_read, |
187 | }; |
188 | |
189 | static const struct file_operations fuse_conn_max_background_ops = { |
190 | .open = nonseekable_open, |
191 | .read = fuse_conn_max_background_read, |
192 | .write = fuse_conn_max_background_write, |
193 | }; |
194 | |
195 | static const struct file_operations fuse_conn_congestion_threshold_ops = { |
196 | .open = nonseekable_open, |
197 | .read = fuse_conn_congestion_threshold_read, |
198 | .write = fuse_conn_congestion_threshold_write, |
199 | }; |
200 | |
201 | static struct dentry *fuse_ctl_add_dentry(struct dentry *parent, |
202 | struct fuse_conn *fc, |
203 | const char *name, |
204 | int mode, int nlink, |
205 | const struct inode_operations *iop, |
206 | const struct file_operations *fop) |
207 | { |
208 | struct dentry *dentry; |
209 | struct inode *inode; |
210 | |
211 | BUG_ON(fc->ctl_ndents >= FUSE_CTL_NUM_DENTRIES); |
212 | dentry = d_alloc_name(parent, name); |
213 | if (!dentry) |
214 | return NULL; |
215 | |
216 | fc->ctl_dentry[fc->ctl_ndents++] = dentry; |
217 | inode = new_inode(fuse_control_sb); |
218 | if (!inode) |
219 | return NULL; |
220 | |
221 | inode->i_mode = mode; |
222 | inode->i_uid = fc->user_id; |
223 | inode->i_gid = fc->group_id; |
224 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
225 | /* setting ->i_op to NULL is not allowed */ |
226 | if (iop) |
227 | inode->i_op = iop; |
228 | inode->i_fop = fop; |
229 | inode->i_nlink = nlink; |
230 | inode->i_private = fc; |
231 | d_add(dentry, inode); |
232 | return dentry; |
233 | } |
234 | |
235 | /* |
236 | * Add a connection to the control filesystem (if it exists). Caller |
237 | * must hold fuse_mutex |
238 | */ |
239 | int fuse_ctl_add_conn(struct fuse_conn *fc) |
240 | { |
241 | struct dentry *parent; |
242 | char name[32]; |
243 | |
244 | if (!fuse_control_sb) |
245 | return 0; |
246 | |
247 | parent = fuse_control_sb->s_root; |
248 | inc_nlink(parent->d_inode); |
249 | sprintf(name, "%u", fc->dev); |
250 | parent = fuse_ctl_add_dentry(parent, fc, name, S_IFDIR | 0500, 2, |
251 | &simple_dir_inode_operations, |
252 | &simple_dir_operations); |
253 | if (!parent) |
254 | goto err; |
255 | |
256 | if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400, 1, |
257 | NULL, &fuse_ctl_waiting_ops) || |
258 | !fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200, 1, |
259 | NULL, &fuse_ctl_abort_ops) || |
260 | !fuse_ctl_add_dentry(parent, fc, "max_background", S_IFREG | 0600, |
261 | 1, NULL, &fuse_conn_max_background_ops) || |
262 | !fuse_ctl_add_dentry(parent, fc, "congestion_threshold", |
263 | S_IFREG | 0600, 1, NULL, |
264 | &fuse_conn_congestion_threshold_ops)) |
265 | goto err; |
266 | |
267 | return 0; |
268 | |
269 | err: |
270 | fuse_ctl_remove_conn(fc); |
271 | return -ENOMEM; |
272 | } |
273 | |
274 | /* |
275 | * Remove a connection from the control filesystem (if it exists). |
276 | * Caller must hold fuse_mutex |
277 | */ |
278 | void fuse_ctl_remove_conn(struct fuse_conn *fc) |
279 | { |
280 | int i; |
281 | |
282 | if (!fuse_control_sb) |
283 | return; |
284 | |
285 | for (i = fc->ctl_ndents - 1; i >= 0; i--) { |
286 | struct dentry *dentry = fc->ctl_dentry[i]; |
287 | dentry->d_inode->i_private = NULL; |
288 | d_drop(dentry); |
289 | dput(dentry); |
290 | } |
291 | drop_nlink(fuse_control_sb->s_root->d_inode); |
292 | } |
293 | |
294 | static int fuse_ctl_fill_super(struct super_block *sb, void *data, int silent) |
295 | { |
296 | struct tree_descr empty_descr = {""}; |
297 | struct fuse_conn *fc; |
298 | int err; |
299 | |
300 | err = simple_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr); |
301 | if (err) |
302 | return err; |
303 | |
304 | mutex_lock(&fuse_mutex); |
305 | BUG_ON(fuse_control_sb); |
306 | fuse_control_sb = sb; |
307 | list_for_each_entry(fc, &fuse_conn_list, entry) { |
308 | err = fuse_ctl_add_conn(fc); |
309 | if (err) { |
310 | fuse_control_sb = NULL; |
311 | mutex_unlock(&fuse_mutex); |
312 | return err; |
313 | } |
314 | } |
315 | mutex_unlock(&fuse_mutex); |
316 | |
317 | return 0; |
318 | } |
319 | |
320 | static int fuse_ctl_get_sb(struct file_system_type *fs_type, int flags, |
321 | const char *dev_name, void *raw_data, |
322 | struct vfsmount *mnt) |
323 | { |
324 | return get_sb_single(fs_type, flags, raw_data, |
325 | fuse_ctl_fill_super, mnt); |
326 | } |
327 | |
328 | static void fuse_ctl_kill_sb(struct super_block *sb) |
329 | { |
330 | struct fuse_conn *fc; |
331 | |
332 | mutex_lock(&fuse_mutex); |
333 | fuse_control_sb = NULL; |
334 | list_for_each_entry(fc, &fuse_conn_list, entry) |
335 | fc->ctl_ndents = 0; |
336 | mutex_unlock(&fuse_mutex); |
337 | |
338 | kill_litter_super(sb); |
339 | } |
340 | |
341 | static struct file_system_type fuse_ctl_fs_type = { |
342 | .owner = THIS_MODULE, |
343 | .name = "fusectl", |
344 | .get_sb = fuse_ctl_get_sb, |
345 | .kill_sb = fuse_ctl_kill_sb, |
346 | }; |
347 | |
348 | int __init fuse_ctl_init(void) |
349 | { |
350 | return register_filesystem(&fuse_ctl_fs_type); |
351 | } |
352 | |
353 | void fuse_ctl_cleanup(void) |
354 | { |
355 | unregister_filesystem(&fuse_ctl_fs_type); |
356 | } |
357 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9