Commit | Line | Data |
---|---|---|
f3bc08c5 MD |
1 | /* |
2 | * ring_buffer_vfs.c | |
3 | * | |
f3bc08c5 MD |
4 | * Ring Buffer VFS file operations. |
5 | * | |
886d51a3 MD |
6 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
f3bc08c5 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/fs.h> | |
25 | #include <linux/compat.h> | |
26 | ||
27 | #include "../../wrapper/ringbuffer/backend.h" | |
28 | #include "../../wrapper/ringbuffer/frontend.h" | |
29 | #include "../../wrapper/ringbuffer/vfs.h" | |
30 | #include "../../wrapper/poll.h" | |
31 | ||
32 | static int put_ulong(unsigned long val, unsigned long arg) | |
33 | { | |
34 | return put_user(val, (unsigned long __user *)arg); | |
35 | } | |
36 | ||
37 | #ifdef CONFIG_COMPAT | |
38 | static int compat_put_ulong(compat_ulong_t val, unsigned long arg) | |
39 | { | |
40 | return put_user(val, (compat_ulong_t __user *)compat_ptr(arg)); | |
41 | } | |
42 | #endif | |
43 | ||
d83004aa JD |
44 | int lib_ring_buffer_open(struct inode *inode, struct file *file, |
45 | struct lib_ring_buffer *buf) | |
f3bc08c5 | 46 | { |
f3bc08c5 MD |
47 | int ret; |
48 | ||
733ce41d MD |
49 | if (!buf) |
50 | return -EINVAL; | |
51 | ||
f3bc08c5 MD |
52 | ret = lib_ring_buffer_open_read(buf); |
53 | if (ret) | |
54 | return ret; | |
55 | ||
f3bc08c5 MD |
56 | ret = nonseekable_open(inode, file); |
57 | if (ret) | |
58 | goto release_read; | |
59 | return 0; | |
60 | ||
61 | release_read: | |
62 | lib_ring_buffer_release_read(buf); | |
63 | return ret; | |
64 | } | |
d83004aa | 65 | EXPORT_SYMBOL_GPL(lib_ring_buffer_open); |
f3bc08c5 MD |
66 | |
67 | /** | |
d83004aa | 68 | * vfs_lib_ring_buffer_open - ring buffer open file operation |
f3bc08c5 MD |
69 | * @inode: opened inode |
70 | * @file: opened file | |
71 | * | |
d83004aa JD |
72 | * Open implementation. Makes sure only one open instance of a buffer is |
73 | * done at a given moment. | |
f3bc08c5 | 74 | */ |
d83004aa JD |
75 | static |
76 | int vfs_lib_ring_buffer_open(struct inode *inode, struct file *file) | |
f3bc08c5 | 77 | { |
d83004aa JD |
78 | struct lib_ring_buffer *buf = inode->i_private; |
79 | ||
80 | file->private_data = buf; | |
81 | return lib_ring_buffer_open(inode, file, buf); | |
82 | } | |
f3bc08c5 | 83 | |
d83004aa JD |
84 | int lib_ring_buffer_release(struct inode *inode, struct file *file, |
85 | struct lib_ring_buffer *buf) | |
86 | { | |
f3bc08c5 MD |
87 | lib_ring_buffer_release_read(buf); |
88 | ||
89 | return 0; | |
90 | } | |
d83004aa | 91 | EXPORT_SYMBOL_GPL(lib_ring_buffer_release); |
f3bc08c5 MD |
92 | |
93 | /** | |
d83004aa JD |
94 | * vfs_lib_ring_buffer_release - ring buffer release file operation |
95 | * @inode: opened inode | |
96 | * @file: opened file | |
f3bc08c5 | 97 | * |
d83004aa | 98 | * Release implementation. |
f3bc08c5 | 99 | */ |
d83004aa JD |
100 | static |
101 | int vfs_lib_ring_buffer_release(struct inode *inode, struct file *file) | |
102 | { | |
103 | struct lib_ring_buffer *buf = file->private_data; | |
104 | ||
105 | return lib_ring_buffer_release(inode, file, buf); | |
106 | } | |
107 | ||
108 | unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait, | |
109 | struct lib_ring_buffer *buf) | |
f3bc08c5 MD |
110 | { |
111 | unsigned int mask = 0; | |
f3bc08c5 | 112 | struct channel *chan = buf->backend.chan; |
5a8fd222 | 113 | const struct lib_ring_buffer_config *config = &chan->backend.config; |
254ec7bc | 114 | int finalized, disabled; |
f3bc08c5 MD |
115 | |
116 | if (filp->f_mode & FMODE_READ) { | |
a33e44a6 | 117 | poll_wait_set_exclusive(wait); |
f3bc08c5 MD |
118 | poll_wait(filp, &buf->read_wait, wait); |
119 | ||
120 | finalized = lib_ring_buffer_is_finalized(config, buf); | |
254ec7bc MD |
121 | disabled = lib_ring_buffer_channel_is_disabled(chan); |
122 | ||
f3bc08c5 MD |
123 | /* |
124 | * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering | |
125 | * finalized load before offsets loads. | |
126 | */ | |
127 | WARN_ON(atomic_long_read(&buf->active_readers) != 1); | |
128 | retry: | |
254ec7bc MD |
129 | if (disabled) |
130 | return POLLERR; | |
131 | ||
f3bc08c5 MD |
132 | if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf), chan) |
133 | - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf), chan) | |
134 | == 0) { | |
135 | if (finalized) | |
136 | return POLLHUP; | |
137 | else { | |
138 | /* | |
139 | * The memory barriers | |
140 | * __wait_event()/wake_up_interruptible() take | |
141 | * care of "raw_spin_is_locked" memory ordering. | |
142 | */ | |
143 | if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock)) | |
144 | goto retry; | |
145 | else | |
146 | return 0; | |
147 | } | |
148 | } else { | |
149 | if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf), | |
150 | chan) | |
151 | - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf), | |
152 | chan) | |
153 | >= chan->backend.buf_size) | |
154 | return POLLPRI | POLLRDBAND; | |
155 | else | |
156 | return POLLIN | POLLRDNORM; | |
157 | } | |
158 | } | |
159 | return mask; | |
160 | } | |
d83004aa | 161 | EXPORT_SYMBOL_GPL(lib_ring_buffer_poll); |
f3bc08c5 MD |
162 | |
163 | /** | |
d83004aa | 164 | * vfs_lib_ring_buffer_poll - ring buffer poll file operation |
f3bc08c5 | 165 | * @filp: the file |
d83004aa | 166 | * @wait: poll table |
f3bc08c5 | 167 | * |
d83004aa | 168 | * Poll implementation. |
f3bc08c5 | 169 | */ |
d83004aa JD |
170 | static |
171 | unsigned int vfs_lib_ring_buffer_poll(struct file *filp, poll_table *wait) | |
f3bc08c5 MD |
172 | { |
173 | struct lib_ring_buffer *buf = filp->private_data; | |
d83004aa JD |
174 | |
175 | return lib_ring_buffer_poll(filp, wait, buf); | |
176 | } | |
177 | ||
178 | long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, | |
179 | unsigned long arg, struct lib_ring_buffer *buf) | |
180 | { | |
f3bc08c5 | 181 | struct channel *chan = buf->backend.chan; |
5a8fd222 | 182 | const struct lib_ring_buffer_config *config = &chan->backend.config; |
f3bc08c5 | 183 | |
254ec7bc MD |
184 | if (lib_ring_buffer_channel_is_disabled(chan)) |
185 | return -EIO; | |
186 | ||
f3bc08c5 MD |
187 | switch (cmd) { |
188 | case RING_BUFFER_SNAPSHOT: | |
189 | return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot, | |
190 | &buf->prod_snapshot); | |
191 | case RING_BUFFER_SNAPSHOT_GET_CONSUMED: | |
192 | return put_ulong(buf->cons_snapshot, arg); | |
193 | case RING_BUFFER_SNAPSHOT_GET_PRODUCED: | |
194 | return put_ulong(buf->prod_snapshot, arg); | |
195 | case RING_BUFFER_GET_SUBBUF: | |
196 | { | |
197 | unsigned long uconsume; | |
198 | long ret; | |
199 | ||
200 | ret = get_user(uconsume, (unsigned long __user *) arg); | |
201 | if (ret) | |
202 | return ret; /* will return -EFAULT */ | |
203 | ret = lib_ring_buffer_get_subbuf(buf, uconsume); | |
204 | if (!ret) { | |
205 | /* Set file position to zero at each successful "get" */ | |
206 | filp->f_pos = 0; | |
207 | } | |
208 | return ret; | |
209 | } | |
210 | case RING_BUFFER_PUT_SUBBUF: | |
211 | lib_ring_buffer_put_subbuf(buf); | |
212 | return 0; | |
213 | ||
214 | case RING_BUFFER_GET_NEXT_SUBBUF: | |
215 | { | |
216 | long ret; | |
217 | ||
218 | ret = lib_ring_buffer_get_next_subbuf(buf); | |
219 | if (!ret) { | |
220 | /* Set file position to zero at each successful "get" */ | |
221 | filp->f_pos = 0; | |
222 | } | |
223 | return ret; | |
224 | } | |
225 | case RING_BUFFER_PUT_NEXT_SUBBUF: | |
226 | lib_ring_buffer_put_next_subbuf(buf); | |
227 | return 0; | |
228 | case RING_BUFFER_GET_SUBBUF_SIZE: | |
229 | return put_ulong(lib_ring_buffer_get_read_data_size(config, buf), | |
230 | arg); | |
231 | case RING_BUFFER_GET_PADDED_SUBBUF_SIZE: | |
232 | { | |
233 | unsigned long size; | |
234 | ||
235 | size = lib_ring_buffer_get_read_data_size(config, buf); | |
236 | size = PAGE_ALIGN(size); | |
237 | return put_ulong(size, arg); | |
238 | } | |
239 | case RING_BUFFER_GET_MAX_SUBBUF_SIZE: | |
240 | return put_ulong(chan->backend.subbuf_size, arg); | |
241 | case RING_BUFFER_GET_MMAP_LEN: | |
242 | { | |
243 | unsigned long mmap_buf_len; | |
244 | ||
245 | if (config->output != RING_BUFFER_MMAP) | |
246 | return -EINVAL; | |
247 | mmap_buf_len = chan->backend.buf_size; | |
248 | if (chan->backend.extra_reader_sb) | |
249 | mmap_buf_len += chan->backend.subbuf_size; | |
250 | if (mmap_buf_len > INT_MAX) | |
251 | return -EFBIG; | |
252 | return put_ulong(mmap_buf_len, arg); | |
253 | } | |
254 | case RING_BUFFER_GET_MMAP_READ_OFFSET: | |
255 | { | |
256 | unsigned long sb_bindex; | |
257 | ||
258 | if (config->output != RING_BUFFER_MMAP) | |
259 | return -EINVAL; | |
260 | sb_bindex = subbuffer_id_get_index(config, | |
261 | buf->backend.buf_rsb.id); | |
262 | return put_ulong(buf->backend.array[sb_bindex]->mmap_offset, | |
263 | arg); | |
264 | } | |
5c055266 | 265 | case RING_BUFFER_FLUSH: |
5e391252 | 266 | lib_ring_buffer_switch_remote(buf); |
5c055266 | 267 | return 0; |
f3bc08c5 MD |
268 | default: |
269 | return -ENOIOCTLCMD; | |
270 | } | |
271 | } | |
d83004aa JD |
272 | EXPORT_SYMBOL_GPL(lib_ring_buffer_ioctl); |
273 | ||
274 | /** | |
275 | * vfs_lib_ring_buffer_ioctl - control ring buffer reader synchronization | |
276 | * | |
277 | * @filp: the file | |
278 | * @cmd: the command | |
279 | * @arg: command arg | |
280 | * | |
281 | * This ioctl implements commands necessary for producer/consumer | |
282 | * and flight recorder reader interaction : | |
283 | * RING_BUFFER_GET_NEXT_SUBBUF | |
284 | * Get the next sub-buffer that can be read. It never blocks. | |
285 | * RING_BUFFER_PUT_NEXT_SUBBUF | |
286 | * Release the currently read sub-buffer. | |
287 | * RING_BUFFER_GET_SUBBUF_SIZE | |
288 | * returns the size of the current sub-buffer. | |
289 | * RING_BUFFER_GET_MAX_SUBBUF_SIZE | |
290 | * returns the maximum size for sub-buffers. | |
291 | * RING_BUFFER_GET_NUM_SUBBUF | |
292 | * returns the number of reader-visible sub-buffers in the per cpu | |
293 | * channel (for mmap). | |
294 | * RING_BUFFER_GET_MMAP_READ_OFFSET | |
295 | * returns the offset of the subbuffer belonging to the reader. | |
296 | * Should only be used for mmap clients. | |
297 | */ | |
298 | static | |
299 | long vfs_lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
300 | { | |
301 | struct lib_ring_buffer *buf = filp->private_data; | |
302 | ||
303 | return lib_ring_buffer_ioctl(filp, cmd, arg, buf); | |
304 | } | |
f3bc08c5 MD |
305 | |
306 | #ifdef CONFIG_COMPAT | |
307 | long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd, | |
d83004aa | 308 | unsigned long arg, struct lib_ring_buffer *buf) |
f3bc08c5 | 309 | { |
f3bc08c5 | 310 | struct channel *chan = buf->backend.chan; |
5a8fd222 | 311 | const struct lib_ring_buffer_config *config = &chan->backend.config; |
254ec7bc MD |
312 | |
313 | if (lib_ring_buffer_channel_is_disabled(chan)) | |
314 | return -EIO; | |
f3bc08c5 MD |
315 | |
316 | switch (cmd) { | |
216f7feb | 317 | case RING_BUFFER_COMPAT_SNAPSHOT: |
f3bc08c5 MD |
318 | return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot, |
319 | &buf->prod_snapshot); | |
216f7feb | 320 | case RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED: |
f3bc08c5 | 321 | return compat_put_ulong(buf->cons_snapshot, arg); |
216f7feb | 322 | case RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED: |
f3bc08c5 | 323 | return compat_put_ulong(buf->prod_snapshot, arg); |
216f7feb | 324 | case RING_BUFFER_COMPAT_GET_SUBBUF: |
f3bc08c5 MD |
325 | { |
326 | __u32 uconsume; | |
327 | unsigned long consume; | |
328 | long ret; | |
329 | ||
330 | ret = get_user(uconsume, (__u32 __user *) arg); | |
331 | if (ret) | |
332 | return ret; /* will return -EFAULT */ | |
333 | consume = buf->cons_snapshot; | |
334 | consume &= ~0xFFFFFFFFL; | |
335 | consume |= uconsume; | |
336 | ret = lib_ring_buffer_get_subbuf(buf, consume); | |
337 | if (!ret) { | |
338 | /* Set file position to zero at each successful "get" */ | |
339 | filp->f_pos = 0; | |
340 | } | |
341 | return ret; | |
342 | } | |
216f7feb | 343 | case RING_BUFFER_COMPAT_PUT_SUBBUF: |
f3bc08c5 MD |
344 | lib_ring_buffer_put_subbuf(buf); |
345 | return 0; | |
346 | ||
216f7feb | 347 | case RING_BUFFER_COMPAT_GET_NEXT_SUBBUF: |
f3bc08c5 MD |
348 | { |
349 | long ret; | |
350 | ||
351 | ret = lib_ring_buffer_get_next_subbuf(buf); | |
352 | if (!ret) { | |
353 | /* Set file position to zero at each successful "get" */ | |
354 | filp->f_pos = 0; | |
355 | } | |
356 | return ret; | |
357 | } | |
216f7feb | 358 | case RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF: |
f3bc08c5 MD |
359 | lib_ring_buffer_put_next_subbuf(buf); |
360 | return 0; | |
216f7feb | 361 | case RING_BUFFER_COMPAT_GET_SUBBUF_SIZE: |
f3bc08c5 MD |
362 | { |
363 | unsigned long data_size; | |
364 | ||
365 | data_size = lib_ring_buffer_get_read_data_size(config, buf); | |
366 | if (data_size > UINT_MAX) | |
367 | return -EFBIG; | |
4343ec8e | 368 | return compat_put_ulong(data_size, arg); |
f3bc08c5 | 369 | } |
216f7feb | 370 | case RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE: |
f3bc08c5 MD |
371 | { |
372 | unsigned long size; | |
373 | ||
374 | size = lib_ring_buffer_get_read_data_size(config, buf); | |
375 | size = PAGE_ALIGN(size); | |
376 | if (size > UINT_MAX) | |
377 | return -EFBIG; | |
4343ec8e | 378 | return compat_put_ulong(size, arg); |
f3bc08c5 | 379 | } |
216f7feb | 380 | case RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE: |
f3bc08c5 MD |
381 | if (chan->backend.subbuf_size > UINT_MAX) |
382 | return -EFBIG; | |
4343ec8e | 383 | return compat_put_ulong(chan->backend.subbuf_size, arg); |
216f7feb | 384 | case RING_BUFFER_COMPAT_GET_MMAP_LEN: |
f3bc08c5 MD |
385 | { |
386 | unsigned long mmap_buf_len; | |
387 | ||
388 | if (config->output != RING_BUFFER_MMAP) | |
389 | return -EINVAL; | |
390 | mmap_buf_len = chan->backend.buf_size; | |
391 | if (chan->backend.extra_reader_sb) | |
392 | mmap_buf_len += chan->backend.subbuf_size; | |
393 | if (mmap_buf_len > UINT_MAX) | |
394 | return -EFBIG; | |
4343ec8e | 395 | return compat_put_ulong(mmap_buf_len, arg); |
f3bc08c5 | 396 | } |
216f7feb | 397 | case RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET: |
f3bc08c5 MD |
398 | { |
399 | unsigned long sb_bindex, read_offset; | |
400 | ||
401 | if (config->output != RING_BUFFER_MMAP) | |
402 | return -EINVAL; | |
403 | sb_bindex = subbuffer_id_get_index(config, | |
404 | buf->backend.buf_rsb.id); | |
405 | read_offset = buf->backend.array[sb_bindex]->mmap_offset; | |
406 | if (read_offset > UINT_MAX) | |
407 | return -EINVAL; | |
4343ec8e | 408 | return compat_put_ulong(read_offset, arg); |
f3bc08c5 | 409 | } |
216f7feb | 410 | case RING_BUFFER_COMPAT_FLUSH: |
5e391252 | 411 | lib_ring_buffer_switch_remote(buf); |
5c055266 | 412 | return 0; |
f3bc08c5 MD |
413 | default: |
414 | return -ENOIOCTLCMD; | |
415 | } | |
416 | } | |
d83004aa JD |
417 | EXPORT_SYMBOL_GPL(lib_ring_buffer_compat_ioctl); |
418 | ||
419 | static | |
420 | long vfs_lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd, | |
421 | unsigned long arg) | |
422 | { | |
423 | struct lib_ring_buffer *buf = filp->private_data; | |
424 | ||
425 | return lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf); | |
426 | } | |
f3bc08c5 MD |
427 | #endif |
428 | ||
429 | const struct file_operations lib_ring_buffer_file_operations = { | |
a33c9927 | 430 | .owner = THIS_MODULE, |
d83004aa JD |
431 | .open = vfs_lib_ring_buffer_open, |
432 | .release = vfs_lib_ring_buffer_release, | |
433 | .poll = vfs_lib_ring_buffer_poll, | |
434 | .splice_read = vfs_lib_ring_buffer_splice_read, | |
435 | .mmap = vfs_lib_ring_buffer_mmap, | |
436 | .unlocked_ioctl = vfs_lib_ring_buffer_ioctl, | |
437 | .llseek = vfs_lib_ring_buffer_no_llseek, | |
f3bc08c5 | 438 | #ifdef CONFIG_COMPAT |
d83004aa | 439 | .compat_ioctl = vfs_lib_ring_buffer_compat_ioctl, |
f3bc08c5 MD |
440 | #endif |
441 | }; | |
442 | EXPORT_SYMBOL_GPL(lib_ring_buffer_file_operations); | |
443 | ||
444 | MODULE_LICENSE("GPL and additional rights"); | |
445 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
446 | MODULE_DESCRIPTION("Ring Buffer Library VFS"); |