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-rw-r--r--fs/relayfs/inode.c581
1 files changed, 0 insertions, 581 deletions
diff --git a/fs/relayfs/inode.c b/fs/relayfs/inode.c
deleted file mode 100644
index 383523011aad..000000000000
--- a/fs/relayfs/inode.c
+++ /dev/null
@@ -1,581 +0,0 @@
1/*
2 * VFS-related code for RelayFS, a high-speed data relay filesystem.
3 *
4 * Copyright (C) 2003-2005 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp
5 * Copyright (C) 2003-2005 - Karim Yaghmour <karim@opersys.com>
6 *
7 * Based on ramfs, Copyright (C) 2002 - Linus Torvalds
8 *
9 * This file is released under the GPL.
10 */
11
12#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/mount.h>
15#include <linux/pagemap.h>
16#include <linux/init.h>
17#include <linux/string.h>
18#include <linux/backing-dev.h>
19#include <linux/namei.h>
20#include <linux/poll.h>
21#include <linux/relayfs_fs.h>
22#include "relay.h"
23#include "buffers.h"
24
25#define RELAYFS_MAGIC 0xF0B4A981
26
27static struct vfsmount * relayfs_mount;
28static int relayfs_mount_count;
29
30static struct backing_dev_info relayfs_backing_dev_info = {
31 .ra_pages = 0, /* No readahead */
32 .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
33};
34
35static struct inode *relayfs_get_inode(struct super_block *sb,
36 int mode,
37 struct file_operations *fops,
38 void *data)
39{
40 struct inode *inode;
41
42 inode = new_inode(sb);
43 if (!inode)
44 return NULL;
45
46 inode->i_mode = mode;
47 inode->i_uid = 0;
48 inode->i_gid = 0;
49 inode->i_blksize = PAGE_CACHE_SIZE;
50 inode->i_blocks = 0;
51 inode->i_mapping->backing_dev_info = &relayfs_backing_dev_info;
52 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
53 switch (mode & S_IFMT) {
54 case S_IFREG:
55 inode->i_fop = fops;
56 if (data)
57 inode->u.generic_ip = data;
58 break;
59 case S_IFDIR:
60 inode->i_op = &simple_dir_inode_operations;
61 inode->i_fop = &simple_dir_operations;
62
63 /* directory inodes start off with i_nlink == 2 (for "." entry) */
64 inode->i_nlink++;
65 break;
66 default:
67 break;
68 }
69
70 return inode;
71}
72
73/**
74 * relayfs_create_entry - create a relayfs directory or file
75 * @name: the name of the file to create
76 * @parent: parent directory
77 * @mode: mode
78 * @fops: file operations to use for the file
79 * @data: user-associated data for this file
80 *
81 * Returns the new dentry, NULL on failure
82 *
83 * Creates a file or directory with the specifed permissions.
84 */
85static struct dentry *relayfs_create_entry(const char *name,
86 struct dentry *parent,
87 int mode,
88 struct file_operations *fops,
89 void *data)
90{
91 struct dentry *d;
92 struct inode *inode;
93 int error = 0;
94
95 BUG_ON(!name || !(S_ISREG(mode) || S_ISDIR(mode)));
96
97 error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count);
98 if (error) {
99 printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error);
100 return NULL;
101 }
102
103 if (!parent && relayfs_mount && relayfs_mount->mnt_sb)
104 parent = relayfs_mount->mnt_sb->s_root;
105
106 if (!parent) {
107 simple_release_fs(&relayfs_mount, &relayfs_mount_count);
108 return NULL;
109 }
110
111 parent = dget(parent);
112 mutex_lock(&parent->d_inode->i_mutex);
113 d = lookup_one_len(name, parent, strlen(name));
114 if (IS_ERR(d)) {
115 d = NULL;
116 goto release_mount;
117 }
118
119 if (d->d_inode) {
120 d = NULL;
121 goto release_mount;
122 }
123
124 inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data);
125 if (!inode) {
126 d = NULL;
127 goto release_mount;
128 }
129
130 d_instantiate(d, inode);
131 dget(d); /* Extra count - pin the dentry in core */
132
133 if (S_ISDIR(mode))
134 parent->d_inode->i_nlink++;
135
136 goto exit;
137
138release_mount:
139 simple_release_fs(&relayfs_mount, &relayfs_mount_count);
140
141exit:
142 mutex_unlock(&parent->d_inode->i_mutex);
143 dput(parent);
144 return d;
145}
146
147/**
148 * relayfs_create_file - create a file in the relay filesystem
149 * @name: the name of the file to create
150 * @parent: parent directory
151 * @mode: mode, if not specied the default perms are used
152 * @fops: file operations to use for the file
153 * @data: user-associated data for this file
154 *
155 * Returns file dentry if successful, NULL otherwise.
156 *
157 * The file will be created user r on behalf of current user.
158 */
159struct dentry *relayfs_create_file(const char *name,
160 struct dentry *parent,
161 int mode,
162 struct file_operations *fops,
163 void *data)
164{
165 BUG_ON(!fops);
166
167 if (!mode)
168 mode = S_IRUSR;
169 mode = (mode & S_IALLUGO) | S_IFREG;
170
171 return relayfs_create_entry(name, parent, mode, fops, data);
172}
173
174/**
175 * relayfs_create_dir - create a directory in the relay filesystem
176 * @name: the name of the directory to create
177 * @parent: parent directory, NULL if parent should be fs root
178 *
179 * Returns directory dentry if successful, NULL otherwise.
180 *
181 * The directory will be created world rwx on behalf of current user.
182 */
183struct dentry *relayfs_create_dir(const char *name, struct dentry *parent)
184{
185 int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
186 return relayfs_create_entry(name, parent, mode, NULL, NULL);
187}
188
189/**
190 * relayfs_remove - remove a file or directory in the relay filesystem
191 * @dentry: file or directory dentry
192 *
193 * Returns 0 if successful, negative otherwise.
194 */
195int relayfs_remove(struct dentry *dentry)
196{
197 struct dentry *parent;
198 int error = 0;
199
200 if (!dentry)
201 return -EINVAL;
202 parent = dentry->d_parent;
203 if (!parent)
204 return -EINVAL;
205
206 parent = dget(parent);
207 mutex_lock(&parent->d_inode->i_mutex);
208 if (dentry->d_inode) {
209 if (S_ISDIR(dentry->d_inode->i_mode))
210 error = simple_rmdir(parent->d_inode, dentry);
211 else
212 error = simple_unlink(parent->d_inode, dentry);
213 if (!error)
214 d_delete(dentry);
215 }
216 if (!error)
217 dput(dentry);
218 mutex_unlock(&parent->d_inode->i_mutex);
219 dput(parent);
220
221 if (!error)
222 simple_release_fs(&relayfs_mount, &relayfs_mount_count);
223
224 return error;
225}
226
227/**
228 * relayfs_remove_file - remove a file from relay filesystem
229 * @dentry: directory dentry
230 *
231 * Returns 0 if successful, negative otherwise.
232 */
233int relayfs_remove_file(struct dentry *dentry)
234{
235 return relayfs_remove(dentry);
236}
237
238/**
239 * relayfs_remove_dir - remove a directory in the relay filesystem
240 * @dentry: directory dentry
241 *
242 * Returns 0 if successful, negative otherwise.
243 */
244int relayfs_remove_dir(struct dentry *dentry)
245{
246 return relayfs_remove(dentry);
247}
248
249/**
250 * relay_file_open - open file op for relay files
251 * @inode: the inode
252 * @filp: the file
253 *
254 * Increments the channel buffer refcount.
255 */
256static int relay_file_open(struct inode *inode, struct file *filp)
257{
258 struct rchan_buf *buf = inode->u.generic_ip;
259 kref_get(&buf->kref);
260 filp->private_data = buf;
261
262 return 0;
263}
264
265/**
266 * relay_file_mmap - mmap file op for relay files
267 * @filp: the file
268 * @vma: the vma describing what to map
269 *
270 * Calls upon relay_mmap_buf to map the file into user space.
271 */
272static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
273{
274 struct rchan_buf *buf = filp->private_data;
275 return relay_mmap_buf(buf, vma);
276}
277
278/**
279 * relay_file_poll - poll file op for relay files
280 * @filp: the file
281 * @wait: poll table
282 *
283 * Poll implemention.
284 */
285static unsigned int relay_file_poll(struct file *filp, poll_table *wait)
286{
287 unsigned int mask = 0;
288 struct rchan_buf *buf = filp->private_data;
289
290 if (buf->finalized)
291 return POLLERR;
292
293 if (filp->f_mode & FMODE_READ) {
294 poll_wait(filp, &buf->read_wait, wait);
295 if (!relay_buf_empty(buf))
296 mask |= POLLIN | POLLRDNORM;
297 }
298
299 return mask;
300}
301
302/**
303 * relay_file_release - release file op for relay files
304 * @inode: the inode
305 * @filp: the file
306 *
307 * Decrements the channel refcount, as the filesystem is
308 * no longer using it.
309 */
310static int relay_file_release(struct inode *inode, struct file *filp)
311{
312 struct rchan_buf *buf = filp->private_data;
313 kref_put(&buf->kref, relay_remove_buf);
314
315 return 0;
316}
317
318/**
319 * relay_file_read_consume - update the consumed count for the buffer
320 */
321static void relay_file_read_consume(struct rchan_buf *buf,
322 size_t read_pos,
323 size_t bytes_consumed)
324{
325 size_t subbuf_size = buf->chan->subbuf_size;
326 size_t n_subbufs = buf->chan->n_subbufs;
327 size_t read_subbuf;
328
329 if (buf->bytes_consumed + bytes_consumed > subbuf_size) {
330 relay_subbufs_consumed(buf->chan, buf->cpu, 1);
331 buf->bytes_consumed = 0;
332 }
333
334 buf->bytes_consumed += bytes_consumed;
335 read_subbuf = read_pos / buf->chan->subbuf_size;
336 if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
337 if ((read_subbuf == buf->subbufs_produced % n_subbufs) &&
338 (buf->offset == subbuf_size))
339 return;
340 relay_subbufs_consumed(buf->chan, buf->cpu, 1);
341 buf->bytes_consumed = 0;
342 }
343}
344
345/**
346 * relay_file_read_avail - boolean, are there unconsumed bytes available?
347 */
348static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
349{
350 size_t bytes_produced, bytes_consumed, write_offset;
351 size_t subbuf_size = buf->chan->subbuf_size;
352 size_t n_subbufs = buf->chan->n_subbufs;
353 size_t produced = buf->subbufs_produced % n_subbufs;
354 size_t consumed = buf->subbufs_consumed % n_subbufs;
355
356 write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
357
358 if (consumed > produced) {
359 if ((produced > n_subbufs) &&
360 (produced + n_subbufs - consumed <= n_subbufs))
361 produced += n_subbufs;
362 } else if (consumed == produced) {
363 if (buf->offset > subbuf_size) {
364 produced += n_subbufs;
365 if (buf->subbufs_produced == buf->subbufs_consumed)
366 consumed += n_subbufs;
367 }
368 }
369
370 if (buf->offset > subbuf_size)
371 bytes_produced = (produced - 1) * subbuf_size + write_offset;
372 else
373 bytes_produced = produced * subbuf_size + write_offset;
374 bytes_consumed = consumed * subbuf_size + buf->bytes_consumed;
375
376 if (bytes_produced == bytes_consumed)
377 return 0;
378
379 relay_file_read_consume(buf, read_pos, 0);
380
381 return 1;
382}
383
384/**
385 * relay_file_read_subbuf_avail - return bytes available in sub-buffer
386 */
387static size_t relay_file_read_subbuf_avail(size_t read_pos,
388 struct rchan_buf *buf)
389{
390 size_t padding, avail = 0;
391 size_t read_subbuf, read_offset, write_subbuf, write_offset;
392 size_t subbuf_size = buf->chan->subbuf_size;
393
394 write_subbuf = (buf->data - buf->start) / subbuf_size;
395 write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
396 read_subbuf = read_pos / subbuf_size;
397 read_offset = read_pos % subbuf_size;
398 padding = buf->padding[read_subbuf];
399
400 if (read_subbuf == write_subbuf) {
401 if (read_offset + padding < write_offset)
402 avail = write_offset - (read_offset + padding);
403 } else
404 avail = (subbuf_size - padding) - read_offset;
405
406 return avail;
407}
408
409/**
410 * relay_file_read_start_pos - find the first available byte to read
411 *
412 * If the read_pos is in the middle of padding, return the
413 * position of the first actually available byte, otherwise
414 * return the original value.
415 */
416static size_t relay_file_read_start_pos(size_t read_pos,
417 struct rchan_buf *buf)
418{
419 size_t read_subbuf, padding, padding_start, padding_end;
420 size_t subbuf_size = buf->chan->subbuf_size;
421 size_t n_subbufs = buf->chan->n_subbufs;
422
423 read_subbuf = read_pos / subbuf_size;
424 padding = buf->padding[read_subbuf];
425 padding_start = (read_subbuf + 1) * subbuf_size - padding;
426 padding_end = (read_subbuf + 1) * subbuf_size;
427 if (read_pos >= padding_start && read_pos < padding_end) {
428 read_subbuf = (read_subbuf + 1) % n_subbufs;
429 read_pos = read_subbuf * subbuf_size;
430 }
431
432 return read_pos;
433}
434
435/**
436 * relay_file_read_end_pos - return the new read position
437 */
438static size_t relay_file_read_end_pos(struct rchan_buf *buf,
439 size_t read_pos,
440 size_t count)
441{
442 size_t read_subbuf, padding, end_pos;
443 size_t subbuf_size = buf->chan->subbuf_size;
444 size_t n_subbufs = buf->chan->n_subbufs;
445
446 read_subbuf = read_pos / subbuf_size;
447 padding = buf->padding[read_subbuf];
448 if (read_pos % subbuf_size + count + padding == subbuf_size)
449 end_pos = (read_subbuf + 1) * subbuf_size;
450 else
451 end_pos = read_pos + count;
452 if (end_pos >= subbuf_size * n_subbufs)
453 end_pos = 0;
454
455 return end_pos;
456}
457
458/**
459 * relay_file_read - read file op for relay files
460 * @filp: the file
461 * @buffer: the userspace buffer
462 * @count: number of bytes to read
463 * @ppos: position to read from
464 *
465 * Reads count bytes or the number of bytes available in the
466 * current sub-buffer being read, whichever is smaller.
467 */
468static ssize_t relay_file_read(struct file *filp,
469 char __user *buffer,
470 size_t count,
471 loff_t *ppos)
472{
473 struct rchan_buf *buf = filp->private_data;
474 struct inode *inode = filp->f_dentry->d_inode;
475 size_t read_start, avail;
476 ssize_t ret = 0;
477 void *from;
478
479 mutex_lock(&inode->i_mutex);
480 if(!relay_file_read_avail(buf, *ppos))
481 goto out;
482
483 read_start = relay_file_read_start_pos(*ppos, buf);
484 avail = relay_file_read_subbuf_avail(read_start, buf);
485 if (!avail)
486 goto out;
487
488 from = buf->start + read_start;
489 ret = count = min(count, avail);
490 if (copy_to_user(buffer, from, count)) {
491 ret = -EFAULT;
492 goto out;
493 }
494 relay_file_read_consume(buf, read_start, count);
495 *ppos = relay_file_read_end_pos(buf, read_start, count);
496out:
497 mutex_unlock(&inode->i_mutex);
498 return ret;
499}
500
501struct file_operations relay_file_operations = {
502 .open = relay_file_open,
503 .poll = relay_file_poll,
504 .mmap = relay_file_mmap,
505 .read = relay_file_read,
506 .llseek = no_llseek,
507 .release = relay_file_release,
508};
509
510static struct super_operations relayfs_ops = {
511 .statfs = simple_statfs,
512 .drop_inode = generic_delete_inode,
513};
514
515static int relayfs_fill_super(struct super_block * sb, void * data, int silent)
516{
517 struct inode *inode;
518 struct dentry *root;
519 int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
520
521 sb->s_blocksize = PAGE_CACHE_SIZE;
522 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
523 sb->s_magic = RELAYFS_MAGIC;
524 sb->s_op = &relayfs_ops;
525 inode = relayfs_get_inode(sb, mode, NULL, NULL);
526
527 if (!inode)
528 return -ENOMEM;
529
530 root = d_alloc_root(inode);
531 if (!root) {
532 iput(inode);
533 return -ENOMEM;
534 }
535 sb->s_root = root;
536
537 return 0;
538}
539
540static struct super_block * relayfs_get_sb(struct file_system_type *fs_type,
541 int flags, const char *dev_name,
542 void *data)
543{
544 return get_sb_single(fs_type, flags, data, relayfs_fill_super);
545}
546
547static struct file_system_type relayfs_fs_type = {
548 .owner = THIS_MODULE,
549 .name = "relayfs",
550 .get_sb = relayfs_get_sb,
551 .kill_sb = kill_litter_super,
552};
553
554static int __init init_relayfs_fs(void)
555{
556 return register_filesystem(&relayfs_fs_type);
557}
558
559static void __exit exit_relayfs_fs(void)
560{
561
562
563
564
565
566 unregister_filesystem(&relayfs_fs_type);
567}
568
569module_init(init_relayfs_fs)
570module_exit(exit_relayfs_fs)
571
572EXPORT_SYMBOL_GPL(relay_file_operations);
573EXPORT_SYMBOL_GPL(relayfs_create_dir);
574EXPORT_SYMBOL_GPL(relayfs_remove_dir);
575EXPORT_SYMBOL_GPL(relayfs_create_file);
576EXPORT_SYMBOL_GPL(relayfs_remove_file);
577
578MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>");
579MODULE_DESCRIPTION("Relay Filesystem");
580MODULE_LICENSE("GPL");
581
generated by cgit v1.2.2 (git 2.25.0) at 2026-04-26 22:38:13 -0400