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authorJens Axboe <axboe@suse.de>2006-03-23 13:56:55 -0500
committerJens Axboe <axboe@suse.de>2006-03-23 13:56:55 -0500
commitb86ff981a8252d83d6a7719ae09f3a05307e3592 (patch)
treeba8839f46cb140664e6a1ff6c7361b7424a95a7f /fs/relayfs
parentb0e6e962992b76580f4900b166a337bad7c1e81b (diff)
[PATCH] relay: migrate from relayfs to a generic relay API
Original patch from Paul Mundt, sysfs parts removed by me since they were broken. Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'fs/relayfs')
-rw-r--r--fs/relayfs/Makefile4
-rw-r--r--fs/relayfs/buffers.c190
-rw-r--r--fs/relayfs/buffers.h12
-rw-r--r--fs/relayfs/inode.c581
-rw-r--r--fs/relayfs/relay.c482
-rw-r--r--fs/relayfs/relay.h8
6 files changed, 0 insertions, 1277 deletions
diff --git a/fs/relayfs/Makefile b/fs/relayfs/Makefile
deleted file mode 100644
index e76e182cdb38..000000000000
--- a/fs/relayfs/Makefile
+++ /dev/null
@@ -1,4 +0,0 @@
1obj-$(CONFIG_RELAYFS_FS) += relayfs.o
2
3relayfs-y := relay.o inode.o buffers.o
4
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}
diff --git a/fs/relayfs/buffers.h b/fs/relayfs/buffers.h
deleted file mode 100644
index 37a12493f641..000000000000
--- a/fs/relayfs/buffers.h
+++ /dev/null
@@ -1,12 +0,0 @@
1#ifndef _BUFFERS_H
2#define _BUFFERS_H
3
4/* This inspired by rtai/shmem */
5#define FIX_SIZE(x) (((x) - 1) & PAGE_MASK) + PAGE_SIZE
6
7extern int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma);
8extern struct rchan_buf *relay_create_buf(struct rchan *chan);
9extern void relay_destroy_buf(struct rchan_buf *buf);
10extern void relay_remove_buf(struct kref *kref);
11
12#endif/* _BUFFERS_H */
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
diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
deleted file mode 100644
index abf3ceaace49..000000000000
--- a/fs/relayfs/relay.c
+++ /dev/null
@@ -1,482 +0,0 @@
1/*
2 * Public API and common code for RelayFS.
3 *
4 * See Documentation/filesystems/relayfs.txt for an overview of relayfs.
5 *
6 * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
7 * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
8 *
9 * This file is released under the GPL.
10 */
11
12#include <linux/errno.h>
13#include <linux/stddef.h>
14#include <linux/slab.h>
15#include <linux/module.h>
16#include <linux/string.h>
17#include <linux/relayfs_fs.h>
18#include "relay.h"
19#include "buffers.h"
20
21/**
22 * relay_buf_empty - boolean, is the channel buffer empty?
23 * @buf: channel buffer
24 *
25 * Returns 1 if the buffer is empty, 0 otherwise.
26 */
27int relay_buf_empty(struct rchan_buf *buf)
28{
29 return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1;
30}
31
32/**
33 * relay_buf_full - boolean, is the channel buffer full?
34 * @buf: channel buffer
35 *
36 * Returns 1 if the buffer is full, 0 otherwise.
37 */
38int relay_buf_full(struct rchan_buf *buf)
39{
40 size_t ready = buf->subbufs_produced - buf->subbufs_consumed;
41 return (ready >= buf->chan->n_subbufs) ? 1 : 0;
42}
43
44/*
45 * High-level relayfs kernel API and associated functions.
46 */
47
48/*
49 * rchan_callback implementations defining default channel behavior. Used
50 * in place of corresponding NULL values in client callback struct.
51 */
52
53/*
54 * subbuf_start() default callback. Does nothing.
55 */
56static int subbuf_start_default_callback (struct rchan_buf *buf,
57 void *subbuf,
58 void *prev_subbuf,
59 size_t prev_padding)
60{
61 if (relay_buf_full(buf))
62 return 0;
63
64 return 1;
65}
66
67/*
68 * buf_mapped() default callback. Does nothing.
69 */
70static void buf_mapped_default_callback(struct rchan_buf *buf,
71 struct file *filp)
72{
73}
74
75/*
76 * buf_unmapped() default callback. Does nothing.
77 */
78static void buf_unmapped_default_callback(struct rchan_buf *buf,
79 struct file *filp)
80{
81}
82
83/*
84 * create_buf_file_create() default callback. Creates file to represent buf.
85 */
86static struct dentry *create_buf_file_default_callback(const char *filename,
87 struct dentry *parent,
88 int mode,
89 struct rchan_buf *buf,
90 int *is_global)
91{
92 return relayfs_create_file(filename, parent, mode,
93 &relay_file_operations, buf);
94}
95
96/*
97 * remove_buf_file() default callback. Removes file representing relay buffer.
98 */
99static int remove_buf_file_default_callback(struct dentry *dentry)
100{
101 return relayfs_remove(dentry);
102}
103
104/* relay channel default callbacks */
105static struct rchan_callbacks default_channel_callbacks = {
106 .subbuf_start = subbuf_start_default_callback,
107 .buf_mapped = buf_mapped_default_callback,
108 .buf_unmapped = buf_unmapped_default_callback,
109 .create_buf_file = create_buf_file_default_callback,
110 .remove_buf_file = remove_buf_file_default_callback,
111};
112
113/**
114 * wakeup_readers - wake up readers waiting on a channel
115 * @private: the channel buffer
116 *
117 * This is the work function used to defer reader waking. The
118 * reason waking is deferred is that calling directly from write
119 * causes problems if you're writing from say the scheduler.
120 */
121static void wakeup_readers(void *private)
122{
123 struct rchan_buf *buf = private;
124 wake_up_interruptible(&buf->read_wait);
125}
126
127/**
128 * __relay_reset - reset a channel buffer
129 * @buf: the channel buffer
130 * @init: 1 if this is a first-time initialization
131 *
132 * See relay_reset for description of effect.
133 */
134static inline void __relay_reset(struct rchan_buf *buf, unsigned int init)
135{
136 size_t i;
137
138 if (init) {
139 init_waitqueue_head(&buf->read_wait);
140 kref_init(&buf->kref);
141 INIT_WORK(&buf->wake_readers, NULL, NULL);
142 } else {
143 cancel_delayed_work(&buf->wake_readers);
144 flush_scheduled_work();
145 }
146
147 buf->subbufs_produced = 0;
148 buf->subbufs_consumed = 0;
149 buf->bytes_consumed = 0;
150 buf->finalized = 0;
151 buf->data = buf->start;
152 buf->offset = 0;
153
154 for (i = 0; i < buf->chan->n_subbufs; i++)
155 buf->padding[i] = 0;
156
157 buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0);
158}
159
160/**
161 * relay_reset - reset the channel
162 * @chan: the channel
163 *
164 * This has the effect of erasing all data from all channel buffers
165 * and restarting the channel in its initial state. The buffers
166 * are not freed, so any mappings are still in effect.
167 *
168 * NOTE: Care should be taken that the channel isn't actually
169 * being used by anything when this call is made.
170 */
171void relay_reset(struct rchan *chan)
172{
173 unsigned int i;
174 struct rchan_buf *prev = NULL;
175
176 if (!chan)
177 return;
178
179 for (i = 0; i < NR_CPUS; i++) {
180 if (!chan->buf[i] || chan->buf[i] == prev)
181 break;
182 __relay_reset(chan->buf[i], 0);
183 prev = chan->buf[i];
184 }
185}
186
187/**
188 * relay_open_buf - create a new channel buffer in relayfs
189 *
190 * Internal - used by relay_open().
191 */
192static struct rchan_buf *relay_open_buf(struct rchan *chan,
193 const char *filename,
194 struct dentry *parent,
195 int *is_global)
196{
197 struct rchan_buf *buf;
198 struct dentry *dentry;
199
200 if (*is_global)
201 return chan->buf[0];
202
203 buf = relay_create_buf(chan);
204 if (!buf)
205 return NULL;
206
207 /* Create file in fs */
208 dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
209 buf, is_global);
210 if (!dentry) {
211 relay_destroy_buf(buf);
212 return NULL;
213 }
214
215 buf->dentry = dentry;
216 __relay_reset(buf, 1);
217
218 return buf;
219}
220
221/**
222 * relay_close_buf - close a channel buffer
223 * @buf: channel buffer
224 *
225 * Marks the buffer finalized and restores the default callbacks.
226 * The channel buffer and channel buffer data structure are then freed
227 * automatically when the last reference is given up.
228 */
229static inline void relay_close_buf(struct rchan_buf *buf)
230{
231 buf->finalized = 1;
232 buf->chan->cb = &default_channel_callbacks;
233 cancel_delayed_work(&buf->wake_readers);
234 flush_scheduled_work();
235 kref_put(&buf->kref, relay_remove_buf);
236}
237
238static inline void setup_callbacks(struct rchan *chan,
239 struct rchan_callbacks *cb)
240{
241 if (!cb) {
242 chan->cb = &default_channel_callbacks;
243 return;
244 }
245
246 if (!cb->subbuf_start)
247 cb->subbuf_start = subbuf_start_default_callback;
248 if (!cb->buf_mapped)
249 cb->buf_mapped = buf_mapped_default_callback;
250 if (!cb->buf_unmapped)
251 cb->buf_unmapped = buf_unmapped_default_callback;
252 if (!cb->create_buf_file)
253 cb->create_buf_file = create_buf_file_default_callback;
254 if (!cb->remove_buf_file)
255 cb->remove_buf_file = remove_buf_file_default_callback;
256 chan->cb = cb;
257}
258
259/**
260 * relay_open - create a new relayfs channel
261 * @base_filename: base name of files to create
262 * @parent: dentry of parent directory, NULL for root directory
263 * @subbuf_size: size of sub-buffers
264 * @n_subbufs: number of sub-buffers
265 * @cb: client callback functions
266 *
267 * Returns channel pointer if successful, NULL otherwise.
268 *
269 * Creates a channel buffer for each cpu using the sizes and
270 * attributes specified. The created channel buffer files
271 * will be named base_filename0...base_filenameN-1. File
272 * permissions will be S_IRUSR.
273 */
274struct rchan *relay_open(const char *base_filename,
275 struct dentry *parent,
276 size_t subbuf_size,
277 size_t n_subbufs,
278 struct rchan_callbacks *cb)
279{
280 unsigned int i;
281 struct rchan *chan;
282 char *tmpname;
283 int is_global = 0;
284
285 if (!base_filename)
286 return NULL;
287
288 if (!(subbuf_size && n_subbufs))
289 return NULL;
290
291 chan = kcalloc(1, sizeof(struct rchan), GFP_KERNEL);
292 if (!chan)
293 return NULL;
294
295 chan->version = RELAYFS_CHANNEL_VERSION;
296 chan->n_subbufs = n_subbufs;
297 chan->subbuf_size = subbuf_size;
298 chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs);
299 setup_callbacks(chan, cb);
300 kref_init(&chan->kref);
301
302 tmpname = kmalloc(NAME_MAX + 1, GFP_KERNEL);
303 if (!tmpname)
304 goto free_chan;
305
306 for_each_online_cpu(i) {
307 sprintf(tmpname, "%s%d", base_filename, i);
308 chan->buf[i] = relay_open_buf(chan, tmpname, parent,
309 &is_global);
310 chan->buf[i]->cpu = i;
311 if (!chan->buf[i])
312 goto free_bufs;
313 }
314
315 kfree(tmpname);
316 return chan;
317
318free_bufs:
319 for (i = 0; i < NR_CPUS; i++) {
320 if (!chan->buf[i])
321 break;
322 relay_close_buf(chan->buf[i]);
323 if (is_global)
324 break;
325 }
326 kfree(tmpname);
327
328free_chan:
329 kref_put(&chan->kref, relay_destroy_channel);
330 return NULL;
331}
332
333/**
334 * relay_switch_subbuf - switch to a new sub-buffer
335 * @buf: channel buffer
336 * @length: size of current event
337 *
338 * Returns either the length passed in or 0 if full.
339
340 * Performs sub-buffer-switch tasks such as invoking callbacks,
341 * updating padding counts, waking up readers, etc.
342 */
343size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
344{
345 void *old, *new;
346 size_t old_subbuf, new_subbuf;
347
348 if (unlikely(length > buf->chan->subbuf_size))
349 goto toobig;
350
351 if (buf->offset != buf->chan->subbuf_size + 1) {
352 buf->prev_padding = buf->chan->subbuf_size - buf->offset;
353 old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
354 buf->padding[old_subbuf] = buf->prev_padding;
355 buf->subbufs_produced++;
356 if (waitqueue_active(&buf->read_wait)) {
357 PREPARE_WORK(&buf->wake_readers, wakeup_readers, buf);
358 schedule_delayed_work(&buf->wake_readers, 1);
359 }
360 }
361
362 old = buf->data;
363 new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
364 new = buf->start + new_subbuf * buf->chan->subbuf_size;
365 buf->offset = 0;
366 if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) {
367 buf->offset = buf->chan->subbuf_size + 1;
368 return 0;
369 }
370 buf->data = new;
371 buf->padding[new_subbuf] = 0;
372
373 if (unlikely(length + buf->offset > buf->chan->subbuf_size))
374 goto toobig;
375
376 return length;
377
378toobig:
379 buf->chan->last_toobig = length;
380 return 0;
381}
382
383/**
384 * relay_subbufs_consumed - update the buffer's sub-buffers-consumed count
385 * @chan: the channel
386 * @cpu: the cpu associated with the channel buffer to update
387 * @subbufs_consumed: number of sub-buffers to add to current buf's count
388 *
389 * Adds to the channel buffer's consumed sub-buffer count.
390 * subbufs_consumed should be the number of sub-buffers newly consumed,
391 * not the total consumed.
392 *
393 * NOTE: kernel clients don't need to call this function if the channel
394 * mode is 'overwrite'.
395 */
396void relay_subbufs_consumed(struct rchan *chan,
397 unsigned int cpu,
398 size_t subbufs_consumed)
399{
400 struct rchan_buf *buf;
401
402 if (!chan)
403 return;
404
405 if (cpu >= NR_CPUS || !chan->buf[cpu])
406 return;
407
408 buf = chan->buf[cpu];
409 buf->subbufs_consumed += subbufs_consumed;
410 if (buf->subbufs_consumed > buf->subbufs_produced)
411 buf->subbufs_consumed = buf->subbufs_produced;
412}
413
414/**
415 * relay_destroy_channel - free the channel struct
416 *
417 * Should only be called from kref_put().
418 */
419void relay_destroy_channel(struct kref *kref)
420{
421 struct rchan *chan = container_of(kref, struct rchan, kref);
422 kfree(chan);
423}
424
425/**
426 * relay_close - close the channel
427 * @chan: the channel
428 *
429 * Closes all channel buffers and frees the channel.
430 */
431void relay_close(struct rchan *chan)
432{
433 unsigned int i;
434 struct rchan_buf *prev = NULL;
435
436 if (!chan)
437 return;
438
439 for (i = 0; i < NR_CPUS; i++) {
440 if (!chan->buf[i] || chan->buf[i] == prev)
441 break;
442 relay_close_buf(chan->buf[i]);
443 prev = chan->buf[i];
444 }
445
446 if (chan->last_toobig)
447 printk(KERN_WARNING "relayfs: one or more items not logged "
448 "[item size (%Zd) > sub-buffer size (%Zd)]\n",
449 chan->last_toobig, chan->subbuf_size);
450
451 kref_put(&chan->kref, relay_destroy_channel);
452}
453
454/**
455 * relay_flush - close the channel
456 * @chan: the channel
457 *
458 * Flushes all channel buffers i.e. forces buffer switch.
459 */
460void relay_flush(struct rchan *chan)
461{
462 unsigned int i;
463 struct rchan_buf *prev = NULL;
464
465 if (!chan)
466 return;
467
468 for (i = 0; i < NR_CPUS; i++) {
469 if (!chan->buf[i] || chan->buf[i] == prev)
470 break;
471 relay_switch_subbuf(chan->buf[i], 0);
472 prev = chan->buf[i];
473 }
474}
475
476EXPORT_SYMBOL_GPL(relay_open);
477EXPORT_SYMBOL_GPL(relay_close);
478EXPORT_SYMBOL_GPL(relay_flush);
479EXPORT_SYMBOL_GPL(relay_reset);
480EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
481EXPORT_SYMBOL_GPL(relay_switch_subbuf);
482EXPORT_SYMBOL_GPL(relay_buf_full);
diff --git a/fs/relayfs/relay.h b/fs/relayfs/relay.h
deleted file mode 100644
index 0993d3e5753b..000000000000
--- a/fs/relayfs/relay.h
+++ /dev/null
@@ -1,8 +0,0 @@
1#ifndef _RELAY_H
2#define _RELAY_H
3
4extern int relayfs_remove(struct dentry *dentry);
5extern int relay_buf_empty(struct rchan_buf *buf);
6extern void relay_destroy_channel(struct kref *kref);
7
8#endif /* _RELAY_H */
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-30 07:24:06 -0500