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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/sysfs
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/Makefile6
-rw-r--r--fs/sysfs/bin.c204
-rw-r--r--fs/sysfs/dir.c475
-rw-r--r--fs/sysfs/file.c447
-rw-r--r--fs/sysfs/group.c84
-rw-r--r--fs/sysfs/inode.c165
-rw-r--r--fs/sysfs/mount.c107
-rw-r--r--fs/sysfs/symlink.c180
-rw-r--r--fs/sysfs/sysfs.h95
9 files changed, 1763 insertions, 0 deletions
diff --git a/fs/sysfs/Makefile b/fs/sysfs/Makefile
new file mode 100644
index 000000000000..7a1ceb946b80
--- /dev/null
+++ b/fs/sysfs/Makefile
@@ -0,0 +1,6 @@
1#
2# Makefile for the sysfs virtual filesystem
3#
4
5obj-y := inode.o file.o dir.o symlink.o mount.o bin.o \
6 group.o
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
new file mode 100644
index 000000000000..d4aaa88d0214
--- /dev/null
+++ b/fs/sysfs/bin.c
@@ -0,0 +1,204 @@
1/*
2 * bin.c - binary file operations for sysfs.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Matthew Wilcox
6 * Copyright (c) 2004 Silicon Graphics, Inc.
7 */
8
9#undef DEBUG
10
11#include <linux/errno.h>
12#include <linux/fs.h>
13#include <linux/kobject.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16
17#include <asm/uaccess.h>
18
19#include "sysfs.h"
20
21static int
22fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
23{
24 struct bin_attribute * attr = to_bin_attr(dentry);
25 struct kobject * kobj = to_kobj(dentry->d_parent);
26
27 if (!attr->read)
28 return -EINVAL;
29
30 return attr->read(kobj, buffer, off, count);
31}
32
33static ssize_t
34read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
35{
36 char *buffer = file->private_data;
37 struct dentry *dentry = file->f_dentry;
38 int size = dentry->d_inode->i_size;
39 loff_t offs = *off;
40 int ret;
41
42 if (count > PAGE_SIZE)
43 count = PAGE_SIZE;
44
45 if (size) {
46 if (offs > size)
47 return 0;
48 if (offs + count > size)
49 count = size - offs;
50 }
51
52 ret = fill_read(dentry, buffer, offs, count);
53 if (ret < 0)
54 return ret;
55 count = ret;
56
57 if (copy_to_user(userbuf, buffer, count))
58 return -EFAULT;
59
60 pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count);
61
62 *off = offs + count;
63
64 return count;
65}
66
67static int
68flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
69{
70 struct bin_attribute *attr = to_bin_attr(dentry);
71 struct kobject *kobj = to_kobj(dentry->d_parent);
72
73 if (!attr->write)
74 return -EINVAL;
75
76 return attr->write(kobj, buffer, offset, count);
77}
78
79static ssize_t write(struct file * file, const char __user * userbuf,
80 size_t count, loff_t * off)
81{
82 char *buffer = file->private_data;
83 struct dentry *dentry = file->f_dentry;
84 int size = dentry->d_inode->i_size;
85 loff_t offs = *off;
86
87 if (count > PAGE_SIZE)
88 count = PAGE_SIZE;
89 if (size) {
90 if (offs > size)
91 return 0;
92 if (offs + count > size)
93 count = size - offs;
94 }
95
96 if (copy_from_user(buffer, userbuf, count))
97 return -EFAULT;
98
99 count = flush_write(dentry, buffer, offs, count);
100 if (count > 0)
101 *off = offs + count;
102 return count;
103}
104
105static int mmap(struct file *file, struct vm_area_struct *vma)
106{
107 struct dentry *dentry = file->f_dentry;
108 struct bin_attribute *attr = to_bin_attr(dentry);
109 struct kobject *kobj = to_kobj(dentry->d_parent);
110
111 if (!attr->mmap)
112 return -EINVAL;
113
114 return attr->mmap(kobj, attr, vma);
115}
116
117static int open(struct inode * inode, struct file * file)
118{
119 struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent);
120 struct bin_attribute * attr = to_bin_attr(file->f_dentry);
121 int error = -EINVAL;
122
123 if (!kobj || !attr)
124 goto Done;
125
126 /* Grab the module reference for this attribute if we have one */
127 error = -ENODEV;
128 if (!try_module_get(attr->attr.owner))
129 goto Done;
130
131 error = -EACCES;
132 if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
133 goto Error;
134 if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
135 goto Error;
136
137 error = -ENOMEM;
138 file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
139 if (!file->private_data)
140 goto Error;
141
142 error = 0;
143 goto Done;
144
145 Error:
146 module_put(attr->attr.owner);
147 Done:
148 if (error && kobj)
149 kobject_put(kobj);
150 return error;
151}
152
153static int release(struct inode * inode, struct file * file)
154{
155 struct kobject * kobj = to_kobj(file->f_dentry->d_parent);
156 struct bin_attribute * attr = to_bin_attr(file->f_dentry);
157 u8 * buffer = file->private_data;
158
159 if (kobj)
160 kobject_put(kobj);
161 module_put(attr->attr.owner);
162 kfree(buffer);
163 return 0;
164}
165
166struct file_operations bin_fops = {
167 .read = read,
168 .write = write,
169 .mmap = mmap,
170 .llseek = generic_file_llseek,
171 .open = open,
172 .release = release,
173};
174
175/**
176 * sysfs_create_bin_file - create binary file for object.
177 * @kobj: object.
178 * @attr: attribute descriptor.
179 *
180 */
181
182int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
183{
184 BUG_ON(!kobj || !kobj->dentry || !attr);
185
186 return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
187}
188
189
190/**
191 * sysfs_remove_bin_file - remove binary file for object.
192 * @kobj: object.
193 * @attr: attribute descriptor.
194 *
195 */
196
197int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
198{
199 sysfs_hash_and_remove(kobj->dentry,attr->attr.name);
200 return 0;
201}
202
203EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
204EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
new file mode 100644
index 000000000000..fe198210bc2d
--- /dev/null
+++ b/fs/sysfs/dir.c
@@ -0,0 +1,475 @@
1/*
2 * dir.c - Operations for sysfs directories.
3 */
4
5#undef DEBUG
6
7#include <linux/fs.h>
8#include <linux/mount.h>
9#include <linux/module.h>
10#include <linux/kobject.h>
11#include "sysfs.h"
12
13DECLARE_RWSEM(sysfs_rename_sem);
14
15static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
16{
17 struct sysfs_dirent * sd = dentry->d_fsdata;
18
19 if (sd) {
20 BUG_ON(sd->s_dentry != dentry);
21 sd->s_dentry = NULL;
22 sysfs_put(sd);
23 }
24 iput(inode);
25}
26
27static struct dentry_operations sysfs_dentry_ops = {
28 .d_iput = sysfs_d_iput,
29};
30
31/*
32 * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
33 */
34static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
35 void * element)
36{
37 struct sysfs_dirent * sd;
38
39 sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
40 if (!sd)
41 return NULL;
42
43 memset(sd, 0, sizeof(*sd));
44 atomic_set(&sd->s_count, 1);
45 INIT_LIST_HEAD(&sd->s_children);
46 list_add(&sd->s_sibling, &parent_sd->s_children);
47 sd->s_element = element;
48
49 return sd;
50}
51
52int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
53 void * element, umode_t mode, int type)
54{
55 struct sysfs_dirent * sd;
56
57 sd = sysfs_new_dirent(parent_sd, element);
58 if (!sd)
59 return -ENOMEM;
60
61 sd->s_mode = mode;
62 sd->s_type = type;
63 sd->s_dentry = dentry;
64 if (dentry) {
65 dentry->d_fsdata = sysfs_get(sd);
66 dentry->d_op = &sysfs_dentry_ops;
67 }
68
69 return 0;
70}
71
72static int init_dir(struct inode * inode)
73{
74 inode->i_op = &sysfs_dir_inode_operations;
75 inode->i_fop = &sysfs_dir_operations;
76
77 /* directory inodes start off with i_nlink == 2 (for "." entry) */
78 inode->i_nlink++;
79 return 0;
80}
81
82static int init_file(struct inode * inode)
83{
84 inode->i_size = PAGE_SIZE;
85 inode->i_fop = &sysfs_file_operations;
86 return 0;
87}
88
89static int init_symlink(struct inode * inode)
90{
91 inode->i_op = &sysfs_symlink_inode_operations;
92 return 0;
93}
94
95static int create_dir(struct kobject * k, struct dentry * p,
96 const char * n, struct dentry ** d)
97{
98 int error;
99 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
100
101 down(&p->d_inode->i_sem);
102 *d = sysfs_get_dentry(p,n);
103 if (!IS_ERR(*d)) {
104 error = sysfs_create(*d, mode, init_dir);
105 if (!error) {
106 error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
107 SYSFS_DIR);
108 if (!error) {
109 p->d_inode->i_nlink++;
110 (*d)->d_op = &sysfs_dentry_ops;
111 d_rehash(*d);
112 }
113 }
114 if (error && (error != -EEXIST))
115 d_drop(*d);
116 dput(*d);
117 } else
118 error = PTR_ERR(*d);
119 up(&p->d_inode->i_sem);
120 return error;
121}
122
123
124int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
125{
126 return create_dir(k,k->dentry,n,d);
127}
128
129/**
130 * sysfs_create_dir - create a directory for an object.
131 * @parent: parent parent object.
132 * @kobj: object we're creating directory for.
133 */
134
135int sysfs_create_dir(struct kobject * kobj)
136{
137 struct dentry * dentry = NULL;
138 struct dentry * parent;
139 int error = 0;
140
141 BUG_ON(!kobj);
142
143 if (kobj->parent)
144 parent = kobj->parent->dentry;
145 else if (sysfs_mount && sysfs_mount->mnt_sb)
146 parent = sysfs_mount->mnt_sb->s_root;
147 else
148 return -EFAULT;
149
150 error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
151 if (!error)
152 kobj->dentry = dentry;
153 return error;
154}
155
156/* attaches attribute's sysfs_dirent to the dentry corresponding to the
157 * attribute file
158 */
159static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
160{
161 struct attribute * attr = NULL;
162 struct bin_attribute * bin_attr = NULL;
163 int (* init) (struct inode *) = NULL;
164 int error = 0;
165
166 if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
167 bin_attr = sd->s_element;
168 attr = &bin_attr->attr;
169 } else {
170 attr = sd->s_element;
171 init = init_file;
172 }
173
174 error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
175 if (error)
176 return error;
177
178 if (bin_attr) {
179 dentry->d_inode->i_size = bin_attr->size;
180 dentry->d_inode->i_fop = &bin_fops;
181 }
182 dentry->d_op = &sysfs_dentry_ops;
183 dentry->d_fsdata = sysfs_get(sd);
184 sd->s_dentry = dentry;
185 d_rehash(dentry);
186
187 return 0;
188}
189
190static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
191{
192 int err = 0;
193
194 err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
195 if (!err) {
196 dentry->d_op = &sysfs_dentry_ops;
197 dentry->d_fsdata = sysfs_get(sd);
198 sd->s_dentry = dentry;
199 d_rehash(dentry);
200 }
201 return err;
202}
203
204static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
205 struct nameidata *nd)
206{
207 struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
208 struct sysfs_dirent * sd;
209 int err = 0;
210
211 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
212 if (sd->s_type & SYSFS_NOT_PINNED) {
213 const unsigned char * name = sysfs_get_name(sd);
214
215 if (strcmp(name, dentry->d_name.name))
216 continue;
217
218 if (sd->s_type & SYSFS_KOBJ_LINK)
219 err = sysfs_attach_link(sd, dentry);
220 else
221 err = sysfs_attach_attr(sd, dentry);
222 break;
223 }
224 }
225
226 return ERR_PTR(err);
227}
228
229struct inode_operations sysfs_dir_inode_operations = {
230 .lookup = sysfs_lookup,
231};
232
233static void remove_dir(struct dentry * d)
234{
235 struct dentry * parent = dget(d->d_parent);
236 struct sysfs_dirent * sd;
237
238 down(&parent->d_inode->i_sem);
239 d_delete(d);
240 sd = d->d_fsdata;
241 list_del_init(&sd->s_sibling);
242 sysfs_put(sd);
243 if (d->d_inode)
244 simple_rmdir(parent->d_inode,d);
245
246 pr_debug(" o %s removing done (%d)\n",d->d_name.name,
247 atomic_read(&d->d_count));
248
249 up(&parent->d_inode->i_sem);
250 dput(parent);
251}
252
253void sysfs_remove_subdir(struct dentry * d)
254{
255 remove_dir(d);
256}
257
258
259/**
260 * sysfs_remove_dir - remove an object's directory.
261 * @kobj: object.
262 *
263 * The only thing special about this is that we remove any files in
264 * the directory before we remove the directory, and we've inlined
265 * what used to be sysfs_rmdir() below, instead of calling separately.
266 */
267
268void sysfs_remove_dir(struct kobject * kobj)
269{
270 struct dentry * dentry = dget(kobj->dentry);
271 struct sysfs_dirent * parent_sd;
272 struct sysfs_dirent * sd, * tmp;
273
274 if (!dentry)
275 return;
276
277 pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
278 down(&dentry->d_inode->i_sem);
279 parent_sd = dentry->d_fsdata;
280 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
281 if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
282 continue;
283 list_del_init(&sd->s_sibling);
284 sysfs_drop_dentry(sd, dentry);
285 sysfs_put(sd);
286 }
287 up(&dentry->d_inode->i_sem);
288
289 remove_dir(dentry);
290 /**
291 * Drop reference from dget() on entrance.
292 */
293 dput(dentry);
294}
295
296int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
297{
298 int error = 0;
299 struct dentry * new_dentry, * parent;
300
301 if (!strcmp(kobject_name(kobj), new_name))
302 return -EINVAL;
303
304 if (!kobj->parent)
305 return -EINVAL;
306
307 down_write(&sysfs_rename_sem);
308 parent = kobj->parent->dentry;
309
310 down(&parent->d_inode->i_sem);
311
312 new_dentry = sysfs_get_dentry(parent, new_name);
313 if (!IS_ERR(new_dentry)) {
314 if (!new_dentry->d_inode) {
315 error = kobject_set_name(kobj, "%s", new_name);
316 if (!error) {
317 d_add(new_dentry, NULL);
318 d_move(kobj->dentry, new_dentry);
319 }
320 else
321 d_drop(new_dentry);
322 } else
323 error = -EEXIST;
324 dput(new_dentry);
325 }
326 up(&parent->d_inode->i_sem);
327 up_write(&sysfs_rename_sem);
328
329 return error;
330}
331
332static int sysfs_dir_open(struct inode *inode, struct file *file)
333{
334 struct dentry * dentry = file->f_dentry;
335 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
336
337 down(&dentry->d_inode->i_sem);
338 file->private_data = sysfs_new_dirent(parent_sd, NULL);
339 up(&dentry->d_inode->i_sem);
340
341 return file->private_data ? 0 : -ENOMEM;
342
343}
344
345static int sysfs_dir_close(struct inode *inode, struct file *file)
346{
347 struct dentry * dentry = file->f_dentry;
348 struct sysfs_dirent * cursor = file->private_data;
349
350 down(&dentry->d_inode->i_sem);
351 list_del_init(&cursor->s_sibling);
352 up(&dentry->d_inode->i_sem);
353
354 release_sysfs_dirent(cursor);
355
356 return 0;
357}
358
359/* Relationship between s_mode and the DT_xxx types */
360static inline unsigned char dt_type(struct sysfs_dirent *sd)
361{
362 return (sd->s_mode >> 12) & 15;
363}
364
365static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
366{
367 struct dentry *dentry = filp->f_dentry;
368 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
369 struct sysfs_dirent *cursor = filp->private_data;
370 struct list_head *p, *q = &cursor->s_sibling;
371 ino_t ino;
372 int i = filp->f_pos;
373
374 switch (i) {
375 case 0:
376 ino = dentry->d_inode->i_ino;
377 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
378 break;
379 filp->f_pos++;
380 i++;
381 /* fallthrough */
382 case 1:
383 ino = parent_ino(dentry);
384 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
385 break;
386 filp->f_pos++;
387 i++;
388 /* fallthrough */
389 default:
390 if (filp->f_pos == 2) {
391 list_del(q);
392 list_add(q, &parent_sd->s_children);
393 }
394 for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
395 struct sysfs_dirent *next;
396 const char * name;
397 int len;
398
399 next = list_entry(p, struct sysfs_dirent,
400 s_sibling);
401 if (!next->s_element)
402 continue;
403
404 name = sysfs_get_name(next);
405 len = strlen(name);
406 if (next->s_dentry)
407 ino = next->s_dentry->d_inode->i_ino;
408 else
409 ino = iunique(sysfs_sb, 2);
410
411 if (filldir(dirent, name, len, filp->f_pos, ino,
412 dt_type(next)) < 0)
413 return 0;
414
415 list_del(q);
416 list_add(q, p);
417 p = q;
418 filp->f_pos++;
419 }
420 }
421 return 0;
422}
423
424static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
425{
426 struct dentry * dentry = file->f_dentry;
427
428 down(&dentry->d_inode->i_sem);
429 switch (origin) {
430 case 1:
431 offset += file->f_pos;
432 case 0:
433 if (offset >= 0)
434 break;
435 default:
436 up(&file->f_dentry->d_inode->i_sem);
437 return -EINVAL;
438 }
439 if (offset != file->f_pos) {
440 file->f_pos = offset;
441 if (file->f_pos >= 2) {
442 struct sysfs_dirent *sd = dentry->d_fsdata;
443 struct sysfs_dirent *cursor = file->private_data;
444 struct list_head *p;
445 loff_t n = file->f_pos - 2;
446
447 list_del(&cursor->s_sibling);
448 p = sd->s_children.next;
449 while (n && p != &sd->s_children) {
450 struct sysfs_dirent *next;
451 next = list_entry(p, struct sysfs_dirent,
452 s_sibling);
453 if (next->s_element)
454 n--;
455 p = p->next;
456 }
457 list_add_tail(&cursor->s_sibling, p);
458 }
459 }
460 up(&dentry->d_inode->i_sem);
461 return offset;
462}
463
464struct file_operations sysfs_dir_operations = {
465 .open = sysfs_dir_open,
466 .release = sysfs_dir_close,
467 .llseek = sysfs_dir_lseek,
468 .read = generic_read_dir,
469 .readdir = sysfs_readdir,
470};
471
472EXPORT_SYMBOL_GPL(sysfs_create_dir);
473EXPORT_SYMBOL_GPL(sysfs_remove_dir);
474EXPORT_SYMBOL_GPL(sysfs_rename_dir);
475
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
new file mode 100644
index 000000000000..352f966a1174
--- /dev/null
+++ b/fs/sysfs/file.c
@@ -0,0 +1,447 @@
1/*
2 * file.c - operations for regular (text) files.
3 */
4
5#include <linux/module.h>
6#include <linux/dnotify.h>
7#include <linux/kobject.h>
8#include <asm/uaccess.h>
9#include <asm/semaphore.h>
10
11#include "sysfs.h"
12
13#define to_subsys(k) container_of(k,struct subsystem,kset.kobj)
14#define to_sattr(a) container_of(a,struct subsys_attribute,attr)
15
16/**
17 * Subsystem file operations.
18 * These operations allow subsystems to have files that can be
19 * read/written.
20 */
21static ssize_t
22subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
23{
24 struct subsystem * s = to_subsys(kobj);
25 struct subsys_attribute * sattr = to_sattr(attr);
26 ssize_t ret = 0;
27
28 if (sattr->show)
29 ret = sattr->show(s,page);
30 return ret;
31}
32
33static ssize_t
34subsys_attr_store(struct kobject * kobj, struct attribute * attr,
35 const char * page, size_t count)
36{
37 struct subsystem * s = to_subsys(kobj);
38 struct subsys_attribute * sattr = to_sattr(attr);
39 ssize_t ret = 0;
40
41 if (sattr->store)
42 ret = sattr->store(s,page,count);
43 return ret;
44}
45
46static struct sysfs_ops subsys_sysfs_ops = {
47 .show = subsys_attr_show,
48 .store = subsys_attr_store,
49};
50
51
52struct sysfs_buffer {
53 size_t count;
54 loff_t pos;
55 char * page;
56 struct sysfs_ops * ops;
57 struct semaphore sem;
58 int needs_read_fill;
59};
60
61
62/**
63 * fill_read_buffer - allocate and fill buffer from object.
64 * @dentry: dentry pointer.
65 * @buffer: data buffer for file.
66 *
67 * Allocate @buffer->page, if it hasn't been already, then call the
68 * kobject's show() method to fill the buffer with this attribute's
69 * data.
70 * This is called only once, on the file's first read.
71 */
72static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer)
73{
74 struct attribute * attr = to_attr(dentry);
75 struct kobject * kobj = to_kobj(dentry->d_parent);
76 struct sysfs_ops * ops = buffer->ops;
77 int ret = 0;
78 ssize_t count;
79
80 if (!buffer->page)
81 buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
82 if (!buffer->page)
83 return -ENOMEM;
84
85 count = ops->show(kobj,attr,buffer->page);
86 buffer->needs_read_fill = 0;
87 BUG_ON(count > (ssize_t)PAGE_SIZE);
88 if (count >= 0)
89 buffer->count = count;
90 else
91 ret = count;
92 return ret;
93}
94
95
96/**
97 * flush_read_buffer - push buffer to userspace.
98 * @buffer: data buffer for file.
99 * @userbuf: user-passed buffer.
100 * @count: number of bytes requested.
101 * @ppos: file position.
102 *
103 * Copy the buffer we filled in fill_read_buffer() to userspace.
104 * This is done at the reader's leisure, copying and advancing
105 * the amount they specify each time.
106 * This may be called continuously until the buffer is empty.
107 */
108static int flush_read_buffer(struct sysfs_buffer * buffer, char __user * buf,
109 size_t count, loff_t * ppos)
110{
111 int error;
112
113 if (*ppos > buffer->count)
114 return 0;
115
116 if (count > (buffer->count - *ppos))
117 count = buffer->count - *ppos;
118
119 error = copy_to_user(buf,buffer->page + *ppos,count);
120 if (!error)
121 *ppos += count;
122 return error ? -EFAULT : count;
123}
124
125/**
126 * sysfs_read_file - read an attribute.
127 * @file: file pointer.
128 * @buf: buffer to fill.
129 * @count: number of bytes to read.
130 * @ppos: starting offset in file.
131 *
132 * Userspace wants to read an attribute file. The attribute descriptor
133 * is in the file's ->d_fsdata. The target object is in the directory's
134 * ->d_fsdata.
135 *
136 * We call fill_read_buffer() to allocate and fill the buffer from the
137 * object's show() method exactly once (if the read is happening from
138 * the beginning of the file). That should fill the entire buffer with
139 * all the data the object has to offer for that attribute.
140 * We then call flush_read_buffer() to copy the buffer to userspace
141 * in the increments specified.
142 */
143
144static ssize_t
145sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
146{
147 struct sysfs_buffer * buffer = file->private_data;
148 ssize_t retval = 0;
149
150 down(&buffer->sem);
151 if (buffer->needs_read_fill) {
152 if ((retval = fill_read_buffer(file->f_dentry,buffer)))
153 goto out;
154 }
155 pr_debug("%s: count = %d, ppos = %lld, buf = %s\n",
156 __FUNCTION__,count,*ppos,buffer->page);
157 retval = flush_read_buffer(buffer,buf,count,ppos);
158out:
159 up(&buffer->sem);
160 return retval;
161}
162
163
164/**
165 * fill_write_buffer - copy buffer from userspace.
166 * @buffer: data buffer for file.
167 * @userbuf: data from user.
168 * @count: number of bytes in @userbuf.
169 *
170 * Allocate @buffer->page if it hasn't been already, then
171 * copy the user-supplied buffer into it.
172 */
173
174static int
175fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t count)
176{
177 int error;
178
179 if (!buffer->page)
180 buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
181 if (!buffer->page)
182 return -ENOMEM;
183
184 if (count >= PAGE_SIZE)
185 count = PAGE_SIZE - 1;
186 error = copy_from_user(buffer->page,buf,count);
187 buffer->needs_read_fill = 1;
188 return error ? -EFAULT : count;
189}
190
191
192/**
193 * flush_write_buffer - push buffer to kobject.
194 * @file: file pointer.
195 * @buffer: data buffer for file.
196 *
197 * Get the correct pointers for the kobject and the attribute we're
198 * dealing with, then call the store() method for the attribute,
199 * passing the buffer that we acquired in fill_write_buffer().
200 */
201
202static int
203flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count)
204{
205 struct attribute * attr = to_attr(dentry);
206 struct kobject * kobj = to_kobj(dentry->d_parent);
207 struct sysfs_ops * ops = buffer->ops;
208
209 return ops->store(kobj,attr,buffer->page,count);
210}
211
212
213/**
214 * sysfs_write_file - write an attribute.
215 * @file: file pointer
216 * @buf: data to write
217 * @count: number of bytes
218 * @ppos: starting offset
219 *
220 * Similar to sysfs_read_file(), though working in the opposite direction.
221 * We allocate and fill the data from the user in fill_write_buffer(),
222 * then push it to the kobject in flush_write_buffer().
223 * There is no easy way for us to know if userspace is only doing a partial
224 * write, so we don't support them. We expect the entire buffer to come
225 * on the first write.
226 * Hint: if you're writing a value, first read the file, modify only the
227 * the value you're changing, then write entire buffer back.
228 */
229
230static ssize_t
231sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
232{
233 struct sysfs_buffer * buffer = file->private_data;
234 ssize_t len;
235
236 down(&buffer->sem);
237 len = fill_write_buffer(buffer, buf, count);
238 if (len > 0)
239 len = flush_write_buffer(file->f_dentry, buffer, len);
240 if (len > 0)
241 *ppos += len;
242 up(&buffer->sem);
243 return len;
244}
245
246static int check_perm(struct inode * inode, struct file * file)
247{
248 struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent);
249 struct attribute * attr = to_attr(file->f_dentry);
250 struct sysfs_buffer * buffer;
251 struct sysfs_ops * ops = NULL;
252 int error = 0;
253
254 if (!kobj || !attr)
255 goto Einval;
256
257 /* Grab the module reference for this attribute if we have one */
258 if (!try_module_get(attr->owner)) {
259 error = -ENODEV;
260 goto Done;
261 }
262
263 /* if the kobject has no ktype, then we assume that it is a subsystem
264 * itself, and use ops for it.
265 */
266 if (kobj->kset && kobj->kset->ktype)
267 ops = kobj->kset->ktype->sysfs_ops;
268 else if (kobj->ktype)
269 ops = kobj->ktype->sysfs_ops;
270 else
271 ops = &subsys_sysfs_ops;
272
273 /* No sysfs operations, either from having no subsystem,
274 * or the subsystem have no operations.
275 */
276 if (!ops)
277 goto Eaccess;
278
279 /* File needs write support.
280 * The inode's perms must say it's ok,
281 * and we must have a store method.
282 */
283 if (file->f_mode & FMODE_WRITE) {
284
285 if (!(inode->i_mode & S_IWUGO) || !ops->store)
286 goto Eaccess;
287
288 }
289
290 /* File needs read support.
291 * The inode's perms must say it's ok, and we there
292 * must be a show method for it.
293 */
294 if (file->f_mode & FMODE_READ) {
295 if (!(inode->i_mode & S_IRUGO) || !ops->show)
296 goto Eaccess;
297 }
298
299 /* No error? Great, allocate a buffer for the file, and store it
300 * it in file->private_data for easy access.
301 */
302 buffer = kmalloc(sizeof(struct sysfs_buffer),GFP_KERNEL);
303 if (buffer) {
304 memset(buffer,0,sizeof(struct sysfs_buffer));
305 init_MUTEX(&buffer->sem);
306 buffer->needs_read_fill = 1;
307 buffer->ops = ops;
308 file->private_data = buffer;
309 } else
310 error = -ENOMEM;
311 goto Done;
312
313 Einval:
314 error = -EINVAL;
315 goto Done;
316 Eaccess:
317 error = -EACCES;
318 module_put(attr->owner);
319 Done:
320 if (error && kobj)
321 kobject_put(kobj);
322 return error;
323}
324
325static int sysfs_open_file(struct inode * inode, struct file * filp)
326{
327 return check_perm(inode,filp);
328}
329
330static int sysfs_release(struct inode * inode, struct file * filp)
331{
332 struct kobject * kobj = to_kobj(filp->f_dentry->d_parent);
333 struct attribute * attr = to_attr(filp->f_dentry);
334 struct module * owner = attr->owner;
335 struct sysfs_buffer * buffer = filp->private_data;
336
337 if (kobj)
338 kobject_put(kobj);
339 /* After this point, attr should not be accessed. */
340 module_put(owner);
341
342 if (buffer) {
343 if (buffer->page)
344 free_page((unsigned long)buffer->page);
345 kfree(buffer);
346 }
347 return 0;
348}
349
350struct file_operations sysfs_file_operations = {
351 .read = sysfs_read_file,
352 .write = sysfs_write_file,
353 .llseek = generic_file_llseek,
354 .open = sysfs_open_file,
355 .release = sysfs_release,
356};
357
358
359int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
360{
361 struct sysfs_dirent * parent_sd = dir->d_fsdata;
362 umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG;
363 int error = 0;
364
365 down(&dir->d_inode->i_sem);
366 error = sysfs_make_dirent(parent_sd, NULL, (void *) attr, mode, type);
367 up(&dir->d_inode->i_sem);
368
369 return error;
370}
371
372
373/**
374 * sysfs_create_file - create an attribute file for an object.
375 * @kobj: object we're creating for.
376 * @attr: atrribute descriptor.
377 */
378
379int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
380{
381 BUG_ON(!kobj || !kobj->dentry || !attr);
382
383 return sysfs_add_file(kobj->dentry, attr, SYSFS_KOBJ_ATTR);
384
385}
386
387
388/**
389 * sysfs_update_file - update the modified timestamp on an object attribute.
390 * @kobj: object we're acting for.
391 * @attr: attribute descriptor.
392 *
393 * Also call dnotify for the dentry, which lots of userspace programs
394 * use.
395 */
396int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
397{
398 struct dentry * dir = kobj->dentry;
399 struct dentry * victim;
400 int res = -ENOENT;
401
402 down(&dir->d_inode->i_sem);
403 victim = sysfs_get_dentry(dir, attr->name);
404 if (!IS_ERR(victim)) {
405 /* make sure dentry is really there */
406 if (victim->d_inode &&
407 (victim->d_parent->d_inode == dir->d_inode)) {
408 victim->d_inode->i_mtime = CURRENT_TIME;
409 dnotify_parent(victim, DN_MODIFY);
410
411 /**
412 * Drop reference from initial sysfs_get_dentry().
413 */
414 dput(victim);
415 res = 0;
416 } else
417 d_drop(victim);
418
419 /**
420 * Drop the reference acquired from sysfs_get_dentry() above.
421 */
422 dput(victim);
423 }
424 up(&dir->d_inode->i_sem);
425
426 return res;
427}
428
429
430/**
431 * sysfs_remove_file - remove an object attribute.
432 * @kobj: object we're acting for.
433 * @attr: attribute descriptor.
434 *
435 * Hash the attribute name and kill the victim.
436 */
437
438void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr)
439{
440 sysfs_hash_and_remove(kobj->dentry,attr->name);
441}
442
443
444EXPORT_SYMBOL_GPL(sysfs_create_file);
445EXPORT_SYMBOL_GPL(sysfs_remove_file);
446EXPORT_SYMBOL_GPL(sysfs_update_file);
447
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
new file mode 100644
index 000000000000..f11ac5ea7021
--- /dev/null
+++ b/fs/sysfs/group.c
@@ -0,0 +1,84 @@
1/*
2 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released undert the GPL v2.
8 *
9 */
10
11#include <linux/kobject.h>
12#include <linux/module.h>
13#include <linux/dcache.h>
14#include <linux/err.h>
15#include "sysfs.h"
16
17
18static void remove_files(struct dentry * dir,
19 const struct attribute_group * grp)
20{
21 struct attribute *const* attr;
22
23 for (attr = grp->attrs; *attr; attr++)
24 sysfs_hash_and_remove(dir,(*attr)->name);
25}
26
27static int create_files(struct dentry * dir,
28 const struct attribute_group * grp)
29{
30 struct attribute *const* attr;
31 int error = 0;
32
33 for (attr = grp->attrs; *attr && !error; attr++) {
34 error = sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
35 }
36 if (error)
37 remove_files(dir,grp);
38 return error;
39}
40
41
42int sysfs_create_group(struct kobject * kobj,
43 const struct attribute_group * grp)
44{
45 struct dentry * dir;
46 int error;
47
48 BUG_ON(!kobj || !kobj->dentry);
49
50 if (grp->name) {
51 error = sysfs_create_subdir(kobj,grp->name,&dir);
52 if (error)
53 return error;
54 } else
55 dir = kobj->dentry;
56 dir = dget(dir);
57 if ((error = create_files(dir,grp))) {
58 if (grp->name)
59 sysfs_remove_subdir(dir);
60 }
61 dput(dir);
62 return error;
63}
64
65void sysfs_remove_group(struct kobject * kobj,
66 const struct attribute_group * grp)
67{
68 struct dentry * dir;
69
70 if (grp->name)
71 dir = sysfs_get_dentry(kobj->dentry,grp->name);
72 else
73 dir = dget(kobj->dentry);
74
75 remove_files(dir,grp);
76 if (grp->name)
77 sysfs_remove_subdir(dir);
78 /* release the ref. taken in this routine */
79 dput(dir);
80}
81
82
83EXPORT_SYMBOL_GPL(sysfs_create_group);
84EXPORT_SYMBOL_GPL(sysfs_remove_group);
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
new file mode 100644
index 000000000000..aff7b2dfa8ee
--- /dev/null
+++ b/fs/sysfs/inode.c
@@ -0,0 +1,165 @@
1/*
2 * inode.c - basic inode and dentry operations.
3 *
4 * sysfs is Copyright (c) 2001-3 Patrick Mochel
5 *
6 * Please see Documentation/filesystems/sysfs.txt for more information.
7 */
8
9#undef DEBUG
10
11#include <linux/pagemap.h>
12#include <linux/namei.h>
13#include <linux/backing-dev.h>
14#include "sysfs.h"
15
16extern struct super_block * sysfs_sb;
17
18static struct address_space_operations sysfs_aops = {
19 .readpage = simple_readpage,
20 .prepare_write = simple_prepare_write,
21 .commit_write = simple_commit_write
22};
23
24static struct backing_dev_info sysfs_backing_dev_info = {
25 .ra_pages = 0, /* No readahead */
26 .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
27};
28
29struct inode * sysfs_new_inode(mode_t mode)
30{
31 struct inode * inode = new_inode(sysfs_sb);
32 if (inode) {
33 inode->i_mode = mode;
34 inode->i_uid = 0;
35 inode->i_gid = 0;
36 inode->i_blksize = PAGE_CACHE_SIZE;
37 inode->i_blocks = 0;
38 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
39 inode->i_mapping->a_ops = &sysfs_aops;
40 inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
41 }
42 return inode;
43}
44
45int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
46{
47 int error = 0;
48 struct inode * inode = NULL;
49 if (dentry) {
50 if (!dentry->d_inode) {
51 if ((inode = sysfs_new_inode(mode))) {
52 if (dentry->d_parent && dentry->d_parent->d_inode) {
53 struct inode *p_inode = dentry->d_parent->d_inode;
54 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
55 }
56 goto Proceed;
57 }
58 else
59 error = -ENOMEM;
60 } else
61 error = -EEXIST;
62 } else
63 error = -ENOENT;
64 goto Done;
65
66 Proceed:
67 if (init)
68 error = init(inode);
69 if (!error) {
70 d_instantiate(dentry, inode);
71 if (S_ISDIR(mode))
72 dget(dentry); /* pin only directory dentry in core */
73 } else
74 iput(inode);
75 Done:
76 return error;
77}
78
79struct dentry * sysfs_get_dentry(struct dentry * parent, const char * name)
80{
81 struct qstr qstr;
82
83 qstr.name = name;
84 qstr.len = strlen(name);
85 qstr.hash = full_name_hash(name,qstr.len);
86 return lookup_hash(&qstr,parent);
87}
88
89/*
90 * Get the name for corresponding element represented by the given sysfs_dirent
91 */
92const unsigned char * sysfs_get_name(struct sysfs_dirent *sd)
93{
94 struct attribute * attr;
95 struct bin_attribute * bin_attr;
96 struct sysfs_symlink * sl;
97
98 if (!sd || !sd->s_element)
99 BUG();
100
101 switch (sd->s_type) {
102 case SYSFS_DIR:
103 /* Always have a dentry so use that */
104 return sd->s_dentry->d_name.name;
105
106 case SYSFS_KOBJ_ATTR:
107 attr = sd->s_element;
108 return attr->name;
109
110 case SYSFS_KOBJ_BIN_ATTR:
111 bin_attr = sd->s_element;
112 return bin_attr->attr.name;
113
114 case SYSFS_KOBJ_LINK:
115 sl = sd->s_element;
116 return sl->link_name;
117 }
118 return NULL;
119}
120
121
122/*
123 * Unhashes the dentry corresponding to given sysfs_dirent
124 * Called with parent inode's i_sem held.
125 */
126void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
127{
128 struct dentry * dentry = sd->s_dentry;
129
130 if (dentry) {
131 spin_lock(&dcache_lock);
132 spin_lock(&dentry->d_lock);
133 if (!(d_unhashed(dentry) && dentry->d_inode)) {
134 dget_locked(dentry);
135 __d_drop(dentry);
136 spin_unlock(&dentry->d_lock);
137 spin_unlock(&dcache_lock);
138 simple_unlink(parent->d_inode, dentry);
139 } else {
140 spin_unlock(&dentry->d_lock);
141 spin_unlock(&dcache_lock);
142 }
143 }
144}
145
146void sysfs_hash_and_remove(struct dentry * dir, const char * name)
147{
148 struct sysfs_dirent * sd;
149 struct sysfs_dirent * parent_sd = dir->d_fsdata;
150
151 down(&dir->d_inode->i_sem);
152 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
153 if (!sd->s_element)
154 continue;
155 if (!strcmp(sysfs_get_name(sd), name)) {
156 list_del_init(&sd->s_sibling);
157 sysfs_drop_dentry(sd, dir);
158 sysfs_put(sd);
159 break;
160 }
161 }
162 up(&dir->d_inode->i_sem);
163}
164
165
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
new file mode 100644
index 000000000000..5c805bb1a4b7
--- /dev/null
+++ b/fs/sysfs/mount.c
@@ -0,0 +1,107 @@
1/*
2 * mount.c - operations for initializing and mounting sysfs.
3 */
4
5#define DEBUG
6
7#include <linux/fs.h>
8#include <linux/mount.h>
9#include <linux/pagemap.h>
10#include <linux/init.h>
11
12#include "sysfs.h"
13
14/* Random magic number */
15#define SYSFS_MAGIC 0x62656572
16
17struct vfsmount *sysfs_mount;
18struct super_block * sysfs_sb = NULL;
19kmem_cache_t *sysfs_dir_cachep;
20
21static struct super_operations sysfs_ops = {
22 .statfs = simple_statfs,
23 .drop_inode = generic_delete_inode,
24};
25
26static struct sysfs_dirent sysfs_root = {
27 .s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling),
28 .s_children = LIST_HEAD_INIT(sysfs_root.s_children),
29 .s_element = NULL,
30 .s_type = SYSFS_ROOT,
31};
32
33static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
34{
35 struct inode *inode;
36 struct dentry *root;
37
38 sb->s_blocksize = PAGE_CACHE_SIZE;
39 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
40 sb->s_magic = SYSFS_MAGIC;
41 sb->s_op = &sysfs_ops;
42 sb->s_time_gran = 1;
43 sysfs_sb = sb;
44
45 inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);
46 if (inode) {
47 inode->i_op = &sysfs_dir_inode_operations;
48 inode->i_fop = &sysfs_dir_operations;
49 /* directory inodes start off with i_nlink == 2 (for "." entry) */
50 inode->i_nlink++;
51 } else {
52 pr_debug("sysfs: could not get root inode\n");
53 return -ENOMEM;
54 }
55
56 root = d_alloc_root(inode);
57 if (!root) {
58 pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
59 iput(inode);
60 return -ENOMEM;
61 }
62 root->d_fsdata = &sysfs_root;
63 sb->s_root = root;
64 return 0;
65}
66
67static struct super_block *sysfs_get_sb(struct file_system_type *fs_type,
68 int flags, const char *dev_name, void *data)
69{
70 return get_sb_single(fs_type, flags, data, sysfs_fill_super);
71}
72
73static struct file_system_type sysfs_fs_type = {
74 .name = "sysfs",
75 .get_sb = sysfs_get_sb,
76 .kill_sb = kill_litter_super,
77};
78
79int __init sysfs_init(void)
80{
81 int err = -ENOMEM;
82
83 sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
84 sizeof(struct sysfs_dirent),
85 0, 0, NULL, NULL);
86 if (!sysfs_dir_cachep)
87 goto out;
88
89 err = register_filesystem(&sysfs_fs_type);
90 if (!err) {
91 sysfs_mount = kern_mount(&sysfs_fs_type);
92 if (IS_ERR(sysfs_mount)) {
93 printk(KERN_ERR "sysfs: could not mount!\n");
94 err = PTR_ERR(sysfs_mount);
95 sysfs_mount = NULL;
96 unregister_filesystem(&sysfs_fs_type);
97 goto out_err;
98 }
99 } else
100 goto out_err;
101out:
102 return err;
103out_err:
104 kmem_cache_destroy(sysfs_dir_cachep);
105 sysfs_dir_cachep = NULL;
106 goto out;
107}
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
new file mode 100644
index 000000000000..dfdf70174354
--- /dev/null
+++ b/fs/sysfs/symlink.c
@@ -0,0 +1,180 @@
1/*
2 * symlink.c - operations for sysfs symlinks.
3 */
4
5#include <linux/fs.h>
6#include <linux/module.h>
7#include <linux/kobject.h>
8#include <linux/namei.h>
9
10#include "sysfs.h"
11
12static int object_depth(struct kobject * kobj)
13{
14 struct kobject * p = kobj;
15 int depth = 0;
16 do { depth++; } while ((p = p->parent));
17 return depth;
18}
19
20static int object_path_length(struct kobject * kobj)
21{
22 struct kobject * p = kobj;
23 int length = 1;
24 do {
25 length += strlen(kobject_name(p)) + 1;
26 p = p->parent;
27 } while (p);
28 return length;
29}
30
31static void fill_object_path(struct kobject * kobj, char * buffer, int length)
32{
33 struct kobject * p;
34
35 --length;
36 for (p = kobj; p; p = p->parent) {
37 int cur = strlen(kobject_name(p));
38
39 /* back up enough to print this bus id with '/' */
40 length -= cur;
41 strncpy(buffer + length,kobject_name(p),cur);
42 *(buffer + --length) = '/';
43 }
44}
45
46static int sysfs_add_link(struct dentry * parent, char * name, struct kobject * target)
47{
48 struct sysfs_dirent * parent_sd = parent->d_fsdata;
49 struct sysfs_symlink * sl;
50 int error = 0;
51
52 error = -ENOMEM;
53 sl = kmalloc(sizeof(*sl), GFP_KERNEL);
54 if (!sl)
55 goto exit1;
56
57 sl->link_name = kmalloc(strlen(name) + 1, GFP_KERNEL);
58 if (!sl->link_name)
59 goto exit2;
60
61 strcpy(sl->link_name, name);
62 sl->target_kobj = kobject_get(target);
63
64 error = sysfs_make_dirent(parent_sd, NULL, sl, S_IFLNK|S_IRWXUGO,
65 SYSFS_KOBJ_LINK);
66 if (!error)
67 return 0;
68
69 kfree(sl->link_name);
70exit2:
71 kfree(sl);
72exit1:
73 return error;
74}
75
76/**
77 * sysfs_create_link - create symlink between two objects.
78 * @kobj: object whose directory we're creating the link in.
79 * @target: object we're pointing to.
80 * @name: name of the symlink.
81 */
82int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * name)
83{
84 struct dentry * dentry = kobj->dentry;
85 int error = 0;
86
87 BUG_ON(!kobj || !kobj->dentry || !name);
88
89 down(&dentry->d_inode->i_sem);
90 error = sysfs_add_link(dentry, name, target);
91 up(&dentry->d_inode->i_sem);
92 return error;
93}
94
95
96/**
97 * sysfs_remove_link - remove symlink in object's directory.
98 * @kobj: object we're acting for.
99 * @name: name of the symlink to remove.
100 */
101
102void sysfs_remove_link(struct kobject * kobj, char * name)
103{
104 sysfs_hash_and_remove(kobj->dentry,name);
105}
106
107static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
108 char *path)
109{
110 char * s;
111 int depth, size;
112
113 depth = object_depth(kobj);
114 size = object_path_length(target) + depth * 3 - 1;
115 if (size > PATH_MAX)
116 return -ENAMETOOLONG;
117
118 pr_debug("%s: depth = %d, size = %d\n", __FUNCTION__, depth, size);
119
120 for (s = path; depth--; s += 3)
121 strcpy(s,"../");
122
123 fill_object_path(target, path, size);
124 pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
125
126 return 0;
127}
128
129static int sysfs_getlink(struct dentry *dentry, char * path)
130{
131 struct kobject *kobj, *target_kobj;
132 int error = 0;
133
134 kobj = sysfs_get_kobject(dentry->d_parent);
135 if (!kobj)
136 return -EINVAL;
137
138 target_kobj = sysfs_get_kobject(dentry);
139 if (!target_kobj) {
140 kobject_put(kobj);
141 return -EINVAL;
142 }
143
144 down_read(&sysfs_rename_sem);
145 error = sysfs_get_target_path(kobj, target_kobj, path);
146 up_read(&sysfs_rename_sem);
147
148 kobject_put(kobj);
149 kobject_put(target_kobj);
150 return error;
151
152}
153
154static int sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
155{
156 int error = -ENOMEM;
157 unsigned long page = get_zeroed_page(GFP_KERNEL);
158 if (page)
159 error = sysfs_getlink(dentry, (char *) page);
160 nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
161 return 0;
162}
163
164static void sysfs_put_link(struct dentry *dentry, struct nameidata *nd)
165{
166 char *page = nd_get_link(nd);
167 if (!IS_ERR(page))
168 free_page((unsigned long)page);
169}
170
171struct inode_operations sysfs_symlink_inode_operations = {
172 .readlink = generic_readlink,
173 .follow_link = sysfs_follow_link,
174 .put_link = sysfs_put_link,
175};
176
177
178EXPORT_SYMBOL_GPL(sysfs_create_link);
179EXPORT_SYMBOL_GPL(sysfs_remove_link);
180
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
new file mode 100644
index 000000000000..a8a24a0c0b3b
--- /dev/null
+++ b/fs/sysfs/sysfs.h
@@ -0,0 +1,95 @@
1
2extern struct vfsmount * sysfs_mount;
3extern kmem_cache_t *sysfs_dir_cachep;
4
5extern struct inode * sysfs_new_inode(mode_t mode);
6extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
7
8extern int sysfs_make_dirent(struct sysfs_dirent *, struct dentry *, void *,
9 umode_t, int);
10extern struct dentry * sysfs_get_dentry(struct dentry *, const char *);
11
12extern int sysfs_add_file(struct dentry *, const struct attribute *, int);
13extern void sysfs_hash_and_remove(struct dentry * dir, const char * name);
14
15extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
16extern void sysfs_remove_subdir(struct dentry *);
17
18extern const unsigned char * sysfs_get_name(struct sysfs_dirent *sd);
19extern void sysfs_drop_dentry(struct sysfs_dirent *sd, struct dentry *parent);
20
21extern struct rw_semaphore sysfs_rename_sem;
22extern struct super_block * sysfs_sb;
23extern struct file_operations sysfs_dir_operations;
24extern struct file_operations sysfs_file_operations;
25extern struct file_operations bin_fops;
26extern struct inode_operations sysfs_dir_inode_operations;
27extern struct inode_operations sysfs_symlink_inode_operations;
28
29struct sysfs_symlink {
30 char * link_name;
31 struct kobject * target_kobj;
32};
33
34static inline struct kobject * to_kobj(struct dentry * dentry)
35{
36 struct sysfs_dirent * sd = dentry->d_fsdata;
37 return ((struct kobject *) sd->s_element);
38}
39
40static inline struct attribute * to_attr(struct dentry * dentry)
41{
42 struct sysfs_dirent * sd = dentry->d_fsdata;
43 return ((struct attribute *) sd->s_element);
44}
45
46static inline struct bin_attribute * to_bin_attr(struct dentry * dentry)
47{
48 struct sysfs_dirent * sd = dentry->d_fsdata;
49 return ((struct bin_attribute *) sd->s_element);
50}
51
52static inline struct kobject *sysfs_get_kobject(struct dentry *dentry)
53{
54 struct kobject * kobj = NULL;
55
56 spin_lock(&dcache_lock);
57 if (!d_unhashed(dentry)) {
58 struct sysfs_dirent * sd = dentry->d_fsdata;
59 if (sd->s_type & SYSFS_KOBJ_LINK) {
60 struct sysfs_symlink * sl = sd->s_element;
61 kobj = kobject_get(sl->target_kobj);
62 } else
63 kobj = kobject_get(sd->s_element);
64 }
65 spin_unlock(&dcache_lock);
66
67 return kobj;
68}
69
70static inline void release_sysfs_dirent(struct sysfs_dirent * sd)
71{
72 if (sd->s_type & SYSFS_KOBJ_LINK) {
73 struct sysfs_symlink * sl = sd->s_element;
74 kfree(sl->link_name);
75 kobject_put(sl->target_kobj);
76 kfree(sl);
77 }
78 kmem_cache_free(sysfs_dir_cachep, sd);
79}
80
81static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
82{
83 if (sd) {
84 WARN_ON(!atomic_read(&sd->s_count));
85 atomic_inc(&sd->s_count);
86 }
87 return sd;
88}
89
90static inline void sysfs_put(struct sysfs_dirent * sd)
91{
92 if (atomic_dec_and_test(&sd->s_count))
93 release_sysfs_dirent(sd);
94}
95
generated by cgit v1.2.2 (git 2.25.0) at 2024-09-20 07:51:06 -0400