Commit | Line | Data |
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55716d26 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
b8441ed2 TH |
2 | /* |
3 | * kernfs.h - pseudo filesystem decoupled from vfs locking | |
b8441ed2 TH |
4 | */ |
5 | ||
6 | #ifndef __LINUX_KERNFS_H | |
7 | #define __LINUX_KERNFS_H | |
8 | ||
5d0e26bb | 9 | #include <linux/err.h> |
dd8a5b03 TH |
10 | #include <linux/list.h> |
11 | #include <linux/mutex.h> | |
bc755553 | 12 | #include <linux/idr.h> |
517e64f5 | 13 | #include <linux/lockdep.h> |
cf9e5a73 TH |
14 | #include <linux/rbtree.h> |
15 | #include <linux/atomic.h> | |
79f1c730 AS |
16 | #include <linux/bug.h> |
17 | #include <linux/types.h> | |
488dee96 | 18 | #include <linux/uidgid.h> |
abd54f02 | 19 | #include <linux/wait.h> |
393c3714 | 20 | #include <linux/rwsem.h> |
1d25b84e | 21 | #include <linux/cache.h> |
879f40d1 | 22 | |
5d60418e | 23 | struct file; |
917f56ca | 24 | struct dentry; |
5d60418e | 25 | struct iattr; |
dd8a5b03 TH |
26 | struct seq_file; |
27 | struct vm_area_struct; | |
79f1c730 | 28 | struct vm_operations_struct; |
4b93dc9b TH |
29 | struct super_block; |
30 | struct file_system_type; | |
147e1a97 | 31 | struct poll_table_struct; |
23bf1b6b | 32 | struct fs_context; |
5d60418e | 33 | |
23bf1b6b | 34 | struct kernfs_fs_context; |
c525aadd TH |
35 | struct kernfs_open_node; |
36 | struct kernfs_iattrs; | |
cf9e5a73 | 37 | |
1d25b84e IK |
38 | /* |
39 | * NR_KERNFS_LOCK_BITS determines size (NR_KERNFS_LOCKS) of hash | |
40 | * table of locks. | |
41 | * Having a small hash table would impact scalability, since | |
42 | * more and more kernfs_node objects will end up using same lock | |
43 | * and having a very large hash table would waste memory. | |
44 | * | |
45 | * At the moment size of hash table of locks is being set based on | |
46 | * the number of CPUs as follows: | |
47 | * | |
48 | * NR_CPU NR_KERNFS_LOCK_BITS NR_KERNFS_LOCKS | |
49 | * 1 1 2 | |
50 | * 2-3 2 4 | |
51 | * 4-7 4 16 | |
52 | * 8-15 6 64 | |
53 | * 16-31 8 256 | |
54 | * 32 and more 10 1024 | |
55 | * | |
56 | * The above relation between NR_CPU and number of locks is based | |
57 | * on some internal experimentation which involved booting qemu | |
58 | * with different values of smp, performing some sysfs operations | |
59 | * on all CPUs and observing how increase in number of locks impacts | |
60 | * completion time of these sysfs operations on each CPU. | |
61 | */ | |
62 | #ifdef CONFIG_SMP | |
63 | #define NR_KERNFS_LOCK_BITS (2 * (ilog2(NR_CPUS < 32 ? NR_CPUS : 32))) | |
64 | #else | |
65 | #define NR_KERNFS_LOCK_BITS 1 | |
66 | #endif | |
67 | ||
68 | #define NR_KERNFS_LOCKS (1 << NR_KERNFS_LOCK_BITS) | |
69 | ||
70 | /* | |
71 | * There's one kernfs_open_file for each open file and one kernfs_open_node | |
72 | * for each kernfs_node with one or more open files. | |
73 | * | |
74 | * filp->private_data points to seq_file whose ->private points to | |
75 | * kernfs_open_file. | |
76 | * | |
77 | * kernfs_open_files are chained at kernfs_open_node->files, which is | |
78 | * protected by kernfs_global_locks.open_file_mutex[i]. | |
79 | * | |
80 | * To reduce possible contention in sysfs access, arising due to single | |
81 | * locks, use an array of locks (e.g. open_file_mutex) and use kernfs_node | |
82 | * object address as hash keys to get the index of these locks. | |
83 | * | |
84 | * Hashed mutexes are safe to use here because operations using these don't | |
85 | * rely on global exclusion. | |
86 | * | |
87 | * In future we intend to replace other global locks with hashed ones as well. | |
88 | * kernfs_global_locks acts as a holder for all such hash tables. | |
89 | */ | |
90 | struct kernfs_global_locks { | |
91 | struct mutex open_file_mutex[NR_KERNFS_LOCKS]; | |
92 | }; | |
93 | ||
cf9e5a73 | 94 | enum kernfs_node_type { |
df23fc39 TH |
95 | KERNFS_DIR = 0x0001, |
96 | KERNFS_FILE = 0x0002, | |
97 | KERNFS_LINK = 0x0004, | |
cf9e5a73 TH |
98 | }; |
99 | ||
0c47383b DX |
100 | #define KERNFS_TYPE_MASK 0x000f |
101 | #define KERNFS_FLAG_MASK ~KERNFS_TYPE_MASK | |
102 | #define KERNFS_MAX_USER_XATTRS 128 | |
103 | #define KERNFS_USER_XATTR_SIZE_LIMIT (128 << 10) | |
cf9e5a73 TH |
104 | |
105 | enum kernfs_node_flag { | |
d35258ef | 106 | KERNFS_ACTIVATED = 0x0010, |
df23fc39 TH |
107 | KERNFS_NS = 0x0020, |
108 | KERNFS_HAS_SEQ_SHOW = 0x0040, | |
109 | KERNFS_HAS_MMAP = 0x0080, | |
110 | KERNFS_LOCKDEP = 0x0100, | |
6b0afc2a TH |
111 | KERNFS_SUICIDAL = 0x0400, |
112 | KERNFS_SUICIDED = 0x0800, | |
ea015218 | 113 | KERNFS_EMPTY_DIR = 0x1000, |
0e67db2f | 114 | KERNFS_HAS_RELEASE = 0x2000, |
c2549174 | 115 | KERNFS_REMOVING = 0x4000, |
cf9e5a73 TH |
116 | }; |
117 | ||
d35258ef TH |
118 | /* @flags for kernfs_create_root() */ |
119 | enum kernfs_root_flag { | |
555724a8 TH |
120 | /* |
121 | * kernfs_nodes are created in the deactivated state and invisible. | |
122 | * They require explicit kernfs_activate() to become visible. This | |
123 | * can be used to make related nodes become visible atomically | |
124 | * after all nodes are created successfully. | |
125 | */ | |
126 | KERNFS_ROOT_CREATE_DEACTIVATED = 0x0001, | |
127 | ||
128 | /* | |
0d1a393d | 129 | * For regular files, if the opener has CAP_DAC_OVERRIDE, open(2) |
555724a8 TH |
130 | * succeeds regardless of the RW permissions. sysfs had an extra |
131 | * layer of enforcement where open(2) fails with -EACCES regardless | |
132 | * of CAP_DAC_OVERRIDE if the permission doesn't have the | |
133 | * respective read or write access at all (none of S_IRUGO or | |
134 | * S_IWUGO) or the respective operation isn't implemented. The | |
135 | * following flag enables that behavior. | |
136 | */ | |
137 | KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK = 0x0002, | |
aa818825 SL |
138 | |
139 | /* | |
140 | * The filesystem supports exportfs operation, so userspace can use | |
141 | * fhandle to access nodes of the fs. | |
142 | */ | |
143 | KERNFS_ROOT_SUPPORT_EXPORTOP = 0x0004, | |
0c47383b DX |
144 | |
145 | /* | |
146 | * Support user xattrs to be written to nodes rooted at this root. | |
147 | */ | |
148 | KERNFS_ROOT_SUPPORT_USER_XATTR = 0x0008, | |
d35258ef TH |
149 | }; |
150 | ||
324a56e1 TH |
151 | /* type-specific structures for kernfs_node union members */ |
152 | struct kernfs_elem_dir { | |
cf9e5a73 | 153 | unsigned long subdirs; |
adc5e8b5 | 154 | /* children rbtree starts here and goes through kn->rb */ |
cf9e5a73 TH |
155 | struct rb_root children; |
156 | ||
157 | /* | |
158 | * The kernfs hierarchy this directory belongs to. This fits | |
324a56e1 | 159 | * better directly in kernfs_node but is here to save space. |
cf9e5a73 TH |
160 | */ |
161 | struct kernfs_root *root; | |
895adbec IK |
162 | /* |
163 | * Monotonic revision counter, used to identify if a directory | |
164 | * node has changed during negative dentry revalidation. | |
165 | */ | |
166 | unsigned long rev; | |
cf9e5a73 TH |
167 | }; |
168 | ||
324a56e1 TH |
169 | struct kernfs_elem_symlink { |
170 | struct kernfs_node *target_kn; | |
cf9e5a73 TH |
171 | }; |
172 | ||
324a56e1 | 173 | struct kernfs_elem_attr { |
cf9e5a73 | 174 | const struct kernfs_ops *ops; |
086c00c7 | 175 | struct kernfs_open_node __rcu *open; |
cf9e5a73 | 176 | loff_t size; |
2fd26970 | 177 | struct kernfs_node *notify_next; /* for kernfs_notify() */ |
cf9e5a73 TH |
178 | }; |
179 | ||
180 | /* | |
324a56e1 TH |
181 | * kernfs_node - the building block of kernfs hierarchy. Each and every |
182 | * kernfs node is represented by single kernfs_node. Most fields are | |
cf9e5a73 TH |
183 | * private to kernfs and shouldn't be accessed directly by kernfs users. |
184 | * | |
21774fd8 | 185 | * As long as count reference is held, the kernfs_node itself is |
324a56e1 TH |
186 | * accessible. Dereferencing elem or any other outer entity requires |
187 | * active reference. | |
cf9e5a73 | 188 | */ |
324a56e1 | 189 | struct kernfs_node { |
adc5e8b5 TH |
190 | atomic_t count; |
191 | atomic_t active; | |
cf9e5a73 TH |
192 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
193 | struct lockdep_map dep_map; | |
194 | #endif | |
3eef34ad TH |
195 | /* |
196 | * Use kernfs_get_parent() and kernfs_name/path() instead of | |
197 | * accessing the following two fields directly. If the node is | |
198 | * never moved to a different parent, it is safe to access the | |
199 | * parent directly. | |
200 | */ | |
adc5e8b5 TH |
201 | struct kernfs_node *parent; |
202 | const char *name; | |
cf9e5a73 | 203 | |
adc5e8b5 | 204 | struct rb_node rb; |
cf9e5a73 | 205 | |
adc5e8b5 | 206 | const void *ns; /* namespace tag */ |
9b0925a6 | 207 | unsigned int hash; /* ns + name hash */ |
cf9e5a73 | 208 | union { |
adc5e8b5 TH |
209 | struct kernfs_elem_dir dir; |
210 | struct kernfs_elem_symlink symlink; | |
211 | struct kernfs_elem_attr attr; | |
cf9e5a73 TH |
212 | }; |
213 | ||
214 | void *priv; | |
215 | ||
67c0496e | 216 | /* |
40430452 TH |
217 | * 64bit unique ID. On 64bit ino setups, id is the ino. On 32bit, |
218 | * the low 32bits are ino and upper generation. | |
67c0496e TH |
219 | */ |
220 | u64 id; | |
221 | ||
adc5e8b5 TH |
222 | unsigned short flags; |
223 | umode_t mode; | |
c525aadd | 224 | struct kernfs_iattrs *iattr; |
cf9e5a73 | 225 | }; |
b8441ed2 | 226 | |
80b9bbef | 227 | /* |
90c07c89 TH |
228 | * kernfs_syscall_ops may be specified on kernfs_create_root() to support |
229 | * syscalls. These optional callbacks are invoked on the matching syscalls | |
230 | * and can perform any kernfs operations which don't necessarily have to be | |
231 | * the exact operation requested. An active reference is held for each | |
232 | * kernfs_node parameter. | |
80b9bbef | 233 | */ |
90c07c89 | 234 | struct kernfs_syscall_ops { |
6a7fed4e TH |
235 | int (*show_options)(struct seq_file *sf, struct kernfs_root *root); |
236 | ||
80b9bbef TH |
237 | int (*mkdir)(struct kernfs_node *parent, const char *name, |
238 | umode_t mode); | |
239 | int (*rmdir)(struct kernfs_node *kn); | |
240 | int (*rename)(struct kernfs_node *kn, struct kernfs_node *new_parent, | |
241 | const char *new_name); | |
4f41fc59 SH |
242 | int (*show_path)(struct seq_file *sf, struct kernfs_node *kn, |
243 | struct kernfs_root *root); | |
80b9bbef TH |
244 | }; |
245 | ||
f2eb478f | 246 | struct kernfs_node *kernfs_root_to_node(struct kernfs_root *root); |
ba7443bc | 247 | |
c525aadd | 248 | struct kernfs_open_file { |
dd8a5b03 | 249 | /* published fields */ |
324a56e1 | 250 | struct kernfs_node *kn; |
dd8a5b03 | 251 | struct file *file; |
0e67db2f | 252 | struct seq_file *seq_file; |
2536390d | 253 | void *priv; |
dd8a5b03 TH |
254 | |
255 | /* private fields, do not use outside kernfs proper */ | |
256 | struct mutex mutex; | |
e4234a1f | 257 | struct mutex prealloc_mutex; |
dd8a5b03 TH |
258 | int event; |
259 | struct list_head list; | |
2b75869b | 260 | char *prealloc_buf; |
dd8a5b03 | 261 | |
b7ce40cf | 262 | size_t atomic_write_len; |
a1d82aff | 263 | bool mmapped:1; |
0e67db2f | 264 | bool released:1; |
dd8a5b03 TH |
265 | const struct vm_operations_struct *vm_ops; |
266 | }; | |
267 | ||
f6acf8bb | 268 | struct kernfs_ops { |
0e67db2f TH |
269 | /* |
270 | * Optional open/release methods. Both are called with | |
271 | * @of->seq_file populated. | |
272 | */ | |
273 | int (*open)(struct kernfs_open_file *of); | |
274 | void (*release)(struct kernfs_open_file *of); | |
275 | ||
f6acf8bb TH |
276 | /* |
277 | * Read is handled by either seq_file or raw_read(). | |
278 | * | |
d19b9846 TH |
279 | * If seq_show() is present, seq_file path is active. Other seq |
280 | * operations are optional and if not implemented, the behavior is | |
281 | * equivalent to single_open(). @sf->private points to the | |
c525aadd | 282 | * associated kernfs_open_file. |
f6acf8bb TH |
283 | * |
284 | * read() is bounced through kernel buffer and a read larger than | |
285 | * PAGE_SIZE results in partial operation of PAGE_SIZE. | |
286 | */ | |
287 | int (*seq_show)(struct seq_file *sf, void *v); | |
d19b9846 TH |
288 | |
289 | void *(*seq_start)(struct seq_file *sf, loff_t *ppos); | |
290 | void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos); | |
291 | void (*seq_stop)(struct seq_file *sf, void *v); | |
f6acf8bb | 292 | |
c525aadd | 293 | ssize_t (*read)(struct kernfs_open_file *of, char *buf, size_t bytes, |
f6acf8bb TH |
294 | loff_t off); |
295 | ||
296 | /* | |
4d3773c4 TH |
297 | * write() is bounced through kernel buffer. If atomic_write_len |
298 | * is not set, a write larger than PAGE_SIZE results in partial | |
299 | * operations of PAGE_SIZE chunks. If atomic_write_len is set, | |
300 | * writes upto the specified size are executed atomically but | |
301 | * larger ones are rejected with -E2BIG. | |
f6acf8bb | 302 | */ |
4d3773c4 | 303 | size_t atomic_write_len; |
2b75869b N |
304 | /* |
305 | * "prealloc" causes a buffer to be allocated at open for | |
306 | * all read/write requests. As ->seq_show uses seq_read() | |
307 | * which does its own allocation, it is incompatible with | |
308 | * ->prealloc. Provide ->read and ->write with ->prealloc. | |
309 | */ | |
310 | bool prealloc; | |
c525aadd | 311 | ssize_t (*write)(struct kernfs_open_file *of, char *buf, size_t bytes, |
f6acf8bb TH |
312 | loff_t off); |
313 | ||
147e1a97 JW |
314 | __poll_t (*poll)(struct kernfs_open_file *of, |
315 | struct poll_table_struct *pt); | |
316 | ||
c525aadd | 317 | int (*mmap)(struct kernfs_open_file *of, struct vm_area_struct *vma); |
f6acf8bb TH |
318 | }; |
319 | ||
23bf1b6b DH |
320 | /* |
321 | * The kernfs superblock creation/mount parameter context. | |
322 | */ | |
323 | struct kernfs_fs_context { | |
324 | struct kernfs_root *root; /* Root of the hierarchy being mounted */ | |
325 | void *ns_tag; /* Namespace tag of the mount (or NULL) */ | |
326 | unsigned long magic; /* File system specific magic number */ | |
327 | ||
328 | /* The following are set/used by kernfs_mount() */ | |
329 | bool new_sb_created; /* Set to T if we allocated a new sb */ | |
330 | }; | |
331 | ||
ba341d55 | 332 | #ifdef CONFIG_KERNFS |
879f40d1 | 333 | |
df23fc39 | 334 | static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) |
cf9e5a73 | 335 | { |
df23fc39 | 336 | return kn->flags & KERNFS_TYPE_MASK; |
cf9e5a73 TH |
337 | } |
338 | ||
67c0496e TH |
339 | static inline ino_t kernfs_id_ino(u64 id) |
340 | { | |
40430452 TH |
341 | /* id is ino if ino_t is 64bit; otherwise, low 32bits */ |
342 | if (sizeof(ino_t) >= sizeof(u64)) | |
343 | return id; | |
344 | else | |
345 | return (u32)id; | |
67c0496e TH |
346 | } |
347 | ||
348 | static inline u32 kernfs_id_gen(u64 id) | |
349 | { | |
40430452 TH |
350 | /* gen is fixed at 1 if ino_t is 64bit; otherwise, high 32bits */ |
351 | if (sizeof(ino_t) >= sizeof(u64)) | |
352 | return 1; | |
353 | else | |
354 | return id >> 32; | |
67c0496e TH |
355 | } |
356 | ||
357 | static inline ino_t kernfs_ino(struct kernfs_node *kn) | |
358 | { | |
359 | return kernfs_id_ino(kn->id); | |
360 | } | |
361 | ||
362 | static inline ino_t kernfs_gen(struct kernfs_node *kn) | |
363 | { | |
364 | return kernfs_id_gen(kn->id); | |
365 | } | |
366 | ||
cf9e5a73 TH |
367 | /** |
368 | * kernfs_enable_ns - enable namespace under a directory | |
324a56e1 | 369 | * @kn: directory of interest, should be empty |
cf9e5a73 | 370 | * |
324a56e1 TH |
371 | * This is to be called right after @kn is created to enable namespace |
372 | * under it. All children of @kn must have non-NULL namespace tags and | |
cf9e5a73 TH |
373 | * only the ones which match the super_block's tag will be visible. |
374 | */ | |
324a56e1 | 375 | static inline void kernfs_enable_ns(struct kernfs_node *kn) |
cf9e5a73 | 376 | { |
df23fc39 | 377 | WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR); |
adc5e8b5 | 378 | WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children)); |
df23fc39 | 379 | kn->flags |= KERNFS_NS; |
cf9e5a73 TH |
380 | } |
381 | ||
ac9bba03 TH |
382 | /** |
383 | * kernfs_ns_enabled - test whether namespace is enabled | |
324a56e1 | 384 | * @kn: the node to test |
ac9bba03 TH |
385 | * |
386 | * Test whether namespace filtering is enabled for the children of @ns. | |
387 | */ | |
324a56e1 | 388 | static inline bool kernfs_ns_enabled(struct kernfs_node *kn) |
ac9bba03 | 389 | { |
df23fc39 | 390 | return kn->flags & KERNFS_NS; |
ac9bba03 TH |
391 | } |
392 | ||
3eef34ad | 393 | int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen); |
9f6df573 AK |
394 | int kernfs_path_from_node(struct kernfs_node *root_kn, struct kernfs_node *kn, |
395 | char *buf, size_t buflen); | |
3eef34ad TH |
396 | void pr_cont_kernfs_name(struct kernfs_node *kn); |
397 | void pr_cont_kernfs_path(struct kernfs_node *kn); | |
398 | struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn); | |
324a56e1 TH |
399 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
400 | const char *name, const void *ns); | |
bd96f76a TH |
401 | struct kernfs_node *kernfs_walk_and_get_ns(struct kernfs_node *parent, |
402 | const char *path, const void *ns); | |
324a56e1 TH |
403 | void kernfs_get(struct kernfs_node *kn); |
404 | void kernfs_put(struct kernfs_node *kn); | |
ccf73cf3 | 405 | |
0c23b225 TH |
406 | struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry); |
407 | struct kernfs_root *kernfs_root_from_sb(struct super_block *sb); | |
fb02915f | 408 | struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn); |
0c23b225 | 409 | |
fb3c8315 AK |
410 | struct dentry *kernfs_node_dentry(struct kernfs_node *kn, |
411 | struct super_block *sb); | |
90c07c89 | 412 | struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops, |
d35258ef | 413 | unsigned int flags, void *priv); |
ba7443bc TH |
414 | void kernfs_destroy_root(struct kernfs_root *root); |
415 | ||
324a56e1 | 416 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 | 417 | const char *name, umode_t mode, |
488dee96 | 418 | kuid_t uid, kgid_t gid, |
bb8b9d09 | 419 | void *priv, const void *ns); |
ea015218 EB |
420 | struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent, |
421 | const char *name); | |
2063d608 | 422 | struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent, |
488dee96 DT |
423 | const char *name, umode_t mode, |
424 | kuid_t uid, kgid_t gid, | |
425 | loff_t size, | |
2063d608 TH |
426 | const struct kernfs_ops *ops, |
427 | void *priv, const void *ns, | |
2063d608 | 428 | struct lock_class_key *key); |
324a56e1 TH |
429 | struct kernfs_node *kernfs_create_link(struct kernfs_node *parent, |
430 | const char *name, | |
431 | struct kernfs_node *target); | |
d35258ef | 432 | void kernfs_activate(struct kernfs_node *kn); |
324a56e1 | 433 | void kernfs_remove(struct kernfs_node *kn); |
6b0afc2a TH |
434 | void kernfs_break_active_protection(struct kernfs_node *kn); |
435 | void kernfs_unbreak_active_protection(struct kernfs_node *kn); | |
436 | bool kernfs_remove_self(struct kernfs_node *kn); | |
324a56e1 | 437 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
879f40d1 | 438 | const void *ns); |
324a56e1 | 439 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
890ece16 | 440 | const char *new_name, const void *new_ns); |
324a56e1 | 441 | int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr); |
147e1a97 JW |
442 | __poll_t kernfs_generic_poll(struct kernfs_open_file *of, |
443 | struct poll_table_struct *pt); | |
324a56e1 | 444 | void kernfs_notify(struct kernfs_node *kn); |
879f40d1 | 445 | |
1537ad15 OM |
446 | int kernfs_xattr_get(struct kernfs_node *kn, const char *name, |
447 | void *value, size_t size); | |
448 | int kernfs_xattr_set(struct kernfs_node *kn, const char *name, | |
449 | const void *value, size_t size, int flags); | |
b230d5ab | 450 | |
4b93dc9b | 451 | const void *kernfs_super_ns(struct super_block *sb); |
23bf1b6b DH |
452 | int kernfs_get_tree(struct fs_context *fc); |
453 | void kernfs_free_fs_context(struct fs_context *fc); | |
4b93dc9b TH |
454 | void kernfs_kill_sb(struct super_block *sb); |
455 | ||
456 | void kernfs_init(void); | |
457 | ||
fe0f726c TH |
458 | struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, |
459 | u64 id); | |
ba341d55 | 460 | #else /* CONFIG_KERNFS */ |
879f40d1 | 461 | |
df23fc39 | 462 | static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) |
cf9e5a73 TH |
463 | { return 0; } /* whatever */ |
464 | ||
324a56e1 | 465 | static inline void kernfs_enable_ns(struct kernfs_node *kn) { } |
cf9e5a73 | 466 | |
324a56e1 | 467 | static inline bool kernfs_ns_enabled(struct kernfs_node *kn) |
ac9bba03 TH |
468 | { return false; } |
469 | ||
3eef34ad TH |
470 | static inline int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) |
471 | { return -ENOSYS; } | |
472 | ||
0e0b2afd TH |
473 | static inline int kernfs_path_from_node(struct kernfs_node *root_kn, |
474 | struct kernfs_node *kn, | |
475 | char *buf, size_t buflen) | |
476 | { return -ENOSYS; } | |
477 | ||
3eef34ad TH |
478 | static inline void pr_cont_kernfs_name(struct kernfs_node *kn) { } |
479 | static inline void pr_cont_kernfs_path(struct kernfs_node *kn) { } | |
480 | ||
481 | static inline struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn) | |
482 | { return NULL; } | |
483 | ||
324a56e1 TH |
484 | static inline struct kernfs_node * |
485 | kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name, | |
ccf73cf3 TH |
486 | const void *ns) |
487 | { return NULL; } | |
bd96f76a TH |
488 | static inline struct kernfs_node * |
489 | kernfs_walk_and_get_ns(struct kernfs_node *parent, const char *path, | |
490 | const void *ns) | |
491 | { return NULL; } | |
ccf73cf3 | 492 | |
324a56e1 TH |
493 | static inline void kernfs_get(struct kernfs_node *kn) { } |
494 | static inline void kernfs_put(struct kernfs_node *kn) { } | |
ccf73cf3 | 495 | |
0c23b225 TH |
496 | static inline struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry) |
497 | { return NULL; } | |
498 | ||
499 | static inline struct kernfs_root *kernfs_root_from_sb(struct super_block *sb) | |
500 | { return NULL; } | |
501 | ||
fb02915f TH |
502 | static inline struct inode * |
503 | kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn) | |
504 | { return NULL; } | |
505 | ||
80b9bbef | 506 | static inline struct kernfs_root * |
d35258ef TH |
507 | kernfs_create_root(struct kernfs_syscall_ops *scops, unsigned int flags, |
508 | void *priv) | |
ba7443bc TH |
509 | { return ERR_PTR(-ENOSYS); } |
510 | ||
511 | static inline void kernfs_destroy_root(struct kernfs_root *root) { } | |
512 | ||
324a56e1 | 513 | static inline struct kernfs_node * |
bb8b9d09 | 514 | kernfs_create_dir_ns(struct kernfs_node *parent, const char *name, |
488dee96 DT |
515 | umode_t mode, kuid_t uid, kgid_t gid, |
516 | void *priv, const void *ns) | |
93b2b8e4 TH |
517 | { return ERR_PTR(-ENOSYS); } |
518 | ||
324a56e1 | 519 | static inline struct kernfs_node * |
2063d608 | 520 | __kernfs_create_file(struct kernfs_node *parent, const char *name, |
488dee96 DT |
521 | umode_t mode, kuid_t uid, kgid_t gid, |
522 | loff_t size, const struct kernfs_ops *ops, | |
dfeb0750 | 523 | void *priv, const void *ns, struct lock_class_key *key) |
496f7394 TH |
524 | { return ERR_PTR(-ENOSYS); } |
525 | ||
324a56e1 TH |
526 | static inline struct kernfs_node * |
527 | kernfs_create_link(struct kernfs_node *parent, const char *name, | |
528 | struct kernfs_node *target) | |
5d0e26bb TH |
529 | { return ERR_PTR(-ENOSYS); } |
530 | ||
d35258ef TH |
531 | static inline void kernfs_activate(struct kernfs_node *kn) { } |
532 | ||
324a56e1 | 533 | static inline void kernfs_remove(struct kernfs_node *kn) { } |
879f40d1 | 534 | |
6b0afc2a TH |
535 | static inline bool kernfs_remove_self(struct kernfs_node *kn) |
536 | { return false; } | |
537 | ||
324a56e1 | 538 | static inline int kernfs_remove_by_name_ns(struct kernfs_node *kn, |
879f40d1 TH |
539 | const char *name, const void *ns) |
540 | { return -ENOSYS; } | |
541 | ||
324a56e1 TH |
542 | static inline int kernfs_rename_ns(struct kernfs_node *kn, |
543 | struct kernfs_node *new_parent, | |
890ece16 TH |
544 | const char *new_name, const void *new_ns) |
545 | { return -ENOSYS; } | |
546 | ||
324a56e1 | 547 | static inline int kernfs_setattr(struct kernfs_node *kn, |
5d60418e TH |
548 | const struct iattr *iattr) |
549 | { return -ENOSYS; } | |
550 | ||
324a56e1 | 551 | static inline void kernfs_notify(struct kernfs_node *kn) { } |
024f6471 | 552 | |
1537ad15 OM |
553 | static inline int kernfs_xattr_get(struct kernfs_node *kn, const char *name, |
554 | void *value, size_t size) | |
b230d5ab OM |
555 | { return -ENOSYS; } |
556 | ||
1537ad15 OM |
557 | static inline int kernfs_xattr_set(struct kernfs_node *kn, const char *name, |
558 | const void *value, size_t size, int flags) | |
b230d5ab OM |
559 | { return -ENOSYS; } |
560 | ||
4b93dc9b TH |
561 | static inline const void *kernfs_super_ns(struct super_block *sb) |
562 | { return NULL; } | |
563 | ||
23bf1b6b DH |
564 | static inline int kernfs_get_tree(struct fs_context *fc) |
565 | { return -ENOSYS; } | |
566 | ||
567 | static inline void kernfs_free_fs_context(struct fs_context *fc) { } | |
4b93dc9b TH |
568 | |
569 | static inline void kernfs_kill_sb(struct super_block *sb) { } | |
570 | ||
571 | static inline void kernfs_init(void) { } | |
572 | ||
ba341d55 | 573 | #endif /* CONFIG_KERNFS */ |
879f40d1 | 574 | |
3abb1d90 TH |
575 | /** |
576 | * kernfs_path - build full path of a given node | |
577 | * @kn: kernfs_node of interest | |
578 | * @buf: buffer to copy @kn's name into | |
579 | * @buflen: size of @buf | |
580 | * | |
8f5be0ec KK |
581 | * If @kn is NULL result will be "(null)". |
582 | * | |
583 | * Returns the length of the full path. If the full length is equal to or | |
584 | * greater than @buflen, @buf contains the truncated path with the trailing | |
585 | * '\0'. On error, -errno is returned. | |
3abb1d90 TH |
586 | */ |
587 | static inline int kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen) | |
588 | { | |
589 | return kernfs_path_from_node(kn, NULL, buf, buflen); | |
590 | } | |
591 | ||
324a56e1 TH |
592 | static inline struct kernfs_node * |
593 | kernfs_find_and_get(struct kernfs_node *kn, const char *name) | |
ccf73cf3 | 594 | { |
324a56e1 | 595 | return kernfs_find_and_get_ns(kn, name, NULL); |
ccf73cf3 TH |
596 | } |
597 | ||
bd96f76a TH |
598 | static inline struct kernfs_node * |
599 | kernfs_walk_and_get(struct kernfs_node *kn, const char *path) | |
600 | { | |
601 | return kernfs_walk_and_get_ns(kn, path, NULL); | |
602 | } | |
603 | ||
324a56e1 | 604 | static inline struct kernfs_node * |
bb8b9d09 TH |
605 | kernfs_create_dir(struct kernfs_node *parent, const char *name, umode_t mode, |
606 | void *priv) | |
93b2b8e4 | 607 | { |
488dee96 DT |
608 | return kernfs_create_dir_ns(parent, name, mode, |
609 | GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, | |
610 | priv, NULL); | |
93b2b8e4 TH |
611 | } |
612 | ||
324a56e1 | 613 | static inline int kernfs_remove_by_name(struct kernfs_node *parent, |
879f40d1 TH |
614 | const char *name) |
615 | { | |
616 | return kernfs_remove_by_name_ns(parent, name, NULL); | |
617 | } | |
618 | ||
0c23b225 TH |
619 | static inline int kernfs_rename(struct kernfs_node *kn, |
620 | struct kernfs_node *new_parent, | |
621 | const char *new_name) | |
622 | { | |
623 | return kernfs_rename_ns(kn, new_parent, new_name, NULL); | |
624 | } | |
625 | ||
b8441ed2 | 626 | #endif /* __LINUX_KERNFS_H */ |