1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* fs/ internal definitions
3 *
4 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 struct super_block;
9 struct file_system_type;
10 struct iomap;
11 struct iomap_ops;
12 struct linux_binprm;
13 struct path;
14 struct mount;
15 struct shrink_control;
16 struct fs_context;
17 struct pipe_inode_info;
18 struct iov_iter;
19 struct mnt_idmap;
20
21 /*
22 * block/bdev.c
23 */
24 #ifdef CONFIG_BLOCK
25 extern void __init bdev_cache_init(void);
26 #else
bdev_cache_init(void)27 static inline void bdev_cache_init(void)
28 {
29 }
30 #endif /* CONFIG_BLOCK */
31
32 /*
33 * buffer.c
34 */
35 int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len,
36 get_block_t *get_block, const struct iomap *iomap);
37
38 /*
39 * char_dev.c
40 */
41 extern void __init chrdev_init(void);
42
43 /*
44 * fs_context.c
45 */
46 extern const struct fs_context_operations legacy_fs_context_ops;
47 extern int parse_monolithic_mount_data(struct fs_context *, void *);
48 extern void vfs_clean_context(struct fs_context *fc);
49 extern int finish_clean_context(struct fs_context *fc);
50
51 /*
52 * namei.c
53 */
54 extern int filename_lookup(int dfd, struct filename *name, unsigned flags,
55 struct path *path, struct path *root);
56 int do_rmdir(int dfd, struct filename *name);
57 int do_unlinkat(int dfd, struct filename *name);
58 int may_linkat(struct mnt_idmap *idmap, const struct path *link);
59 int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
60 struct filename *newname, unsigned int flags);
61 int do_mkdirat(int dfd, struct filename *name, umode_t mode);
62 int do_symlinkat(struct filename *from, int newdfd, struct filename *to);
63 int do_linkat(int olddfd, struct filename *old, int newdfd,
64 struct filename *new, int flags);
65
66 /*
67 * namespace.c
68 */
69 extern struct vfsmount *lookup_mnt(const struct path *);
70 extern int finish_automount(struct vfsmount *, const struct path *);
71
72 extern int sb_prepare_remount_readonly(struct super_block *);
73
74 extern void __init mnt_init(void);
75
76 int mnt_get_write_access_file(struct file *file);
77 void mnt_put_write_access_file(struct file *file);
78
79 extern void dissolve_on_fput(struct vfsmount *);
80 extern bool may_mount(void);
81
82 int path_mount(const char *dev_name, struct path *path,
83 const char *type_page, unsigned long flags, void *data_page);
84 int path_umount(struct path *path, int flags);
85
86 int show_path(struct seq_file *m, struct dentry *root);
87
88 /*
89 * fs_struct.c
90 */
91 extern void chroot_fs_refs(const struct path *, const struct path *);
92
93 /*
94 * file_table.c
95 */
96 struct file *alloc_empty_file(int flags, const struct cred *cred);
97 struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);
98 struct file *alloc_empty_backing_file(int flags, const struct cred *cred);
99
file_put_write_access(struct file * file)100 static inline void file_put_write_access(struct file *file)
101 {
102 put_write_access(file->f_inode);
103 mnt_put_write_access(file->f_path.mnt);
104 if (unlikely(file->f_mode & FMODE_BACKING))
105 mnt_put_write_access(backing_file_user_path(file)->mnt);
106 }
107
put_file_access(struct file * file)108 static inline void put_file_access(struct file *file)
109 {
110 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
111 i_readcount_dec(file->f_inode);
112 } else if (file->f_mode & FMODE_WRITER) {
113 file_put_write_access(file);
114 }
115 }
116
117 /*
118 * super.c
119 */
120 extern int reconfigure_super(struct fs_context *);
121 extern bool super_trylock_shared(struct super_block *sb);
122 struct super_block *user_get_super(dev_t, bool excl);
123 void put_super(struct super_block *sb);
124 extern bool mount_capable(struct fs_context *);
125 int sb_init_dio_done_wq(struct super_block *sb);
126
127 /*
128 * Prepare superblock for changing its read-only state (i.e., either remount
129 * read-write superblock read-only or vice versa). After this function returns
130 * mnt_is_readonly() will return true for any mount of the superblock if its
131 * caller is able to observe any changes done by the remount. This holds until
132 * sb_end_ro_state_change() is called.
133 */
sb_start_ro_state_change(struct super_block * sb)134 static inline void sb_start_ro_state_change(struct super_block *sb)
135 {
136 WRITE_ONCE(sb->s_readonly_remount, 1);
137 /*
138 * For RO->RW transition, the barrier pairs with the barrier in
139 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY
140 * cleared, it will see s_readonly_remount set.
141 * For RW->RO transition, the barrier pairs with the barrier in
142 * mnt_get_write_access() before the mnt_is_readonly() check.
143 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD
144 * already cleared, it will see s_readonly_remount set.
145 */
146 smp_wmb();
147 }
148
149 /*
150 * Ends section changing read-only state of the superblock. After this function
151 * returns if mnt_is_readonly() returns false, the caller will be able to
152 * observe all the changes remount did to the superblock.
153 */
sb_end_ro_state_change(struct super_block * sb)154 static inline void sb_end_ro_state_change(struct super_block *sb)
155 {
156 /*
157 * This barrier provides release semantics that pairs with
158 * the smp_rmb() acquire semantics in mnt_is_readonly().
159 * This barrier pair ensure that when mnt_is_readonly() sees
160 * 0 for sb->s_readonly_remount, it will also see all the
161 * preceding flag changes that were made during the RO state
162 * change.
163 */
164 smp_wmb();
165 WRITE_ONCE(sb->s_readonly_remount, 0);
166 }
167
168 /*
169 * open.c
170 */
171 struct open_flags {
172 int open_flag;
173 umode_t mode;
174 int acc_mode;
175 int intent;
176 int lookup_flags;
177 };
178 extern struct file *do_filp_open(int dfd, struct filename *pathname,
179 const struct open_flags *op);
180 extern struct file *do_file_open_root(const struct path *,
181 const char *, const struct open_flags *);
182 extern struct open_how build_open_how(int flags, umode_t mode);
183 extern int build_open_flags(const struct open_how *how, struct open_flags *op);
184 struct file *file_close_fd_locked(struct files_struct *files, unsigned fd);
185
186 long do_ftruncate(struct file *file, loff_t length, int small);
187 long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
188 int chmod_common(const struct path *path, umode_t mode);
189 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
190 int flag);
191 int chown_common(const struct path *path, uid_t user, gid_t group);
192 extern int vfs_open(const struct path *, struct file *);
193
194 /*
195 * inode.c
196 */
197 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc);
198 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry);
199 bool in_group_or_capable(struct mnt_idmap *idmap,
200 const struct inode *inode, vfsgid_t vfsgid);
201
202 /*
203 * fs-writeback.c
204 */
205 extern long get_nr_dirty_inodes(void);
206 void invalidate_inodes(struct super_block *sb);
207
208 /*
209 * dcache.c
210 */
211 extern int d_set_mounted(struct dentry *dentry);
212 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
213 extern struct dentry *d_alloc_cursor(struct dentry *);
214 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
215 extern char *simple_dname(struct dentry *, char *, int);
216 extern void dput_to_list(struct dentry *, struct list_head *);
217 extern void shrink_dentry_list(struct list_head *);
218 extern void shrink_dcache_for_umount(struct super_block *);
219 extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
220 extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
221 const struct qstr *name, unsigned *seq);
222 extern void d_genocide(struct dentry *);
223
224 /*
225 * pipe.c
226 */
227 extern const struct file_operations pipefifo_fops;
228
229 /*
230 * fs_pin.c
231 */
232 extern void group_pin_kill(struct hlist_head *p);
233 extern void mnt_pin_kill(struct mount *m);
234
235 /*
236 * fs/nsfs.c
237 */
238 extern const struct dentry_operations ns_dentry_operations;
239
240 /*
241 * fs/stat.c:
242 */
243
244 int getname_statx_lookup_flags(int flags);
245 int do_statx(int dfd, struct filename *filename, unsigned int flags,
246 unsigned int mask, struct statx __user *buffer);
247
248 /*
249 * fs/splice.c:
250 */
251 ssize_t splice_file_to_pipe(struct file *in,
252 struct pipe_inode_info *opipe,
253 loff_t *offset,
254 size_t len, unsigned int flags);
255
256 /*
257 * fs/xattr.c:
258 */
259 struct xattr_name {
260 char name[XATTR_NAME_MAX + 1];
261 };
262
263 struct xattr_ctx {
264 /* Value of attribute */
265 union {
266 const void __user *cvalue;
267 void __user *value;
268 };
269 void *kvalue;
270 size_t size;
271 /* Attribute name */
272 struct xattr_name *kname;
273 unsigned int flags;
274 };
275
276
277 ssize_t do_getxattr(struct mnt_idmap *idmap,
278 struct dentry *d,
279 struct xattr_ctx *ctx);
280
281 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx);
282 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
283 struct xattr_ctx *ctx);
284 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);
285
286 #ifdef CONFIG_FS_POSIX_ACL
287 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
288 const char *acl_name, const void *kvalue, size_t size);
289 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
290 const char *acl_name, void *kvalue, size_t size);
291 #else
do_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,const void * kvalue,size_t size)292 static inline int do_set_acl(struct mnt_idmap *idmap,
293 struct dentry *dentry, const char *acl_name,
294 const void *kvalue, size_t size)
295 {
296 return -EOPNOTSUPP;
297 }
do_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,void * kvalue,size_t size)298 static inline ssize_t do_get_acl(struct mnt_idmap *idmap,
299 struct dentry *dentry, const char *acl_name,
300 void *kvalue, size_t size)
301 {
302 return -EOPNOTSUPP;
303 }
304 #endif
305
306 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos);
307
308 /*
309 * fs/attr.c
310 */
311 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
312 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
313 void mnt_idmap_put(struct mnt_idmap *idmap);
314 struct stashed_operations {
315 void (*put_data)(void *data);
316 int (*init_inode)(struct inode *inode, void *data);
317 };
318 int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data,
319 struct path *path);
320 void stashed_dentry_prune(struct dentry *dentry);
321