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 extern int __mnt_want_write_file(struct file *);
77 extern void __mnt_drop_write_file(struct 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 /*
87 * fs_struct.c
88 */
89 extern void chroot_fs_refs(const struct path *, const struct path *);
90
91 /*
92 * file_table.c
93 */
94 struct file *alloc_empty_file(int flags, const struct cred *cred);
95 struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);
96 struct file *alloc_empty_backing_file(int flags, const struct cred *cred);
97
put_file_access(struct file * file)98 static inline void put_file_access(struct file *file)
99 {
100 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
101 i_readcount_dec(file->f_inode);
102 } else if (file->f_mode & FMODE_WRITER) {
103 put_write_access(file->f_inode);
104 __mnt_drop_write(file->f_path.mnt);
105 }
106 }
107
108 /*
109 * super.c
110 */
111 extern int reconfigure_super(struct fs_context *);
112 extern bool super_trylock_shared(struct super_block *sb);
113 struct super_block *user_get_super(dev_t, bool excl);
114 void put_super(struct super_block *sb);
115 extern bool mount_capable(struct fs_context *);
116 int sb_init_dio_done_wq(struct super_block *sb);
117
118 /*
119 * Prepare superblock for changing its read-only state (i.e., either remount
120 * read-write superblock read-only or vice versa). After this function returns
121 * mnt_is_readonly() will return true for any mount of the superblock if its
122 * caller is able to observe any changes done by the remount. This holds until
123 * sb_end_ro_state_change() is called.
124 */
sb_start_ro_state_change(struct super_block * sb)125 static inline void sb_start_ro_state_change(struct super_block *sb)
126 {
127 WRITE_ONCE(sb->s_readonly_remount, 1);
128 /*
129 * For RO->RW transition, the barrier pairs with the barrier in
130 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY
131 * cleared, it will see s_readonly_remount set.
132 * For RW->RO transition, the barrier pairs with the barrier in
133 * __mnt_want_write() before the mnt_is_readonly() check. The barrier
134 * makes sure if __mnt_want_write() sees MNT_WRITE_HOLD already
135 * cleared, it will see s_readonly_remount set.
136 */
137 smp_wmb();
138 }
139
140 /*
141 * Ends section changing read-only state of the superblock. After this function
142 * returns if mnt_is_readonly() returns false, the caller will be able to
143 * observe all the changes remount did to the superblock.
144 */
sb_end_ro_state_change(struct super_block * sb)145 static inline void sb_end_ro_state_change(struct super_block *sb)
146 {
147 /*
148 * This barrier provides release semantics that pairs with
149 * the smp_rmb() acquire semantics in mnt_is_readonly().
150 * This barrier pair ensure that when mnt_is_readonly() sees
151 * 0 for sb->s_readonly_remount, it will also see all the
152 * preceding flag changes that were made during the RO state
153 * change.
154 */
155 smp_wmb();
156 WRITE_ONCE(sb->s_readonly_remount, 0);
157 }
158
159 /*
160 * open.c
161 */
162 struct open_flags {
163 int open_flag;
164 umode_t mode;
165 int acc_mode;
166 int intent;
167 int lookup_flags;
168 };
169 extern struct file *do_filp_open(int dfd, struct filename *pathname,
170 const struct open_flags *op);
171 extern struct file *do_file_open_root(const struct path *,
172 const char *, const struct open_flags *);
173 extern struct open_how build_open_how(int flags, umode_t mode);
174 extern int build_open_flags(const struct open_how *how, struct open_flags *op);
175 extern struct file *__close_fd_get_file(unsigned int fd);
176
177 long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
178 int chmod_common(const struct path *path, umode_t mode);
179 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
180 int flag);
181 int chown_common(const struct path *path, uid_t user, gid_t group);
182 extern int vfs_open(const struct path *, struct file *);
183
184 /*
185 * inode.c
186 */
187 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc);
188 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry);
189 bool in_group_or_capable(struct mnt_idmap *idmap,
190 const struct inode *inode, vfsgid_t vfsgid);
191 void lock_two_inodes(struct inode *inode1, struct inode *inode2,
192 unsigned subclass1, unsigned subclass2);
193
194 /*
195 * fs-writeback.c
196 */
197 extern long get_nr_dirty_inodes(void);
198 void invalidate_inodes(struct super_block *sb);
199
200 /*
201 * dcache.c
202 */
203 extern int d_set_mounted(struct dentry *dentry);
204 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
205 extern struct dentry *d_alloc_cursor(struct dentry *);
206 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
207 extern char *simple_dname(struct dentry *, char *, int);
208 extern void dput_to_list(struct dentry *, struct list_head *);
209 extern void shrink_dentry_list(struct list_head *);
210
211 /*
212 * pipe.c
213 */
214 extern const struct file_operations pipefifo_fops;
215
216 /*
217 * fs_pin.c
218 */
219 extern void group_pin_kill(struct hlist_head *p);
220 extern void mnt_pin_kill(struct mount *m);
221
222 /*
223 * fs/nsfs.c
224 */
225 extern const struct dentry_operations ns_dentry_operations;
226
227 /*
228 * fs/stat.c:
229 */
230
231 int getname_statx_lookup_flags(int flags);
232 int do_statx(int dfd, struct filename *filename, unsigned int flags,
233 unsigned int mask, struct statx __user *buffer);
234
235 /*
236 * fs/splice.c:
237 */
238 long splice_file_to_pipe(struct file *in,
239 struct pipe_inode_info *opipe,
240 loff_t *offset,
241 size_t len, unsigned int flags);
242
243 /*
244 * fs/xattr.c:
245 */
246 struct xattr_name {
247 char name[XATTR_NAME_MAX + 1];
248 };
249
250 struct xattr_ctx {
251 /* Value of attribute */
252 union {
253 const void __user *cvalue;
254 void __user *value;
255 };
256 void *kvalue;
257 size_t size;
258 /* Attribute name */
259 struct xattr_name *kname;
260 unsigned int flags;
261 };
262
263
264 ssize_t do_getxattr(struct mnt_idmap *idmap,
265 struct dentry *d,
266 struct xattr_ctx *ctx);
267
268 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx);
269 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
270 struct xattr_ctx *ctx);
271 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);
272
273 #ifdef CONFIG_FS_POSIX_ACL
274 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
275 const char *acl_name, const void *kvalue, size_t size);
276 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
277 const char *acl_name, void *kvalue, size_t size);
278 #else
do_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,const void * kvalue,size_t size)279 static inline int do_set_acl(struct mnt_idmap *idmap,
280 struct dentry *dentry, const char *acl_name,
281 const void *kvalue, size_t size)
282 {
283 return -EOPNOTSUPP;
284 }
do_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,void * kvalue,size_t size)285 static inline ssize_t do_get_acl(struct mnt_idmap *idmap,
286 struct dentry *dentry, const char *acl_name,
287 void *kvalue, size_t size)
288 {
289 return -EOPNOTSUPP;
290 }
291 #endif
292
293 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos);
294
295 /*
296 * fs/attr.c
297 */
298 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
299 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
300 void mnt_idmap_put(struct mnt_idmap *idmap);
301