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 int vfs_tmpfile(struct mnt_idmap *idmap,
66 const struct path *parentpath,
67 struct file *file, umode_t mode);
68
69 /*
70 * namespace.c
71 */
72 extern struct vfsmount *lookup_mnt(const struct path *);
73 extern int finish_automount(struct vfsmount *, const struct path *);
74
75 extern int sb_prepare_remount_readonly(struct super_block *);
76
77 extern void __init mnt_init(void);
78
79 int mnt_get_write_access_file(struct file *file);
80 void mnt_put_write_access_file(struct file *file);
81
82 extern void dissolve_on_fput(struct vfsmount *);
83 extern bool may_mount(void);
84
85 int path_mount(const char *dev_name, struct path *path,
86 const char *type_page, unsigned long flags, void *data_page);
87 int path_umount(struct path *path, int flags);
88
89 int show_path(struct seq_file *m, struct dentry *root);
90
91 /*
92 * fs_struct.c
93 */
94 extern void chroot_fs_refs(const struct path *, const struct path *);
95
96 /*
97 * file_table.c
98 */
99 struct file *alloc_empty_file(int flags, const struct cred *cred);
100 struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);
101 struct file *alloc_empty_backing_file(int flags, const struct cred *cred);
102
file_put_write_access(struct file * file)103 static inline void file_put_write_access(struct file *file)
104 {
105 put_write_access(file->f_inode);
106 mnt_put_write_access(file->f_path.mnt);
107 if (unlikely(file->f_mode & FMODE_BACKING))
108 mnt_put_write_access(backing_file_user_path(file)->mnt);
109 }
110
put_file_access(struct file * file)111 static inline void put_file_access(struct file *file)
112 {
113 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
114 i_readcount_dec(file->f_inode);
115 } else if (file->f_mode & FMODE_WRITER) {
116 file_put_write_access(file);
117 }
118 }
119
120 /*
121 * super.c
122 */
123 extern int reconfigure_super(struct fs_context *);
124 extern bool super_trylock_shared(struct super_block *sb);
125 struct super_block *user_get_super(dev_t, bool excl);
126 void put_super(struct super_block *sb);
127 extern bool mount_capable(struct fs_context *);
128 int sb_init_dio_done_wq(struct super_block *sb);
129
130 /*
131 * Prepare superblock for changing its read-only state (i.e., either remount
132 * read-write superblock read-only or vice versa). After this function returns
133 * mnt_is_readonly() will return true for any mount of the superblock if its
134 * caller is able to observe any changes done by the remount. This holds until
135 * sb_end_ro_state_change() is called.
136 */
sb_start_ro_state_change(struct super_block * sb)137 static inline void sb_start_ro_state_change(struct super_block *sb)
138 {
139 WRITE_ONCE(sb->s_readonly_remount, 1);
140 /*
141 * For RO->RW transition, the barrier pairs with the barrier in
142 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY
143 * cleared, it will see s_readonly_remount set.
144 * For RW->RO transition, the barrier pairs with the barrier in
145 * mnt_get_write_access() before the mnt_is_readonly() check.
146 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD
147 * already cleared, it will see s_readonly_remount set.
148 */
149 smp_wmb();
150 }
151
152 /*
153 * Ends section changing read-only state of the superblock. After this function
154 * returns if mnt_is_readonly() returns false, the caller will be able to
155 * observe all the changes remount did to the superblock.
156 */
sb_end_ro_state_change(struct super_block * sb)157 static inline void sb_end_ro_state_change(struct super_block *sb)
158 {
159 /*
160 * This barrier provides release semantics that pairs with
161 * the smp_rmb() acquire semantics in mnt_is_readonly().
162 * This barrier pair ensure that when mnt_is_readonly() sees
163 * 0 for sb->s_readonly_remount, it will also see all the
164 * preceding flag changes that were made during the RO state
165 * change.
166 */
167 smp_wmb();
168 WRITE_ONCE(sb->s_readonly_remount, 0);
169 }
170
171 /*
172 * open.c
173 */
174 struct open_flags {
175 int open_flag;
176 umode_t mode;
177 int acc_mode;
178 int intent;
179 int lookup_flags;
180 };
181 extern struct file *do_filp_open(int dfd, struct filename *pathname,
182 const struct open_flags *op);
183 extern struct file *do_file_open_root(const struct path *,
184 const char *, const struct open_flags *);
185 extern struct open_how build_open_how(int flags, umode_t mode);
186 extern int build_open_flags(const struct open_how *how, struct open_flags *op);
187 struct file *file_close_fd_locked(struct files_struct *files, unsigned fd);
188
189 long do_ftruncate(struct file *file, loff_t length, int small);
190 long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
191 int chmod_common(const struct path *path, umode_t mode);
192 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
193 int flag);
194 int chown_common(const struct path *path, uid_t user, gid_t group);
195 extern int vfs_open(const struct path *, struct file *);
196
197 /*
198 * inode.c
199 */
200 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc);
201 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry);
202 bool in_group_or_capable(struct mnt_idmap *idmap,
203 const struct inode *inode, vfsgid_t vfsgid);
204
205 /*
206 * fs-writeback.c
207 */
208 extern long get_nr_dirty_inodes(void);
209 void invalidate_inodes(struct super_block *sb);
210
211 /*
212 * dcache.c
213 */
214 extern int d_set_mounted(struct dentry *dentry);
215 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
216 extern struct dentry *d_alloc_cursor(struct dentry *);
217 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
218 extern char *simple_dname(struct dentry *, char *, int);
219 extern void dput_to_list(struct dentry *, struct list_head *);
220 extern void shrink_dentry_list(struct list_head *);
221 extern void shrink_dcache_for_umount(struct super_block *);
222 extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
223 extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
224 const struct qstr *name, unsigned *seq);
225 extern void d_genocide(struct dentry *);
226
227 /*
228 * pipe.c
229 */
230 extern const struct file_operations pipefifo_fops;
231
232 /*
233 * fs_pin.c
234 */
235 extern void group_pin_kill(struct hlist_head *p);
236 extern void mnt_pin_kill(struct mount *m);
237
238 /*
239 * fs/nsfs.c
240 */
241 extern const struct dentry_operations ns_dentry_operations;
242
243 /*
244 * fs/stat.c:
245 */
246
247 int getname_statx_lookup_flags(int flags);
248 int do_statx(int dfd, struct filename *filename, unsigned int flags,
249 unsigned int mask, struct statx __user *buffer);
250
251 /*
252 * fs/splice.c:
253 */
254 ssize_t splice_file_to_pipe(struct file *in,
255 struct pipe_inode_info *opipe,
256 loff_t *offset,
257 size_t len, unsigned int flags);
258
259 /*
260 * fs/xattr.c:
261 */
262 struct xattr_name {
263 char name[XATTR_NAME_MAX + 1];
264 };
265
266 struct xattr_ctx {
267 /* Value of attribute */
268 union {
269 const void __user *cvalue;
270 void __user *value;
271 };
272 void *kvalue;
273 size_t size;
274 /* Attribute name */
275 struct xattr_name *kname;
276 unsigned int flags;
277 };
278
279
280 ssize_t do_getxattr(struct mnt_idmap *idmap,
281 struct dentry *d,
282 struct xattr_ctx *ctx);
283
284 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx);
285 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
286 struct xattr_ctx *ctx);
287 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);
288
289 #ifdef CONFIG_FS_POSIX_ACL
290 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
291 const char *acl_name, const void *kvalue, size_t size);
292 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
293 const char *acl_name, void *kvalue, size_t size);
294 #else
do_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,const void * kvalue,size_t size)295 static inline int do_set_acl(struct mnt_idmap *idmap,
296 struct dentry *dentry, const char *acl_name,
297 const void *kvalue, size_t size)
298 {
299 return -EOPNOTSUPP;
300 }
do_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,void * kvalue,size_t size)301 static inline ssize_t do_get_acl(struct mnt_idmap *idmap,
302 struct dentry *dentry, const char *acl_name,
303 void *kvalue, size_t size)
304 {
305 return -EOPNOTSUPP;
306 }
307 #endif
308
309 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos);
310
311 /*
312 * fs/attr.c
313 */
314 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
315 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
316 void mnt_idmap_put(struct mnt_idmap *idmap);
317 struct stashed_operations {
318 void (*put_data)(void *data);
319 int (*init_inode)(struct inode *inode, void *data);
320 };
321 int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data,
322 struct path *path);
323 void stashed_dentry_prune(struct dentry *dentry);
324