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
8struct super_block;
9struct file_system_type;
10struct iomap;
11struct iomap_ops;
12struct linux_binprm;
13struct path;
14struct mount;
15struct shrink_control;
16struct fs_context;
17struct pipe_inode_info;
18struct iov_iter;
19struct mnt_idmap;
20
21/*
22 * block/bdev.c
23 */
24#ifdef CONFIG_BLOCK
25extern void __init bdev_cache_init(void);
26#else
27static inline void bdev_cache_init(void)
28{
29}
30#endif /* CONFIG_BLOCK */
31
32/*
33 * buffer.c
34 */
35int __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 */
41extern void __init chrdev_init(void);
42
43/*
44 * fs_context.c
45 */
46extern const struct fs_context_operations legacy_fs_context_ops;
47extern int parse_monolithic_mount_data(struct fs_context *, void *);
48extern void vfs_clean_context(struct fs_context *fc);
49extern int finish_clean_context(struct fs_context *fc);
50
51/*
52 * namei.c
53 */
54extern int filename_lookup(int dfd, struct filename *name, unsigned flags,
55 struct path *path, struct path *root);
56int do_rmdir(int dfd, struct filename *name);
57int do_unlinkat(int dfd, struct filename *name);
58int may_linkat(struct mnt_idmap *idmap, const struct path *link);
59int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
60 struct filename *newname, unsigned int flags);
61int do_mkdirat(int dfd, struct filename *name, umode_t mode);
62int do_symlinkat(struct filename *from, int newdfd, struct filename *to);
63int do_linkat(int olddfd, struct filename *old, int newdfd,
64 struct filename *new, int flags);
65
66/*
67 * namespace.c
68 */
69extern struct vfsmount *lookup_mnt(const struct path *);
70extern int finish_automount(struct vfsmount *, const struct path *);
71
72extern int sb_prepare_remount_readonly(struct super_block *);
73
74extern void __init mnt_init(void);
75
76int mnt_get_write_access_file(struct file *file);
77void mnt_put_write_access_file(struct file *file);
78
79extern void dissolve_on_fput(struct vfsmount *);
80extern bool may_mount(void);
81
82int path_mount(const char *dev_name, struct path *path,
83 const char *type_page, unsigned long flags, void *data_page);
84int path_umount(struct path *path, int flags);
85
86/*
87 * fs_struct.c
88 */
89extern void chroot_fs_refs(const struct path *, const struct path *);
90
91/*
92 * file_table.c
93 */
94struct file *alloc_empty_file(int flags, const struct cred *cred);
95struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);
96struct file *alloc_empty_backing_file(int flags, const struct cred *cred);
97void release_empty_file(struct file *f);
98
99static inline void file_put_write_access(struct file *file)
100{
101 put_write_access(inode: file->f_inode);
102 mnt_put_write_access(mnt: file->f_path.mnt);
103 if (unlikely(file->f_mode & FMODE_BACKING))
104 mnt_put_write_access(mnt: backing_file_user_path(f: file)->mnt);
105}
106
107static inline void put_file_access(struct file *file)
108{
109 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
110 i_readcount_dec(inode: file->f_inode);
111 } else if (file->f_mode & FMODE_WRITER) {
112 file_put_write_access(file);
113 }
114}
115
116/*
117 * super.c
118 */
119extern int reconfigure_super(struct fs_context *);
120extern bool super_trylock_shared(struct super_block *sb);
121struct super_block *user_get_super(dev_t, bool excl);
122void put_super(struct super_block *sb);
123extern bool mount_capable(struct fs_context *);
124int sb_init_dio_done_wq(struct super_block *sb);
125
126/*
127 * Prepare superblock for changing its read-only state (i.e., either remount
128 * read-write superblock read-only or vice versa). After this function returns
129 * mnt_is_readonly() will return true for any mount of the superblock if its
130 * caller is able to observe any changes done by the remount. This holds until
131 * sb_end_ro_state_change() is called.
132 */
133static inline void sb_start_ro_state_change(struct super_block *sb)
134{
135 WRITE_ONCE(sb->s_readonly_remount, 1);
136 /*
137 * For RO->RW transition, the barrier pairs with the barrier in
138 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY
139 * cleared, it will see s_readonly_remount set.
140 * For RW->RO transition, the barrier pairs with the barrier in
141 * mnt_get_write_access() before the mnt_is_readonly() check.
142 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD
143 * already cleared, it will see s_readonly_remount set.
144 */
145 smp_wmb();
146}
147
148/*
149 * Ends section changing read-only state of the superblock. After this function
150 * returns if mnt_is_readonly() returns false, the caller will be able to
151 * observe all the changes remount did to the superblock.
152 */
153static inline void sb_end_ro_state_change(struct super_block *sb)
154{
155 /*
156 * This barrier provides release semantics that pairs with
157 * the smp_rmb() acquire semantics in mnt_is_readonly().
158 * This barrier pair ensure that when mnt_is_readonly() sees
159 * 0 for sb->s_readonly_remount, it will also see all the
160 * preceding flag changes that were made during the RO state
161 * change.
162 */
163 smp_wmb();
164 WRITE_ONCE(sb->s_readonly_remount, 0);
165}
166
167/*
168 * open.c
169 */
170struct open_flags {
171 int open_flag;
172 umode_t mode;
173 int acc_mode;
174 int intent;
175 int lookup_flags;
176};
177extern struct file *do_filp_open(int dfd, struct filename *pathname,
178 const struct open_flags *op);
179extern struct file *do_file_open_root(const struct path *,
180 const char *, const struct open_flags *);
181extern struct open_how build_open_how(int flags, umode_t mode);
182extern int build_open_flags(const struct open_how *how, struct open_flags *op);
183extern struct file *__close_fd_get_file(unsigned int fd);
184
185long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
186int chmod_common(const struct path *path, umode_t mode);
187int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
188 int flag);
189int chown_common(const struct path *path, uid_t user, gid_t group);
190extern int vfs_open(const struct path *, struct file *);
191
192/*
193 * inode.c
194 */
195extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc);
196int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry);
197bool in_group_or_capable(struct mnt_idmap *idmap,
198 const struct inode *inode, vfsgid_t vfsgid);
199void lock_two_inodes(struct inode *inode1, struct inode *inode2,
200 unsigned subclass1, unsigned subclass2);
201
202/*
203 * fs-writeback.c
204 */
205extern long get_nr_dirty_inodes(void);
206void invalidate_inodes(struct super_block *sb);
207
208/*
209 * dcache.c
210 */
211extern int d_set_mounted(struct dentry *dentry);
212extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
213extern struct dentry *d_alloc_cursor(struct dentry *);
214extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
215extern char *simple_dname(struct dentry *, char *, int);
216extern void dput_to_list(struct dentry *, struct list_head *);
217extern void shrink_dentry_list(struct list_head *);
218
219/*
220 * pipe.c
221 */
222extern const struct file_operations pipefifo_fops;
223
224/*
225 * fs_pin.c
226 */
227extern void group_pin_kill(struct hlist_head *p);
228extern void mnt_pin_kill(struct mount *m);
229
230/*
231 * fs/nsfs.c
232 */
233extern const struct dentry_operations ns_dentry_operations;
234
235/*
236 * fs/stat.c:
237 */
238
239int getname_statx_lookup_flags(int flags);
240int do_statx(int dfd, struct filename *filename, unsigned int flags,
241 unsigned int mask, struct statx __user *buffer);
242
243/*
244 * fs/splice.c:
245 */
246long splice_file_to_pipe(struct file *in,
247 struct pipe_inode_info *opipe,
248 loff_t *offset,
249 size_t len, unsigned int flags);
250
251/*
252 * fs/xattr.c:
253 */
254struct xattr_name {
255 char name[XATTR_NAME_MAX + 1];
256};
257
258struct xattr_ctx {
259 /* Value of attribute */
260 union {
261 const void __user *cvalue;
262 void __user *value;
263 };
264 void *kvalue;
265 size_t size;
266 /* Attribute name */
267 struct xattr_name *kname;
268 unsigned int flags;
269};
270
271
272ssize_t do_getxattr(struct mnt_idmap *idmap,
273 struct dentry *d,
274 struct xattr_ctx *ctx);
275
276int setxattr_copy(const char __user *name, struct xattr_ctx *ctx);
277int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
278 struct xattr_ctx *ctx);
279int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);
280
281#ifdef CONFIG_FS_POSIX_ACL
282int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
283 const char *acl_name, const void *kvalue, size_t size);
284ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
285 const char *acl_name, void *kvalue, size_t size);
286#else
287static inline int do_set_acl(struct mnt_idmap *idmap,
288 struct dentry *dentry, const char *acl_name,
289 const void *kvalue, size_t size)
290{
291 return -EOPNOTSUPP;
292}
293static inline ssize_t do_get_acl(struct mnt_idmap *idmap,
294 struct dentry *dentry, const char *acl_name,
295 void *kvalue, size_t size)
296{
297 return -EOPNOTSUPP;
298}
299#endif
300
301ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos);
302
303/*
304 * fs/attr.c
305 */
306struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
307struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
308void mnt_idmap_put(struct mnt_idmap *idmap);
309

source code of linux/fs/internal.h