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 struct ns_common; 21 22 /* 23 * block/bdev.c 24 */ 25 #ifdef CONFIG_BLOCK 26 extern void __init bdev_cache_init(void); 27 #else 28 static inline void bdev_cache_init(void) 29 { 30 } 31 #endif /* CONFIG_BLOCK */ 32 33 /* 34 * buffer.c 35 */ 36 int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len, 37 get_block_t *get_block, const struct iomap *iomap); 38 39 /* 40 * char_dev.c 41 */ 42 extern void __init chrdev_init(void); 43 44 /* 45 * fs_context.c 46 */ 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, const struct path *root); 56 int filename_rmdir(int dfd, struct filename *name); 57 int filename_unlinkat(int dfd, struct filename *name); 58 int may_linkat(struct mnt_idmap *idmap, const struct path *link); 59 int filename_renameat2(int olddfd, struct filename *oldname, int newdfd, 60 struct filename *newname, unsigned int flags); 61 int filename_mkdirat(int dfd, struct filename *name, umode_t mode); 62 int filename_mknodat(int dfd, struct filename *name, umode_t mode, unsigned int dev); 63 int filename_symlinkat(struct filename *from, int newdfd, struct filename *to); 64 int filename_linkat(int olddfd, struct filename *old, int newdfd, 65 struct filename *new, int flags); 66 int vfs_tmpfile(struct mnt_idmap *idmap, 67 const struct path *parentpath, 68 struct file *file, umode_t mode); 69 struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *); 70 struct dentry *start_dirop(struct dentry *parent, struct qstr *name, 71 unsigned int lookup_flags); 72 int lookup_noperm_common(struct qstr *qname, struct dentry *base); 73 74 void __init filename_init(void); 75 76 /* 77 * namespace.c 78 */ 79 extern struct vfsmount *lookup_mnt(const struct path *); 80 extern int finish_automount(struct vfsmount *, const struct path *); 81 82 extern int sb_prepare_remount_readonly(struct super_block *); 83 84 extern void __init mnt_init(void); 85 86 int mnt_get_write_access_file(struct file *file); 87 void mnt_put_write_access_file(struct file *file); 88 89 extern void dissolve_on_fput(struct vfsmount *); 90 extern bool may_mount(void); 91 92 int path_mount(const char *dev_name, const struct path *path, 93 const char *type_page, unsigned long flags, void *data_page); 94 int path_umount(const struct path *path, int flags); 95 int path_pivot_root(struct path *new, struct path *old); 96 97 int show_path(struct seq_file *m, struct dentry *root); 98 99 /* 100 * fs_struct.c 101 */ 102 extern void chroot_fs_refs(const struct path *, const struct path *); 103 104 /* 105 * file_table.c 106 */ 107 struct file *alloc_empty_file(int flags, const struct cred *cred); 108 struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred); 109 struct file *alloc_empty_backing_file(int flags, const struct cred *cred, 110 const struct file *user_file); 111 void backing_file_set_user_path(struct file *f, const struct path *path); 112 113 static inline void file_put_write_access(struct file *file) 114 { 115 put_write_access(file->f_inode); 116 mnt_put_write_access(file->f_path.mnt); 117 if (unlikely(file->f_mode & FMODE_BACKING)) 118 mnt_put_write_access(backing_file_user_path(file)->mnt); 119 } 120 121 static inline void put_file_access(struct file *file) 122 { 123 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) { 124 i_readcount_dec(file->f_inode); 125 } else if (file->f_mode & FMODE_WRITER) { 126 file_put_write_access(file); 127 } 128 } 129 130 void fput_close_sync(struct file *); 131 void fput_close(struct file *); 132 133 /* 134 * super.c 135 */ 136 extern int reconfigure_super(struct fs_context *); 137 extern bool super_trylock_shared(struct super_block *sb); 138 struct super_block *user_get_super(dev_t, bool excl); 139 void put_super(struct super_block *sb); 140 extern bool mount_capable(struct fs_context *); 141 int sb_init_dio_done_wq(struct super_block *sb); 142 143 /* 144 * Prepare superblock for changing its read-only state (i.e., either remount 145 * read-write superblock read-only or vice versa). After this function returns 146 * mnt_is_readonly() will return true for any mount of the superblock if its 147 * caller is able to observe any changes done by the remount. This holds until 148 * sb_end_ro_state_change() is called. 149 */ 150 static inline void sb_start_ro_state_change(struct super_block *sb) 151 { 152 WRITE_ONCE(sb->s_readonly_remount, 1); 153 /* 154 * For RO->RW transition, the barrier pairs with the barrier in 155 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY 156 * cleared, it will see s_readonly_remount set. 157 * For RW->RO transition, the barrier pairs with the barrier in 158 * mnt_get_write_access() before the mnt_is_readonly() check. 159 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD 160 * already cleared, it will see s_readonly_remount set. 161 */ 162 smp_wmb(); 163 } 164 165 /* 166 * Ends section changing read-only state of the superblock. After this function 167 * returns if mnt_is_readonly() returns false, the caller will be able to 168 * observe all the changes remount did to the superblock. 169 */ 170 static inline void sb_end_ro_state_change(struct super_block *sb) 171 { 172 /* 173 * This barrier provides release semantics that pairs with 174 * the smp_rmb() acquire semantics in mnt_is_readonly(). 175 * This barrier pair ensure that when mnt_is_readonly() sees 176 * 0 for sb->s_readonly_remount, it will also see all the 177 * preceding flag changes that were made during the RO state 178 * change. 179 */ 180 smp_wmb(); 181 WRITE_ONCE(sb->s_readonly_remount, 0); 182 } 183 184 /* 185 * open.c 186 */ 187 struct open_flags { 188 int open_flag; 189 umode_t mode; 190 int acc_mode; 191 int intent; 192 int lookup_flags; 193 }; 194 extern struct file *do_file_open(int dfd, struct filename *pathname, 195 const struct open_flags *op); 196 extern struct file *do_file_open_root(const struct path *, 197 const char *, const struct open_flags *); 198 extern struct open_how build_open_how(int flags, umode_t mode); 199 extern int build_open_flags(const struct open_how *how, struct open_flags *op); 200 struct file *file_close_fd_locked(struct files_struct *files, unsigned fd); 201 202 int do_ftruncate(struct file *file, loff_t length, unsigned int flags); 203 int chmod_common(const struct path *path, umode_t mode); 204 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, 205 int flag); 206 int chown_common(const struct path *path, uid_t user, gid_t group); 207 extern int vfs_open(const struct path *, struct file *); 208 209 /* 210 * inode.c 211 */ 212 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc); 213 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry); 214 bool in_group_or_capable(struct mnt_idmap *idmap, 215 const struct inode *inode, vfsgid_t vfsgid); 216 217 /* 218 * fs-writeback.c 219 */ 220 long get_nr_dirty_inodes(void); 221 bool sync_lazytime(struct inode *inode); 222 223 /* 224 * dcache.c 225 */ 226 extern int d_set_mounted(struct dentry *dentry); 227 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc); 228 extern struct dentry *d_alloc_cursor(struct dentry *); 229 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); 230 extern char *simple_dname(struct dentry *, char *, int); 231 extern void dput_to_list(struct dentry *, struct list_head *); 232 extern void shrink_dentry_list(struct list_head *); 233 extern void shrink_dcache_for_umount(struct super_block *); 234 extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *); 235 extern struct dentry *__d_lookup_rcu(const struct dentry *parent, 236 const struct qstr *name, unsigned *seq); 237 238 /* 239 * pipe.c 240 */ 241 extern const struct file_operations pipefifo_fops; 242 243 /* 244 * fs_pin.c 245 */ 246 extern void group_pin_kill(struct hlist_head *p); 247 extern void mnt_pin_kill(struct mount *m); 248 249 /* 250 * fs/nsfs.c 251 */ 252 extern const struct dentry_operations ns_dentry_operations; 253 int open_namespace(struct ns_common *ns); 254 struct file *open_namespace_file(struct ns_common *ns); 255 256 /* 257 * fs/stat.c: 258 */ 259 260 int do_statx(int dfd, struct filename *filename, unsigned int flags, 261 unsigned int mask, struct statx __user *buffer); 262 int do_statx_fd(int fd, unsigned int flags, unsigned int mask, 263 struct statx __user *buffer); 264 265 /* 266 * fs/splice.c: 267 */ 268 ssize_t splice_file_to_pipe(struct file *in, 269 struct pipe_inode_info *opipe, 270 loff_t *offset, 271 size_t len, unsigned int flags); 272 273 /* 274 * fs/xattr.c: 275 */ 276 struct xattr_name { 277 char name[XATTR_NAME_MAX + 1]; 278 }; 279 280 struct kernel_xattr_ctx { 281 /* Value of attribute */ 282 union { 283 const void __user *cvalue; 284 void __user *value; 285 }; 286 void *kvalue; 287 size_t size; 288 /* Attribute name */ 289 struct xattr_name *kname; 290 unsigned int flags; 291 }; 292 293 ssize_t file_getxattr(struct file *file, struct kernel_xattr_ctx *ctx); 294 ssize_t filename_getxattr(int dfd, struct filename *filename, 295 unsigned int lookup_flags, struct kernel_xattr_ctx *ctx); 296 int file_setxattr(struct file *file, struct kernel_xattr_ctx *ctx); 297 int filename_setxattr(int dfd, struct filename *filename, 298 unsigned int lookup_flags, struct kernel_xattr_ctx *ctx); 299 int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx); 300 int import_xattr_name(struct xattr_name *kname, const char __user *name); 301 302 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode); 303 304 #ifdef CONFIG_FS_POSIX_ACL 305 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 306 const char *acl_name, const void *kvalue, size_t size); 307 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, 308 const char *acl_name, void *kvalue, size_t size); 309 #else 310 static inline int do_set_acl(struct mnt_idmap *idmap, 311 struct dentry *dentry, const char *acl_name, 312 const void *kvalue, size_t size) 313 { 314 return -EOPNOTSUPP; 315 } 316 static inline ssize_t do_get_acl(struct mnt_idmap *idmap, 317 struct dentry *dentry, const char *acl_name, 318 void *kvalue, size_t size) 319 { 320 return -EOPNOTSUPP; 321 } 322 #endif 323 324 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos); 325 326 /* 327 * fs/attr.c 328 */ 329 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns); 330 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap); 331 void mnt_idmap_put(struct mnt_idmap *idmap); 332 struct stashed_operations { 333 struct dentry *(*stash_dentry)(struct dentry **stashed, 334 struct dentry *dentry); 335 void (*put_data)(void *data); 336 int (*init_inode)(struct inode *inode, void *data); 337 }; 338 int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data, 339 struct path *path); 340 void stashed_dentry_prune(struct dentry *dentry); 341 struct dentry *stash_dentry(struct dentry **stashed, struct dentry *dentry); 342 struct dentry *stashed_dentry_get(struct dentry **stashed); 343 /** 344 * path_mounted - check whether path is mounted 345 * @path: path to check 346 * 347 * Determine whether @path refers to the root of a mount. 348 * 349 * Return: true if @path is the root of a mount, false if not. 350 */ 351 static inline bool path_mounted(const struct path *path) 352 { 353 return path->mnt->mnt_root == path->dentry; 354 } 355 void file_f_owner_release(struct file *file); 356 bool file_seek_cur_needs_f_lock(struct file *file); 357 int statmount_mnt_idmap(struct mnt_idmap *idmap, struct seq_file *seq, bool uid_map); 358 struct dentry *find_next_child(struct dentry *parent, struct dentry *prev); 359 int anon_inode_getattr(struct mnt_idmap *idmap, const struct path *path, 360 struct kstat *stat, u32 request_mask, 361 unsigned int query_flags); 362 int anon_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 363 struct iattr *attr); 364 void pidfs_get_root(struct path *path); 365 void nsfs_get_root(struct path *path); 366