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 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); 102 103 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 } 110 111 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 */ 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 */ 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 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 } 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