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