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 ([email protected]) 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 /* 87 * fs_struct.c 88 */ 89 extern void chroot_fs_refs(const struct path *, const struct path *); 90 91 /* 92 * file_table.c 93 */ 94 struct file *alloc_empty_file(int flags, const struct cred *cred); 95 struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred); 96 struct file *alloc_empty_backing_file(int flags, const struct cred *cred); 97 void release_empty_file(struct file *f); 98 99 static inline void file_put_write_access(struct file *file) 100 { 101 put_write_access(file->f_inode); 102 mnt_put_write_access(file->f_path.mnt); 103 if (unlikely(file->f_mode & FMODE_BACKING)) 104 mnt_put_write_access(backing_file_user_path(file)->mnt); 105 } 106 107 static inline void put_file_access(struct file *file) 108 { 109 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) { 110 i_readcount_dec(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 */ 119 extern int reconfigure_super(struct fs_context *); 120 extern bool super_trylock_shared(struct super_block *sb); 121 struct super_block *user_get_super(dev_t, bool excl); 122 void put_super(struct super_block *sb); 123 extern bool mount_capable(struct fs_context *); 124 int 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 */ 133 static 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 */ 153 static 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 */ 170 struct open_flags { 171 int open_flag; 172 umode_t mode; 173 int acc_mode; 174 int intent; 175 int lookup_flags; 176 }; 177 extern struct file *do_filp_open(int dfd, struct filename *pathname, 178 const struct open_flags *op); 179 extern struct file *do_file_open_root(const struct path *, 180 const char *, const struct open_flags *); 181 extern struct open_how build_open_how(int flags, umode_t mode); 182 extern int build_open_flags(const struct open_how *how, struct open_flags *op); 183 extern struct file *__close_fd_get_file(unsigned int fd); 184 185 long do_sys_ftruncate(unsigned int fd, loff_t length, int small); 186 int chmod_common(const struct path *path, umode_t mode); 187 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, 188 int flag); 189 int chown_common(const struct path *path, uid_t user, gid_t group); 190 extern int vfs_open(const struct path *, struct file *); 191 192 /* 193 * inode.c 194 */ 195 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc); 196 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry); 197 bool in_group_or_capable(struct mnt_idmap *idmap, 198 const struct inode *inode, vfsgid_t vfsgid); 199 200 /* 201 * fs-writeback.c 202 */ 203 extern long get_nr_dirty_inodes(void); 204 void invalidate_inodes(struct super_block *sb); 205 206 /* 207 * dcache.c 208 */ 209 extern int d_set_mounted(struct dentry *dentry); 210 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc); 211 extern struct dentry *d_alloc_cursor(struct dentry *); 212 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); 213 extern char *simple_dname(struct dentry *, char *, int); 214 extern void dput_to_list(struct dentry *, struct list_head *); 215 extern void shrink_dentry_list(struct list_head *); 216 217 /* 218 * pipe.c 219 */ 220 extern const struct file_operations pipefifo_fops; 221 222 /* 223 * fs_pin.c 224 */ 225 extern void group_pin_kill(struct hlist_head *p); 226 extern void mnt_pin_kill(struct mount *m); 227 228 /* 229 * fs/nsfs.c 230 */ 231 extern const struct dentry_operations ns_dentry_operations; 232 233 /* 234 * fs/stat.c: 235 */ 236 237 int getname_statx_lookup_flags(int flags); 238 int do_statx(int dfd, struct filename *filename, unsigned int flags, 239 unsigned int mask, struct statx __user *buffer); 240 241 /* 242 * fs/splice.c: 243 */ 244 long splice_file_to_pipe(struct file *in, 245 struct pipe_inode_info *opipe, 246 loff_t *offset, 247 size_t len, unsigned int flags); 248 249 /* 250 * fs/xattr.c: 251 */ 252 struct xattr_name { 253 char name[XATTR_NAME_MAX + 1]; 254 }; 255 256 struct xattr_ctx { 257 /* Value of attribute */ 258 union { 259 const void __user *cvalue; 260 void __user *value; 261 }; 262 void *kvalue; 263 size_t size; 264 /* Attribute name */ 265 struct xattr_name *kname; 266 unsigned int flags; 267 }; 268 269 270 ssize_t do_getxattr(struct mnt_idmap *idmap, 271 struct dentry *d, 272 struct xattr_ctx *ctx); 273 274 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx); 275 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, 276 struct xattr_ctx *ctx); 277 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode); 278 279 #ifdef CONFIG_FS_POSIX_ACL 280 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 281 const char *acl_name, const void *kvalue, size_t size); 282 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, 283 const char *acl_name, void *kvalue, size_t size); 284 #else 285 static inline int do_set_acl(struct mnt_idmap *idmap, 286 struct dentry *dentry, const char *acl_name, 287 const void *kvalue, size_t size) 288 { 289 return -EOPNOTSUPP; 290 } 291 static inline ssize_t do_get_acl(struct mnt_idmap *idmap, 292 struct dentry *dentry, const char *acl_name, 293 void *kvalue, size_t size) 294 { 295 return -EOPNOTSUPP; 296 } 297 #endif 298 299 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos); 300 301 /* 302 * fs/attr.c 303 */ 304 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns); 305 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap); 306 void mnt_idmap_put(struct mnt_idmap *idmap); 307