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 98 static inline void file_put_write_access(struct file *file) 99 { 100 put_write_access(file->f_inode); 101 mnt_put_write_access(file->f_path.mnt); 102 if (unlikely(file->f_mode & FMODE_BACKING)) 103 mnt_put_write_access(backing_file_user_path(file)->mnt); 104 } 105 106 static inline void put_file_access(struct file *file) 107 { 108 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) { 109 i_readcount_dec(file->f_inode); 110 } else if (file->f_mode & FMODE_WRITER) { 111 file_put_write_access(file); 112 } 113 } 114 115 /* 116 * super.c 117 */ 118 extern int reconfigure_super(struct fs_context *); 119 extern bool super_trylock_shared(struct super_block *sb); 120 struct super_block *user_get_super(dev_t, bool excl); 121 void put_super(struct super_block *sb); 122 extern bool mount_capable(struct fs_context *); 123 int sb_init_dio_done_wq(struct super_block *sb); 124 125 /* 126 * Prepare superblock for changing its read-only state (i.e., either remount 127 * read-write superblock read-only or vice versa). After this function returns 128 * mnt_is_readonly() will return true for any mount of the superblock if its 129 * caller is able to observe any changes done by the remount. This holds until 130 * sb_end_ro_state_change() is called. 131 */ 132 static inline void sb_start_ro_state_change(struct super_block *sb) 133 { 134 WRITE_ONCE(sb->s_readonly_remount, 1); 135 /* 136 * For RO->RW transition, the barrier pairs with the barrier in 137 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY 138 * cleared, it will see s_readonly_remount set. 139 * For RW->RO transition, the barrier pairs with the barrier in 140 * mnt_get_write_access() before the mnt_is_readonly() check. 141 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD 142 * already cleared, it will see s_readonly_remount set. 143 */ 144 smp_wmb(); 145 } 146 147 /* 148 * Ends section changing read-only state of the superblock. After this function 149 * returns if mnt_is_readonly() returns false, the caller will be able to 150 * observe all the changes remount did to the superblock. 151 */ 152 static inline void sb_end_ro_state_change(struct super_block *sb) 153 { 154 /* 155 * This barrier provides release semantics that pairs with 156 * the smp_rmb() acquire semantics in mnt_is_readonly(). 157 * This barrier pair ensure that when mnt_is_readonly() sees 158 * 0 for sb->s_readonly_remount, it will also see all the 159 * preceding flag changes that were made during the RO state 160 * change. 161 */ 162 smp_wmb(); 163 WRITE_ONCE(sb->s_readonly_remount, 0); 164 } 165 166 /* 167 * open.c 168 */ 169 struct open_flags { 170 int open_flag; 171 umode_t mode; 172 int acc_mode; 173 int intent; 174 int lookup_flags; 175 }; 176 extern struct file *do_filp_open(int dfd, struct filename *pathname, 177 const struct open_flags *op); 178 extern struct file *do_file_open_root(const struct path *, 179 const char *, const struct open_flags *); 180 extern struct open_how build_open_how(int flags, umode_t mode); 181 extern int build_open_flags(const struct open_how *how, struct open_flags *op); 182 struct file *file_close_fd_locked(struct files_struct *files, unsigned fd); 183 184 long do_sys_ftruncate(unsigned int fd, loff_t length, int small); 185 int chmod_common(const struct path *path, umode_t mode); 186 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, 187 int flag); 188 int chown_common(const struct path *path, uid_t user, gid_t group); 189 extern int vfs_open(const struct path *, struct file *); 190 191 /* 192 * inode.c 193 */ 194 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc); 195 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry); 196 bool in_group_or_capable(struct mnt_idmap *idmap, 197 const struct inode *inode, vfsgid_t vfsgid); 198 void lock_two_inodes(struct inode *inode1, struct inode *inode2, 199 unsigned subclass1, unsigned subclass2); 200 201 /* 202 * fs-writeback.c 203 */ 204 extern long get_nr_dirty_inodes(void); 205 void invalidate_inodes(struct super_block *sb); 206 207 /* 208 * dcache.c 209 */ 210 extern int d_set_mounted(struct dentry *dentry); 211 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc); 212 extern struct dentry *d_alloc_cursor(struct dentry *); 213 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); 214 extern char *simple_dname(struct dentry *, char *, int); 215 extern void dput_to_list(struct dentry *, struct list_head *); 216 extern void shrink_dentry_list(struct list_head *); 217 218 /* 219 * pipe.c 220 */ 221 extern const struct file_operations pipefifo_fops; 222 223 /* 224 * fs_pin.c 225 */ 226 extern void group_pin_kill(struct hlist_head *p); 227 extern void mnt_pin_kill(struct mount *m); 228 229 /* 230 * fs/nsfs.c 231 */ 232 extern const struct dentry_operations ns_dentry_operations; 233 234 /* 235 * fs/stat.c: 236 */ 237 238 int getname_statx_lookup_flags(int flags); 239 int do_statx(int dfd, struct filename *filename, unsigned int flags, 240 unsigned int mask, struct statx __user *buffer); 241 242 /* 243 * fs/splice.c: 244 */ 245 long splice_file_to_pipe(struct file *in, 246 struct pipe_inode_info *opipe, 247 loff_t *offset, 248 size_t len, unsigned int flags); 249 250 /* 251 * fs/xattr.c: 252 */ 253 struct xattr_name { 254 char name[XATTR_NAME_MAX + 1]; 255 }; 256 257 struct xattr_ctx { 258 /* Value of attribute */ 259 union { 260 const void __user *cvalue; 261 void __user *value; 262 }; 263 void *kvalue; 264 size_t size; 265 /* Attribute name */ 266 struct xattr_name *kname; 267 unsigned int flags; 268 }; 269 270 271 ssize_t do_getxattr(struct mnt_idmap *idmap, 272 struct dentry *d, 273 struct xattr_ctx *ctx); 274 275 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx); 276 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, 277 struct xattr_ctx *ctx); 278 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode); 279 280 #ifdef CONFIG_FS_POSIX_ACL 281 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 282 const char *acl_name, const void *kvalue, size_t size); 283 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, 284 const char *acl_name, void *kvalue, size_t size); 285 #else 286 static inline int do_set_acl(struct mnt_idmap *idmap, 287 struct dentry *dentry, const char *acl_name, 288 const void *kvalue, size_t size) 289 { 290 return -EOPNOTSUPP; 291 } 292 static inline ssize_t do_get_acl(struct mnt_idmap *idmap, 293 struct dentry *dentry, const char *acl_name, 294 void *kvalue, size_t size) 295 { 296 return -EOPNOTSUPP; 297 } 298 #endif 299 300 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos); 301 302 /* 303 * fs/attr.c 304 */ 305 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns); 306 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap); 307 void mnt_idmap_put(struct mnt_idmap *idmap); 308