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 extern int __mnt_want_write_file(struct file *); 77 extern void __mnt_drop_write_file(struct 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 put_file_access(struct file *file) 99 { 100 if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) { 101 i_readcount_dec(file->f_inode); 102 } else if (file->f_mode & FMODE_WRITER) { 103 put_write_access(file->f_inode); 104 __mnt_drop_write(file->f_path.mnt); 105 } 106 } 107 108 /* 109 * super.c 110 */ 111 extern int reconfigure_super(struct fs_context *); 112 extern bool super_trylock_shared(struct super_block *sb); 113 struct super_block *user_get_super(dev_t, bool excl); 114 void put_super(struct super_block *sb); 115 extern bool mount_capable(struct fs_context *); 116 int sb_init_dio_done_wq(struct super_block *sb); 117 118 /* 119 * Prepare superblock for changing its read-only state (i.e., either remount 120 * read-write superblock read-only or vice versa). After this function returns 121 * mnt_is_readonly() will return true for any mount of the superblock if its 122 * caller is able to observe any changes done by the remount. This holds until 123 * sb_end_ro_state_change() is called. 124 */ 125 static inline void sb_start_ro_state_change(struct super_block *sb) 126 { 127 WRITE_ONCE(sb->s_readonly_remount, 1); 128 /* 129 * For RO->RW transition, the barrier pairs with the barrier in 130 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY 131 * cleared, it will see s_readonly_remount set. 132 * For RW->RO transition, the barrier pairs with the barrier in 133 * __mnt_want_write() before the mnt_is_readonly() check. The barrier 134 * makes sure if __mnt_want_write() sees MNT_WRITE_HOLD already 135 * cleared, it will see s_readonly_remount set. 136 */ 137 smp_wmb(); 138 } 139 140 /* 141 * Ends section changing read-only state of the superblock. After this function 142 * returns if mnt_is_readonly() returns false, the caller will be able to 143 * observe all the changes remount did to the superblock. 144 */ 145 static inline void sb_end_ro_state_change(struct super_block *sb) 146 { 147 /* 148 * This barrier provides release semantics that pairs with 149 * the smp_rmb() acquire semantics in mnt_is_readonly(). 150 * This barrier pair ensure that when mnt_is_readonly() sees 151 * 0 for sb->s_readonly_remount, it will also see all the 152 * preceding flag changes that were made during the RO state 153 * change. 154 */ 155 smp_wmb(); 156 WRITE_ONCE(sb->s_readonly_remount, 0); 157 } 158 159 /* 160 * open.c 161 */ 162 struct open_flags { 163 int open_flag; 164 umode_t mode; 165 int acc_mode; 166 int intent; 167 int lookup_flags; 168 }; 169 extern struct file *do_filp_open(int dfd, struct filename *pathname, 170 const struct open_flags *op); 171 extern struct file *do_file_open_root(const struct path *, 172 const char *, const struct open_flags *); 173 extern struct open_how build_open_how(int flags, umode_t mode); 174 extern int build_open_flags(const struct open_how *how, struct open_flags *op); 175 extern struct file *__close_fd_get_file(unsigned int fd); 176 177 long do_sys_ftruncate(unsigned int fd, loff_t length, int small); 178 int chmod_common(const struct path *path, umode_t mode); 179 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, 180 int flag); 181 int chown_common(const struct path *path, uid_t user, gid_t group); 182 extern int vfs_open(const struct path *, struct file *); 183 184 /* 185 * inode.c 186 */ 187 extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc); 188 int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry); 189 bool in_group_or_capable(struct mnt_idmap *idmap, 190 const struct inode *inode, vfsgid_t vfsgid); 191 void lock_two_inodes(struct inode *inode1, struct inode *inode2, 192 unsigned subclass1, unsigned subclass2); 193 194 /* 195 * fs-writeback.c 196 */ 197 extern long get_nr_dirty_inodes(void); 198 void invalidate_inodes(struct super_block *sb); 199 200 /* 201 * dcache.c 202 */ 203 extern int d_set_mounted(struct dentry *dentry); 204 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc); 205 extern struct dentry *d_alloc_cursor(struct dentry *); 206 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); 207 extern char *simple_dname(struct dentry *, char *, int); 208 extern void dput_to_list(struct dentry *, struct list_head *); 209 extern void shrink_dentry_list(struct list_head *); 210 211 /* 212 * pipe.c 213 */ 214 extern const struct file_operations pipefifo_fops; 215 216 /* 217 * fs_pin.c 218 */ 219 extern void group_pin_kill(struct hlist_head *p); 220 extern void mnt_pin_kill(struct mount *m); 221 222 /* 223 * fs/nsfs.c 224 */ 225 extern const struct dentry_operations ns_dentry_operations; 226 227 /* 228 * fs/stat.c: 229 */ 230 231 int getname_statx_lookup_flags(int flags); 232 int do_statx(int dfd, struct filename *filename, unsigned int flags, 233 unsigned int mask, struct statx __user *buffer); 234 235 /* 236 * fs/splice.c: 237 */ 238 long splice_file_to_pipe(struct file *in, 239 struct pipe_inode_info *opipe, 240 loff_t *offset, 241 size_t len, unsigned int flags); 242 243 /* 244 * fs/xattr.c: 245 */ 246 struct xattr_name { 247 char name[XATTR_NAME_MAX + 1]; 248 }; 249 250 struct xattr_ctx { 251 /* Value of attribute */ 252 union { 253 const void __user *cvalue; 254 void __user *value; 255 }; 256 void *kvalue; 257 size_t size; 258 /* Attribute name */ 259 struct xattr_name *kname; 260 unsigned int flags; 261 }; 262 263 264 ssize_t do_getxattr(struct mnt_idmap *idmap, 265 struct dentry *d, 266 struct xattr_ctx *ctx); 267 268 int setxattr_copy(const char __user *name, struct xattr_ctx *ctx); 269 int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, 270 struct xattr_ctx *ctx); 271 int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode); 272 273 #ifdef CONFIG_FS_POSIX_ACL 274 int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 275 const char *acl_name, const void *kvalue, size_t size); 276 ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, 277 const char *acl_name, void *kvalue, size_t size); 278 #else 279 static inline int do_set_acl(struct mnt_idmap *idmap, 280 struct dentry *dentry, const char *acl_name, 281 const void *kvalue, size_t size) 282 { 283 return -EOPNOTSUPP; 284 } 285 static inline ssize_t do_get_acl(struct mnt_idmap *idmap, 286 struct dentry *dentry, const char *acl_name, 287 void *kvalue, size_t size) 288 { 289 return -EOPNOTSUPP; 290 } 291 #endif 292 293 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos); 294 295 /* 296 * fs/attr.c 297 */ 298 struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns); 299 struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap); 300 void mnt_idmap_put(struct mnt_idmap *idmap); 301