1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ufs/namei.c 4 * 5 * Migration to usage of "page cache" on May 2006 by 6 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base. 7 * 8 * Copyright (C) 1998 9 * Daniel Pirkl <daniel.pirkl@email.cz> 10 * Charles University, Faculty of Mathematics and Physics 11 * 12 * from 13 * 14 * linux/fs/ext2/namei.c 15 * 16 * Copyright (C) 1992, 1993, 1994, 1995 17 * Remy Card (card@masi.ibp.fr) 18 * Laboratoire MASI - Institut Blaise Pascal 19 * Universite Pierre et Marie Curie (Paris VI) 20 * 21 * from 22 * 23 * linux/fs/minix/namei.c 24 * 25 * Copyright (C) 1991, 1992 Linus Torvalds 26 * 27 * Big-endian to little-endian byte-swapping/bitmaps by 28 * David S. Miller (davem@caip.rutgers.edu), 1995 29 */ 30 31 #include <linux/time.h> 32 #include <linux/fs.h> 33 34 #include "ufs_fs.h" 35 #include "ufs.h" 36 #include "util.h" 37 38 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode) 39 { 40 int err = ufs_add_link(dentry, inode); 41 if (!err) { 42 d_instantiate_new(dentry, inode); 43 return 0; 44 } 45 inode_dec_link_count(inode); 46 discard_new_inode(inode); 47 return err; 48 } 49 50 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) 51 { 52 struct inode * inode = NULL; 53 ino_t ino; 54 55 if (dentry->d_name.len > UFS_MAXNAMLEN) 56 return ERR_PTR(-ENAMETOOLONG); 57 58 ino = ufs_inode_by_name(dir, &dentry->d_name); 59 if (ino) 60 inode = ufs_iget(dir->i_sb, ino); 61 return d_splice_alias(inode, dentry); 62 } 63 64 /* 65 * By the time this is called, we already have created 66 * the directory cache entry for the new file, but it 67 * is so far negative - it has no inode. 68 * 69 * If the create succeeds, we fill in the inode information 70 * with d_instantiate(). 71 */ 72 static int ufs_create (struct mnt_idmap * idmap, 73 struct inode * dir, struct dentry * dentry, umode_t mode, 74 bool excl) 75 { 76 struct inode *inode; 77 78 inode = ufs_new_inode(dir, mode); 79 if (IS_ERR(inode)) 80 return PTR_ERR(inode); 81 82 inode->i_op = &ufs_file_inode_operations; 83 inode->i_fop = &ufs_file_operations; 84 inode->i_mapping->a_ops = &ufs_aops; 85 mark_inode_dirty(inode); 86 return ufs_add_nondir(dentry, inode); 87 } 88 89 static int ufs_mknod(struct mnt_idmap *idmap, struct inode *dir, 90 struct dentry *dentry, umode_t mode, dev_t rdev) 91 { 92 struct inode *inode; 93 int err; 94 95 if (!old_valid_dev(rdev)) 96 return -EINVAL; 97 98 inode = ufs_new_inode(dir, mode); 99 err = PTR_ERR(inode); 100 if (!IS_ERR(inode)) { 101 init_special_inode(inode, mode, rdev); 102 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev); 103 mark_inode_dirty(inode); 104 err = ufs_add_nondir(dentry, inode); 105 } 106 return err; 107 } 108 109 static int ufs_symlink (struct mnt_idmap * idmap, struct inode * dir, 110 struct dentry * dentry, const char * symname) 111 { 112 struct super_block * sb = dir->i_sb; 113 int err; 114 unsigned l = strlen(symname)+1; 115 struct inode * inode; 116 117 if (l > sb->s_blocksize) 118 return -ENAMETOOLONG; 119 120 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); 121 err = PTR_ERR(inode); 122 if (IS_ERR(inode)) 123 return err; 124 125 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) { 126 /* slow symlink */ 127 inode->i_op = &page_symlink_inode_operations; 128 inode_nohighmem(inode); 129 inode->i_mapping->a_ops = &ufs_aops; 130 err = page_symlink(inode, symname, l); 131 if (err) 132 goto out_fail; 133 } else { 134 /* fast symlink */ 135 inode->i_op = &simple_symlink_inode_operations; 136 inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink; 137 memcpy(inode->i_link, symname, l); 138 inode->i_size = l-1; 139 } 140 mark_inode_dirty(inode); 141 142 return ufs_add_nondir(dentry, inode); 143 144 out_fail: 145 inode_dec_link_count(inode); 146 discard_new_inode(inode); 147 return err; 148 } 149 150 static int ufs_link (struct dentry * old_dentry, struct inode * dir, 151 struct dentry *dentry) 152 { 153 struct inode *inode = d_inode(old_dentry); 154 int error; 155 156 inode->i_ctime = current_time(inode); 157 inode_inc_link_count(inode); 158 ihold(inode); 159 160 error = ufs_add_link(dentry, inode); 161 if (error) { 162 inode_dec_link_count(inode); 163 iput(inode); 164 } else 165 d_instantiate(dentry, inode); 166 return error; 167 } 168 169 static int ufs_mkdir(struct mnt_idmap * idmap, struct inode * dir, 170 struct dentry * dentry, umode_t mode) 171 { 172 struct inode * inode; 173 int err; 174 175 inode_inc_link_count(dir); 176 177 inode = ufs_new_inode(dir, S_IFDIR|mode); 178 err = PTR_ERR(inode); 179 if (IS_ERR(inode)) 180 goto out_dir; 181 182 inode->i_op = &ufs_dir_inode_operations; 183 inode->i_fop = &ufs_dir_operations; 184 inode->i_mapping->a_ops = &ufs_aops; 185 186 inode_inc_link_count(inode); 187 188 err = ufs_make_empty(inode, dir); 189 if (err) 190 goto out_fail; 191 192 err = ufs_add_link(dentry, inode); 193 if (err) 194 goto out_fail; 195 196 d_instantiate_new(dentry, inode); 197 return 0; 198 199 out_fail: 200 inode_dec_link_count(inode); 201 inode_dec_link_count(inode); 202 discard_new_inode(inode); 203 out_dir: 204 inode_dec_link_count(dir); 205 return err; 206 } 207 208 static int ufs_unlink(struct inode *dir, struct dentry *dentry) 209 { 210 struct inode * inode = d_inode(dentry); 211 struct ufs_dir_entry *de; 212 struct page *page; 213 int err = -ENOENT; 214 215 de = ufs_find_entry(dir, &dentry->d_name, &page); 216 if (!de) 217 goto out; 218 219 err = ufs_delete_entry(dir, de, page); 220 if (err) 221 goto out; 222 223 inode->i_ctime = dir->i_ctime; 224 inode_dec_link_count(inode); 225 err = 0; 226 out: 227 return err; 228 } 229 230 static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 231 { 232 struct inode * inode = d_inode(dentry); 233 int err= -ENOTEMPTY; 234 235 if (ufs_empty_dir (inode)) { 236 err = ufs_unlink(dir, dentry); 237 if (!err) { 238 inode->i_size = 0; 239 inode_dec_link_count(inode); 240 inode_dec_link_count(dir); 241 } 242 } 243 return err; 244 } 245 246 static int ufs_rename(struct mnt_idmap *idmap, struct inode *old_dir, 247 struct dentry *old_dentry, struct inode *new_dir, 248 struct dentry *new_dentry, unsigned int flags) 249 { 250 struct inode *old_inode = d_inode(old_dentry); 251 struct inode *new_inode = d_inode(new_dentry); 252 struct page *dir_page = NULL; 253 struct ufs_dir_entry * dir_de = NULL; 254 struct page *old_page; 255 struct ufs_dir_entry *old_de; 256 int err = -ENOENT; 257 258 if (flags & ~RENAME_NOREPLACE) 259 return -EINVAL; 260 261 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 262 if (!old_de) 263 goto out; 264 265 if (S_ISDIR(old_inode->i_mode)) { 266 err = -EIO; 267 dir_de = ufs_dotdot(old_inode, &dir_page); 268 if (!dir_de) 269 goto out_old; 270 } 271 272 if (new_inode) { 273 struct page *new_page; 274 struct ufs_dir_entry *new_de; 275 276 err = -ENOTEMPTY; 277 if (dir_de && !ufs_empty_dir(new_inode)) 278 goto out_dir; 279 280 err = -ENOENT; 281 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 282 if (!new_de) 283 goto out_dir; 284 ufs_set_link(new_dir, new_de, new_page, old_inode, 1); 285 new_inode->i_ctime = current_time(new_inode); 286 if (dir_de) 287 drop_nlink(new_inode); 288 inode_dec_link_count(new_inode); 289 } else { 290 err = ufs_add_link(new_dentry, old_inode); 291 if (err) 292 goto out_dir; 293 if (dir_de) 294 inode_inc_link_count(new_dir); 295 } 296 297 /* 298 * Like most other Unix systems, set the ctime for inodes on a 299 * rename. 300 */ 301 old_inode->i_ctime = current_time(old_inode); 302 303 ufs_delete_entry(old_dir, old_de, old_page); 304 mark_inode_dirty(old_inode); 305 306 if (dir_de) { 307 if (old_dir != new_dir) 308 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0); 309 else { 310 kunmap(dir_page); 311 put_page(dir_page); 312 } 313 inode_dec_link_count(old_dir); 314 } 315 return 0; 316 317 318 out_dir: 319 if (dir_de) { 320 kunmap(dir_page); 321 put_page(dir_page); 322 } 323 out_old: 324 kunmap(old_page); 325 put_page(old_page); 326 out: 327 return err; 328 } 329 330 const struct inode_operations ufs_dir_inode_operations = { 331 .create = ufs_create, 332 .lookup = ufs_lookup, 333 .link = ufs_link, 334 .unlink = ufs_unlink, 335 .symlink = ufs_symlink, 336 .mkdir = ufs_mkdir, 337 .rmdir = ufs_rmdir, 338 .mknod = ufs_mknod, 339 .rename = ufs_rename, 340 }; 341