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 unlock_new_inode(inode); 43 d_instantiate(dentry, inode); 44 return 0; 45 } 46 inode_dec_link_count(inode); 47 unlock_new_inode(inode); 48 iput(inode); 49 return err; 50 } 51 52 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) 53 { 54 struct inode * inode = NULL; 55 ino_t ino; 56 57 if (dentry->d_name.len > UFS_MAXNAMLEN) 58 return ERR_PTR(-ENAMETOOLONG); 59 60 ino = ufs_inode_by_name(dir, &dentry->d_name); 61 if (ino) 62 inode = ufs_iget(dir->i_sb, ino); 63 return d_splice_alias(inode, dentry); 64 } 65 66 /* 67 * By the time this is called, we already have created 68 * the directory cache entry for the new file, but it 69 * is so far negative - it has no inode. 70 * 71 * If the create succeeds, we fill in the inode information 72 * with d_instantiate(). 73 */ 74 static int ufs_create (struct inode * dir, struct dentry * dentry, umode_t mode, 75 bool excl) 76 { 77 struct inode *inode; 78 79 inode = ufs_new_inode(dir, mode); 80 if (IS_ERR(inode)) 81 return PTR_ERR(inode); 82 83 inode->i_op = &ufs_file_inode_operations; 84 inode->i_fop = &ufs_file_operations; 85 inode->i_mapping->a_ops = &ufs_aops; 86 mark_inode_dirty(inode); 87 return ufs_add_nondir(dentry, inode); 88 } 89 90 static int ufs_mknod(struct inode *dir, 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 inode * dir, struct dentry * dentry, 110 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 unlock_new_inode(inode); 147 iput(inode); 148 return err; 149 } 150 151 static int ufs_link (struct dentry * old_dentry, struct inode * dir, 152 struct dentry *dentry) 153 { 154 struct inode *inode = d_inode(old_dentry); 155 int error; 156 157 inode->i_ctime = current_time(inode); 158 inode_inc_link_count(inode); 159 ihold(inode); 160 161 error = ufs_add_link(dentry, inode); 162 if (error) { 163 inode_dec_link_count(inode); 164 iput(inode); 165 } else 166 d_instantiate(dentry, inode); 167 return error; 168 } 169 170 static int ufs_mkdir(struct inode * dir, 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 unlock_new_inode(inode); 197 d_instantiate(dentry, inode); 198 return 0; 199 200 out_fail: 201 inode_dec_link_count(inode); 202 inode_dec_link_count(inode); 203 unlock_new_inode(inode); 204 iput (inode); 205 out_dir: 206 inode_dec_link_count(dir); 207 return err; 208 } 209 210 static int ufs_unlink(struct inode *dir, struct dentry *dentry) 211 { 212 struct inode * inode = d_inode(dentry); 213 struct ufs_dir_entry *de; 214 struct page *page; 215 int err = -ENOENT; 216 217 de = ufs_find_entry(dir, &dentry->d_name, &page); 218 if (!de) 219 goto out; 220 221 err = ufs_delete_entry(dir, de, page); 222 if (err) 223 goto out; 224 225 inode->i_ctime = dir->i_ctime; 226 inode_dec_link_count(inode); 227 err = 0; 228 out: 229 return err; 230 } 231 232 static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 233 { 234 struct inode * inode = d_inode(dentry); 235 int err= -ENOTEMPTY; 236 237 if (ufs_empty_dir (inode)) { 238 err = ufs_unlink(dir, dentry); 239 if (!err) { 240 inode->i_size = 0; 241 inode_dec_link_count(inode); 242 inode_dec_link_count(dir); 243 } 244 } 245 return err; 246 } 247 248 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry, 249 struct inode *new_dir, struct dentry *new_dentry, 250 unsigned int flags) 251 { 252 struct inode *old_inode = d_inode(old_dentry); 253 struct inode *new_inode = d_inode(new_dentry); 254 struct page *dir_page = NULL; 255 struct ufs_dir_entry * dir_de = NULL; 256 struct page *old_page; 257 struct ufs_dir_entry *old_de; 258 int err = -ENOENT; 259 260 if (flags & ~RENAME_NOREPLACE) 261 return -EINVAL; 262 263 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 264 if (!old_de) 265 goto out; 266 267 if (S_ISDIR(old_inode->i_mode)) { 268 err = -EIO; 269 dir_de = ufs_dotdot(old_inode, &dir_page); 270 if (!dir_de) 271 goto out_old; 272 } 273 274 if (new_inode) { 275 struct page *new_page; 276 struct ufs_dir_entry *new_de; 277 278 err = -ENOTEMPTY; 279 if (dir_de && !ufs_empty_dir(new_inode)) 280 goto out_dir; 281 282 err = -ENOENT; 283 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 284 if (!new_de) 285 goto out_dir; 286 ufs_set_link(new_dir, new_de, new_page, old_inode, 1); 287 new_inode->i_ctime = current_time(new_inode); 288 if (dir_de) 289 drop_nlink(new_inode); 290 inode_dec_link_count(new_inode); 291 } else { 292 err = ufs_add_link(new_dentry, old_inode); 293 if (err) 294 goto out_dir; 295 if (dir_de) 296 inode_inc_link_count(new_dir); 297 } 298 299 /* 300 * Like most other Unix systems, set the ctime for inodes on a 301 * rename. 302 */ 303 old_inode->i_ctime = current_time(old_inode); 304 305 ufs_delete_entry(old_dir, old_de, old_page); 306 mark_inode_dirty(old_inode); 307 308 if (dir_de) { 309 if (old_dir != new_dir) 310 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0); 311 else { 312 kunmap(dir_page); 313 put_page(dir_page); 314 } 315 inode_dec_link_count(old_dir); 316 } 317 return 0; 318 319 320 out_dir: 321 if (dir_de) { 322 kunmap(dir_page); 323 put_page(dir_page); 324 } 325 out_old: 326 kunmap(old_page); 327 put_page(old_page); 328 out: 329 return err; 330 } 331 332 const struct inode_operations ufs_dir_inode_operations = { 333 .create = ufs_create, 334 .lookup = ufs_lookup, 335 .link = ufs_link, 336 .unlink = ufs_unlink, 337 .symlink = ufs_symlink, 338 .mkdir = ufs_mkdir, 339 .rmdir = ufs_rmdir, 340 .mknod = ufs_mknod, 341 .rename = ufs_rename, 342 }; 343