1 /* 2 * linux/fs/ufs/namei.c 3 * 4 * Migration to usage of "page cache" on May 2006 by 5 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base. 6 * 7 * Copyright (C) 1998 8 * Daniel Pirkl <daniel.pirkl@email.cz> 9 * Charles University, Faculty of Mathematics and Physics 10 * 11 * from 12 * 13 * linux/fs/ext2/namei.c 14 * 15 * Copyright (C) 1992, 1993, 1994, 1995 16 * Remy Card (card@masi.ibp.fr) 17 * Laboratoire MASI - Institut Blaise Pascal 18 * Universite Pierre et Marie Curie (Paris VI) 19 * 20 * from 21 * 22 * linux/fs/minix/namei.c 23 * 24 * Copyright (C) 1991, 1992 Linus Torvalds 25 * 26 * Big-endian to little-endian byte-swapping/bitmaps by 27 * David S. Miller (davem@caip.rutgers.edu), 1995 28 */ 29 30 #include <linux/time.h> 31 #include <linux/fs.h> 32 #include <linux/smp_lock.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(dentry, inode); 43 return 0; 44 } 45 inode_dec_link_count(inode); 46 iput(inode); 47 return err; 48 } 49 50 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) 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 lock_kernel(); 59 ino = ufs_inode_by_name(dir, &dentry->d_name); 60 if (ino) { 61 inode = ufs_iget(dir->i_sb, ino); 62 if (IS_ERR(inode)) { 63 unlock_kernel(); 64 return ERR_CAST(inode); 65 } 66 } 67 unlock_kernel(); 68 d_add(dentry, inode); 69 return NULL; 70 } 71 72 /* 73 * By the time this is called, we already have created 74 * the directory cache entry for the new file, but it 75 * is so far negative - it has no inode. 76 * 77 * If the create succeeds, we fill in the inode information 78 * with d_instantiate(). 79 */ 80 static int ufs_create (struct inode * dir, struct dentry * dentry, int mode, 81 struct nameidata *nd) 82 { 83 struct inode *inode; 84 int err; 85 86 UFSD("BEGIN\n"); 87 88 inode = ufs_new_inode(dir, mode); 89 err = PTR_ERR(inode); 90 91 if (!IS_ERR(inode)) { 92 inode->i_op = &ufs_file_inode_operations; 93 inode->i_fop = &ufs_file_operations; 94 inode->i_mapping->a_ops = &ufs_aops; 95 mark_inode_dirty(inode); 96 lock_kernel(); 97 err = ufs_add_nondir(dentry, inode); 98 unlock_kernel(); 99 } 100 UFSD("END: err=%d\n", err); 101 return err; 102 } 103 104 static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev) 105 { 106 struct inode *inode; 107 int err; 108 109 if (!old_valid_dev(rdev)) 110 return -EINVAL; 111 112 inode = ufs_new_inode(dir, mode); 113 err = PTR_ERR(inode); 114 if (!IS_ERR(inode)) { 115 init_special_inode(inode, mode, rdev); 116 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev); 117 mark_inode_dirty(inode); 118 lock_kernel(); 119 err = ufs_add_nondir(dentry, inode); 120 unlock_kernel(); 121 } 122 return err; 123 } 124 125 static int ufs_symlink (struct inode * dir, struct dentry * dentry, 126 const char * symname) 127 { 128 struct super_block * sb = dir->i_sb; 129 int err = -ENAMETOOLONG; 130 unsigned l = strlen(symname)+1; 131 struct inode * inode; 132 133 if (l > sb->s_blocksize) 134 goto out_notlocked; 135 136 lock_kernel(); 137 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); 138 err = PTR_ERR(inode); 139 if (IS_ERR(inode)) 140 goto out; 141 142 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) { 143 /* slow symlink */ 144 inode->i_op = &ufs_symlink_inode_operations; 145 inode->i_mapping->a_ops = &ufs_aops; 146 err = page_symlink(inode, symname, l); 147 if (err) 148 goto out_fail; 149 } else { 150 /* fast symlink */ 151 inode->i_op = &ufs_fast_symlink_inode_operations; 152 memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l); 153 inode->i_size = l-1; 154 } 155 mark_inode_dirty(inode); 156 157 err = ufs_add_nondir(dentry, inode); 158 out: 159 unlock_kernel(); 160 out_notlocked: 161 return err; 162 163 out_fail: 164 inode_dec_link_count(inode); 165 iput(inode); 166 goto out; 167 } 168 169 static int ufs_link (struct dentry * old_dentry, struct inode * dir, 170 struct dentry *dentry) 171 { 172 struct inode *inode = old_dentry->d_inode; 173 int error; 174 175 lock_kernel(); 176 if (inode->i_nlink >= UFS_LINK_MAX) { 177 unlock_kernel(); 178 return -EMLINK; 179 } 180 181 inode->i_ctime = CURRENT_TIME_SEC; 182 inode_inc_link_count(inode); 183 ihold(inode); 184 185 error = ufs_add_nondir(dentry, inode); 186 unlock_kernel(); 187 return error; 188 } 189 190 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode) 191 { 192 struct inode * inode; 193 int err = -EMLINK; 194 195 if (dir->i_nlink >= UFS_LINK_MAX) 196 goto out; 197 198 lock_kernel(); 199 inode_inc_link_count(dir); 200 201 inode = ufs_new_inode(dir, S_IFDIR|mode); 202 err = PTR_ERR(inode); 203 if (IS_ERR(inode)) 204 goto out_dir; 205 206 inode->i_op = &ufs_dir_inode_operations; 207 inode->i_fop = &ufs_dir_operations; 208 inode->i_mapping->a_ops = &ufs_aops; 209 210 inode_inc_link_count(inode); 211 212 err = ufs_make_empty(inode, dir); 213 if (err) 214 goto out_fail; 215 216 err = ufs_add_link(dentry, inode); 217 if (err) 218 goto out_fail; 219 unlock_kernel(); 220 221 d_instantiate(dentry, inode); 222 out: 223 return err; 224 225 out_fail: 226 inode_dec_link_count(inode); 227 inode_dec_link_count(inode); 228 iput (inode); 229 out_dir: 230 inode_dec_link_count(dir); 231 unlock_kernel(); 232 goto out; 233 } 234 235 static int ufs_unlink(struct inode *dir, struct dentry *dentry) 236 { 237 struct inode * inode = dentry->d_inode; 238 struct ufs_dir_entry *de; 239 struct page *page; 240 int err = -ENOENT; 241 242 de = ufs_find_entry(dir, &dentry->d_name, &page); 243 if (!de) 244 goto out; 245 246 err = ufs_delete_entry(dir, de, page); 247 if (err) 248 goto out; 249 250 inode->i_ctime = dir->i_ctime; 251 inode_dec_link_count(inode); 252 err = 0; 253 out: 254 return err; 255 } 256 257 static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 258 { 259 struct inode * inode = dentry->d_inode; 260 int err= -ENOTEMPTY; 261 262 lock_kernel(); 263 if (ufs_empty_dir (inode)) { 264 err = ufs_unlink(dir, dentry); 265 if (!err) { 266 inode->i_size = 0; 267 inode_dec_link_count(inode); 268 inode_dec_link_count(dir); 269 } 270 } 271 unlock_kernel(); 272 return err; 273 } 274 275 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry, 276 struct inode *new_dir, struct dentry *new_dentry) 277 { 278 struct inode *old_inode = old_dentry->d_inode; 279 struct inode *new_inode = new_dentry->d_inode; 280 struct page *dir_page = NULL; 281 struct ufs_dir_entry * dir_de = NULL; 282 struct page *old_page; 283 struct ufs_dir_entry *old_de; 284 int err = -ENOENT; 285 286 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 287 if (!old_de) 288 goto out; 289 290 if (S_ISDIR(old_inode->i_mode)) { 291 err = -EIO; 292 dir_de = ufs_dotdot(old_inode, &dir_page); 293 if (!dir_de) 294 goto out_old; 295 } 296 297 if (new_inode) { 298 struct page *new_page; 299 struct ufs_dir_entry *new_de; 300 301 err = -ENOTEMPTY; 302 if (dir_de && !ufs_empty_dir(new_inode)) 303 goto out_dir; 304 305 err = -ENOENT; 306 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 307 if (!new_de) 308 goto out_dir; 309 ufs_set_link(new_dir, new_de, new_page, old_inode); 310 new_inode->i_ctime = CURRENT_TIME_SEC; 311 if (dir_de) 312 drop_nlink(new_inode); 313 inode_dec_link_count(new_inode); 314 } else { 315 if (dir_de) { 316 err = -EMLINK; 317 if (new_dir->i_nlink >= UFS_LINK_MAX) 318 goto out_dir; 319 } 320 err = ufs_add_link(new_dentry, old_inode); 321 if (err) 322 goto out_dir; 323 if (dir_de) 324 inode_inc_link_count(new_dir); 325 } 326 327 /* 328 * Like most other Unix systems, set the ctime for inodes on a 329 * rename. 330 */ 331 old_inode->i_ctime = CURRENT_TIME_SEC; 332 333 ufs_delete_entry(old_dir, old_de, old_page); 334 mark_inode_dirty(old_inode); 335 336 if (dir_de) { 337 ufs_set_link(old_inode, dir_de, dir_page, new_dir); 338 inode_dec_link_count(old_dir); 339 } 340 return 0; 341 342 343 out_dir: 344 if (dir_de) { 345 kunmap(dir_page); 346 page_cache_release(dir_page); 347 } 348 out_old: 349 kunmap(old_page); 350 page_cache_release(old_page); 351 out: 352 return err; 353 } 354 355 const struct inode_operations ufs_dir_inode_operations = { 356 .create = ufs_create, 357 .lookup = ufs_lookup, 358 .link = ufs_link, 359 .unlink = ufs_unlink, 360 .symlink = ufs_symlink, 361 .mkdir = ufs_mkdir, 362 .rmdir = ufs_rmdir, 363 .mknod = ufs_mknod, 364 .rename = ufs_rename, 365 }; 366