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 33 #include "ufs_fs.h" 34 #include "ufs.h" 35 #include "util.h" 36 37 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode) 38 { 39 int err = ufs_add_link(dentry, inode); 40 if (!err) { 41 unlock_new_inode(inode); 42 d_instantiate(dentry, inode); 43 return 0; 44 } 45 inode_dec_link_count(inode); 46 unlock_new_inode(inode); 47 iput(inode); 48 return err; 49 } 50 51 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) 52 { 53 struct inode * inode = NULL; 54 ino_t ino; 55 56 if (dentry->d_name.len > UFS_MAXNAMLEN) 57 return ERR_PTR(-ENAMETOOLONG); 58 59 lock_ufs(dir->i_sb); 60 ino = ufs_inode_by_name(dir, &dentry->d_name); 61 if (ino) 62 inode = ufs_iget(dir->i_sb, ino); 63 unlock_ufs(dir->i_sb); 64 return d_splice_alias(inode, dentry); 65 } 66 67 /* 68 * By the time this is called, we already have created 69 * the directory cache entry for the new file, but it 70 * is so far negative - it has no inode. 71 * 72 * If the create succeeds, we fill in the inode information 73 * with d_instantiate(). 74 */ 75 static int ufs_create (struct inode * dir, struct dentry * dentry, umode_t mode, 76 bool excl) 77 { 78 struct inode *inode; 79 int err; 80 81 UFSD("BEGIN\n"); 82 83 inode = ufs_new_inode(dir, mode); 84 err = PTR_ERR(inode); 85 86 if (!IS_ERR(inode)) { 87 inode->i_op = &ufs_file_inode_operations; 88 inode->i_fop = &ufs_file_operations; 89 inode->i_mapping->a_ops = &ufs_aops; 90 mark_inode_dirty(inode); 91 lock_ufs(dir->i_sb); 92 err = ufs_add_nondir(dentry, inode); 93 unlock_ufs(dir->i_sb); 94 } 95 UFSD("END: err=%d\n", err); 96 return err; 97 } 98 99 static int ufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) 100 { 101 struct inode *inode; 102 int err; 103 104 if (!old_valid_dev(rdev)) 105 return -EINVAL; 106 107 inode = ufs_new_inode(dir, mode); 108 err = PTR_ERR(inode); 109 if (!IS_ERR(inode)) { 110 init_special_inode(inode, mode, rdev); 111 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev); 112 mark_inode_dirty(inode); 113 lock_ufs(dir->i_sb); 114 err = ufs_add_nondir(dentry, inode); 115 unlock_ufs(dir->i_sb); 116 } 117 return err; 118 } 119 120 static int ufs_symlink (struct inode * dir, struct dentry * dentry, 121 const char * symname) 122 { 123 struct super_block * sb = dir->i_sb; 124 int err = -ENAMETOOLONG; 125 unsigned l = strlen(symname)+1; 126 struct inode * inode; 127 128 if (l > sb->s_blocksize) 129 goto out_notlocked; 130 131 lock_ufs(dir->i_sb); 132 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); 133 err = PTR_ERR(inode); 134 if (IS_ERR(inode)) 135 goto out; 136 137 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) { 138 /* slow symlink */ 139 inode->i_op = &ufs_symlink_inode_operations; 140 inode->i_mapping->a_ops = &ufs_aops; 141 err = page_symlink(inode, symname, l); 142 if (err) 143 goto out_fail; 144 } else { 145 /* fast symlink */ 146 inode->i_op = &ufs_fast_symlink_inode_operations; 147 memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l); 148 inode->i_size = l-1; 149 } 150 mark_inode_dirty(inode); 151 152 err = ufs_add_nondir(dentry, inode); 153 out: 154 unlock_ufs(dir->i_sb); 155 out_notlocked: 156 return err; 157 158 out_fail: 159 inode_dec_link_count(inode); 160 unlock_new_inode(inode); 161 iput(inode); 162 goto out; 163 } 164 165 static int ufs_link (struct dentry * old_dentry, struct inode * dir, 166 struct dentry *dentry) 167 { 168 struct inode *inode = d_inode(old_dentry); 169 int error; 170 171 lock_ufs(dir->i_sb); 172 173 inode->i_ctime = CURRENT_TIME_SEC; 174 inode_inc_link_count(inode); 175 ihold(inode); 176 177 error = ufs_add_link(dentry, inode); 178 if (error) { 179 inode_dec_link_count(inode); 180 iput(inode); 181 } else 182 d_instantiate(dentry, inode); 183 unlock_ufs(dir->i_sb); 184 return error; 185 } 186 187 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) 188 { 189 struct inode * inode; 190 int err; 191 192 lock_ufs(dir->i_sb); 193 inode_inc_link_count(dir); 194 195 inode = ufs_new_inode(dir, S_IFDIR|mode); 196 err = PTR_ERR(inode); 197 if (IS_ERR(inode)) 198 goto out_dir; 199 200 inode->i_op = &ufs_dir_inode_operations; 201 inode->i_fop = &ufs_dir_operations; 202 inode->i_mapping->a_ops = &ufs_aops; 203 204 inode_inc_link_count(inode); 205 206 err = ufs_make_empty(inode, dir); 207 if (err) 208 goto out_fail; 209 210 err = ufs_add_link(dentry, inode); 211 if (err) 212 goto out_fail; 213 unlock_ufs(dir->i_sb); 214 215 unlock_new_inode(inode); 216 d_instantiate(dentry, inode); 217 out: 218 return err; 219 220 out_fail: 221 inode_dec_link_count(inode); 222 inode_dec_link_count(inode); 223 unlock_new_inode(inode); 224 iput (inode); 225 out_dir: 226 inode_dec_link_count(dir); 227 unlock_ufs(dir->i_sb); 228 goto out; 229 } 230 231 static int ufs_unlink(struct inode *dir, struct dentry *dentry) 232 { 233 struct inode * inode = d_inode(dentry); 234 struct ufs_dir_entry *de; 235 struct page *page; 236 int err = -ENOENT; 237 238 de = ufs_find_entry(dir, &dentry->d_name, &page); 239 if (!de) 240 goto out; 241 242 err = ufs_delete_entry(dir, de, page); 243 if (err) 244 goto out; 245 246 inode->i_ctime = dir->i_ctime; 247 inode_dec_link_count(inode); 248 err = 0; 249 out: 250 return err; 251 } 252 253 static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 254 { 255 struct inode * inode = d_inode(dentry); 256 int err= -ENOTEMPTY; 257 258 lock_ufs(dir->i_sb); 259 if (ufs_empty_dir (inode)) { 260 err = ufs_unlink(dir, dentry); 261 if (!err) { 262 inode->i_size = 0; 263 inode_dec_link_count(inode); 264 inode_dec_link_count(dir); 265 } 266 } 267 unlock_ufs(dir->i_sb); 268 return err; 269 } 270 271 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry, 272 struct inode *new_dir, struct dentry *new_dentry) 273 { 274 struct inode *old_inode = d_inode(old_dentry); 275 struct inode *new_inode = d_inode(new_dentry); 276 struct page *dir_page = NULL; 277 struct ufs_dir_entry * dir_de = NULL; 278 struct page *old_page; 279 struct ufs_dir_entry *old_de; 280 int err = -ENOENT; 281 282 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 283 if (!old_de) 284 goto out; 285 286 if (S_ISDIR(old_inode->i_mode)) { 287 err = -EIO; 288 dir_de = ufs_dotdot(old_inode, &dir_page); 289 if (!dir_de) 290 goto out_old; 291 } 292 293 if (new_inode) { 294 struct page *new_page; 295 struct ufs_dir_entry *new_de; 296 297 err = -ENOTEMPTY; 298 if (dir_de && !ufs_empty_dir(new_inode)) 299 goto out_dir; 300 301 err = -ENOENT; 302 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 303 if (!new_de) 304 goto out_dir; 305 ufs_set_link(new_dir, new_de, new_page, old_inode); 306 new_inode->i_ctime = CURRENT_TIME_SEC; 307 if (dir_de) 308 drop_nlink(new_inode); 309 inode_dec_link_count(new_inode); 310 } else { 311 err = ufs_add_link(new_dentry, old_inode); 312 if (err) 313 goto out_dir; 314 if (dir_de) 315 inode_inc_link_count(new_dir); 316 } 317 318 /* 319 * Like most other Unix systems, set the ctime for inodes on a 320 * rename. 321 */ 322 old_inode->i_ctime = CURRENT_TIME_SEC; 323 324 ufs_delete_entry(old_dir, old_de, old_page); 325 mark_inode_dirty(old_inode); 326 327 if (dir_de) { 328 ufs_set_link(old_inode, dir_de, dir_page, new_dir); 329 inode_dec_link_count(old_dir); 330 } 331 return 0; 332 333 334 out_dir: 335 if (dir_de) { 336 kunmap(dir_page); 337 page_cache_release(dir_page); 338 } 339 out_old: 340 kunmap(old_page); 341 page_cache_release(old_page); 342 out: 343 return err; 344 } 345 346 const struct inode_operations ufs_dir_inode_operations = { 347 .create = ufs_create, 348 .lookup = ufs_lookup, 349 .link = ufs_link, 350 .unlink = ufs_unlink, 351 .symlink = ufs_symlink, 352 .mkdir = ufs_mkdir, 353 .rmdir = ufs_rmdir, 354 .mknod = ufs_mknod, 355 .rename = ufs_rename, 356 }; 357