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