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 ino = ufs_inode_by_name(dir, &dentry->d_name); 60 if (ino) 61 inode = ufs_iget(dir->i_sb, ino); 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 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 inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) 90 { 91 struct inode *inode; 92 int err; 93 94 if (!old_valid_dev(rdev)) 95 return -EINVAL; 96 97 inode = ufs_new_inode(dir, mode); 98 err = PTR_ERR(inode); 99 if (!IS_ERR(inode)) { 100 init_special_inode(inode, mode, rdev); 101 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev); 102 mark_inode_dirty(inode); 103 err = ufs_add_nondir(dentry, inode); 104 } 105 return err; 106 } 107 108 static int ufs_symlink (struct inode * dir, struct dentry * dentry, 109 const char * symname) 110 { 111 struct super_block * sb = dir->i_sb; 112 int err; 113 unsigned l = strlen(symname)+1; 114 struct inode * inode; 115 116 if (l > sb->s_blocksize) 117 return -ENAMETOOLONG; 118 119 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); 120 err = PTR_ERR(inode); 121 if (IS_ERR(inode)) 122 return err; 123 124 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) { 125 /* slow symlink */ 126 inode->i_op = &page_symlink_inode_operations; 127 inode->i_mapping->a_ops = &ufs_aops; 128 err = page_symlink(inode, symname, l); 129 if (err) 130 goto out_fail; 131 } else { 132 /* fast symlink */ 133 inode->i_op = &simple_symlink_inode_operations; 134 inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink; 135 memcpy(inode->i_link, symname, l); 136 inode->i_size = l-1; 137 } 138 mark_inode_dirty(inode); 139 140 return ufs_add_nondir(dentry, inode); 141 142 out_fail: 143 inode_dec_link_count(inode); 144 unlock_new_inode(inode); 145 iput(inode); 146 return err; 147 } 148 149 static int ufs_link (struct dentry * old_dentry, struct inode * dir, 150 struct dentry *dentry) 151 { 152 struct inode *inode = d_inode(old_dentry); 153 int error; 154 155 inode->i_ctime = CURRENT_TIME_SEC; 156 inode_inc_link_count(inode); 157 ihold(inode); 158 159 error = ufs_add_link(dentry, inode); 160 if (error) { 161 inode_dec_link_count(inode); 162 iput(inode); 163 } else 164 d_instantiate(dentry, inode); 165 return error; 166 } 167 168 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) 169 { 170 struct inode * inode; 171 int err; 172 173 inode_inc_link_count(dir); 174 175 inode = ufs_new_inode(dir, S_IFDIR|mode); 176 err = PTR_ERR(inode); 177 if (IS_ERR(inode)) 178 goto out_dir; 179 180 inode->i_op = &ufs_dir_inode_operations; 181 inode->i_fop = &ufs_dir_operations; 182 inode->i_mapping->a_ops = &ufs_aops; 183 184 inode_inc_link_count(inode); 185 186 err = ufs_make_empty(inode, dir); 187 if (err) 188 goto out_fail; 189 190 err = ufs_add_link(dentry, inode); 191 if (err) 192 goto out_fail; 193 194 unlock_new_inode(inode); 195 d_instantiate(dentry, inode); 196 return 0; 197 198 out_fail: 199 inode_dec_link_count(inode); 200 inode_dec_link_count(inode); 201 unlock_new_inode(inode); 202 iput (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 inode *old_dir, struct dentry *old_dentry, 247 struct inode *new_dir, struct dentry *new_dentry) 248 { 249 struct inode *old_inode = d_inode(old_dentry); 250 struct inode *new_inode = d_inode(new_dentry); 251 struct page *dir_page = NULL; 252 struct ufs_dir_entry * dir_de = NULL; 253 struct page *old_page; 254 struct ufs_dir_entry *old_de; 255 int err = -ENOENT; 256 257 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 258 if (!old_de) 259 goto out; 260 261 if (S_ISDIR(old_inode->i_mode)) { 262 err = -EIO; 263 dir_de = ufs_dotdot(old_inode, &dir_page); 264 if (!dir_de) 265 goto out_old; 266 } 267 268 if (new_inode) { 269 struct page *new_page; 270 struct ufs_dir_entry *new_de; 271 272 err = -ENOTEMPTY; 273 if (dir_de && !ufs_empty_dir(new_inode)) 274 goto out_dir; 275 276 err = -ENOENT; 277 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 278 if (!new_de) 279 goto out_dir; 280 ufs_set_link(new_dir, new_de, new_page, old_inode, 1); 281 new_inode->i_ctime = CURRENT_TIME_SEC; 282 if (dir_de) 283 drop_nlink(new_inode); 284 inode_dec_link_count(new_inode); 285 } else { 286 err = ufs_add_link(new_dentry, old_inode); 287 if (err) 288 goto out_dir; 289 if (dir_de) 290 inode_inc_link_count(new_dir); 291 } 292 293 /* 294 * Like most other Unix systems, set the ctime for inodes on a 295 * rename. 296 */ 297 old_inode->i_ctime = CURRENT_TIME_SEC; 298 299 ufs_delete_entry(old_dir, old_de, old_page); 300 mark_inode_dirty(old_inode); 301 302 if (dir_de) { 303 if (old_dir != new_dir) 304 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0); 305 else { 306 kunmap(dir_page); 307 page_cache_release(dir_page); 308 } 309 inode_dec_link_count(old_dir); 310 } 311 return 0; 312 313 314 out_dir: 315 if (dir_de) { 316 kunmap(dir_page); 317 page_cache_release(dir_page); 318 } 319 out_old: 320 kunmap(old_page); 321 page_cache_release(old_page); 322 out: 323 return err; 324 } 325 326 const struct inode_operations ufs_dir_inode_operations = { 327 .create = ufs_create, 328 .lookup = ufs_lookup, 329 .link = ufs_link, 330 .unlink = ufs_unlink, 331 .symlink = ufs_symlink, 332 .mkdir = ufs_mkdir, 333 .rmdir = ufs_rmdir, 334 .mknod = ufs_mknod, 335 .rename = ufs_rename, 336 }; 337