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 = &ufs_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 = &ufs_fast_symlink_inode_operations; 134 memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l); 135 inode->i_size = l-1; 136 } 137 mark_inode_dirty(inode); 138 139 return ufs_add_nondir(dentry, inode); 140 141 out_fail: 142 inode_dec_link_count(inode); 143 unlock_new_inode(inode); 144 iput(inode); 145 return err; 146 } 147 148 static int ufs_link (struct dentry * old_dentry, struct inode * dir, 149 struct dentry *dentry) 150 { 151 struct inode *inode = d_inode(old_dentry); 152 int error; 153 154 inode->i_ctime = CURRENT_TIME_SEC; 155 inode_inc_link_count(inode); 156 ihold(inode); 157 158 error = ufs_add_link(dentry, inode); 159 if (error) { 160 inode_dec_link_count(inode); 161 iput(inode); 162 } else 163 d_instantiate(dentry, inode); 164 return error; 165 } 166 167 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) 168 { 169 struct inode * inode; 170 int err; 171 172 inode_inc_link_count(dir); 173 174 inode = ufs_new_inode(dir, S_IFDIR|mode); 175 err = PTR_ERR(inode); 176 if (IS_ERR(inode)) 177 goto out_dir; 178 179 inode->i_op = &ufs_dir_inode_operations; 180 inode->i_fop = &ufs_dir_operations; 181 inode->i_mapping->a_ops = &ufs_aops; 182 183 inode_inc_link_count(inode); 184 185 err = ufs_make_empty(inode, dir); 186 if (err) 187 goto out_fail; 188 189 err = ufs_add_link(dentry, inode); 190 if (err) 191 goto out_fail; 192 193 unlock_new_inode(inode); 194 d_instantiate(dentry, inode); 195 return 0; 196 197 out_fail: 198 inode_dec_link_count(inode); 199 inode_dec_link_count(inode); 200 unlock_new_inode(inode); 201 iput (inode); 202 out_dir: 203 inode_dec_link_count(dir); 204 return err; 205 } 206 207 static int ufs_unlink(struct inode *dir, struct dentry *dentry) 208 { 209 struct inode * inode = d_inode(dentry); 210 struct ufs_dir_entry *de; 211 struct page *page; 212 int err = -ENOENT; 213 214 de = ufs_find_entry(dir, &dentry->d_name, &page); 215 if (!de) 216 goto out; 217 218 err = ufs_delete_entry(dir, de, page); 219 if (err) 220 goto out; 221 222 inode->i_ctime = dir->i_ctime; 223 inode_dec_link_count(inode); 224 err = 0; 225 out: 226 return err; 227 } 228 229 static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 230 { 231 struct inode * inode = d_inode(dentry); 232 int err= -ENOTEMPTY; 233 234 if (ufs_empty_dir (inode)) { 235 err = ufs_unlink(dir, dentry); 236 if (!err) { 237 inode->i_size = 0; 238 inode_dec_link_count(inode); 239 inode_dec_link_count(dir); 240 } 241 } 242 return err; 243 } 244 245 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry, 246 struct inode *new_dir, struct dentry *new_dentry) 247 { 248 struct inode *old_inode = d_inode(old_dentry); 249 struct inode *new_inode = d_inode(new_dentry); 250 struct page *dir_page = NULL; 251 struct ufs_dir_entry * dir_de = NULL; 252 struct page *old_page; 253 struct ufs_dir_entry *old_de; 254 int err = -ENOENT; 255 256 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 257 if (!old_de) 258 goto out; 259 260 if (S_ISDIR(old_inode->i_mode)) { 261 err = -EIO; 262 dir_de = ufs_dotdot(old_inode, &dir_page); 263 if (!dir_de) 264 goto out_old; 265 } 266 267 if (new_inode) { 268 struct page *new_page; 269 struct ufs_dir_entry *new_de; 270 271 err = -ENOTEMPTY; 272 if (dir_de && !ufs_empty_dir(new_inode)) 273 goto out_dir; 274 275 err = -ENOENT; 276 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 277 if (!new_de) 278 goto out_dir; 279 ufs_set_link(new_dir, new_de, new_page, old_inode, 1); 280 new_inode->i_ctime = CURRENT_TIME_SEC; 281 if (dir_de) 282 drop_nlink(new_inode); 283 inode_dec_link_count(new_inode); 284 } else { 285 err = ufs_add_link(new_dentry, old_inode); 286 if (err) 287 goto out_dir; 288 if (dir_de) 289 inode_inc_link_count(new_dir); 290 } 291 292 /* 293 * Like most other Unix systems, set the ctime for inodes on a 294 * rename. 295 */ 296 old_inode->i_ctime = CURRENT_TIME_SEC; 297 298 ufs_delete_entry(old_dir, old_de, old_page); 299 mark_inode_dirty(old_inode); 300 301 if (dir_de) { 302 if (old_dir != new_dir) 303 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0); 304 else { 305 kunmap(dir_page); 306 page_cache_release(dir_page); 307 } 308 inode_dec_link_count(old_dir); 309 } 310 return 0; 311 312 313 out_dir: 314 if (dir_de) { 315 kunmap(dir_page); 316 page_cache_release(dir_page); 317 } 318 out_old: 319 kunmap(old_page); 320 page_cache_release(old_page); 321 out: 322 return err; 323 } 324 325 const struct inode_operations ufs_dir_inode_operations = { 326 .create = ufs_create, 327 .lookup = ufs_lookup, 328 .link = ufs_link, 329 .unlink = ufs_unlink, 330 .symlink = ufs_symlink, 331 .mkdir = ufs_mkdir, 332 .rmdir = ufs_rmdir, 333 .mknod = ufs_mknod, 334 .rename = ufs_rename, 335 }; 336