1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ufs/namei.c 4 * 5 * Migration to usage of "page cache" on May 2006 by 6 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base. 7 * 8 * Copyright (C) 1998 9 * Daniel Pirkl <daniel.pirkl@email.cz> 10 * Charles University, Faculty of Mathematics and Physics 11 * 12 * from 13 * 14 * linux/fs/ext2/namei.c 15 * 16 * Copyright (C) 1992, 1993, 1994, 1995 17 * Remy Card (card@masi.ibp.fr) 18 * Laboratoire MASI - Institut Blaise Pascal 19 * Universite Pierre et Marie Curie (Paris VI) 20 * 21 * from 22 * 23 * linux/fs/minix/namei.c 24 * 25 * Copyright (C) 1991, 1992 Linus Torvalds 26 * 27 * Big-endian to little-endian byte-swapping/bitmaps by 28 * David S. Miller (davem@caip.rutgers.edu), 1995 29 */ 30 31 #include <linux/time.h> 32 #include <linux/fs.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_new(dentry, inode); 43 return 0; 44 } 45 inode_dec_link_count(inode); 46 discard_new_inode(inode); 47 return err; 48 } 49 50 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) 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 ino = ufs_inode_by_name(dir, &dentry->d_name); 59 if (ino) 60 inode = ufs_iget(dir->i_sb, ino); 61 return d_splice_alias(inode, dentry); 62 } 63 64 /* 65 * By the time this is called, we already have created 66 * the directory cache entry for the new file, but it 67 * is so far negative - it has no inode. 68 * 69 * If the create succeeds, we fill in the inode information 70 * with d_instantiate(). 71 */ 72 static int ufs_create (struct inode * dir, struct dentry * dentry, umode_t mode, 73 bool excl) 74 { 75 struct inode *inode; 76 77 inode = ufs_new_inode(dir, mode); 78 if (IS_ERR(inode)) 79 return PTR_ERR(inode); 80 81 inode->i_op = &ufs_file_inode_operations; 82 inode->i_fop = &ufs_file_operations; 83 inode->i_mapping->a_ops = &ufs_aops; 84 mark_inode_dirty(inode); 85 return ufs_add_nondir(dentry, inode); 86 } 87 88 static int ufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) 89 { 90 struct inode *inode; 91 int err; 92 93 if (!old_valid_dev(rdev)) 94 return -EINVAL; 95 96 inode = ufs_new_inode(dir, mode); 97 err = PTR_ERR(inode); 98 if (!IS_ERR(inode)) { 99 init_special_inode(inode, mode, rdev); 100 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev); 101 mark_inode_dirty(inode); 102 err = ufs_add_nondir(dentry, inode); 103 } 104 return err; 105 } 106 107 static int ufs_symlink (struct inode * dir, struct dentry * dentry, 108 const char * symname) 109 { 110 struct super_block * sb = dir->i_sb; 111 int err; 112 unsigned l = strlen(symname)+1; 113 struct inode * inode; 114 115 if (l > sb->s_blocksize) 116 return -ENAMETOOLONG; 117 118 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); 119 err = PTR_ERR(inode); 120 if (IS_ERR(inode)) 121 return err; 122 123 if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) { 124 /* slow symlink */ 125 inode->i_op = &page_symlink_inode_operations; 126 inode_nohighmem(inode); 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 discard_new_inode(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(inode); 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 d_instantiate_new(dentry, inode); 194 return 0; 195 196 out_fail: 197 inode_dec_link_count(inode); 198 inode_dec_link_count(inode); 199 discard_new_inode(inode); 200 out_dir: 201 inode_dec_link_count(dir); 202 return err; 203 } 204 205 static int ufs_unlink(struct inode *dir, struct dentry *dentry) 206 { 207 struct inode * inode = d_inode(dentry); 208 struct ufs_dir_entry *de; 209 struct page *page; 210 int err = -ENOENT; 211 212 de = ufs_find_entry(dir, &dentry->d_name, &page); 213 if (!de) 214 goto out; 215 216 err = ufs_delete_entry(dir, de, page); 217 if (err) 218 goto out; 219 220 inode->i_ctime = dir->i_ctime; 221 inode_dec_link_count(inode); 222 err = 0; 223 out: 224 return err; 225 } 226 227 static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 228 { 229 struct inode * inode = d_inode(dentry); 230 int err= -ENOTEMPTY; 231 232 if (ufs_empty_dir (inode)) { 233 err = ufs_unlink(dir, dentry); 234 if (!err) { 235 inode->i_size = 0; 236 inode_dec_link_count(inode); 237 inode_dec_link_count(dir); 238 } 239 } 240 return err; 241 } 242 243 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry, 244 struct inode *new_dir, struct dentry *new_dentry, 245 unsigned int flags) 246 { 247 struct inode *old_inode = d_inode(old_dentry); 248 struct inode *new_inode = d_inode(new_dentry); 249 struct page *dir_page = NULL; 250 struct ufs_dir_entry * dir_de = NULL; 251 struct page *old_page; 252 struct ufs_dir_entry *old_de; 253 int err = -ENOENT; 254 255 if (flags & ~RENAME_NOREPLACE) 256 return -EINVAL; 257 258 old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page); 259 if (!old_de) 260 goto out; 261 262 if (S_ISDIR(old_inode->i_mode)) { 263 err = -EIO; 264 dir_de = ufs_dotdot(old_inode, &dir_page); 265 if (!dir_de) 266 goto out_old; 267 } 268 269 if (new_inode) { 270 struct page *new_page; 271 struct ufs_dir_entry *new_de; 272 273 err = -ENOTEMPTY; 274 if (dir_de && !ufs_empty_dir(new_inode)) 275 goto out_dir; 276 277 err = -ENOENT; 278 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page); 279 if (!new_de) 280 goto out_dir; 281 ufs_set_link(new_dir, new_de, new_page, old_inode, 1); 282 new_inode->i_ctime = current_time(new_inode); 283 if (dir_de) 284 drop_nlink(new_inode); 285 inode_dec_link_count(new_inode); 286 } else { 287 err = ufs_add_link(new_dentry, old_inode); 288 if (err) 289 goto out_dir; 290 if (dir_de) 291 inode_inc_link_count(new_dir); 292 } 293 294 /* 295 * Like most other Unix systems, set the ctime for inodes on a 296 * rename. 297 */ 298 old_inode->i_ctime = current_time(old_inode); 299 300 ufs_delete_entry(old_dir, old_de, old_page); 301 mark_inode_dirty(old_inode); 302 303 if (dir_de) { 304 if (old_dir != new_dir) 305 ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0); 306 else { 307 kunmap(dir_page); 308 put_page(dir_page); 309 } 310 inode_dec_link_count(old_dir); 311 } 312 return 0; 313 314 315 out_dir: 316 if (dir_de) { 317 kunmap(dir_page); 318 put_page(dir_page); 319 } 320 out_old: 321 kunmap(old_page); 322 put_page(old_page); 323 out: 324 return err; 325 } 326 327 const struct inode_operations ufs_dir_inode_operations = { 328 .create = ufs_create, 329 .lookup = ufs_lookup, 330 .link = ufs_link, 331 .unlink = ufs_unlink, 332 .symlink = ufs_symlink, 333 .mkdir = ufs_mkdir, 334 .rmdir = ufs_rmdir, 335 .mknod = ufs_mknod, 336 .rename = ufs_rename, 337 }; 338