1 /* 2 * linux/fs/minix/namei.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 #include "minix.h" 8 9 static int add_nondir(struct dentry *dentry, struct inode *inode) 10 { 11 int err = minix_add_link(dentry, inode); 12 if (!err) { 13 d_instantiate(dentry, inode); 14 return 0; 15 } 16 inode_dec_link_count(inode); 17 iput(inode); 18 return err; 19 } 20 21 static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) 22 { 23 struct inode * inode = NULL; 24 ino_t ino; 25 26 if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen) 27 return ERR_PTR(-ENAMETOOLONG); 28 29 ino = minix_inode_by_name(dentry); 30 if (ino) { 31 inode = minix_iget(dir->i_sb, ino); 32 if (IS_ERR(inode)) 33 return ERR_CAST(inode); 34 } 35 d_add(dentry, inode); 36 return NULL; 37 } 38 39 static int minix_mknod(struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev) 40 { 41 int error; 42 struct inode *inode; 43 44 if (!old_valid_dev(rdev)) 45 return -EINVAL; 46 47 inode = minix_new_inode(dir, mode, &error); 48 49 if (inode) { 50 minix_set_inode(inode, rdev); 51 mark_inode_dirty(inode); 52 error = add_nondir(dentry, inode); 53 } 54 return error; 55 } 56 57 static int minix_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 58 { 59 int error; 60 struct inode *inode = minix_new_inode(dir, mode, &error); 61 if (inode) { 62 minix_set_inode(inode, 0); 63 mark_inode_dirty(inode); 64 d_tmpfile(dentry, inode); 65 } 66 return error; 67 } 68 69 static int minix_create(struct inode *dir, struct dentry *dentry, umode_t mode, 70 bool excl) 71 { 72 return minix_mknod(dir, dentry, mode, 0); 73 } 74 75 static int minix_symlink(struct inode * dir, struct dentry *dentry, 76 const char * symname) 77 { 78 int err = -ENAMETOOLONG; 79 int i = strlen(symname)+1; 80 struct inode * inode; 81 82 if (i > dir->i_sb->s_blocksize) 83 goto out; 84 85 inode = minix_new_inode(dir, S_IFLNK | 0777, &err); 86 if (!inode) 87 goto out; 88 89 minix_set_inode(inode, 0); 90 err = page_symlink(inode, symname, i); 91 if (err) 92 goto out_fail; 93 94 err = add_nondir(dentry, inode); 95 out: 96 return err; 97 98 out_fail: 99 inode_dec_link_count(inode); 100 iput(inode); 101 goto out; 102 } 103 104 static int minix_link(struct dentry * old_dentry, struct inode * dir, 105 struct dentry *dentry) 106 { 107 struct inode *inode = d_inode(old_dentry); 108 109 inode->i_ctime = CURRENT_TIME_SEC; 110 inode_inc_link_count(inode); 111 ihold(inode); 112 return add_nondir(dentry, inode); 113 } 114 115 static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode) 116 { 117 struct inode * inode; 118 int err; 119 120 inode_inc_link_count(dir); 121 122 inode = minix_new_inode(dir, S_IFDIR | mode, &err); 123 if (!inode) 124 goto out_dir; 125 126 minix_set_inode(inode, 0); 127 128 inode_inc_link_count(inode); 129 130 err = minix_make_empty(inode, dir); 131 if (err) 132 goto out_fail; 133 134 err = minix_add_link(dentry, inode); 135 if (err) 136 goto out_fail; 137 138 d_instantiate(dentry, inode); 139 out: 140 return err; 141 142 out_fail: 143 inode_dec_link_count(inode); 144 inode_dec_link_count(inode); 145 iput(inode); 146 out_dir: 147 inode_dec_link_count(dir); 148 goto out; 149 } 150 151 static int minix_unlink(struct inode * dir, struct dentry *dentry) 152 { 153 int err = -ENOENT; 154 struct inode * inode = d_inode(dentry); 155 struct page * page; 156 struct minix_dir_entry * de; 157 158 de = minix_find_entry(dentry, &page); 159 if (!de) 160 goto end_unlink; 161 162 err = minix_delete_entry(de, page); 163 if (err) 164 goto end_unlink; 165 166 inode->i_ctime = dir->i_ctime; 167 inode_dec_link_count(inode); 168 end_unlink: 169 return err; 170 } 171 172 static int minix_rmdir(struct inode * dir, struct dentry *dentry) 173 { 174 struct inode * inode = d_inode(dentry); 175 int err = -ENOTEMPTY; 176 177 if (minix_empty_dir(inode)) { 178 err = minix_unlink(dir, dentry); 179 if (!err) { 180 inode_dec_link_count(dir); 181 inode_dec_link_count(inode); 182 } 183 } 184 return err; 185 } 186 187 static int minix_rename(struct inode * old_dir, struct dentry *old_dentry, 188 struct inode * new_dir, struct dentry *new_dentry) 189 { 190 struct inode * old_inode = d_inode(old_dentry); 191 struct inode * new_inode = d_inode(new_dentry); 192 struct page * dir_page = NULL; 193 struct minix_dir_entry * dir_de = NULL; 194 struct page * old_page; 195 struct minix_dir_entry * old_de; 196 int err = -ENOENT; 197 198 old_de = minix_find_entry(old_dentry, &old_page); 199 if (!old_de) 200 goto out; 201 202 if (S_ISDIR(old_inode->i_mode)) { 203 err = -EIO; 204 dir_de = minix_dotdot(old_inode, &dir_page); 205 if (!dir_de) 206 goto out_old; 207 } 208 209 if (new_inode) { 210 struct page * new_page; 211 struct minix_dir_entry * new_de; 212 213 err = -ENOTEMPTY; 214 if (dir_de && !minix_empty_dir(new_inode)) 215 goto out_dir; 216 217 err = -ENOENT; 218 new_de = minix_find_entry(new_dentry, &new_page); 219 if (!new_de) 220 goto out_dir; 221 minix_set_link(new_de, new_page, old_inode); 222 new_inode->i_ctime = CURRENT_TIME_SEC; 223 if (dir_de) 224 drop_nlink(new_inode); 225 inode_dec_link_count(new_inode); 226 } else { 227 err = minix_add_link(new_dentry, old_inode); 228 if (err) 229 goto out_dir; 230 if (dir_de) 231 inode_inc_link_count(new_dir); 232 } 233 234 minix_delete_entry(old_de, old_page); 235 mark_inode_dirty(old_inode); 236 237 if (dir_de) { 238 minix_set_link(dir_de, dir_page, new_dir); 239 inode_dec_link_count(old_dir); 240 } 241 return 0; 242 243 out_dir: 244 if (dir_de) { 245 kunmap(dir_page); 246 put_page(dir_page); 247 } 248 out_old: 249 kunmap(old_page); 250 put_page(old_page); 251 out: 252 return err; 253 } 254 255 /* 256 * directories can handle most operations... 257 */ 258 const struct inode_operations minix_dir_inode_operations = { 259 .create = minix_create, 260 .lookup = minix_lookup, 261 .link = minix_link, 262 .unlink = minix_unlink, 263 .symlink = minix_symlink, 264 .mkdir = minix_mkdir, 265 .rmdir = minix_rmdir, 266 .mknod = minix_mknod, 267 .rename = minix_rename, 268 .getattr = minix_getattr, 269 .tmpfile = minix_tmpfile, 270 }; 271