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, struct nameidata *nd) 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, int 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_create(struct inode * dir, struct dentry *dentry, int mode, 58 struct nameidata *nd) 59 { 60 return minix_mknod(dir, dentry, mode, 0); 61 } 62 63 static int minix_symlink(struct inode * dir, struct dentry *dentry, 64 const char * symname) 65 { 66 int err = -ENAMETOOLONG; 67 int i = strlen(symname)+1; 68 struct inode * inode; 69 70 if (i > dir->i_sb->s_blocksize) 71 goto out; 72 73 inode = minix_new_inode(dir, S_IFLNK | 0777, &err); 74 if (!inode) 75 goto out; 76 77 minix_set_inode(inode, 0); 78 err = page_symlink(inode, symname, i); 79 if (err) 80 goto out_fail; 81 82 err = add_nondir(dentry, inode); 83 out: 84 return err; 85 86 out_fail: 87 inode_dec_link_count(inode); 88 iput(inode); 89 goto out; 90 } 91 92 static int minix_link(struct dentry * old_dentry, struct inode * dir, 93 struct dentry *dentry) 94 { 95 struct inode *inode = old_dentry->d_inode; 96 97 if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max) 98 return -EMLINK; 99 100 inode->i_ctime = CURRENT_TIME_SEC; 101 inode_inc_link_count(inode); 102 ihold(inode); 103 return add_nondir(dentry, inode); 104 } 105 106 static int minix_mkdir(struct inode * dir, struct dentry *dentry, int mode) 107 { 108 struct inode * inode; 109 int err = -EMLINK; 110 111 if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max) 112 goto out; 113 114 inode_inc_link_count(dir); 115 116 inode = minix_new_inode(dir, S_IFDIR | mode, &err); 117 if (!inode) 118 goto out_dir; 119 120 minix_set_inode(inode, 0); 121 122 inode_inc_link_count(inode); 123 124 err = minix_make_empty(inode, dir); 125 if (err) 126 goto out_fail; 127 128 err = minix_add_link(dentry, inode); 129 if (err) 130 goto out_fail; 131 132 d_instantiate(dentry, inode); 133 out: 134 return err; 135 136 out_fail: 137 inode_dec_link_count(inode); 138 inode_dec_link_count(inode); 139 iput(inode); 140 out_dir: 141 inode_dec_link_count(dir); 142 goto out; 143 } 144 145 static int minix_unlink(struct inode * dir, struct dentry *dentry) 146 { 147 int err = -ENOENT; 148 struct inode * inode = dentry->d_inode; 149 struct page * page; 150 struct minix_dir_entry * de; 151 152 de = minix_find_entry(dentry, &page); 153 if (!de) 154 goto end_unlink; 155 156 err = minix_delete_entry(de, page); 157 if (err) 158 goto end_unlink; 159 160 inode->i_ctime = dir->i_ctime; 161 inode_dec_link_count(inode); 162 end_unlink: 163 return err; 164 } 165 166 static int minix_rmdir(struct inode * dir, struct dentry *dentry) 167 { 168 struct inode * inode = dentry->d_inode; 169 int err = -ENOTEMPTY; 170 171 if (minix_empty_dir(inode)) { 172 err = minix_unlink(dir, dentry); 173 if (!err) { 174 inode_dec_link_count(dir); 175 inode_dec_link_count(inode); 176 } 177 } 178 return err; 179 } 180 181 static int minix_rename(struct inode * old_dir, struct dentry *old_dentry, 182 struct inode * new_dir, struct dentry *new_dentry) 183 { 184 struct minix_sb_info * info = minix_sb(old_dir->i_sb); 185 struct inode * old_inode = old_dentry->d_inode; 186 struct inode * new_inode = new_dentry->d_inode; 187 struct page * dir_page = NULL; 188 struct minix_dir_entry * dir_de = NULL; 189 struct page * old_page; 190 struct minix_dir_entry * old_de; 191 int err = -ENOENT; 192 193 old_de = minix_find_entry(old_dentry, &old_page); 194 if (!old_de) 195 goto out; 196 197 if (S_ISDIR(old_inode->i_mode)) { 198 err = -EIO; 199 dir_de = minix_dotdot(old_inode, &dir_page); 200 if (!dir_de) 201 goto out_old; 202 } 203 204 if (new_inode) { 205 struct page * new_page; 206 struct minix_dir_entry * new_de; 207 208 err = -ENOTEMPTY; 209 if (dir_de && !minix_empty_dir(new_inode)) 210 goto out_dir; 211 212 err = -ENOENT; 213 new_de = minix_find_entry(new_dentry, &new_page); 214 if (!new_de) 215 goto out_dir; 216 minix_set_link(new_de, new_page, old_inode); 217 new_inode->i_ctime = CURRENT_TIME_SEC; 218 if (dir_de) 219 drop_nlink(new_inode); 220 inode_dec_link_count(new_inode); 221 } else { 222 if (dir_de) { 223 err = -EMLINK; 224 if (new_dir->i_nlink >= info->s_link_max) 225 goto out_dir; 226 } 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 page_cache_release(dir_page); 247 } 248 out_old: 249 kunmap(old_page); 250 page_cache_release(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 }; 270