1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/minix/namei.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 #include "minix.h" 9 10 static int add_nondir(struct dentry *dentry, struct inode *inode) 11 { 12 int err = minix_add_link(dentry, inode); 13 if (!err) { 14 d_instantiate(dentry, inode); 15 return 0; 16 } 17 inode_dec_link_count(inode); 18 iput(inode); 19 return err; 20 } 21 22 static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) 23 { 24 struct inode * inode = NULL; 25 ino_t ino; 26 27 if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen) 28 return ERR_PTR(-ENAMETOOLONG); 29 30 ino = minix_inode_by_name(dentry); 31 if (ino) { 32 inode = minix_iget(dir->i_sb, ino); 33 if (IS_ERR(inode)) 34 return ERR_CAST(inode); 35 } 36 d_add(dentry, inode); 37 return NULL; 38 } 39 40 static int minix_mknod(struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev) 41 { 42 int error; 43 struct inode *inode; 44 45 if (!old_valid_dev(rdev)) 46 return -EINVAL; 47 48 inode = minix_new_inode(dir, mode, &error); 49 50 if (inode) { 51 minix_set_inode(inode, rdev); 52 mark_inode_dirty(inode); 53 error = add_nondir(dentry, inode); 54 } 55 return error; 56 } 57 58 static int minix_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 59 { 60 int error; 61 struct inode *inode = minix_new_inode(dir, mode, &error); 62 if (inode) { 63 minix_set_inode(inode, 0); 64 mark_inode_dirty(inode); 65 d_tmpfile(dentry, inode); 66 } 67 return error; 68 } 69 70 static int minix_create(struct inode *dir, struct dentry *dentry, umode_t mode, 71 bool excl) 72 { 73 return minix_mknod(dir, dentry, mode, 0); 74 } 75 76 static int minix_symlink(struct inode * dir, struct dentry *dentry, 77 const char * symname) 78 { 79 int err = -ENAMETOOLONG; 80 int i = strlen(symname)+1; 81 struct inode * inode; 82 83 if (i > dir->i_sb->s_blocksize) 84 goto out; 85 86 inode = minix_new_inode(dir, S_IFLNK | 0777, &err); 87 if (!inode) 88 goto out; 89 90 minix_set_inode(inode, 0); 91 err = page_symlink(inode, symname, i); 92 if (err) 93 goto out_fail; 94 95 err = add_nondir(dentry, inode); 96 out: 97 return err; 98 99 out_fail: 100 inode_dec_link_count(inode); 101 iput(inode); 102 goto out; 103 } 104 105 static int minix_link(struct dentry * old_dentry, struct inode * dir, 106 struct dentry *dentry) 107 { 108 struct inode *inode = d_inode(old_dentry); 109 110 inode->i_ctime = current_time(inode); 111 inode_inc_link_count(inode); 112 ihold(inode); 113 return add_nondir(dentry, inode); 114 } 115 116 static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode) 117 { 118 struct inode * inode; 119 int err; 120 121 inode_inc_link_count(dir); 122 123 inode = minix_new_inode(dir, S_IFDIR | mode, &err); 124 if (!inode) 125 goto out_dir; 126 127 minix_set_inode(inode, 0); 128 129 inode_inc_link_count(inode); 130 131 err = minix_make_empty(inode, dir); 132 if (err) 133 goto out_fail; 134 135 err = minix_add_link(dentry, inode); 136 if (err) 137 goto out_fail; 138 139 d_instantiate(dentry, inode); 140 out: 141 return err; 142 143 out_fail: 144 inode_dec_link_count(inode); 145 inode_dec_link_count(inode); 146 iput(inode); 147 out_dir: 148 inode_dec_link_count(dir); 149 goto out; 150 } 151 152 static int minix_unlink(struct inode * dir, struct dentry *dentry) 153 { 154 int err = -ENOENT; 155 struct inode * inode = d_inode(dentry); 156 struct page * page; 157 struct minix_dir_entry * de; 158 159 de = minix_find_entry(dentry, &page); 160 if (!de) 161 goto end_unlink; 162 163 err = minix_delete_entry(de, page); 164 if (err) 165 goto end_unlink; 166 167 inode->i_ctime = dir->i_ctime; 168 inode_dec_link_count(inode); 169 end_unlink: 170 return err; 171 } 172 173 static int minix_rmdir(struct inode * dir, struct dentry *dentry) 174 { 175 struct inode * inode = d_inode(dentry); 176 int err = -ENOTEMPTY; 177 178 if (minix_empty_dir(inode)) { 179 err = minix_unlink(dir, dentry); 180 if (!err) { 181 inode_dec_link_count(dir); 182 inode_dec_link_count(inode); 183 } 184 } 185 return err; 186 } 187 188 static int minix_rename(struct inode * old_dir, struct dentry *old_dentry, 189 struct inode * new_dir, struct dentry *new_dentry, 190 unsigned int flags) 191 { 192 struct inode * old_inode = d_inode(old_dentry); 193 struct inode * new_inode = d_inode(new_dentry); 194 struct page * dir_page = NULL; 195 struct minix_dir_entry * dir_de = NULL; 196 struct page * old_page; 197 struct minix_dir_entry * old_de; 198 int err = -ENOENT; 199 200 if (flags & ~RENAME_NOREPLACE) 201 return -EINVAL; 202 203 old_de = minix_find_entry(old_dentry, &old_page); 204 if (!old_de) 205 goto out; 206 207 if (S_ISDIR(old_inode->i_mode)) { 208 err = -EIO; 209 dir_de = minix_dotdot(old_inode, &dir_page); 210 if (!dir_de) 211 goto out_old; 212 } 213 214 if (new_inode) { 215 struct page * new_page; 216 struct minix_dir_entry * new_de; 217 218 err = -ENOTEMPTY; 219 if (dir_de && !minix_empty_dir(new_inode)) 220 goto out_dir; 221 222 err = -ENOENT; 223 new_de = minix_find_entry(new_dentry, &new_page); 224 if (!new_de) 225 goto out_dir; 226 minix_set_link(new_de, new_page, old_inode); 227 new_inode->i_ctime = current_time(new_inode); 228 if (dir_de) 229 drop_nlink(new_inode); 230 inode_dec_link_count(new_inode); 231 } else { 232 err = minix_add_link(new_dentry, old_inode); 233 if (err) 234 goto out_dir; 235 if (dir_de) 236 inode_inc_link_count(new_dir); 237 } 238 239 minix_delete_entry(old_de, old_page); 240 mark_inode_dirty(old_inode); 241 242 if (dir_de) { 243 minix_set_link(dir_de, dir_page, new_dir); 244 inode_dec_link_count(old_dir); 245 } 246 return 0; 247 248 out_dir: 249 if (dir_de) { 250 kunmap(dir_page); 251 put_page(dir_page); 252 } 253 out_old: 254 kunmap(old_page); 255 put_page(old_page); 256 out: 257 return err; 258 } 259 260 /* 261 * directories can handle most operations... 262 */ 263 const struct inode_operations minix_dir_inode_operations = { 264 .create = minix_create, 265 .lookup = minix_lookup, 266 .link = minix_link, 267 .unlink = minix_unlink, 268 .symlink = minix_symlink, 269 .mkdir = minix_mkdir, 270 .rmdir = minix_rmdir, 271 .mknod = minix_mknod, 272 .rename = minix_rename, 273 .getattr = minix_getattr, 274 .tmpfile = minix_tmpfile, 275 }; 276