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