fs/minix/namei.c

   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, 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_create(struct inode *dir, struct dentry *dentry, umode_t 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         inode->i_ctime = CURRENT_TIME_SEC;
  98         inode_inc_link_count(inode);
  99         ihold(inode);
 100         return add_nondir(dentry, inode);
 101 }
 102
 103 static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
 104 {
 105         struct inode * inode;
 106         int err;
 107
 108         inode_inc_link_count(dir);
 109
 110         inode = minix_new_inode(dir, S_IFDIR | mode, &err);
 111         if (!inode)
 112                 goto out_dir;
 113
 114         minix_set_inode(inode, 0);
 115
 116         inode_inc_link_count(inode);
 117
 118         err = minix_make_empty(inode, dir);
 119         if (err)
 120                 goto out_fail;
 121
 122         err = minix_add_link(dentry, inode);
 123         if (err)
 124                 goto out_fail;
 125
 126         d_instantiate(dentry, inode);
 127 out:
 128         return err;
 129
 130 out_fail:
 131         inode_dec_link_count(inode);
 132         inode_dec_link_count(inode);
 133         iput(inode);
 134 out_dir:
 135         inode_dec_link_count(dir);
 136         goto out;
 137 }
 138
 139 static int minix_unlink(struct inode * dir, struct dentry *dentry)
 140 {
 141         int err = -ENOENT;
 142         struct inode * inode = dentry->d_inode;
 143         struct page * page;
 144         struct minix_dir_entry * de;
 145
 146         de = minix_find_entry(dentry, &page);
 147         if (!de)
 148                 goto end_unlink;
 149
 150         err = minix_delete_entry(de, page);
 151         if (err)
 152                 goto end_unlink;
 153
 154         inode->i_ctime = dir->i_ctime;
 155         inode_dec_link_count(inode);
 156 end_unlink:
 157         return err;
 158 }
 159
 160 static int minix_rmdir(struct inode * dir, struct dentry *dentry)
 161 {
 162         struct inode * inode = dentry->d_inode;
 163         int err = -ENOTEMPTY;
 164
 165         if (minix_empty_dir(inode)) {
 166                 err = minix_unlink(dir, dentry);
 167                 if (!err) {
 168                         inode_dec_link_count(dir);
 169                         inode_dec_link_count(inode);
 170                 }
 171         }
 172         return err;
 173 }
 174
 175 static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
 176                            struct inode * new_dir, struct dentry *new_dentry)
 177 {
 178         struct inode * old_inode = old_dentry->d_inode;
 179         struct inode * new_inode = new_dentry->d_inode;
 180         struct page * dir_page = NULL;
 181         struct minix_dir_entry * dir_de = NULL;
 182         struct page * old_page;
 183         struct minix_dir_entry * old_de;
 184         int err = -ENOENT;
 185
 186         old_de = minix_find_entry(old_dentry, &old_page);
 187         if (!old_de)
 188                 goto out;
 189
 190         if (S_ISDIR(old_inode->i_mode)) {
 191                 err = -EIO;
 192                 dir_de = minix_dotdot(old_inode, &dir_page);
 193                 if (!dir_de)
 194                         goto out_old;
 195         }
 196
 197         if (new_inode) {
 198                 struct page * new_page;
 199                 struct minix_dir_entry * new_de;
 200
 201                 err = -ENOTEMPTY;
 202                 if (dir_de && !minix_empty_dir(new_inode))
 203                         goto out_dir;
 204
 205                 err = -ENOENT;
 206                 new_de = minix_find_entry(new_dentry, &new_page);
 207                 if (!new_de)
 208                         goto out_dir;
 209                 minix_set_link(new_de, new_page, old_inode);
 210                 new_inode->i_ctime = CURRENT_TIME_SEC;
 211                 if (dir_de)
 212                         drop_nlink(new_inode);
 213                 inode_dec_link_count(new_inode);
 214         } else {
 215                 err = minix_add_link(new_dentry, old_inode);
 216                 if (err)
 217                         goto out_dir;
 218                 if (dir_de)
 219                         inode_inc_link_count(new_dir);
 220         }
 221
 222         minix_delete_entry(old_de, old_page);
 223         mark_inode_dirty(old_inode);
 224
 225         if (dir_de) {
 226                 minix_set_link(dir_de, dir_page, new_dir);
 227                 inode_dec_link_count(old_dir);
 228         }
 229         return 0;
 230
 231 out_dir:
 232         if (dir_de) {
 233                 kunmap(dir_page);
 234                 page_cache_release(dir_page);
 235         }
 236 out_old:
 237         kunmap(old_page);
 238         page_cache_release(old_page);
 239 out:
 240         return err;
 241 }
 242
 243 /*
 244  * directories can handle most operations...
 245  */
 246 const struct inode_operations minix_dir_inode_operations = {
 247         .create         = minix_create,
 248         .lookup         = minix_lookup,
 249         .link           = minix_link,
 250         .unlink         = minix_unlink,
 251         .symlink        = minix_symlink,
 252         .mkdir          = minix_mkdir,
 253         .rmdir          = minix_rmdir,
 254         .mknod          = minix_mknod,
 255         .rename         = minix_rename,
 256         .getattr        = minix_getattr,
 257 };