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, 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                 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         .tmpfile        = minix_tmpfile,
 270 };