fs/ufs/namei.c

   1 /*
   2  * linux/fs/ufs/namei.c
   3  *
   4  * Migration to usage of "page cache" on May 2006 by
   5  * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
   6  *
   7  * Copyright (C) 1998
   8  * Daniel Pirkl <daniel.pirkl@email.cz>
   9  * Charles University, Faculty of Mathematics and Physics
  10  *
  11  *  from
  12  *
  13  *  linux/fs/ext2/namei.c
  14  *
  15  * Copyright (C) 1992, 1993, 1994, 1995
  16  * Remy Card (card@masi.ibp.fr)
  17  * Laboratoire MASI - Institut Blaise Pascal
  18  * Universite Pierre et Marie Curie (Paris VI)
  19  *
  20  *  from
  21  *
  22  *  linux/fs/minix/namei.c
  23  *
  24  *  Copyright (C) 1991, 1992  Linus Torvalds
  25  *
  26  *  Big-endian to little-endian byte-swapping/bitmaps by
  27  *        David S. Miller (davem@caip.rutgers.edu), 1995
  28  */
  29
  30 #include <linux/time.h>
  31 #include <linux/fs.h>
  32
  33 #include "ufs_fs.h"
  34 #include "ufs.h"
  35 #include "util.h"
  36
  37 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
  38 {
  39         int err = ufs_add_link(dentry, inode);
  40         if (!err) {
  41                 d_instantiate_new(dentry, inode);
  42                 return 0;
  43         }
  44         inode_dec_link_count(inode);
  45         unlock_new_inode(inode);
  46         iput(inode);
  47         return err;
  48 }
  49
  50 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
  51 {
  52         struct inode * inode = NULL;
  53         ino_t ino;
  54
  55         if (dentry->d_name.len > UFS_MAXNAMLEN)
  56                 return ERR_PTR(-ENAMETOOLONG);
  57
  58         ino = ufs_inode_by_name(dir, &dentry->d_name);
  59         if (ino)
  60                 inode = ufs_iget(dir->i_sb, ino);
  61         return d_splice_alias(inode, dentry);
  62 }
  63
  64 /*
  65  * By the time this is called, we already have created
  66  * the directory cache entry for the new file, but it
  67  * is so far negative - it has no inode.
  68  *
  69  * If the create succeeds, we fill in the inode information
  70  * with d_instantiate().
  71  */
  72 static int ufs_create (struct inode * dir, struct dentry * dentry, umode_t mode,
  73                 bool excl)
  74 {
  75         struct inode *inode;
  76
  77         inode = ufs_new_inode(dir, mode);
  78         if (IS_ERR(inode))
  79                 return PTR_ERR(inode);
  80
  81         inode->i_op = &ufs_file_inode_operations;
  82         inode->i_fop = &ufs_file_operations;
  83         inode->i_mapping->a_ops = &ufs_aops;
  84         mark_inode_dirty(inode);
  85         return ufs_add_nondir(dentry, inode);
  86 }
  87
  88 static int ufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
  89 {
  90         struct inode *inode;
  91         int err;
  92
  93         if (!old_valid_dev(rdev))
  94                 return -EINVAL;
  95
  96         inode = ufs_new_inode(dir, mode);
  97         err = PTR_ERR(inode);
  98         if (!IS_ERR(inode)) {
  99                 init_special_inode(inode, mode, rdev);
 100                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 101                 mark_inode_dirty(inode);
 102                 err = ufs_add_nondir(dentry, inode);
 103         }
 104         return err;
 105 }
 106
 107 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 108         const char * symname)
 109 {
 110         struct super_block * sb = dir->i_sb;
 111         int err;
 112         unsigned l = strlen(symname)+1;
 113         struct inode * inode;
 114
 115         if (l > sb->s_blocksize)
 116                 return -ENAMETOOLONG;
 117
 118         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 119         err = PTR_ERR(inode);
 120         if (IS_ERR(inode))
 121                 return err;
 122
 123         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 124                 /* slow symlink */
 125                 inode->i_op = &page_symlink_inode_operations;
 126                 inode_nohighmem(inode);
 127                 inode->i_mapping->a_ops = &ufs_aops;
 128                 err = page_symlink(inode, symname, l);
 129                 if (err)
 130                         goto out_fail;
 131         } else {
 132                 /* fast symlink */
 133                 inode->i_op = &simple_symlink_inode_operations;
 134                 inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
 135                 memcpy(inode->i_link, symname, l);
 136                 inode->i_size = l-1;
 137         }
 138         mark_inode_dirty(inode);
 139
 140         return ufs_add_nondir(dentry, inode);
 141
 142 out_fail:
 143         inode_dec_link_count(inode);
 144         unlock_new_inode(inode);
 145         iput(inode);
 146         return err;
 147 }
 148
 149 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 150         struct dentry *dentry)
 151 {
 152         struct inode *inode = d_inode(old_dentry);
 153         int error;
 154
 155         inode->i_ctime = current_time(inode);
 156         inode_inc_link_count(inode);
 157         ihold(inode);
 158
 159         error = ufs_add_link(dentry, inode);
 160         if (error) {
 161                 inode_dec_link_count(inode);
 162                 iput(inode);
 163         } else
 164                 d_instantiate(dentry, inode);
 165         return error;
 166 }
 167
 168 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 169 {
 170         struct inode * inode;
 171         int err;
 172
 173         inode_inc_link_count(dir);
 174
 175         inode = ufs_new_inode(dir, S_IFDIR|mode);
 176         err = PTR_ERR(inode);
 177         if (IS_ERR(inode))
 178                 goto out_dir;
 179
 180         inode->i_op = &ufs_dir_inode_operations;
 181         inode->i_fop = &ufs_dir_operations;
 182         inode->i_mapping->a_ops = &ufs_aops;
 183
 184         inode_inc_link_count(inode);
 185
 186         err = ufs_make_empty(inode, dir);
 187         if (err)
 188                 goto out_fail;
 189
 190         err = ufs_add_link(dentry, inode);
 191         if (err)
 192                 goto out_fail;
 193
 194         d_instantiate_new(dentry, inode);
 195         return 0;
 196
 197 out_fail:
 198         inode_dec_link_count(inode);
 199         inode_dec_link_count(inode);
 200         unlock_new_inode(inode);
 201         iput (inode);
 202 out_dir:
 203         inode_dec_link_count(dir);
 204         return err;
 205 }
 206
 207 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 208 {
 209         struct inode * inode = d_inode(dentry);
 210         struct ufs_dir_entry *de;
 211         struct page *page;
 212         int err = -ENOENT;
 213
 214         de = ufs_find_entry(dir, &dentry->d_name, &page);
 215         if (!de)
 216                 goto out;
 217
 218         err = ufs_delete_entry(dir, de, page);
 219         if (err)
 220                 goto out;
 221
 222         inode->i_ctime = dir->i_ctime;
 223         inode_dec_link_count(inode);
 224         err = 0;
 225 out:
 226         return err;
 227 }
 228
 229 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 230 {
 231         struct inode * inode = d_inode(dentry);
 232         int err= -ENOTEMPTY;
 233
 234         if (ufs_empty_dir (inode)) {
 235                 err = ufs_unlink(dir, dentry);
 236                 if (!err) {
 237                         inode->i_size = 0;
 238                         inode_dec_link_count(inode);
 239                         inode_dec_link_count(dir);
 240                 }
 241         }
 242         return err;
 243 }
 244
 245 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 246                       struct inode *new_dir, struct dentry *new_dentry,
 247                       unsigned int flags)
 248 {
 249         struct inode *old_inode = d_inode(old_dentry);
 250         struct inode *new_inode = d_inode(new_dentry);
 251         struct page *dir_page = NULL;
 252         struct ufs_dir_entry * dir_de = NULL;
 253         struct page *old_page;
 254         struct ufs_dir_entry *old_de;
 255         int err = -ENOENT;
 256
 257         if (flags & ~RENAME_NOREPLACE)
 258                 return -EINVAL;
 259
 260         old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 261         if (!old_de)
 262                 goto out;
 263
 264         if (S_ISDIR(old_inode->i_mode)) {
 265                 err = -EIO;
 266                 dir_de = ufs_dotdot(old_inode, &dir_page);
 267                 if (!dir_de)
 268                         goto out_old;
 269         }
 270
 271         if (new_inode) {
 272                 struct page *new_page;
 273                 struct ufs_dir_entry *new_de;
 274
 275                 err = -ENOTEMPTY;
 276                 if (dir_de && !ufs_empty_dir(new_inode))
 277                         goto out_dir;
 278
 279                 err = -ENOENT;
 280                 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 281                 if (!new_de)
 282                         goto out_dir;
 283                 ufs_set_link(new_dir, new_de, new_page, old_inode, 1);
 284                 new_inode->i_ctime = current_time(new_inode);
 285                 if (dir_de)
 286                         drop_nlink(new_inode);
 287                 inode_dec_link_count(new_inode);
 288         } else {
 289                 err = ufs_add_link(new_dentry, old_inode);
 290                 if (err)
 291                         goto out_dir;
 292                 if (dir_de)
 293                         inode_inc_link_count(new_dir);
 294         }
 295
 296         /*
 297          * Like most other Unix systems, set the ctime for inodes on a
 298          * rename.
 299          */
 300         old_inode->i_ctime = current_time(old_inode);
 301
 302         ufs_delete_entry(old_dir, old_de, old_page);
 303         mark_inode_dirty(old_inode);
 304
 305         if (dir_de) {
 306                 if (old_dir != new_dir)
 307                         ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0);
 308                 else {
 309                         kunmap(dir_page);
 310                         put_page(dir_page);
 311                 }
 312                 inode_dec_link_count(old_dir);
 313         }
 314         return 0;
 315
 316
 317 out_dir:
 318         if (dir_de) {
 319                 kunmap(dir_page);
 320                 put_page(dir_page);
 321         }
 322 out_old:
 323         kunmap(old_page);
 324         put_page(old_page);
 325 out:
 326         return err;
 327 }
 328
 329 const struct inode_operations ufs_dir_inode_operations = {
 330         .create         = ufs_create,
 331         .lookup         = ufs_lookup,
 332         .link           = ufs_link,
 333         .unlink         = ufs_unlink,
 334         .symlink        = ufs_symlink,
 335         .mkdir          = ufs_mkdir,
 336         .rmdir          = ufs_rmdir,
 337         .mknod          = ufs_mknod,
 338         .rename         = ufs_rename,
 339 };