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(dentry, inode);
  42                 return 0;
  43         }
  44         inode_dec_link_count(inode);
  45         iput(inode);
  46         return err;
  47 }
  48
  49 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
  50 {
  51         struct inode * inode = NULL;
  52         ino_t ino;
  53
  54         if (dentry->d_name.len > UFS_MAXNAMLEN)
  55                 return ERR_PTR(-ENAMETOOLONG);
  56
  57         lock_ufs(dir->i_sb);
  58         ino = ufs_inode_by_name(dir, &dentry->d_name);
  59         if (ino)
  60                 inode = ufs_iget(dir->i_sb, ino);
  61         unlock_ufs(dir->i_sb);
  62         return d_splice_alias(inode, dentry);
  63 }
  64
  65 /*
  66  * By the time this is called, we already have created
  67  * the directory cache entry for the new file, but it
  68  * is so far negative - it has no inode.
  69  *
  70  * If the create succeeds, we fill in the inode information
  71  * with d_instantiate().
  72  */
  73 static int ufs_create (struct inode * dir, struct dentry * dentry, int mode,
  74                 struct nameidata *nd)
  75 {
  76         struct inode *inode;
  77         int err;
  78
  79         UFSD("BEGIN\n");
  80
  81         inode = ufs_new_inode(dir, mode);
  82         err = PTR_ERR(inode);
  83
  84         if (!IS_ERR(inode)) {
  85                 inode->i_op = &ufs_file_inode_operations;
  86                 inode->i_fop = &ufs_file_operations;
  87                 inode->i_mapping->a_ops = &ufs_aops;
  88                 mark_inode_dirty(inode);
  89                 lock_ufs(dir->i_sb);
  90                 err = ufs_add_nondir(dentry, inode);
  91                 unlock_ufs(dir->i_sb);
  92         }
  93         UFSD("END: err=%d\n", err);
  94         return err;
  95 }
  96
  97 static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
  98 {
  99         struct inode *inode;
 100         int err;
 101
 102         if (!old_valid_dev(rdev))
 103                 return -EINVAL;
 104
 105         inode = ufs_new_inode(dir, mode);
 106         err = PTR_ERR(inode);
 107         if (!IS_ERR(inode)) {
 108                 init_special_inode(inode, mode, rdev);
 109                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 110                 mark_inode_dirty(inode);
 111                 lock_ufs(dir->i_sb);
 112                 err = ufs_add_nondir(dentry, inode);
 113                 unlock_ufs(dir->i_sb);
 114         }
 115         return err;
 116 }
 117
 118 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 119         const char * symname)
 120 {
 121         struct super_block * sb = dir->i_sb;
 122         int err = -ENAMETOOLONG;
 123         unsigned l = strlen(symname)+1;
 124         struct inode * inode;
 125
 126         if (l > sb->s_blocksize)
 127                 goto out_notlocked;
 128
 129         lock_ufs(dir->i_sb);
 130         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 131         err = PTR_ERR(inode);
 132         if (IS_ERR(inode))
 133                 goto out;
 134
 135         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 136                 /* slow symlink */
 137                 inode->i_op = &ufs_symlink_inode_operations;
 138                 inode->i_mapping->a_ops = &ufs_aops;
 139                 err = page_symlink(inode, symname, l);
 140                 if (err)
 141                         goto out_fail;
 142         } else {
 143                 /* fast symlink */
 144                 inode->i_op = &ufs_fast_symlink_inode_operations;
 145                 memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l);
 146                 inode->i_size = l-1;
 147         }
 148         mark_inode_dirty(inode);
 149
 150         err = ufs_add_nondir(dentry, inode);
 151 out:
 152         unlock_ufs(dir->i_sb);
 153 out_notlocked:
 154         return err;
 155
 156 out_fail:
 157         inode_dec_link_count(inode);
 158         iput(inode);
 159         goto out;
 160 }
 161
 162 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 163         struct dentry *dentry)
 164 {
 165         struct inode *inode = old_dentry->d_inode;
 166         int error;
 167
 168         lock_ufs(dir->i_sb);
 169         if (inode->i_nlink >= UFS_LINK_MAX) {
 170                 unlock_ufs(dir->i_sb);
 171                 return -EMLINK;
 172         }
 173
 174         inode->i_ctime = CURRENT_TIME_SEC;
 175         inode_inc_link_count(inode);
 176         ihold(inode);
 177
 178         error = ufs_add_nondir(dentry, inode);
 179         unlock_ufs(dir->i_sb);
 180         return error;
 181 }
 182
 183 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 184 {
 185         struct inode * inode;
 186         int err = -EMLINK;
 187
 188         if (dir->i_nlink >= UFS_LINK_MAX)
 189                 goto out;
 190
 191         lock_ufs(dir->i_sb);
 192         inode_inc_link_count(dir);
 193
 194         inode = ufs_new_inode(dir, S_IFDIR|mode);
 195         err = PTR_ERR(inode);
 196         if (IS_ERR(inode))
 197                 goto out_dir;
 198
 199         inode->i_op = &ufs_dir_inode_operations;
 200         inode->i_fop = &ufs_dir_operations;
 201         inode->i_mapping->a_ops = &ufs_aops;
 202
 203         inode_inc_link_count(inode);
 204
 205         err = ufs_make_empty(inode, dir);
 206         if (err)
 207                 goto out_fail;
 208
 209         err = ufs_add_link(dentry, inode);
 210         if (err)
 211                 goto out_fail;
 212         unlock_ufs(dir->i_sb);
 213
 214         d_instantiate(dentry, inode);
 215 out:
 216         return err;
 217
 218 out_fail:
 219         inode_dec_link_count(inode);
 220         inode_dec_link_count(inode);
 221         iput (inode);
 222 out_dir:
 223         inode_dec_link_count(dir);
 224         unlock_ufs(dir->i_sb);
 225         goto out;
 226 }
 227
 228 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 229 {
 230         struct inode * inode = dentry->d_inode;
 231         struct ufs_dir_entry *de;
 232         struct page *page;
 233         int err = -ENOENT;
 234
 235         de = ufs_find_entry(dir, &dentry->d_name, &page);
 236         if (!de)
 237                 goto out;
 238
 239         err = ufs_delete_entry(dir, de, page);
 240         if (err)
 241                 goto out;
 242
 243         inode->i_ctime = dir->i_ctime;
 244         inode_dec_link_count(inode);
 245         err = 0;
 246 out:
 247         return err;
 248 }
 249
 250 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 251 {
 252         struct inode * inode = dentry->d_inode;
 253         int err= -ENOTEMPTY;
 254
 255         lock_ufs(dir->i_sb);
 256         if (ufs_empty_dir (inode)) {
 257                 err = ufs_unlink(dir, dentry);
 258                 if (!err) {
 259                         inode->i_size = 0;
 260                         inode_dec_link_count(inode);
 261                         inode_dec_link_count(dir);
 262                 }
 263         }
 264         unlock_ufs(dir->i_sb);
 265         return err;
 266 }
 267
 268 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 269                       struct inode *new_dir, struct dentry *new_dentry)
 270 {
 271         struct inode *old_inode = old_dentry->d_inode;
 272         struct inode *new_inode = new_dentry->d_inode;
 273         struct page *dir_page = NULL;
 274         struct ufs_dir_entry * dir_de = NULL;
 275         struct page *old_page;
 276         struct ufs_dir_entry *old_de;
 277         int err = -ENOENT;
 278
 279         old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 280         if (!old_de)
 281                 goto out;
 282
 283         if (S_ISDIR(old_inode->i_mode)) {
 284                 err = -EIO;
 285                 dir_de = ufs_dotdot(old_inode, &dir_page);
 286                 if (!dir_de)
 287                         goto out_old;
 288         }
 289
 290         if (new_inode) {
 291                 struct page *new_page;
 292                 struct ufs_dir_entry *new_de;
 293
 294                 err = -ENOTEMPTY;
 295                 if (dir_de && !ufs_empty_dir(new_inode))
 296                         goto out_dir;
 297
 298                 err = -ENOENT;
 299                 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 300                 if (!new_de)
 301                         goto out_dir;
 302                 ufs_set_link(new_dir, new_de, new_page, old_inode);
 303                 new_inode->i_ctime = CURRENT_TIME_SEC;
 304                 if (dir_de)
 305                         drop_nlink(new_inode);
 306                 inode_dec_link_count(new_inode);
 307         } else {
 308                 if (dir_de) {
 309                         err = -EMLINK;
 310                         if (new_dir->i_nlink >= UFS_LINK_MAX)
 311                                 goto out_dir;
 312                 }
 313                 err = ufs_add_link(new_dentry, old_inode);
 314                 if (err)
 315                         goto out_dir;
 316                 if (dir_de)
 317                         inode_inc_link_count(new_dir);
 318         }
 319
 320         /*
 321          * Like most other Unix systems, set the ctime for inodes on a
 322          * rename.
 323          */
 324         old_inode->i_ctime = CURRENT_TIME_SEC;
 325
 326         ufs_delete_entry(old_dir, old_de, old_page);
 327         mark_inode_dirty(old_inode);
 328
 329         if (dir_de) {
 330                 ufs_set_link(old_inode, dir_de, dir_page, new_dir);
 331                 inode_dec_link_count(old_dir);
 332         }
 333         return 0;
 334
 335
 336 out_dir:
 337         if (dir_de) {
 338                 kunmap(dir_page);
 339                 page_cache_release(dir_page);
 340         }
 341 out_old:
 342         kunmap(old_page);
 343         page_cache_release(old_page);
 344 out:
 345         return err;
 346 }
 347
 348 const struct inode_operations ufs_dir_inode_operations = {
 349         .create         = ufs_create,
 350         .lookup         = ufs_lookup,
 351         .link           = ufs_link,
 352         .unlink         = ufs_unlink,
 353         .symlink        = ufs_symlink,
 354         .mkdir          = ufs_mkdir,
 355         .rmdir          = ufs_rmdir,
 356         .mknod          = ufs_mknod,
 357         .rename         = ufs_rename,
 358 };