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 #include <linux/smp_lock.h>
  33 #include <linux/quotaops.h>
  34
  35 #include "ufs_fs.h"
  36 #include "ufs.h"
  37 #include "util.h"
  38
  39 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
  40 {
  41         int err = ufs_add_link(dentry, inode);
  42         if (!err) {
  43                 d_instantiate(dentry, inode);
  44                 return 0;
  45         }
  46         inode_dec_link_count(inode);
  47         iput(inode);
  48         return err;
  49 }
  50
  51 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
  52 {
  53         struct inode * inode = NULL;
  54         ino_t ino;
  55
  56         if (dentry->d_name.len > UFS_MAXNAMLEN)
  57                 return ERR_PTR(-ENAMETOOLONG);
  58
  59         lock_kernel();
  60         ino = ufs_inode_by_name(dir, &dentry->d_name);
  61         if (ino) {
  62                 inode = ufs_iget(dir->i_sb, ino);
  63                 if (IS_ERR(inode)) {
  64                         unlock_kernel();
  65                         return ERR_CAST(inode);
  66                 }
  67         }
  68         unlock_kernel();
  69         d_add(dentry, inode);
  70         return NULL;
  71 }
  72
  73 /*
  74  * By the time this is called, we already have created
  75  * the directory cache entry for the new file, but it
  76  * is so far negative - it has no inode.
  77  *
  78  * If the create succeeds, we fill in the inode information
  79  * with d_instantiate().
  80  */
  81 static int ufs_create (struct inode * dir, struct dentry * dentry, int mode,
  82                 struct nameidata *nd)
  83 {
  84         struct inode *inode;
  85         int err;
  86
  87         UFSD("BEGIN\n");
  88
  89         dquot_initialize(dir);
  90
  91         inode = ufs_new_inode(dir, mode);
  92         err = PTR_ERR(inode);
  93
  94         if (!IS_ERR(inode)) {
  95                 inode->i_op = &ufs_file_inode_operations;
  96                 inode->i_fop = &ufs_file_operations;
  97                 inode->i_mapping->a_ops = &ufs_aops;
  98                 mark_inode_dirty(inode);
  99                 lock_kernel();
 100                 err = ufs_add_nondir(dentry, inode);
 101                 unlock_kernel();
 102         }
 103         UFSD("END: err=%d\n", err);
 104         return err;
 105 }
 106
 107 static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
 108 {
 109         struct inode *inode;
 110         int err;
 111
 112         if (!old_valid_dev(rdev))
 113                 return -EINVAL;
 114
 115         dquot_initialize(dir);
 116
 117         inode = ufs_new_inode(dir, mode);
 118         err = PTR_ERR(inode);
 119         if (!IS_ERR(inode)) {
 120                 init_special_inode(inode, mode, rdev);
 121                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 122                 mark_inode_dirty(inode);
 123                 lock_kernel();
 124                 err = ufs_add_nondir(dentry, inode);
 125                 unlock_kernel();
 126         }
 127         return err;
 128 }
 129
 130 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 131         const char * symname)
 132 {
 133         struct super_block * sb = dir->i_sb;
 134         int err = -ENAMETOOLONG;
 135         unsigned l = strlen(symname)+1;
 136         struct inode * inode;
 137
 138         if (l > sb->s_blocksize)
 139                 goto out_notlocked;
 140
 141         dquot_initialize(dir);
 142
 143         lock_kernel();
 144         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 145         err = PTR_ERR(inode);
 146         if (IS_ERR(inode))
 147                 goto out;
 148
 149         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 150                 /* slow symlink */
 151                 inode->i_op = &ufs_symlink_inode_operations;
 152                 inode->i_mapping->a_ops = &ufs_aops;
 153                 err = page_symlink(inode, symname, l);
 154                 if (err)
 155                         goto out_fail;
 156         } else {
 157                 /* fast symlink */
 158                 inode->i_op = &ufs_fast_symlink_inode_operations;
 159                 memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l);
 160                 inode->i_size = l-1;
 161         }
 162         mark_inode_dirty(inode);
 163
 164         err = ufs_add_nondir(dentry, inode);
 165 out:
 166         unlock_kernel();
 167 out_notlocked:
 168         return err;
 169
 170 out_fail:
 171         inode_dec_link_count(inode);
 172         iput(inode);
 173         goto out;
 174 }
 175
 176 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 177         struct dentry *dentry)
 178 {
 179         struct inode *inode = old_dentry->d_inode;
 180         int error;
 181
 182         lock_kernel();
 183         if (inode->i_nlink >= UFS_LINK_MAX) {
 184                 unlock_kernel();
 185                 return -EMLINK;
 186         }
 187
 188         dquot_initialize(dir);
 189
 190         inode->i_ctime = CURRENT_TIME_SEC;
 191         inode_inc_link_count(inode);
 192         atomic_inc(&inode->i_count);
 193
 194         error = ufs_add_nondir(dentry, inode);
 195         unlock_kernel();
 196         return error;
 197 }
 198
 199 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 200 {
 201         struct inode * inode;
 202         int err = -EMLINK;
 203
 204         if (dir->i_nlink >= UFS_LINK_MAX)
 205                 goto out;
 206
 207         dquot_initialize(dir);
 208
 209         lock_kernel();
 210         inode_inc_link_count(dir);
 211
 212         inode = ufs_new_inode(dir, S_IFDIR|mode);
 213         err = PTR_ERR(inode);
 214         if (IS_ERR(inode))
 215                 goto out_dir;
 216
 217         inode->i_op = &ufs_dir_inode_operations;
 218         inode->i_fop = &ufs_dir_operations;
 219         inode->i_mapping->a_ops = &ufs_aops;
 220
 221         inode_inc_link_count(inode);
 222
 223         err = ufs_make_empty(inode, dir);
 224         if (err)
 225                 goto out_fail;
 226
 227         err = ufs_add_link(dentry, inode);
 228         if (err)
 229                 goto out_fail;
 230         unlock_kernel();
 231
 232         d_instantiate(dentry, inode);
 233 out:
 234         return err;
 235
 236 out_fail:
 237         inode_dec_link_count(inode);
 238         inode_dec_link_count(inode);
 239         iput (inode);
 240 out_dir:
 241         inode_dec_link_count(dir);
 242         unlock_kernel();
 243         goto out;
 244 }
 245
 246 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 247 {
 248         struct inode * inode = dentry->d_inode;
 249         struct ufs_dir_entry *de;
 250         struct page *page;
 251         int err = -ENOENT;
 252
 253         dquot_initialize(dir);
 254
 255         de = ufs_find_entry(dir, &dentry->d_name, &page);
 256         if (!de)
 257                 goto out;
 258
 259         err = ufs_delete_entry(dir, de, page);
 260         if (err)
 261                 goto out;
 262
 263         inode->i_ctime = dir->i_ctime;
 264         inode_dec_link_count(inode);
 265         err = 0;
 266 out:
 267         return err;
 268 }
 269
 270 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 271 {
 272         struct inode * inode = dentry->d_inode;
 273         int err= -ENOTEMPTY;
 274
 275         lock_kernel();
 276         if (ufs_empty_dir (inode)) {
 277                 err = ufs_unlink(dir, dentry);
 278                 if (!err) {
 279                         inode->i_size = 0;
 280                         inode_dec_link_count(inode);
 281                         inode_dec_link_count(dir);
 282                 }
 283         }
 284         unlock_kernel();
 285         return err;
 286 }
 287
 288 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 289                       struct inode *new_dir, struct dentry *new_dentry)
 290 {
 291         struct inode *old_inode = old_dentry->d_inode;
 292         struct inode *new_inode = new_dentry->d_inode;
 293         struct page *dir_page = NULL;
 294         struct ufs_dir_entry * dir_de = NULL;
 295         struct page *old_page;
 296         struct ufs_dir_entry *old_de;
 297         int err = -ENOENT;
 298
 299         dquot_initialize(old_dir);
 300         dquot_initialize(new_dir);
 301
 302         old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 303         if (!old_de)
 304                 goto out;
 305
 306         if (S_ISDIR(old_inode->i_mode)) {
 307                 err = -EIO;
 308                 dir_de = ufs_dotdot(old_inode, &dir_page);
 309                 if (!dir_de)
 310                         goto out_old;
 311         }
 312
 313         if (new_inode) {
 314                 struct page *new_page;
 315                 struct ufs_dir_entry *new_de;
 316
 317                 err = -ENOTEMPTY;
 318                 if (dir_de && !ufs_empty_dir(new_inode))
 319                         goto out_dir;
 320
 321                 err = -ENOENT;
 322                 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 323                 if (!new_de)
 324                         goto out_dir;
 325                 inode_inc_link_count(old_inode);
 326                 ufs_set_link(new_dir, new_de, new_page, old_inode);
 327                 new_inode->i_ctime = CURRENT_TIME_SEC;
 328                 if (dir_de)
 329                         drop_nlink(new_inode);
 330                 inode_dec_link_count(new_inode);
 331         } else {
 332                 if (dir_de) {
 333                         err = -EMLINK;
 334                         if (new_dir->i_nlink >= UFS_LINK_MAX)
 335                                 goto out_dir;
 336                 }
 337                 inode_inc_link_count(old_inode);
 338                 err = ufs_add_link(new_dentry, old_inode);
 339                 if (err) {
 340                         inode_dec_link_count(old_inode);
 341                         goto out_dir;
 342                 }
 343                 if (dir_de)
 344                         inode_inc_link_count(new_dir);
 345         }
 346
 347         /*
 348          * Like most other Unix systems, set the ctime for inodes on a
 349          * rename.
 350          * inode_dec_link_count() will mark the inode dirty.
 351          */
 352         old_inode->i_ctime = CURRENT_TIME_SEC;
 353
 354         ufs_delete_entry(old_dir, old_de, old_page);
 355         inode_dec_link_count(old_inode);
 356
 357         if (dir_de) {
 358                 ufs_set_link(old_inode, dir_de, dir_page, new_dir);
 359                 inode_dec_link_count(old_dir);
 360         }
 361         return 0;
 362
 363
 364 out_dir:
 365         if (dir_de) {
 366                 kunmap(dir_page);
 367                 page_cache_release(dir_page);
 368         }
 369 out_old:
 370         kunmap(old_page);
 371         page_cache_release(old_page);
 372 out:
 373         return err;
 374 }
 375
 376 const struct inode_operations ufs_dir_inode_operations = {
 377         .create         = ufs_create,
 378         .lookup         = ufs_lookup,
 379         .link           = ufs_link,
 380         .unlink         = ufs_unlink,
 381         .symlink        = ufs_symlink,
 382         .mkdir          = ufs_mkdir,
 383         .rmdir          = ufs_rmdir,
 384         .mknod          = ufs_mknod,
 385         .rename         = ufs_rename,
 386 };