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