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