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, unsigned int flags)
  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, umode_t mode,
  74                 bool excl)
  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, umode_t 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
 170         inode->i_ctime = CURRENT_TIME_SEC;
 171         inode_inc_link_count(inode);
 172         ihold(inode);
 173
 174         error = ufs_add_nondir(dentry, inode);
 175         unlock_ufs(dir->i_sb);
 176         return error;
 177 }
 178
 179 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 180 {
 181         struct inode * inode;
 182         int err;
 183
 184         lock_ufs(dir->i_sb);
 185         inode_inc_link_count(dir);
 186
 187         inode = ufs_new_inode(dir, S_IFDIR|mode);
 188         err = PTR_ERR(inode);
 189         if (IS_ERR(inode))
 190                 goto out_dir;
 191
 192         inode->i_op = &ufs_dir_inode_operations;
 193         inode->i_fop = &ufs_dir_operations;
 194         inode->i_mapping->a_ops = &ufs_aops;
 195
 196         inode_inc_link_count(inode);
 197
 198         err = ufs_make_empty(inode, dir);
 199         if (err)
 200                 goto out_fail;
 201
 202         err = ufs_add_link(dentry, inode);
 203         if (err)
 204                 goto out_fail;
 205         unlock_ufs(dir->i_sb);
 206
 207         d_instantiate(dentry, inode);
 208 out:
 209         return err;
 210
 211 out_fail:
 212         inode_dec_link_count(inode);
 213         inode_dec_link_count(inode);
 214         iput (inode);
 215 out_dir:
 216         inode_dec_link_count(dir);
 217         unlock_ufs(dir->i_sb);
 218         goto out;
 219 }
 220
 221 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 222 {
 223         struct inode * inode = dentry->d_inode;
 224         struct ufs_dir_entry *de;
 225         struct page *page;
 226         int err = -ENOENT;
 227
 228         de = ufs_find_entry(dir, &dentry->d_name, &page);
 229         if (!de)
 230                 goto out;
 231
 232         err = ufs_delete_entry(dir, de, page);
 233         if (err)
 234                 goto out;
 235
 236         inode->i_ctime = dir->i_ctime;
 237         inode_dec_link_count(inode);
 238         err = 0;
 239 out:
 240         return err;
 241 }
 242
 243 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 244 {
 245         struct inode * inode = dentry->d_inode;
 246         int err= -ENOTEMPTY;
 247
 248         lock_ufs(dir->i_sb);
 249         if (ufs_empty_dir (inode)) {
 250                 err = ufs_unlink(dir, dentry);
 251                 if (!err) {
 252                         inode->i_size = 0;
 253                         inode_dec_link_count(inode);
 254                         inode_dec_link_count(dir);
 255                 }
 256         }
 257         unlock_ufs(dir->i_sb);
 258         return err;
 259 }
 260
 261 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 262                       struct inode *new_dir, struct dentry *new_dentry)
 263 {
 264         struct inode *old_inode = old_dentry->d_inode;
 265         struct inode *new_inode = new_dentry->d_inode;
 266         struct page *dir_page = NULL;
 267         struct ufs_dir_entry * dir_de = NULL;
 268         struct page *old_page;
 269         struct ufs_dir_entry *old_de;
 270         int err = -ENOENT;
 271
 272         old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 273         if (!old_de)
 274                 goto out;
 275
 276         if (S_ISDIR(old_inode->i_mode)) {
 277                 err = -EIO;
 278                 dir_de = ufs_dotdot(old_inode, &dir_page);
 279                 if (!dir_de)
 280                         goto out_old;
 281         }
 282
 283         if (new_inode) {
 284                 struct page *new_page;
 285                 struct ufs_dir_entry *new_de;
 286
 287                 err = -ENOTEMPTY;
 288                 if (dir_de && !ufs_empty_dir(new_inode))
 289                         goto out_dir;
 290
 291                 err = -ENOENT;
 292                 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 293                 if (!new_de)
 294                         goto out_dir;
 295                 ufs_set_link(new_dir, new_de, new_page, old_inode);
 296                 new_inode->i_ctime = CURRENT_TIME_SEC;
 297                 if (dir_de)
 298                         drop_nlink(new_inode);
 299                 inode_dec_link_count(new_inode);
 300         } else {
 301                 err = ufs_add_link(new_dentry, old_inode);
 302                 if (err)
 303                         goto out_dir;
 304                 if (dir_de)
 305                         inode_inc_link_count(new_dir);
 306         }
 307
 308         /*
 309          * Like most other Unix systems, set the ctime for inodes on a
 310          * rename.
 311          */
 312         old_inode->i_ctime = CURRENT_TIME_SEC;
 313
 314         ufs_delete_entry(old_dir, old_de, old_page);
 315         mark_inode_dirty(old_inode);
 316
 317         if (dir_de) {
 318                 ufs_set_link(old_inode, dir_de, dir_page, new_dir);
 319                 inode_dec_link_count(old_dir);
 320         }
 321         return 0;
 322
 323
 324 out_dir:
 325         if (dir_de) {
 326                 kunmap(dir_page);
 327                 page_cache_release(dir_page);
 328         }
 329 out_old:
 330         kunmap(old_page);
 331         page_cache_release(old_page);
 332 out:
 333         return err;
 334 }
 335
 336 const struct inode_operations ufs_dir_inode_operations = {
 337         .create         = ufs_create,
 338         .lookup         = ufs_lookup,
 339         .link           = ufs_link,
 340         .unlink         = ufs_unlink,
 341         .symlink        = ufs_symlink,
 342         .mkdir          = ufs_mkdir,
 343         .rmdir          = ufs_rmdir,
 344         .mknod          = ufs_mknod,
 345         .rename         = ufs_rename,
 346 };