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                 unlock_new_inode(inode);
  42                 d_instantiate(dentry, inode);
  43                 return 0;
  44         }
  45         inode_dec_link_count(inode);
  46         unlock_new_inode(inode);
  47         iput(inode);
  48         return err;
  49 }
  50
  51 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
  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         ino = ufs_inode_by_name(dir, &dentry->d_name);
  60         if (ino)
  61                 inode = ufs_iget(dir->i_sb, ino);
  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
  78         inode = ufs_new_inode(dir, mode);
  79         if (IS_ERR(inode))
  80                 return PTR_ERR(inode);
  81
  82         inode->i_op = &ufs_file_inode_operations;
  83         inode->i_fop = &ufs_file_operations;
  84         inode->i_mapping->a_ops = &ufs_aops;
  85         mark_inode_dirty(inode);
  86         return ufs_add_nondir(dentry, inode);
  87 }
  88
  89 static int ufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
  90 {
  91         struct inode *inode;
  92         int err;
  93
  94         if (!old_valid_dev(rdev))
  95                 return -EINVAL;
  96
  97         inode = ufs_new_inode(dir, mode);
  98         err = PTR_ERR(inode);
  99         if (!IS_ERR(inode)) {
 100                 init_special_inode(inode, mode, rdev);
 101                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 102                 mark_inode_dirty(inode);
 103                 err = ufs_add_nondir(dentry, inode);
 104         }
 105         return err;
 106 }
 107
 108 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 109         const char * symname)
 110 {
 111         struct super_block * sb = dir->i_sb;
 112         int err;
 113         unsigned l = strlen(symname)+1;
 114         struct inode * inode;
 115
 116         if (l > sb->s_blocksize)
 117                 return -ENAMETOOLONG;
 118
 119         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 120         err = PTR_ERR(inode);
 121         if (IS_ERR(inode))
 122                 return err;
 123
 124         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 125                 /* slow symlink */
 126                 inode->i_op = &page_symlink_inode_operations;
 127                 inode_nohighmem(inode);
 128                 inode->i_mapping->a_ops = &ufs_aops;
 129                 err = page_symlink(inode, symname, l);
 130                 if (err)
 131                         goto out_fail;
 132         } else {
 133                 /* fast symlink */
 134                 inode->i_op = &simple_symlink_inode_operations;
 135                 inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
 136                 memcpy(inode->i_link, symname, l);
 137                 inode->i_size = l-1;
 138         }
 139         mark_inode_dirty(inode);
 140
 141         return ufs_add_nondir(dentry, inode);
 142
 143 out_fail:
 144         inode_dec_link_count(inode);
 145         unlock_new_inode(inode);
 146         iput(inode);
 147         return err;
 148 }
 149
 150 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 151         struct dentry *dentry)
 152 {
 153         struct inode *inode = d_inode(old_dentry);
 154         int error;
 155
 156         inode->i_ctime = CURRENT_TIME_SEC;
 157         inode_inc_link_count(inode);
 158         ihold(inode);
 159
 160         error = ufs_add_link(dentry, inode);
 161         if (error) {
 162                 inode_dec_link_count(inode);
 163                 iput(inode);
 164         } else
 165                 d_instantiate(dentry, inode);
 166         return error;
 167 }
 168
 169 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 170 {
 171         struct inode * inode;
 172         int err;
 173
 174         inode_inc_link_count(dir);
 175
 176         inode = ufs_new_inode(dir, S_IFDIR|mode);
 177         err = PTR_ERR(inode);
 178         if (IS_ERR(inode))
 179                 goto out_dir;
 180
 181         inode->i_op = &ufs_dir_inode_operations;
 182         inode->i_fop = &ufs_dir_operations;
 183         inode->i_mapping->a_ops = &ufs_aops;
 184
 185         inode_inc_link_count(inode);
 186
 187         err = ufs_make_empty(inode, dir);
 188         if (err)
 189                 goto out_fail;
 190
 191         err = ufs_add_link(dentry, inode);
 192         if (err)
 193                 goto out_fail;
 194
 195         unlock_new_inode(inode);
 196         d_instantiate(dentry, inode);
 197         return 0;
 198
 199 out_fail:
 200         inode_dec_link_count(inode);
 201         inode_dec_link_count(inode);
 202         unlock_new_inode(inode);
 203         iput (inode);
 204 out_dir:
 205         inode_dec_link_count(dir);
 206         return err;
 207 }
 208
 209 static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 210 {
 211         struct inode * inode = d_inode(dentry);
 212         struct ufs_dir_entry *de;
 213         struct page *page;
 214         int err = -ENOENT;
 215
 216         de = ufs_find_entry(dir, &dentry->d_name, &page);
 217         if (!de)
 218                 goto out;
 219
 220         err = ufs_delete_entry(dir, de, page);
 221         if (err)
 222                 goto out;
 223
 224         inode->i_ctime = dir->i_ctime;
 225         inode_dec_link_count(inode);
 226         err = 0;
 227 out:
 228         return err;
 229 }
 230
 231 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 232 {
 233         struct inode * inode = d_inode(dentry);
 234         int err= -ENOTEMPTY;
 235
 236         if (ufs_empty_dir (inode)) {
 237                 err = ufs_unlink(dir, dentry);
 238                 if (!err) {
 239                         inode->i_size = 0;
 240                         inode_dec_link_count(inode);
 241                         inode_dec_link_count(dir);
 242                 }
 243         }
 244         return err;
 245 }
 246
 247 static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 248                       struct inode *new_dir, struct dentry *new_dentry)
 249 {
 250         struct inode *old_inode = d_inode(old_dentry);
 251         struct inode *new_inode = d_inode(new_dentry);
 252         struct page *dir_page = NULL;
 253         struct ufs_dir_entry * dir_de = NULL;
 254         struct page *old_page;
 255         struct ufs_dir_entry *old_de;
 256         int err = -ENOENT;
 257
 258         old_de = ufs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 259         if (!old_de)
 260                 goto out;
 261
 262         if (S_ISDIR(old_inode->i_mode)) {
 263                 err = -EIO;
 264                 dir_de = ufs_dotdot(old_inode, &dir_page);
 265                 if (!dir_de)
 266                         goto out_old;
 267         }
 268
 269         if (new_inode) {
 270                 struct page *new_page;
 271                 struct ufs_dir_entry *new_de;
 272
 273                 err = -ENOTEMPTY;
 274                 if (dir_de && !ufs_empty_dir(new_inode))
 275                         goto out_dir;
 276
 277                 err = -ENOENT;
 278                 new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 279                 if (!new_de)
 280                         goto out_dir;
 281                 ufs_set_link(new_dir, new_de, new_page, old_inode, 1);
 282                 new_inode->i_ctime = CURRENT_TIME_SEC;
 283                 if (dir_de)
 284                         drop_nlink(new_inode);
 285                 inode_dec_link_count(new_inode);
 286         } else {
 287                 err = ufs_add_link(new_dentry, old_inode);
 288                 if (err)
 289                         goto out_dir;
 290                 if (dir_de)
 291                         inode_inc_link_count(new_dir);
 292         }
 293
 294         /*
 295          * Like most other Unix systems, set the ctime for inodes on a
 296          * rename.
 297          */
 298         old_inode->i_ctime = CURRENT_TIME_SEC;
 299
 300         ufs_delete_entry(old_dir, old_de, old_page);
 301         mark_inode_dirty(old_inode);
 302
 303         if (dir_de) {
 304                 if (old_dir != new_dir)
 305                         ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0);
 306                 else {
 307                         kunmap(dir_page);
 308                         page_cache_release(dir_page);
 309                 }
 310                 inode_dec_link_count(old_dir);
 311         }
 312         return 0;
 313
 314
 315 out_dir:
 316         if (dir_de) {
 317                 kunmap(dir_page);
 318                 page_cache_release(dir_page);
 319         }
 320 out_old:
 321         kunmap(old_page);
 322         page_cache_release(old_page);
 323 out:
 324         return err;
 325 }
 326
 327 const struct inode_operations ufs_dir_inode_operations = {
 328         .create         = ufs_create,
 329         .lookup         = ufs_lookup,
 330         .link           = ufs_link,
 331         .unlink         = ufs_unlink,
 332         .symlink        = ufs_symlink,
 333         .mkdir          = ufs_mkdir,
 334         .rmdir          = ufs_rmdir,
 335         .mknod          = ufs_mknod,
 336         .rename         = ufs_rename,
 337 };