fs/ufs/namei.c

   1 /*
   2  * linux/fs/ufs/namei.c
   3  *
   4  * Copyright (C) 1998
   5  * Daniel Pirkl <daniel.pirkl@email.cz>
   6  * Charles University, Faculty of Mathematics and Physics
   7  *
   8  *  from
   9  *
  10  *  linux/fs/ext2/namei.c
  11  *
  12  * Copyright (C) 1992, 1993, 1994, 1995
  13  * Remy Card (card@masi.ibp.fr)
  14  * Laboratoire MASI - Institut Blaise Pascal
  15  * Universite Pierre et Marie Curie (Paris VI)
  16  *
  17  *  from
  18  *
  19  *  linux/fs/minix/namei.c
  20  *
  21  *  Copyright (C) 1991, 1992  Linus Torvalds
  22  *
  23  *  Big-endian to little-endian byte-swapping/bitmaps by
  24  *        David S. Miller (davem@caip.rutgers.edu), 1995
  25  */
  26
  27 #include <linux/time.h>
  28 #include <linux/fs.h>
  29 #include <linux/ufs_fs.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/buffer_head.h>
  32 #include "swab.h"       /* will go away - see comment in mknod() */
  33 #include "util.h"
  34
  35 /*
  36 #undef UFS_NAMEI_DEBUG
  37 */
  38 #define UFS_NAMEI_DEBUG
  39
  40 #ifdef UFS_NAMEI_DEBUG
  41 #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
  42 #else
  43 #define UFSD(x)
  44 #endif
  45
  46 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
  47 {
  48         int err = ufs_add_link(dentry, inode);
  49         if (!err) {
  50                 d_instantiate(dentry, inode);
  51                 return 0;
  52         }
  53         inode_dec_link_count(inode);
  54         iput(inode);
  55         return err;
  56 }
  57
  58 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
  59 {
  60         struct inode * inode = NULL;
  61         ino_t ino;
  62
  63         if (dentry->d_name.len > UFS_MAXNAMLEN)
  64                 return ERR_PTR(-ENAMETOOLONG);
  65
  66         lock_kernel();
  67         ino = ufs_inode_by_name(dir, dentry);
  68         if (ino) {
  69                 inode = iget(dir->i_sb, ino);
  70                 if (!inode) {
  71                         unlock_kernel();
  72                         return ERR_PTR(-EACCES);
  73                 }
  74         }
  75         unlock_kernel();
  76         d_add(dentry, inode);
  77         return NULL;
  78 }
  79
  80 /*
  81  * By the time this is called, we already have created
  82  * the directory cache entry for the new file, but it
  83  * is so far negative - it has no inode.
  84  *
  85  * If the create succeeds, we fill in the inode information
  86  * with d_instantiate().
  87  */
  88 static int ufs_create (struct inode * dir, struct dentry * dentry, int mode,
  89                 struct nameidata *nd)
  90 {
  91         struct inode * inode = ufs_new_inode(dir, mode);
  92         int err = PTR_ERR(inode);
  93         if (!IS_ERR(inode)) {
  94                 inode->i_op = &ufs_file_inode_operations;
  95                 inode->i_fop = &ufs_file_operations;
  96                 inode->i_mapping->a_ops = &ufs_aops;
  97                 mark_inode_dirty(inode);
  98                 lock_kernel();
  99                 err = ufs_add_nondir(dentry, inode);
 100                 unlock_kernel();
 101         }
 102         return err;
 103 }
 104
 105 static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
 106 {
 107         struct inode *inode;
 108         int err;
 109
 110         if (!old_valid_dev(rdev))
 111                 return -EINVAL;
 112         inode = ufs_new_inode(dir, mode);
 113         err = PTR_ERR(inode);
 114         if (!IS_ERR(inode)) {
 115                 init_special_inode(inode, mode, rdev);
 116                 /* NOTE: that'll go when we get wide dev_t */
 117                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 118                 mark_inode_dirty(inode);
 119                 lock_kernel();
 120                 err = ufs_add_nondir(dentry, inode);
 121                 unlock_kernel();
 122         }
 123         return err;
 124 }
 125
 126 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 127         const char * symname)
 128 {
 129         struct super_block * sb = dir->i_sb;
 130         int err = -ENAMETOOLONG;
 131         unsigned l = strlen(symname)+1;
 132         struct inode * inode;
 133
 134         if (l > sb->s_blocksize)
 135                 goto out;
 136
 137         lock_kernel();
 138         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 139         err = PTR_ERR(inode);
 140         if (IS_ERR(inode))
 141                 goto out;
 142
 143         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 144                 /* slow symlink */
 145                 inode->i_op = &page_symlink_inode_operations;
 146                 inode->i_mapping->a_ops = &ufs_aops;
 147                 err = page_symlink(inode, symname, l);
 148                 if (err)
 149                         goto out_fail;
 150         } else {
 151                 /* fast symlink */
 152                 inode->i_op = &ufs_fast_symlink_inode_operations;
 153                 memcpy((char*)&UFS_I(inode)->i_u1.i_data,symname,l);
 154                 inode->i_size = l-1;
 155         }
 156         mark_inode_dirty(inode);
 157
 158         err = ufs_add_nondir(dentry, inode);
 159 out:
 160         unlock_kernel();
 161         return err;
 162
 163 out_fail:
 164         inode_dec_link_count(inode);
 165         iput(inode);
 166         goto out;
 167 }
 168
 169 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 170         struct dentry *dentry)
 171 {
 172         struct inode *inode = old_dentry->d_inode;
 173         int error;
 174
 175         lock_kernel();
 176         if (inode->i_nlink >= UFS_LINK_MAX) {
 177                 unlock_kernel();
 178                 return -EMLINK;
 179         }
 180
 181         inode->i_ctime = CURRENT_TIME_SEC;
 182         inode_inc_link_count(inode);
 183         atomic_inc(&inode->i_count);
 184
 185         error = ufs_add_nondir(dentry, inode);
 186         unlock_kernel();
 187         return error;
 188 }
 189
 190 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 191 {
 192         struct inode * inode;
 193         int err = -EMLINK;
 194
 195         if (dir->i_nlink >= UFS_LINK_MAX)
 196                 goto out;
 197
 198         lock_kernel();
 199         inode_inc_link_count(dir);
 200
 201         inode = ufs_new_inode(dir, S_IFDIR|mode);
 202         err = PTR_ERR(inode);
 203         if (IS_ERR(inode))
 204                 goto out_dir;
 205
 206         inode->i_op = &ufs_dir_inode_operations;
 207         inode->i_fop = &ufs_dir_operations;
 208
 209         inode_inc_link_count(inode);
 210
 211         err = ufs_make_empty(inode, dir);
 212         if (err)
 213                 goto out_fail;
 214
 215         err = ufs_add_link(dentry, inode);
 216         if (err)
 217                 goto out_fail;
 218         unlock_kernel();
 219
 220         d_instantiate(dentry, inode);
 221 out:
 222         return err;
 223
 224 out_fail:
 225         inode_dec_link_count(inode);
 226         inode_dec_link_count(inode);
 227         iput (inode);
 228 out_dir:
 229         inode_dec_link_count(dir);
 230         unlock_kernel();
 231         goto out;
 232 }
 233
 234 static int ufs_unlink(struct inode * dir, struct dentry *dentry)
 235 {
 236         struct inode * inode = dentry->d_inode;
 237         struct buffer_head * bh;
 238         struct ufs_dir_entry * de;
 239         int err = -ENOENT;
 240
 241         lock_kernel();
 242         de = ufs_find_entry (dentry, &bh);
 243         if (!de)
 244                 goto out;
 245
 246         err = ufs_delete_entry (dir, de, bh);
 247         if (err)
 248                 goto out;
 249
 250         inode->i_ctime = dir->i_ctime;
 251         inode_dec_link_count(inode);
 252         err = 0;
 253 out:
 254         unlock_kernel();
 255         return err;
 256 }
 257
 258 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 259 {
 260         struct inode * inode = dentry->d_inode;
 261         int err= -ENOTEMPTY;
 262
 263         lock_kernel();
 264         if (ufs_empty_dir (inode)) {
 265                 err = ufs_unlink(dir, dentry);
 266                 if (!err) {
 267                         inode->i_size = 0;
 268                         inode_dec_link_count(inode);
 269                         inode_dec_link_count(dir);
 270                 }
 271         }
 272         unlock_kernel();
 273         return err;
 274 }
 275
 276 static int ufs_rename (struct inode * old_dir, struct dentry * old_dentry,
 277         struct inode * new_dir, struct dentry * new_dentry )
 278 {
 279         struct inode *old_inode = old_dentry->d_inode;
 280         struct inode *new_inode = new_dentry->d_inode;
 281         struct buffer_head *dir_bh = NULL;
 282         struct ufs_dir_entry *dir_de = NULL;
 283         struct buffer_head *old_bh;
 284         struct ufs_dir_entry *old_de;
 285         int err = -ENOENT;
 286
 287         lock_kernel();
 288         old_de = ufs_find_entry (old_dentry, &old_bh);
 289         if (!old_de)
 290                 goto out;
 291
 292         if (S_ISDIR(old_inode->i_mode)) {
 293                 err = -EIO;
 294                 dir_de = ufs_dotdot(old_inode, &dir_bh);
 295                 if (!dir_de)
 296                         goto out_old;
 297         }
 298
 299         if (new_inode) {
 300                 struct buffer_head *new_bh;
 301                 struct ufs_dir_entry *new_de;
 302
 303                 err = -ENOTEMPTY;
 304                 if (dir_de && !ufs_empty_dir (new_inode))
 305                         goto out_dir;
 306                 err = -ENOENT;
 307                 new_de = ufs_find_entry (new_dentry, &new_bh);
 308                 if (!new_de)
 309                         goto out_dir;
 310                 inode_inc_link_count(old_inode);
 311                 ufs_set_link(new_dir, new_de, new_bh, old_inode);
 312                 new_inode->i_ctime = CURRENT_TIME_SEC;
 313                 if (dir_de)
 314                         new_inode->i_nlink--;
 315                 inode_dec_link_count(new_inode);
 316         } else {
 317                 if (dir_de) {
 318                         err = -EMLINK;
 319                         if (new_dir->i_nlink >= UFS_LINK_MAX)
 320                                 goto out_dir;
 321                 }
 322                 inode_inc_link_count(old_inode);
 323                 err = ufs_add_link(new_dentry, old_inode);
 324                 if (err) {
 325                         inode_dec_link_count(old_inode);
 326                         goto out_dir;
 327                 }
 328                 if (dir_de)
 329                         inode_inc_link_count(new_dir);
 330         }
 331
 332         ufs_delete_entry (old_dir, old_de, old_bh);
 333
 334         inode_dec_link_count(old_inode);
 335
 336         if (dir_de) {
 337                 ufs_set_link(old_inode, dir_de, dir_bh, new_dir);
 338                 inode_dec_link_count(old_dir);
 339         }
 340         unlock_kernel();
 341         return 0;
 342
 343 out_dir:
 344         if (dir_de)
 345                 brelse(dir_bh);
 346 out_old:
 347         brelse (old_bh);
 348 out:
 349         unlock_kernel();
 350         return err;
 351 }
 352
 353 struct inode_operations ufs_dir_inode_operations = {
 354         .create         = ufs_create,
 355         .lookup         = ufs_lookup,
 356         .link           = ufs_link,
 357         .unlink         = ufs_unlink,
 358         .symlink        = ufs_symlink,
 359         .mkdir          = ufs_mkdir,
 360         .rmdir          = ufs_rmdir,
 361         .mknod          = ufs_mknod,
 362         .rename         = ufs_rename,
 363 };