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 void ufs_inc_count(struct inode *inode)
  47 {
  48         inode->i_nlink++;
  49         mark_inode_dirty(inode);
  50 }
  51
  52 static inline void ufs_dec_count(struct inode *inode)
  53 {
  54         inode->i_nlink--;
  55         mark_inode_dirty(inode);
  56 }
  57
  58 static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
  59 {
  60         int err = ufs_add_link(dentry, inode);
  61         if (!err) {
  62                 d_instantiate(dentry, inode);
  63                 return 0;
  64         }
  65         ufs_dec_count(inode);
  66         iput(inode);
  67         return err;
  68 }
  69
  70 static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
  71 {
  72         struct inode * inode = NULL;
  73         ino_t ino;
  74
  75         if (dentry->d_name.len > UFS_MAXNAMLEN)
  76                 return ERR_PTR(-ENAMETOOLONG);
  77
  78         lock_kernel();
  79         ino = ufs_inode_by_name(dir, dentry);
  80         if (ino) {
  81                 inode = iget(dir->i_sb, ino);
  82                 if (!inode) {
  83                         unlock_kernel();
  84                         return ERR_PTR(-EACCES);
  85                 }
  86         }
  87         unlock_kernel();
  88         d_add(dentry, inode);
  89         return NULL;
  90 }
  91
  92 /*
  93  * By the time this is called, we already have created
  94  * the directory cache entry for the new file, but it
  95  * is so far negative - it has no inode.
  96  *
  97  * If the create succeeds, we fill in the inode information
  98  * with d_instantiate().
  99  */
 100 static int ufs_create (struct inode * dir, struct dentry * dentry, int mode,
 101                 struct nameidata *nd)
 102 {
 103         struct inode * inode = ufs_new_inode(dir, mode);
 104         int err = PTR_ERR(inode);
 105         if (!IS_ERR(inode)) {
 106                 inode->i_op = &ufs_file_inode_operations;
 107                 inode->i_fop = &ufs_file_operations;
 108                 inode->i_mapping->a_ops = &ufs_aops;
 109                 mark_inode_dirty(inode);
 110                 lock_kernel();
 111                 err = ufs_add_nondir(dentry, inode);
 112                 unlock_kernel();
 113         }
 114         return err;
 115 }
 116
 117 static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
 118 {
 119         struct inode *inode;
 120         int err;
 121
 122         if (!old_valid_dev(rdev))
 123                 return -EINVAL;
 124         inode = ufs_new_inode(dir, mode);
 125         err = PTR_ERR(inode);
 126         if (!IS_ERR(inode)) {
 127                 init_special_inode(inode, mode, rdev);
 128                 /* NOTE: that'll go when we get wide dev_t */
 129                 ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
 130                 mark_inode_dirty(inode);
 131                 lock_kernel();
 132                 err = ufs_add_nondir(dentry, inode);
 133                 unlock_kernel();
 134         }
 135         return err;
 136 }
 137
 138 static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 139         const char * symname)
 140 {
 141         struct super_block * sb = dir->i_sb;
 142         int err = -ENAMETOOLONG;
 143         unsigned l = strlen(symname)+1;
 144         struct inode * inode;
 145
 146         if (l > sb->s_blocksize)
 147                 goto out;
 148
 149         lock_kernel();
 150         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 151         err = PTR_ERR(inode);
 152         if (IS_ERR(inode))
 153                 goto out;
 154
 155         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
 156                 /* slow symlink */
 157                 inode->i_op = &page_symlink_inode_operations;
 158                 inode->i_mapping->a_ops = &ufs_aops;
 159                 err = page_symlink(inode, symname, l);
 160                 if (err)
 161                         goto out_fail;
 162         } else {
 163                 /* fast symlink */
 164                 inode->i_op = &ufs_fast_symlink_inode_operations;
 165                 memcpy((char*)&UFS_I(inode)->i_u1.i_data,symname,l);
 166                 inode->i_size = l-1;
 167         }
 168         mark_inode_dirty(inode);
 169
 170         err = ufs_add_nondir(dentry, inode);
 171 out:
 172         unlock_kernel();
 173         return err;
 174
 175 out_fail:
 176         ufs_dec_count(inode);
 177         iput(inode);
 178         goto out;
 179 }
 180
 181 static int ufs_link (struct dentry * old_dentry, struct inode * dir,
 182         struct dentry *dentry)
 183 {
 184         struct inode *inode = old_dentry->d_inode;
 185         int error;
 186
 187         lock_kernel();
 188         if (inode->i_nlink >= UFS_LINK_MAX) {
 189                 unlock_kernel();
 190                 return -EMLINK;
 191         }
 192
 193         inode->i_ctime = CURRENT_TIME_SEC;
 194         ufs_inc_count(inode);
 195         atomic_inc(&inode->i_count);
 196
 197         error = ufs_add_nondir(dentry, inode);
 198         unlock_kernel();
 199         return error;
 200 }
 201
 202 static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 203 {
 204         struct inode * inode;
 205         int err = -EMLINK;
 206
 207         if (dir->i_nlink >= UFS_LINK_MAX)
 208                 goto out;
 209
 210         lock_kernel();
 211         ufs_inc_count(dir);
 212
 213         inode = ufs_new_inode(dir, S_IFDIR|mode);
 214         err = PTR_ERR(inode);
 215         if (IS_ERR(inode))
 216                 goto out_dir;
 217
 218         inode->i_op = &ufs_dir_inode_operations;
 219         inode->i_fop = &ufs_dir_operations;
 220
 221         ufs_inc_count(inode);
 222
 223         err = ufs_make_empty(inode, dir);
 224         if (err)
 225                 goto out_fail;
 226
 227         err = ufs_add_link(dentry, inode);
 228         if (err)
 229                 goto out_fail;
 230         unlock_kernel();
 231
 232         d_instantiate(dentry, inode);
 233 out:
 234         return err;
 235
 236 out_fail:
 237         ufs_dec_count(inode);
 238         ufs_dec_count(inode);
 239         iput (inode);
 240 out_dir:
 241         ufs_dec_count(dir);
 242         unlock_kernel();
 243         goto out;
 244 }
 245
 246 static int ufs_unlink(struct inode * dir, struct dentry *dentry)
 247 {
 248         struct inode * inode = dentry->d_inode;
 249         struct buffer_head * bh;
 250         struct ufs_dir_entry * de;
 251         int err = -ENOENT;
 252
 253         lock_kernel();
 254         de = ufs_find_entry (dentry, &bh);
 255         if (!de)
 256                 goto out;
 257
 258         err = ufs_delete_entry (dir, de, bh);
 259         if (err)
 260                 goto out;
 261
 262         inode->i_ctime = dir->i_ctime;
 263         ufs_dec_count(inode);
 264         err = 0;
 265 out:
 266         unlock_kernel();
 267         return err;
 268 }
 269
 270 static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 271 {
 272         struct inode * inode = dentry->d_inode;
 273         int err= -ENOTEMPTY;
 274
 275         lock_kernel();
 276         if (ufs_empty_dir (inode)) {
 277                 err = ufs_unlink(dir, dentry);
 278                 if (!err) {
 279                         inode->i_size = 0;
 280                         ufs_dec_count(inode);
 281                         ufs_dec_count(dir);
 282                 }
 283         }
 284         unlock_kernel();
 285         return err;
 286 }
 287
 288 static int ufs_rename (struct inode * old_dir, struct dentry * old_dentry,
 289         struct inode * new_dir, struct dentry * new_dentry )
 290 {
 291         struct inode *old_inode = old_dentry->d_inode;
 292         struct inode *new_inode = new_dentry->d_inode;
 293         struct buffer_head *dir_bh = NULL;
 294         struct ufs_dir_entry *dir_de = NULL;
 295         struct buffer_head *old_bh;
 296         struct ufs_dir_entry *old_de;
 297         int err = -ENOENT;
 298
 299         lock_kernel();
 300         old_de = ufs_find_entry (old_dentry, &old_bh);
 301         if (!old_de)
 302                 goto out;
 303
 304         if (S_ISDIR(old_inode->i_mode)) {
 305                 err = -EIO;
 306                 dir_de = ufs_dotdot(old_inode, &dir_bh);
 307                 if (!dir_de)
 308                         goto out_old;
 309         }
 310
 311         if (new_inode) {
 312                 struct buffer_head *new_bh;
 313                 struct ufs_dir_entry *new_de;
 314
 315                 err = -ENOTEMPTY;
 316                 if (dir_de && !ufs_empty_dir (new_inode))
 317                         goto out_dir;
 318                 err = -ENOENT;
 319                 new_de = ufs_find_entry (new_dentry, &new_bh);
 320                 if (!new_de)
 321                         goto out_dir;
 322                 ufs_inc_count(old_inode);
 323                 ufs_set_link(new_dir, new_de, new_bh, old_inode);
 324                 new_inode->i_ctime = CURRENT_TIME_SEC;
 325                 if (dir_de)
 326                         new_inode->i_nlink--;
 327                 ufs_dec_count(new_inode);
 328         } else {
 329                 if (dir_de) {
 330                         err = -EMLINK;
 331                         if (new_dir->i_nlink >= UFS_LINK_MAX)
 332                                 goto out_dir;
 333                 }
 334                 ufs_inc_count(old_inode);
 335                 err = ufs_add_link(new_dentry, old_inode);
 336                 if (err) {
 337                         ufs_dec_count(old_inode);
 338                         goto out_dir;
 339                 }
 340                 if (dir_de)
 341                         ufs_inc_count(new_dir);
 342         }
 343
 344         ufs_delete_entry (old_dir, old_de, old_bh);
 345
 346         ufs_dec_count(old_inode);
 347
 348         if (dir_de) {
 349                 ufs_set_link(old_inode, dir_de, dir_bh, new_dir);
 350                 ufs_dec_count(old_dir);
 351         }
 352         unlock_kernel();
 353         return 0;
 354
 355 out_dir:
 356         if (dir_de)
 357                 brelse(dir_bh);
 358 out_old:
 359         brelse (old_bh);
 360 out:
 361         unlock_kernel();
 362         return err;
 363 }
 364
 365 struct inode_operations ufs_dir_inode_operations = {
 366         .create         = ufs_create,
 367         .lookup         = ufs_lookup,
 368         .link           = ufs_link,
 369         .unlink         = ufs_unlink,
 370         .symlink        = ufs_symlink,
 371         .mkdir          = ufs_mkdir,
 372         .rmdir          = ufs_rmdir,
 373         .mknod          = ufs_mknod,
 374         .rename         = ufs_rename,
 375 };