fs/reiserfs/dir.c

   1 /*
   2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3  */
   4
   5 #include <linux/config.h>
   6 #include <linux/string.h>
   7 #include <linux/errno.h>
   8 #include <linux/fs.h>
   9 #include <linux/reiserfs_fs.h>
  10 #include <linux/stat.h>
  11 #include <linux/smp_lock.h>
  12 #include <linux/buffer_head.h>
  13 #include <asm/uaccess.h>
  14
  15 extern struct reiserfs_key  MIN_KEY;
  16
  17 static int reiserfs_readdir (struct file *, void *, filldir_t);
  18 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) ;
  19
  20 struct file_operations reiserfs_dir_operations = {
  21     .read       = generic_read_dir,
  22     .readdir    = reiserfs_readdir,
  23     .fsync      = reiserfs_dir_fsync,
  24     .ioctl      = reiserfs_ioctl,
  25 };
  26
  27 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) {
  28   struct inode *inode = dentry->d_inode;
  29   int err;
  30   reiserfs_write_lock(inode->i_sb);
  31   err = reiserfs_commit_for_inode(inode) ;
  32   reiserfs_write_unlock(inode->i_sb) ;
  33   if (err < 0)
  34       return err;
  35   return 0;
  36 }
  37
  38
  39 #define store_ih(where,what) copy_item_head (where, what)
  40
  41 //
  42 static int reiserfs_readdir (struct file * filp, void * dirent, filldir_t filldir)
  43 {
  44     struct inode *inode = filp->f_dentry->d_inode;
  45     struct cpu_key pos_key;     /* key of current position in the directory (key of directory entry) */
  46     INITIALIZE_PATH (path_to_entry);
  47     struct buffer_head * bh;
  48     int item_num, entry_num;
  49     const struct reiserfs_key * rkey;
  50     struct item_head * ih, tmp_ih;
  51     int search_res;
  52     char * local_buf;
  53     loff_t next_pos;
  54     char small_buf[32] ; /* avoid kmalloc if we can */
  55     struct reiserfs_dir_entry de;
  56     int ret = 0;
  57
  58     reiserfs_write_lock(inode->i_sb);
  59
  60     reiserfs_check_lock_depth(inode->i_sb, "readdir") ;
  61
  62     /* form key for search the next directory entry using f_pos field of
  63        file structure */
  64     make_cpu_key (&pos_key, inode, (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET,
  65                   TYPE_DIRENTRY, 3);
  66     next_pos = cpu_key_k_offset (&pos_key);
  67
  68     /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos);*/
  69
  70     path_to_entry.reada = PATH_READA;
  71     while (1) {
  72     research:
  73         /* search the directory item, containing entry with specified key */
  74         search_res = search_by_entry_key (inode->i_sb, &pos_key, &path_to_entry, &de);
  75         if (search_res == IO_ERROR) {
  76             // FIXME: we could just skip part of directory which could
  77             // not be read
  78             ret = -EIO;
  79             goto out;
  80         }
  81         entry_num = de.de_entry_num;
  82         bh = de.de_bh;
  83         item_num = de.de_item_num;
  84         ih = de.de_ih;
  85         store_ih (&tmp_ih, ih);
  86
  87         /* we must have found item, that is item of this directory, */
  88         RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key),
  89                 "vs-9000: found item %h does not match to dir we readdir %K",
  90                 ih, &pos_key);
  91         RFALSE( item_num > B_NR_ITEMS (bh) - 1,
  92                 "vs-9005 item_num == %d, item amount == %d",
  93                 item_num, B_NR_ITEMS (bh));
  94
  95         /* and entry must be not more than number of entries in the item */
  96         RFALSE( I_ENTRY_COUNT (ih) < entry_num,
  97                 "vs-9010: entry number is too big %d (%d)",
  98                 entry_num, I_ENTRY_COUNT (ih));
  99
 100         if (search_res == POSITION_FOUND || entry_num < I_ENTRY_COUNT (ih)) {
 101             /* go through all entries in the directory item beginning from the entry, that has been found */
 102             struct reiserfs_de_head * deh = B_I_DEH (bh, ih) + entry_num;
 103
 104             for (; entry_num < I_ENTRY_COUNT (ih); entry_num ++, deh ++) {
 105                 int d_reclen;
 106                 char * d_name;
 107                 off_t d_off;
 108                 ino_t d_ino;
 109
 110                 if (!de_visible (deh))
 111                     /* it is hidden entry */
 112                     continue;
 113                 d_reclen = entry_length (bh, ih, entry_num);
 114                 d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
 115                 if (!d_name[d_reclen - 1])
 116                     d_reclen = strlen (d_name);
 117
 118                 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)){
 119                     /* too big to send back to VFS */
 120                     continue ;
 121                 }
 122
 123                 /* Ignore the .reiserfs_priv entry */
 124                 if (reiserfs_xattrs (inode->i_sb) &&
 125                     !old_format_only(inode->i_sb) &&
 126                     filp->f_dentry == inode->i_sb->s_root &&
 127                     REISERFS_SB(inode->i_sb)->priv_root &&
 128                     REISERFS_SB(inode->i_sb)->priv_root->d_inode &&
 129                     deh_objectid(deh) == le32_to_cpu (INODE_PKEY(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->k_objectid)) {
 130                   continue;
 131                 }
 132
 133                 d_off = deh_offset (deh);
 134                 filp->f_pos = d_off ;
 135                 d_ino = deh_objectid (deh);
 136                 if (d_reclen <= 32) {
 137                   local_buf = small_buf ;
 138                 } else {
 139                     local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ;
 140                     if (!local_buf) {
 141                         pathrelse (&path_to_entry);
 142                         ret = -ENOMEM ;
 143                         goto out;
 144                     }
 145                     if (item_moved (&tmp_ih, &path_to_entry)) {
 146                         reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
 147                         goto research;
 148                     }
 149                 }
 150                 // Note, that we copy name to user space via temporary
 151                 // buffer (local_buf) because filldir will block if
 152                 // user space buffer is swapped out. At that time
 153                 // entry can move to somewhere else
 154                 memcpy (local_buf, d_name, d_reclen);
 155                 if (filldir (dirent, local_buf, d_reclen, d_off, d_ino,
 156                              DT_UNKNOWN) < 0) {
 157                     if (local_buf != small_buf) {
 158                         reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
 159                     }
 160                     goto end;
 161                 }
 162                 if (local_buf != small_buf) {
 163                     reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
 164                 }
 165
 166                 // next entry should be looked for with such offset
 167                 next_pos = deh_offset (deh) + 1;
 168
 169                 if (item_moved (&tmp_ih, &path_to_entry)) {
 170                     goto research;
 171                 }
 172             } /* for */
 173         }
 174
 175         if (item_num != B_NR_ITEMS (bh) - 1)
 176             // end of directory has been reached
 177             goto end;
 178
 179         /* item we went through is last item of node. Using right
 180            delimiting key check is it directory end */
 181         rkey = get_rkey (&path_to_entry, inode->i_sb);
 182         if (! comp_le_keys (rkey, &MIN_KEY)) {
 183             /* set pos_key to key, that is the smallest and greater
 184                that key of the last entry in the item */
 185             set_cpu_key_k_offset (&pos_key, next_pos);
 186             continue;
 187         }
 188
 189         if ( COMP_SHORT_KEYS (rkey, &pos_key)) {
 190             // end of directory has been reached
 191             goto end;
 192         }
 193
 194         /* directory continues in the right neighboring block */
 195         set_cpu_key_k_offset (&pos_key, le_key_k_offset (KEY_FORMAT_3_5, rkey));
 196
 197     } /* while */
 198
 199
 200  end:
 201     filp->f_pos = next_pos;
 202     pathrelse (&path_to_entry);
 203     reiserfs_check_path(&path_to_entry) ;
 204  out:
 205     reiserfs_write_unlock(inode->i_sb);
 206     return ret;
 207 }
 208
 209 /* compose directory item containing "." and ".." entries (entries are
 210    not aligned to 4 byte boundary) */
 211 /* the last four params are LE */
 212 void make_empty_dir_item_v1 (char * body, __u32 dirid, __u32 objid,
 213                              __u32 par_dirid, __u32 par_objid)
 214 {
 215     struct reiserfs_de_head * deh;
 216
 217     memset (body, 0, EMPTY_DIR_SIZE_V1);
 218     deh = (struct reiserfs_de_head *)body;
 219
 220     /* direntry header of "." */
 221     put_deh_offset( &(deh[0]), DOT_OFFSET );
 222     /* these two are from make_le_item_head, and are are LE */
 223     deh[0].deh_dir_id = dirid;
 224     deh[0].deh_objectid = objid;
 225     deh[0].deh_state = 0; /* Endian safe if 0 */
 226     put_deh_location( &(deh[0]), EMPTY_DIR_SIZE_V1 - strlen( "." ));
 227     mark_de_visible(&(deh[0]));
 228
 229     /* direntry header of ".." */
 230     put_deh_offset( &(deh[1]), DOT_DOT_OFFSET);
 231     /* key of ".." for the root directory */
 232     /* these two are from the inode, and are are LE */
 233     deh[1].deh_dir_id = par_dirid;
 234     deh[1].deh_objectid = par_objid;
 235     deh[1].deh_state = 0; /* Endian safe if 0 */
 236     put_deh_location( &(deh[1]), deh_location( &(deh[0]) ) - strlen( ".." ) );
 237     mark_de_visible(&(deh[1]));
 238
 239     /* copy ".." and "." */
 240     memcpy (body + deh_location( &(deh[0]) ), ".", 1);
 241     memcpy (body + deh_location( &(deh[1]) ), "..", 2);
 242 }
 243
 244 /* compose directory item containing "." and ".." entries */
 245 void make_empty_dir_item (char * body, __u32 dirid, __u32 objid,
 246                           __u32 par_dirid, __u32 par_objid)
 247 {
 248     struct reiserfs_de_head * deh;
 249
 250     memset (body, 0, EMPTY_DIR_SIZE);
 251     deh = (struct reiserfs_de_head *)body;
 252
 253     /* direntry header of "." */
 254     put_deh_offset( &(deh[0]), DOT_OFFSET );
 255     /* these two are from make_le_item_head, and are are LE */
 256     deh[0].deh_dir_id = dirid;
 257     deh[0].deh_objectid = objid;
 258     deh[0].deh_state = 0; /* Endian safe if 0 */
 259     put_deh_location( &(deh[0]), EMPTY_DIR_SIZE - ROUND_UP( strlen( "." ) ) );
 260     mark_de_visible(&(deh[0]));
 261
 262     /* direntry header of ".." */
 263     put_deh_offset( &(deh[1]), DOT_DOT_OFFSET );
 264     /* key of ".." for the root directory */
 265     /* these two are from the inode, and are are LE */
 266     deh[1].deh_dir_id = par_dirid;
 267     deh[1].deh_objectid = par_objid;
 268     deh[1].deh_state = 0; /* Endian safe if 0 */
 269     put_deh_location( &(deh[1]), deh_location( &(deh[0])) - ROUND_UP( strlen( ".." ) ) );
 270     mark_de_visible(&(deh[1]));
 271
 272     /* copy ".." and "." */
 273     memcpy (body + deh_location( &(deh[0]) ), ".", 1);
 274     memcpy (body + deh_location( &(deh[1]) ), "..", 2);
 275 }