git.oblomov.eu Git - linux-2.6/blob - 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,
  19                               int datasync);
  20
  21 struct file_operations reiserfs_dir_operations = {
  22         .read = generic_read_dir,
  23         .readdir = reiserfs_readdir,
  24         .fsync = reiserfs_dir_fsync,
  25         .ioctl = reiserfs_ioctl,
  26 };
  27
  28 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
  29                               int datasync)
  30 {
  31         struct inode *inode = dentry->d_inode;
  32         int err;
  33         reiserfs_write_lock(inode->i_sb);
  34         err = reiserfs_commit_for_inode(inode);
  35         reiserfs_write_unlock(inode->i_sb);
  36         if (err < 0)
  37                 return err;
  38         return 0;
  39 }
  40
  41 #define store_ih(where,what) copy_item_head (where, what)
  42
  43 //
  44 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
  45 {
  46         struct inode *inode = filp->f_dentry->d_inode;
  47         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
  48         INITIALIZE_PATH(path_to_entry);
  49         struct buffer_head *bh;
  50         int item_num, entry_num;
  51         const struct reiserfs_key *rkey;
  52         struct item_head *ih, tmp_ih;
  53         int search_res;
  54         char *local_buf;
  55         loff_t next_pos;
  56         char small_buf[32];     /* avoid kmalloc if we can */
  57         struct reiserfs_dir_entry de;
  58         int ret = 0;
  59
  60         reiserfs_write_lock(inode->i_sb);
  61
  62         reiserfs_check_lock_depth(inode->i_sb, "readdir");
  63
  64         /* form key for search the next directory entry using f_pos field of
  65            file structure */
  66         make_cpu_key(&pos_key, inode,
  67                      (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
  68                      3);
  69         next_pos = cpu_key_k_offset(&pos_key);
  70
  71         /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
  72
  73         path_to_entry.reada = PATH_READA;
  74         while (1) {
  75               research:
  76                 /* search the directory item, containing entry with specified key */
  77                 search_res =
  78                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
  79                                         &de);
  80                 if (search_res == IO_ERROR) {
  81                         // FIXME: we could just skip part of directory which could
  82                         // not be read
  83                         ret = -EIO;
  84                         goto out;
  85                 }
  86                 entry_num = de.de_entry_num;
  87                 bh = de.de_bh;
  88                 item_num = de.de_item_num;
  89                 ih = de.de_ih;
  90                 store_ih(&tmp_ih, ih);
  91
  92                 /* we must have found item, that is item of this directory, */
  93                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
  94                        "vs-9000: found item %h does not match to dir we readdir %K",
  95                        ih, &pos_key);
  96                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
  97                        "vs-9005 item_num == %d, item amount == %d",
  98                        item_num, B_NR_ITEMS(bh));
  99
 100                 /* and entry must be not more than number of entries in the item */
 101                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
 102                        "vs-9010: entry number is too big %d (%d)",
 103                        entry_num, I_ENTRY_COUNT(ih));
 104
 105                 if (search_res == POSITION_FOUND
 106                     || entry_num < I_ENTRY_COUNT(ih)) {
 107                         /* go through all entries in the directory item beginning from the entry, that has been found */
 108                         struct reiserfs_de_head *deh =
 109                             B_I_DEH(bh, ih) + entry_num;
 110
 111                         for (; entry_num < I_ENTRY_COUNT(ih);
 112                              entry_num++, deh++) {
 113                                 int d_reclen;
 114                                 char *d_name;
 115                                 off_t d_off;
 116                                 ino_t d_ino;
 117
 118                                 if (!de_visible(deh))
 119                                         /* it is hidden entry */
 120                                         continue;
 121                                 d_reclen = entry_length(bh, ih, entry_num);
 122                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
 123                                 if (!d_name[d_reclen - 1])
 124                                         d_reclen = strlen(d_name);
 125
 126                                 if (d_reclen >
 127                                     REISERFS_MAX_NAME(inode->i_sb->
 128                                                       s_blocksize)) {
 129                                         /* too big to send back to VFS */
 130                                         continue;
 131                                 }
 132
 133                                 /* Ignore the .reiserfs_priv entry */
 134                                 if (reiserfs_xattrs(inode->i_sb) &&
 135                                     !old_format_only(inode->i_sb) &&
 136                                     filp->f_dentry == inode->i_sb->s_root &&
 137                                     REISERFS_SB(inode->i_sb)->priv_root &&
 138                                     REISERFS_SB(inode->i_sb)->priv_root->d_inode
 139                                     && deh_objectid(deh) ==
 140                                     le32_to_cpu(INODE_PKEY
 141                                                 (REISERFS_SB(inode->i_sb)->
 142                                                  priv_root->d_inode)->
 143                                                 k_objectid)) {
 144                                         continue;
 145                                 }
 146
 147                                 d_off = deh_offset(deh);
 148                                 filp->f_pos = d_off;
 149                                 d_ino = deh_objectid(deh);
 150                                 if (d_reclen <= 32) {
 151                                         local_buf = small_buf;
 152                                 } else {
 153                                         local_buf = kmalloc(d_reclen,
 154                                                             GFP_NOFS);
 155                                         if (!local_buf) {
 156                                                 pathrelse(&path_to_entry);
 157                                                 ret = -ENOMEM;
 158                                                 goto out;
 159                                         }
 160                                         if (item_moved(&tmp_ih, &path_to_entry)) {
 161                                                 kfree(local_buf);
 162                                                 goto research;
 163                                         }
 164                                 }
 165                                 // Note, that we copy name to user space via temporary
 166                                 // buffer (local_buf) because filldir will block if
 167                                 // user space buffer is swapped out. At that time
 168                                 // entry can move to somewhere else
 169                                 memcpy(local_buf, d_name, d_reclen);
 170                                 if (filldir
 171                                     (dirent, local_buf, d_reclen, d_off, d_ino,
 172                                      DT_UNKNOWN) < 0) {
 173                                         if (local_buf != small_buf) {
 174                                                 kfree(local_buf);
 175                                         }
 176                                         goto end;
 177                                 }
 178                                 if (local_buf != small_buf) {
 179                                         kfree(local_buf);
 180                                 }
 181                                 // next entry should be looked for with such offset
 182                                 next_pos = deh_offset(deh) + 1;
 183
 184                                 if (item_moved(&tmp_ih, &path_to_entry)) {
 185                                         goto research;
 186                                 }
 187                         }       /* for */
 188                 }
 189
 190                 if (item_num != B_NR_ITEMS(bh) - 1)
 191                         // end of directory has been reached
 192                         goto end;
 193
 194                 /* item we went through is last item of node. Using right
 195                    delimiting key check is it directory end */
 196                 rkey = get_rkey(&path_to_entry, inode->i_sb);
 197                 if (!comp_le_keys(rkey, &MIN_KEY)) {
 198                         /* set pos_key to key, that is the smallest and greater
 199                            that key of the last entry in the item */
 200                         set_cpu_key_k_offset(&pos_key, next_pos);
 201                         continue;
 202                 }
 203
 204                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
 205                         // end of directory has been reached
 206                         goto end;
 207                 }
 208
 209                 /* directory continues in the right neighboring block */
 210                 set_cpu_key_k_offset(&pos_key,
 211                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
 212
 213         }                       /* while */
 214
 215       end:
 216         filp->f_pos = next_pos;
 217         pathrelse(&path_to_entry);
 218         reiserfs_check_path(&path_to_entry);
 219       out:
 220         reiserfs_write_unlock(inode->i_sb);
 221         return ret;
 222 }
 223
 224 /* compose directory item containing "." and ".." entries (entries are
 225    not aligned to 4 byte boundary) */
 226 /* the last four params are LE */
 227 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
 228                             __le32 par_dirid, __le32 par_objid)
 229 {
 230         struct reiserfs_de_head *deh;
 231
 232         memset(body, 0, EMPTY_DIR_SIZE_V1);
 233         deh = (struct reiserfs_de_head *)body;
 234
 235         /* direntry header of "." */
 236         put_deh_offset(&(deh[0]), DOT_OFFSET);
 237         /* these two are from make_le_item_head, and are are LE */
 238         deh[0].deh_dir_id = dirid;
 239         deh[0].deh_objectid = objid;
 240         deh[0].deh_state = 0;   /* Endian safe if 0 */
 241         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
 242         mark_de_visible(&(deh[0]));
 243
 244         /* direntry header of ".." */
 245         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
 246         /* key of ".." for the root directory */
 247         /* these two are from the inode, and are are LE */
 248         deh[1].deh_dir_id = par_dirid;
 249         deh[1].deh_objectid = par_objid;
 250         deh[1].deh_state = 0;   /* Endian safe if 0 */
 251         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
 252         mark_de_visible(&(deh[1]));
 253
 254         /* copy ".." and "." */
 255         memcpy(body + deh_location(&(deh[0])), ".", 1);
 256         memcpy(body + deh_location(&(deh[1])), "..", 2);
 257 }
 258
 259 /* compose directory item containing "." and ".." entries */
 260 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
 261                          __le32 par_dirid, __le32 par_objid)
 262 {
 263         struct reiserfs_de_head *deh;
 264
 265         memset(body, 0, EMPTY_DIR_SIZE);
 266         deh = (struct reiserfs_de_head *)body;
 267
 268         /* direntry header of "." */
 269         put_deh_offset(&(deh[0]), DOT_OFFSET);
 270         /* these two are from make_le_item_head, and are are LE */
 271         deh[0].deh_dir_id = dirid;
 272         deh[0].deh_objectid = objid;
 273         deh[0].deh_state = 0;   /* Endian safe if 0 */
 274         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
 275         mark_de_visible(&(deh[0]));
 276
 277         /* direntry header of ".." */
 278         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
 279         /* key of ".." for the root directory */
 280         /* these two are from the inode, and are are LE */
 281         deh[1].deh_dir_id = par_dirid;
 282         deh[1].deh_objectid = par_objid;
 283         deh[1].deh_state = 0;   /* Endian safe if 0 */
 284         put_deh_location(&(deh[1]),
 285                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
 286         mark_de_visible(&(deh[1]));
 287
 288         /* copy ".." and "." */
 289         memcpy(body + deh_location(&(deh[0])), ".", 1);
 290         memcpy(body + deh_location(&(deh[1])), "..", 2);
 291 }