fs/reiserfs/dir.c

   1 /*
   2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3  */
   4
   5 #include <linux/string.h>
   6 #include <linux/errno.h>
   7 #include <linux/fs.h>
   8 #include <linux/reiserfs_fs.h>
   9 #include <linux/stat.h>
  10 #include <linux/smp_lock.h>
  11 #include <linux/buffer_head.h>
  12 #include <asm/uaccess.h>
  13
  14 extern struct reiserfs_key MIN_KEY;
  15
  16 static int reiserfs_readdir(struct file *, void *, filldir_t);
  17 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
  18                               int datasync);
  19
  20 const 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,
  28                               int datasync)
  29 {
  30         struct inode *inode = dentry->d_inode;
  31         int err;
  32         reiserfs_write_lock(inode->i_sb);
  33         err = reiserfs_commit_for_inode(inode);
  34         reiserfs_write_unlock(inode->i_sb);
  35         if (err < 0)
  36                 return err;
  37         return 0;
  38 }
  39
  40 #define store_ih(where,what) copy_item_head (where, what)
  41
  42 //
  43 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
  44 {
  45         struct inode *inode = filp->f_dentry->d_inode;
  46         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
  47         INITIALIZE_PATH(path_to_entry);
  48         struct buffer_head *bh;
  49         int item_num, entry_num;
  50         const struct reiserfs_key *rkey;
  51         struct item_head *ih, tmp_ih;
  52         int search_res;
  53         char *local_buf;
  54         loff_t next_pos;
  55         char small_buf[32];     /* avoid kmalloc if we can */
  56         struct reiserfs_dir_entry de;
  57         int ret = 0;
  58
  59         reiserfs_write_lock(inode->i_sb);
  60
  61         reiserfs_check_lock_depth(inode->i_sb, "readdir");
  62
  63         /* form key for search the next directory entry using f_pos field of
  64            file structure */
  65         make_cpu_key(&pos_key, inode,
  66                      (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
  67                      3);
  68         next_pos = cpu_key_k_offset(&pos_key);
  69
  70         /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
  71
  72         path_to_entry.reada = PATH_READA;
  73         while (1) {
  74               research:
  75                 /* search the directory item, containing entry with specified key */
  76                 search_res =
  77                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
  78                                         &de);
  79                 if (search_res == IO_ERROR) {
  80                         // FIXME: we could just skip part of directory which could
  81                         // not be read
  82                         ret = -EIO;
  83                         goto out;
  84                 }
  85                 entry_num = de.de_entry_num;
  86                 bh = de.de_bh;
  87                 item_num = de.de_item_num;
  88                 ih = de.de_ih;
  89                 store_ih(&tmp_ih, ih);
  90
  91                 /* we must have found item, that is item of this directory, */
  92                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
  93                        "vs-9000: found item %h does not match to dir we readdir %K",
  94                        ih, &pos_key);
  95                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
  96                        "vs-9005 item_num == %d, item amount == %d",
  97                        item_num, B_NR_ITEMS(bh));
  98
  99                 /* and entry must be not more than number of entries in the item */
 100                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
 101                        "vs-9010: entry number is too big %d (%d)",
 102                        entry_num, I_ENTRY_COUNT(ih));
 103
 104                 if (search_res == POSITION_FOUND
 105                     || entry_num < I_ENTRY_COUNT(ih)) {
 106                         /* go through all entries in the directory item beginning from the entry, that has been found */
 107                         struct reiserfs_de_head *deh =
 108                             B_I_DEH(bh, ih) + entry_num;
 109
 110                         for (; entry_num < I_ENTRY_COUNT(ih);
 111                              entry_num++, deh++) {
 112                                 int d_reclen;
 113                                 char *d_name;
 114                                 off_t d_off;
 115                                 ino_t d_ino;
 116
 117                                 if (!de_visible(deh))
 118                                         /* it is hidden entry */
 119                                         continue;
 120                                 d_reclen = entry_length(bh, ih, entry_num);
 121                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
 122                                 if (!d_name[d_reclen - 1])
 123                                         d_reclen = strlen(d_name);
 124
 125                                 if (d_reclen >
 126                                     REISERFS_MAX_NAME(inode->i_sb->
 127                                                       s_blocksize)) {
 128                                         /* too big to send back to VFS */
 129                                         continue;
 130                                 }
 131
 132                                 /* Ignore the .reiserfs_priv entry */
 133                                 if (reiserfs_xattrs(inode->i_sb) &&
 134                                     !old_format_only(inode->i_sb) &&
 135                                     filp->f_dentry == inode->i_sb->s_root &&
 136                                     REISERFS_SB(inode->i_sb)->priv_root &&
 137                                     REISERFS_SB(inode->i_sb)->priv_root->d_inode
 138                                     && deh_objectid(deh) ==
 139                                     le32_to_cpu(INODE_PKEY
 140                                                 (REISERFS_SB(inode->i_sb)->
 141                                                  priv_root->d_inode)->
 142                                                 k_objectid)) {
 143                                         continue;
 144                                 }
 145
 146                                 d_off = deh_offset(deh);
 147                                 filp->f_pos = d_off;
 148                                 d_ino = deh_objectid(deh);
 149                                 if (d_reclen <= 32) {
 150                                         local_buf = small_buf;
 151                                 } else {
 152                                         local_buf = kmalloc(d_reclen,
 153                                                             GFP_NOFS);
 154                                         if (!local_buf) {
 155                                                 pathrelse(&path_to_entry);
 156                                                 ret = -ENOMEM;
 157                                                 goto out;
 158                                         }
 159                                         if (item_moved(&tmp_ih, &path_to_entry)) {
 160                                                 kfree(local_buf);
 161                                                 goto research;
 162                                         }
 163                                 }
 164                                 // Note, that we copy name to user space via temporary
 165                                 // buffer (local_buf) because filldir will block if
 166                                 // user space buffer is swapped out. At that time
 167                                 // entry can move to somewhere else
 168                                 memcpy(local_buf, d_name, d_reclen);
 169                                 if (filldir
 170                                     (dirent, local_buf, d_reclen, d_off, d_ino,
 171                                      DT_UNKNOWN) < 0) {
 172                                         if (local_buf != small_buf) {
 173                                                 kfree(local_buf);
 174                                         }
 175                                         goto end;
 176                                 }
 177                                 if (local_buf != small_buf) {
 178                                         kfree(local_buf);
 179                                 }
 180                                 // next entry should be looked for with such offset
 181                                 next_pos = deh_offset(deh) + 1;
 182
 183                                 if (item_moved(&tmp_ih, &path_to_entry)) {
 184                                         goto research;
 185                                 }
 186                         }       /* for */
 187                 }
 188
 189                 if (item_num != B_NR_ITEMS(bh) - 1)
 190                         // end of directory has been reached
 191                         goto end;
 192
 193                 /* item we went through is last item of node. Using right
 194                    delimiting key check is it directory end */
 195                 rkey = get_rkey(&path_to_entry, inode->i_sb);
 196                 if (!comp_le_keys(rkey, &MIN_KEY)) {
 197                         /* set pos_key to key, that is the smallest and greater
 198                            that key of the last entry in the item */
 199                         set_cpu_key_k_offset(&pos_key, next_pos);
 200                         continue;
 201                 }
 202
 203                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
 204                         // end of directory has been reached
 205                         goto end;
 206                 }
 207
 208                 /* directory continues in the right neighboring block */
 209                 set_cpu_key_k_offset(&pos_key,
 210                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
 211
 212         }                       /* while */
 213
 214       end:
 215         filp->f_pos = next_pos;
 216         pathrelse(&path_to_entry);
 217         reiserfs_check_path(&path_to_entry);
 218       out:
 219         reiserfs_write_unlock(inode->i_sb);
 220         return ret;
 221 }
 222
 223 /* compose directory item containing "." and ".." entries (entries are
 224    not aligned to 4 byte boundary) */
 225 /* the last four params are LE */
 226 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
 227                             __le32 par_dirid, __le32 par_objid)
 228 {
 229         struct reiserfs_de_head *deh;
 230
 231         memset(body, 0, EMPTY_DIR_SIZE_V1);
 232         deh = (struct reiserfs_de_head *)body;
 233
 234         /* direntry header of "." */
 235         put_deh_offset(&(deh[0]), DOT_OFFSET);
 236         /* these two are from make_le_item_head, and are are LE */
 237         deh[0].deh_dir_id = dirid;
 238         deh[0].deh_objectid = objid;
 239         deh[0].deh_state = 0;   /* Endian safe if 0 */
 240         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
 241         mark_de_visible(&(deh[0]));
 242
 243         /* direntry header of ".." */
 244         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
 245         /* key of ".." for the root directory */
 246         /* these two are from the inode, and are are LE */
 247         deh[1].deh_dir_id = par_dirid;
 248         deh[1].deh_objectid = par_objid;
 249         deh[1].deh_state = 0;   /* Endian safe if 0 */
 250         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
 251         mark_de_visible(&(deh[1]));
 252
 253         /* copy ".." and "." */
 254         memcpy(body + deh_location(&(deh[0])), ".", 1);
 255         memcpy(body + deh_location(&(deh[1])), "..", 2);
 256 }
 257
 258 /* compose directory item containing "." and ".." entries */
 259 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
 260                          __le32 par_dirid, __le32 par_objid)
 261 {
 262         struct reiserfs_de_head *deh;
 263
 264         memset(body, 0, EMPTY_DIR_SIZE);
 265         deh = (struct reiserfs_de_head *)body;
 266
 267         /* direntry header of "." */
 268         put_deh_offset(&(deh[0]), DOT_OFFSET);
 269         /* these two are from make_le_item_head, and are are LE */
 270         deh[0].deh_dir_id = dirid;
 271         deh[0].deh_objectid = objid;
 272         deh[0].deh_state = 0;   /* Endian safe if 0 */
 273         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
 274         mark_de_visible(&(deh[0]));
 275
 276         /* direntry header of ".." */
 277         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
 278         /* key of ".." for the root directory */
 279         /* these two are from the inode, and are are LE */
 280         deh[1].deh_dir_id = par_dirid;
 281         deh[1].deh_objectid = par_objid;
 282         deh[1].deh_state = 0;   /* Endian safe if 0 */
 283         put_deh_location(&(deh[1]),
 284                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
 285         mark_de_visible(&(deh[1]));
 286
 287         /* copy ".." and "." */
 288         memcpy(body + deh_location(&(deh[0])), ".", 1);
 289         memcpy(body + deh_location(&(deh[1])), "..", 2);
 290 }