LXR linux/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/buffer_head.h>
  11#include <asm/uaccess.h>
  12
  13extern const struct reiserfs_key MIN_KEY;
  14
  15static int reiserfs_readdir(struct file *, void *, filldir_t);
  16static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
  17                              int datasync);
  18
  19const struct file_operations reiserfs_dir_operations = {
  20        .read = generic_read_dir,
  21        .readdir = reiserfs_readdir,
  22        .fsync = reiserfs_dir_fsync,
  23        .ioctl = reiserfs_ioctl,
  24#ifdef CONFIG_COMPAT
  25        .compat_ioctl = reiserfs_compat_ioctl,
  26#endif
  27};
  28
  29static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
  30                              int datasync)
  31{
  32        struct inode *inode = dentry->d_inode;
  33        int err;
  34        reiserfs_write_lock(inode->i_sb);
  35        err = reiserfs_commit_for_inode(inode);
  36        reiserfs_write_unlock(inode->i_sb);
  37        if (err < 0)
  38                return err;
  39        return 0;
  40}
  41
  42#define store_ih(where,what) copy_item_head (where, what)
  43
  44//
  45static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
  46{
  47        struct inode *inode = filp->f_path.dentry->d_inode;
  48        struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
  49        INITIALIZE_PATH(path_to_entry);
  50        struct buffer_head *bh;
  51        int item_num, entry_num;
  52        const struct reiserfs_key *rkey;
  53        struct item_head *ih, tmp_ih;
  54        int search_res;
  55        char *local_buf;
  56        loff_t next_pos;
  57        char small_buf[32];     /* avoid kmalloc if we can */
  58        struct reiserfs_dir_entry de;
  59        int ret = 0;
  60
  61        reiserfs_write_lock(inode->i_sb);
  62
  63        reiserfs_check_lock_depth(inode->i_sb, "readdir");
  64
  65        /* form key for search the next directory entry using f_pos field of
  66           file structure */
  67        make_cpu_key(&pos_key, inode,
  68                     (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
  69                     3);
  70        next_pos = cpu_key_k_offset(&pos_key);
  71
  72        /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
  73
  74        path_to_entry.reada = PATH_READA;
  75        while (1) {
  76              research:
  77                /* search the directory item, containing entry with specified key */
  78                search_res =
  79                    search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
  80                                        &de);
  81                if (search_res == IO_ERROR) {
  82                        // FIXME: we could just skip part of directory which could
  83                        // not be read
  84                        ret = -EIO;
  85                        goto out;
  86                }
  87                entry_num = de.de_entry_num;
  88                bh = de.de_bh;
  89                item_num = de.de_item_num;
  90                ih = de.de_ih;
  91                store_ih(&tmp_ih, ih);
  92
  93                /* we must have found item, that is item of this directory, */
  94                RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
  95                       "vs-9000: found item %h does not match to dir we readdir %K",
  96                       ih, &pos_key);
  97                RFALSE(item_num > B_NR_ITEMS(bh) - 1,
  98                       "vs-9005 item_num == %d, item amount == %d",
  99                       item_num, B_NR_ITEMS(bh));
 100
 101                /* and entry must be not more than number of entries in the item */
 102                RFALSE(I_ENTRY_COUNT(ih) < entry_num,
 103                       "vs-9010: entry number is too big %d (%d)",
 104                       entry_num, I_ENTRY_COUNT(ih));
 105
 106                if (search_res == POSITION_FOUND
 107                    || entry_num < I_ENTRY_COUNT(ih)) {
 108                        /* go through all entries in the directory item beginning from the entry, that has been found */
 109                        struct reiserfs_de_head *deh =
 110                            B_I_DEH(bh, ih) + entry_num;
 111
 112                        for (; entry_num < I_ENTRY_COUNT(ih);
 113                             entry_num++, deh++) {
 114                                int d_reclen;
 115                                char *d_name;
 116                                off_t d_off;
 117                                ino_t d_ino;
 118
 119                                if (!de_visible(deh))
 120                                        /* it is hidden entry */
 121                                        continue;
 122                                d_reclen = entry_length(bh, ih, entry_num);
 123                                d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
 124
 125                                if (d_reclen <= 0 ||
 126                                    d_name + d_reclen > bh->b_data + bh->b_size) {
 127                                        /* There is corrupted data in entry,
 128                                         * We'd better stop here */
 129                                        pathrelse(&path_to_entry);
 130                                        ret = -EIO;
 131                                        goto out;
 132                                }
 133
 134                                if (!d_name[d_reclen - 1])
 135                                        d_reclen = strlen(d_name);
 136
 137                                if (d_reclen >
 138                                    REISERFS_MAX_NAME(inode->i_sb->
 139                                                      s_blocksize)) {
 140                                        /* too big to send back to VFS */
 141                                        continue;
 142                                }
 143
 144                                /* Ignore the .reiserfs_priv entry */
 145                                if (reiserfs_xattrs(inode->i_sb) &&
 146                                    !old_format_only(inode->i_sb) &&
 147                                    filp->f_path.dentry == inode->i_sb->s_root &&
 148                                    REISERFS_SB(inode->i_sb)->priv_root &&
 149                                    REISERFS_SB(inode->i_sb)->priv_root->d_inode
 150                                    && deh_objectid(deh) ==
 151                                    le32_to_cpu(INODE_PKEY
 152                                                (REISERFS_SB(inode->i_sb)->
 153                                                 priv_root->d_inode)->
 154                                                k_objectid)) {
 155                                        continue;
 156                                }
 157
 158                                d_off = deh_offset(deh);
 159                                filp->f_pos = d_off;
 160                                d_ino = deh_objectid(deh);
 161                                if (d_reclen <= 32) {
 162                                        local_buf = small_buf;
 163                                } else {
 164                                        local_buf = kmalloc(d_reclen,
 165                                                            GFP_NOFS);
 166                                        if (!local_buf) {
 167                                                pathrelse(&path_to_entry);
 168                                                ret = -ENOMEM;
 169                                                goto out;
 170                                        }
 171                                        if (item_moved(&tmp_ih, &path_to_entry)) {
 172                                                kfree(local_buf);
 173                                                goto research;
 174                                        }
 175                                }
 176                                // Note, that we copy name to user space via temporary
 177                                // buffer (local_buf) because filldir will block if
 178                                // user space buffer is swapped out. At that time
 179                                // entry can move to somewhere else
 180                                memcpy(local_buf, d_name, d_reclen);
 181                                if (filldir
 182                                    (dirent, local_buf, d_reclen, d_off, d_ino,
 183                                     DT_UNKNOWN) < 0) {
 184                                        if (local_buf != small_buf) {
 185                                                kfree(local_buf);
 186                                        }
 187                                        goto end;
 188                                }
 189                                if (local_buf != small_buf) {
 190                                        kfree(local_buf);
 191                                }
 192                                // next entry should be looked for with such offset
 193                                next_pos = deh_offset(deh) + 1;
 194
 195                                if (item_moved(&tmp_ih, &path_to_entry)) {
 196                                        goto research;
 197                                }
 198                        }       /* for */
 199                }
 200
 201                if (item_num != B_NR_ITEMS(bh) - 1)
 202                        // end of directory has been reached
 203                        goto end;
 204
 205                /* item we went through is last item of node. Using right
 206                   delimiting key check is it directory end */
 207                rkey = get_rkey(&path_to_entry, inode->i_sb);
 208                if (!comp_le_keys(rkey, &MIN_KEY)) {
 209                        /* set pos_key to key, that is the smallest and greater
 210                           that key of the last entry in the item */
 211                        set_cpu_key_k_offset(&pos_key, next_pos);
 212                        continue;
 213                }
 214
 215                if (COMP_SHORT_KEYS(rkey, &pos_key)) {
 216                        // end of directory has been reached
 217                        goto end;
 218                }
 219
 220                /* directory continues in the right neighboring block */
 221                set_cpu_key_k_offset(&pos_key,
 222                                     le_key_k_offset(KEY_FORMAT_3_5, rkey));
 223
 224        }                       /* while */
 225
 226      end:
 227        filp->f_pos = next_pos;
 228        pathrelse(&path_to_entry);
 229        reiserfs_check_path(&path_to_entry);
 230      out:
 231        reiserfs_write_unlock(inode->i_sb);
 232        return ret;
 233}
 234
 235/* compose directory item containing "." and ".." entries (entries are
 236   not aligned to 4 byte boundary) */
 237/* the last four params are LE */
 238void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
 239                            __le32 par_dirid, __le32 par_objid)
 240{
 241        struct reiserfs_de_head *deh;
 242
 243        memset(body, 0, EMPTY_DIR_SIZE_V1);
 244        deh = (struct reiserfs_de_head *)body;
 245
 246        /* direntry header of "." */
 247        put_deh_offset(&(deh[0]), DOT_OFFSET);
 248        /* these two are from make_le_item_head, and are are LE */
 249        deh[0].deh_dir_id = dirid;
 250        deh[0].deh_objectid = objid;
 251        deh[0].deh_state = 0;   /* Endian safe if 0 */
 252        put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
 253        mark_de_visible(&(deh[0]));
 254
 255        /* direntry header of ".." */
 256        put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
 257        /* key of ".." for the root directory */
 258        /* these two are from the inode, and are are LE */
 259        deh[1].deh_dir_id = par_dirid;
 260        deh[1].deh_objectid = par_objid;
 261        deh[1].deh_state = 0;   /* Endian safe if 0 */
 262        put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
 263        mark_de_visible(&(deh[1]));
 264
 265        /* copy ".." and "." */
 266        memcpy(body + deh_location(&(deh[0])), ".", 1);
 267        memcpy(body + deh_location(&(deh[1])), "..", 2);
 268}
 269
 270/* compose directory item containing "." and ".." entries */
 271void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
 272                         __le32 par_dirid, __le32 par_objid)
 273{
 274        struct reiserfs_de_head *deh;
 275
 276        memset(body, 0, EMPTY_DIR_SIZE);
 277        deh = (struct reiserfs_de_head *)body;
 278
 279        /* direntry header of "." */
 280        put_deh_offset(&(deh[0]), DOT_OFFSET);
 281        /* these two are from make_le_item_head, and are are LE */
 282        deh[0].deh_dir_id = dirid;
 283        deh[0].deh_objectid = objid;
 284        deh[0].deh_state = 0;   /* Endian safe if 0 */
 285        put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
 286        mark_de_visible(&(deh[0]));
 287
 288        /* direntry header of ".." */
 289        put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
 290        /* key of ".." for the root directory */
 291        /* these two are from the inode, and are are LE */
 292        deh[1].deh_dir_id = par_dirid;
 293        deh[1].deh_objectid = par_objid;
 294        deh[1].deh_state = 0;   /* Endian safe if 0 */
 295        put_deh_location(&(deh[1]),
 296                         deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
 297        mark_de_visible(&(deh[1]));
 298
 299        /* copy ".." and "." */
 300        memcpy(body + deh_location(&(deh[0])), ".", 1);
 301        memcpy(body + deh_location(&(deh[1])), "..", 2);
 302}
 303