Exemplo n.º 1
0
/* first calls search_by_key, then, if item is not found looks for the entry inside directory item indicated by
   search_by_key. (We assign a key to each directory item, and place multiple entries in a single directory item.)
   Fills the path to the entry, and to the entry position in the item */
int search_by_entry_key (struct super_block * sb, struct key * key, struct path * path, int * pos_in_item, int * repeat)
{
  /* search for a directory item using key of entry */
  if (search_by_key (sb, key, path, repeat, DISK_LEAF_NODE_LEVEL, READ_BLOCKS) == ITEM_FOUND) {
    *pos_in_item = 0;
    return POSITION_FOUND;
  }
#ifdef REISERFS_CHECK
  if (!PATH_LAST_POSITION (path))
    reiserfs_panic (sb, "vs-7000: search_by_entry_key: search_by_key returned item position == 0");
#endif /* REISERFS_CHECK */
  PATH_LAST_POSITION (path) --;

#ifdef REISERFS_CHECK
  {
    struct item_head * ih = B_N_PITEM_HEAD (PATH_PLAST_BUFFER (path), PATH_LAST_POSITION (path));

    if (!I_IS_DIRECTORY_ITEM (ih) || COMP_SHORT_KEYS (&(ih->ih_key), key)) {
      print_block (PATH_PLAST_BUFFER (path), 0, -1, -1);
      reiserfs_panic (sb, "vs-7005: search_by_entry_key: found item %h is not directory item or "
		      "does not belong to the same directory as key %k", ih, key);
    }
  }
#endif /* REISERFS_CHECK */

  /* binary search in directory item by third component of the key */
  return bin_search_in_dir_item (PATH_PITEM_HEAD (path), B_I_DEH (PATH_PLAST_BUFFER (path), PATH_PITEM_HEAD (path)), key, pos_in_item);
}
Exemplo n.º 2
0
/* The function is NOT SCHEDULE-SAFE! */
int search_by_entry_key(struct super_block *sb, const struct cpu_key *key,
			struct treepath *path, struct reiserfs_dir_entry *de)
{
	int retval;

	retval = search_item(sb, key, path);
	switch (retval) {
	case ITEM_NOT_FOUND:
		if (!PATH_LAST_POSITION(path)) {
			reiserfs_error(sb, "vs-7000", "search_by_key "
				       "returned item position == 0");
			pathrelse(path);
			return IO_ERROR;
		}
		PATH_LAST_POSITION(path)--;

	case ITEM_FOUND:
		break;

	case IO_ERROR:
		return retval;

	default:
		pathrelse(path);
		reiserfs_error(sb, "vs-7002", "no path to here");
		return IO_ERROR;
	}

	set_de_item_location(de, path);

#ifdef CONFIG_REISERFS_CHECK
	if (!is_direntry_le_ih(de->de_ih) ||
	    COMP_SHORT_KEYS(&de->de_ih->ih_key, key)) {
		print_block(de->de_bh, 0, -1, -1);
		reiserfs_panic(sb, "vs-7005", "found item %h is not directory "
			       "item or does not belong to the same directory "
			       "as key %K", de->de_ih, key);
	}
#endif				/* CONFIG_REISERFS_CHECK */

	/*
	 * binary search in directory item by third component of the
	 * key. sets de->de_entry_num of de
	 */
	retval = bin_search_in_dir_item(de, cpu_key_k_offset(key));
	path->pos_in_item = de->de_entry_num;
	if (retval != NAME_NOT_FOUND) {
		/*
		 * ugly, but rename needs de_bh, de_deh, de_name,
		 * de_namelen, de_objectid set
		 */
		set_de_name_and_namelen(de);
		set_de_object_key(de);
	}
	return retval;
}
Exemplo n.º 3
0
static int reiserfs_find_entry (struct inode * dir, const char * name, int namelen, struct path * path_to_entry, struct reiserfs_dir_entry * de)
{
  struct key key_to_search;
  int repeat;
  int retval;

  if (!dir || !dir->i_sb)
    return POSITION_NOT_FOUND;

  if ((unsigned int)namelen > REISERFS_MAX_NAME_LEN (dir->i_sb->s_blocksize))
    return POSITION_NOT_FOUND;

  /* there are no entries having the same third component of key, so
     fourth key component is not used */
  copy_key (&key_to_search, INODE_PKEY (dir));
  key_to_search.k_offset = get_third_component (name, namelen);
  key_to_search.k_uniqueness = DIRENTRY_UNIQUENESS;

  while (1) {
    /* search for a directory item using the formed key */
    if (search_by_key (dir->i_sb, &key_to_search, path_to_entry, &repeat, DISK_LEAF_NODE_LEVEL, READ_BLOCKS) == ITEM_NOT_FOUND) {
      /* take previous item */
#ifdef REISERFS_CHECK
      if (!PATH_LAST_POSITION (path_to_entry))
	reiserfs_panic (dir->i_sb, "vs-7010: reiserfs_find_entry: search_by_key returned bad position == 0");
#endif /* REISERFS_CHECK */
      PATH_LAST_POSITION (path_to_entry) --;
    }
    
    de->de_bh = PATH_PLAST_BUFFER (path_to_entry);
    de->de_item_num = PATH_LAST_POSITION (path_to_entry);
    de->de_ih = B_N_PITEM_HEAD (de->de_bh, de->de_item_num);
    de->de_deh = B_I_DEH (de->de_bh, de->de_ih);

#ifdef REISERFS_CHECK
    if (!I_IS_DIRECTORY_ITEM (de->de_ih) || COMP_SHORT_KEYS (&(de->de_ih->ih_key), INODE_PKEY (dir)))
      reiserfs_panic (dir->i_sb, "vs-7020: reiserfs_find_entry: item must be an item of the same directory item as inode");
#endif /* REISERFS_CHECK */

    /* we do not check whether bin_search_in_dir_item found the given key, even if so, we still have
       to compare names */
    bin_search_in_dir_item (de->de_ih, de->de_deh, &key_to_search, &(de->de_entry_num));

    /* compare names for all entries having given hash value */
    retval = linear_search_in_dir_item (&key_to_search, de, name, namelen);
    if (retval != GOTO_PREVIOUS_ITEM)
      /* there is no need to scan directory anymore. Given entry found or does not exist */
      return retval;

    /* there is left neighboring item of this directory and given entry can be there */
    key_to_search.k_offset = de->de_ih->ih_key.k_offset - 1;
    pathrelse (path_to_entry);

  } /* while (1) */
}
Exemplo n.º 4
0
static int reiserfs_readdir (struct file * filp, void * dirent, filldir_t filldir)
{
    struct inode *inode = filp->f_dentry->d_inode;
    struct cpu_key pos_key;	/* key of current position in the directory (key of directory entry) */
    INITIALIZE_PATH (path_to_entry);
    struct buffer_head * bh;
    int item_num, entry_num;
    const struct key * rkey;
    struct item_head * ih, tmp_ih;
    int search_res;
    char * local_buf;
    loff_t next_pos;
    char small_buf[32] ; /* avoid kmalloc if we can */
    struct reiserfs_dir_entry de;


    reiserfs_check_lock_depth("readdir") ;

    /* form key for search the next directory entry using f_pos field of
       file structure */
    make_cpu_key (&pos_key, inode, (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET,
		  TYPE_DIRENTRY, 3);
    next_pos = cpu_key_k_offset (&pos_key);

    /*  reiserfs_warning ("reiserfs_readdir 1: f_pos = %Ld\n", filp->f_pos);*/

    while (1) {
    research:
	/* search the directory item, containing entry with specified key */
	search_res = search_by_entry_key (inode->i_sb, &pos_key, &path_to_entry, &de);
	if (search_res == IO_ERROR) {
	    // FIXME: we could just skip part of directory which could
	    // not be read
	    return -EIO;
	}
	entry_num = de.de_entry_num;
	bh = de.de_bh;
	item_num = de.de_item_num;
	ih = de.de_ih;
	store_ih (&tmp_ih, ih);
		
	/* we must have found item, that is item of this directory, */
	RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key),
		"vs-9000: found item %h does not match to dir we readdir %K",
		ih, &pos_key);
	RFALSE( item_num > B_NR_ITEMS (bh) - 1,
		"vs-9005 item_num == %d, item amount == %d", 
		item_num, B_NR_ITEMS (bh));
      
	/* and entry must be not more than number of entries in the item */
	RFALSE( I_ENTRY_COUNT (ih) < entry_num,
		"vs-9010: entry number is too big %d (%d)", 
		entry_num, I_ENTRY_COUNT (ih));

	if (search_res == POSITION_FOUND || entry_num < I_ENTRY_COUNT (ih)) {
	    /* go through all entries in the directory item beginning from the entry, that has been found */
	    struct reiserfs_de_head * deh = B_I_DEH (bh, ih) + entry_num;

	    for (; entry_num < I_ENTRY_COUNT (ih); entry_num ++, deh ++) {
		int d_reclen;
		char * d_name;
		off_t d_off;
		ino_t d_ino;

		if (!de_visible (deh))
		    /* it is hidden entry */
		    continue;
		d_reclen = entry_length (bh, ih, entry_num);
		d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
		if (!d_name[d_reclen - 1])
		    d_reclen = strlen (d_name);
	
		if (d_reclen > REISERFS_MAX_NAME_LEN(inode->i_sb->s_blocksize)){
		    /* too big to send back to VFS */
		    continue ;
		}
		d_off = deh_offset (deh);
		filp->f_pos = d_off ;
		d_ino = deh_objectid (deh);
		if (d_reclen <= 32) {
		  local_buf = small_buf ;
		} else {
		    local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ;
		    if (!local_buf) {
			pathrelse (&path_to_entry);
			return -ENOMEM ;
		    }
		    if (item_moved (&tmp_ih, &path_to_entry)) {
			reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
			goto research;
		    }
		}
		// Note, that we copy name to user space via temporary
		// buffer (local_buf) because filldir will block if
		// user space buffer is swapped out. At that time
		// entry can move to somewhere else
		memcpy (local_buf, d_name, d_reclen);
		if (filldir (dirent, local_buf, d_reclen, d_off, d_ino, 
		             DT_UNKNOWN) < 0) {
		    if (local_buf != small_buf) {
			reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
		    }
		    goto end;
		}
		if (local_buf != small_buf) {
		    reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
		}

		// next entry should be looked for with such offset
		next_pos = deh_offset (deh) + 1;

		if (item_moved (&tmp_ih, &path_to_entry)) {
		    goto research;
		}
	    } /* for */
	}

	if (item_num != B_NR_ITEMS (bh) - 1)
	    // end of directory has been reached
	    goto end;

	/* item we went through is last item of node. Using right
	   delimiting key check is it directory end */
	rkey = get_rkey (&path_to_entry, inode->i_sb);
	if (! comp_le_keys (rkey, &MIN_KEY)) {
	    /* set pos_key to key, that is the smallest and greater
	       that key of the last entry in the item */
	    set_cpu_key_k_offset (&pos_key, next_pos);
	    continue;
	}

	if ( COMP_SHORT_KEYS (rkey, &pos_key)) {
	    // end of directory has been reached
	    goto end;
	}
	
	/* directory continues in the right neighboring block */
	set_cpu_key_k_offset (&pos_key, le_key_k_offset (KEY_FORMAT_3_5, rkey));

    } /* while */


 end:
    // FIXME: ext2_readdir does not reset f_pos
    filp->f_pos = next_pos;
    pathrelse (&path_to_entry);
    reiserfs_check_path(&path_to_entry) ;
    UPDATE_ATIME(inode) ;
    return 0;
}
Exemplo n.º 5
0
int
reiserfs_readdir(struct vop_readdir_args  /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		struct ucred *a_cred;
		int *a_eofflag;
		int *a_ncookies;
		u_long **a_cookies;
	} */*ap)
{
	int error = 0;
	struct dirent dstdp;
	struct uio *uio = ap->a_uio;

	off_t next_pos;
	struct buf *bp;
	struct item_head *ih;
	struct cpu_key pos_key;
	const struct key *rkey;
	struct reiserfs_node *ip;
	struct reiserfs_dir_entry de;
	INITIALIZE_PATH(path_to_entry);
	int entry_num, item_num, search_res;

	/* The NFS part */
	int ncookies = 0;
	u_long *cookies = NULL;

	/*
	 * Form key for search the next directory entry using f_pos field of
	 * file structure
	 */
	ip = VTOI(ap->a_vp);
	make_cpu_key(&pos_key,
	    ip, uio->uio_offset ? uio->uio_offset : DOT_OFFSET,
	    TYPE_DIRENTRY, 3);
	next_pos = cpu_key_k_offset(&pos_key);

	reiserfs_log(LOG_DEBUG, "listing entries for "
	    "(objectid=%d, dirid=%d)\n",
	    pos_key.on_disk_key.k_objectid, pos_key.on_disk_key.k_dir_id);
	reiserfs_log(LOG_DEBUG, "uio_offset = %jd, uio_resid = %d\n",
	    (intmax_t)uio->uio_offset, uio->uio_resid);

	if (ap->a_ncookies && ap->a_cookies) {
		cookies = (u_long *)malloc(
		    uio->uio_resid / 16 * sizeof(u_long),
		    M_REISERFSCOOKIES, M_WAITOK);
	}

	while (1) {
		//research:
		/*
		 * Search the directory item, containing entry with
		 * specified key
		 */
		reiserfs_log(LOG_DEBUG, "search directory to read\n");
		search_res = search_by_entry_key(ip->i_reiserfs, &pos_key,
		    &path_to_entry, &de);
		if (search_res == IO_ERROR) {
			error = EIO;
			goto out;
		}

		entry_num = de.de_entry_num;
		item_num  = de.de_item_num;
		bp = de.de_bp;
		ih = de.de_ih;

		if (search_res == POSITION_FOUND ||
		    entry_num < I_ENTRY_COUNT(ih)) {
			/*
			 * Go through all entries in the directory item
			 * beginning from the entry, that has been found.
			 */
			struct reiserfs_de_head *deh = B_I_DEH(bp, ih) +
			    entry_num;

			if (ap->a_ncookies == NULL) {
				cookies = NULL;
			} else {
				//ncookies = 
			}

			reiserfs_log(LOG_DEBUG,
			    "walking through directory entries\n");
			for (; entry_num < I_ENTRY_COUNT(ih);
			    entry_num++, deh++) {
				int d_namlen;
				char *d_name;
				off_t d_off;
				ino_t d_ino;

				if (!de_visible(deh)) {
					/* It is hidden entry */
					continue;
				}

				d_namlen = entry_length(bp, ih, entry_num);
				d_name   = B_I_DEH_ENTRY_FILE_NAME(bp, ih, deh);
				if (!d_name[d_namlen - 1])
					d_namlen = strlen(d_name);
				reiserfs_log(LOG_DEBUG, "  - `%s' (len=%d)\n",
				    d_name, d_namlen);

				if (d_namlen > REISERFS_MAX_NAME(
				    ip->i_reiserfs->s_blocksize)) {
					/* Too big to send back to VFS */
					continue;
				}

#if 0
				/* Ignore the .reiserfs_priv entry */
				if (reiserfs_xattrs(ip->i_reiserfs) &&
				    !old_format_only(ip->i_reiserfs) &&
				    filp->f_dentry == ip->i_reiserfs->s_root &&
				    REISERFS_SB(ip->i_reiserfs)->priv_root &&
				    REISERFS_SB(ip->i_reiserfs)->priv_root->d_inode &&
				    deh_objectid(deh) ==
				    le32toh(INODE_PKEY(REISERFS_SB(
				    ip->i_reiserfs)->priv_root->d_inode)->k_objectid)) {
					continue;
				}
#endif

				d_off = deh_offset(deh);
				d_ino = deh_objectid(deh);
				uio->uio_offset = d_off;

				/* Copy to user land */
				dstdp.d_fileno = d_ino;
				dstdp.d_type   = DT_UNKNOWN;
				dstdp.d_namlen = d_namlen;
				dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp);
				bcopy(d_name, dstdp.d_name, dstdp.d_namlen);
				bzero(dstdp.d_name + dstdp.d_namlen,
				    dstdp.d_reclen -
				    offsetof(struct dirent, d_name) -
				    dstdp.d_namlen);

				if (d_namlen > 0) {
					if (dstdp.d_reclen <= uio->uio_resid) {
						reiserfs_log(LOG_DEBUG, "     copying to user land\n");
						error = uiomove(&dstdp,
						    dstdp.d_reclen, uio);
						if (error)
							goto end;
						if (cookies != NULL) {
							cookies[ncookies] =
							    d_off;
							ncookies++;
						}
					} else
						break;
				} else {
					error = EIO;
					break;
				}

				next_pos = deh_offset(deh) + 1;
			}
			reiserfs_log(LOG_DEBUG, "...done\n");
		}

		reiserfs_log(LOG_DEBUG, "checking item num (%d == %d ?)\n",
		    item_num, B_NR_ITEMS(bp) - 1);
		if (item_num != B_NR_ITEMS(bp) - 1) {
			/* End of directory has been reached */
			reiserfs_log(LOG_DEBUG, "end reached\n");
			if (ap->a_eofflag)
				*ap->a_eofflag = 1;
			goto end;
		}

		/*
		 * Item we went through is last item of node. Using right
		 * delimiting key check is it directory end
		 */
		reiserfs_log(LOG_DEBUG, "get right key\n");
		rkey = get_rkey(&path_to_entry, ip->i_reiserfs);
		reiserfs_log(LOG_DEBUG, "right key = (objectid=%d, dirid=%d)\n",
		    rkey->k_objectid, rkey->k_dir_id);

		reiserfs_log(LOG_DEBUG, "compare it to MIN_KEY\n");
		reiserfs_log(LOG_DEBUG, "MIN KEY = (objectid=%d, dirid=%d)\n",
		    MIN_KEY.k_objectid, MIN_KEY.k_dir_id);
		if (comp_le_keys(rkey, &MIN_KEY) == 0) {
			/* Set pos_key to key, that is the smallest and greater
			 * that key of the last entry in the item */
			reiserfs_log(LOG_DEBUG, "continuing on the right\n");
			set_cpu_key_k_offset(&pos_key, next_pos);
			continue;
		}

		reiserfs_log(LOG_DEBUG, "compare it to pos_key\n");
		reiserfs_log(LOG_DEBUG, "pos key = (objectid=%d, dirid=%d)\n",
		    pos_key.on_disk_key.k_objectid,
		    pos_key.on_disk_key.k_dir_id);
		if (COMP_SHORT_KEYS(rkey, &pos_key)) {
			/* End of directory has been reached */
			reiserfs_log(LOG_DEBUG, "end reached (right)\n");
			if (ap->a_eofflag)
				*ap->a_eofflag = 1;
			goto end;
		}

		/* Directory continues in the right neighboring block */
		reiserfs_log(LOG_DEBUG, "continuing with a new offset\n");
		set_cpu_key_k_offset(&pos_key,
		    le_key_k_offset(KEY_FORMAT_3_5, rkey));
		reiserfs_log(LOG_DEBUG,
		    "new pos key = (objectid=%d, dirid=%d)\n",
		    pos_key.on_disk_key.k_objectid,
		    pos_key.on_disk_key.k_dir_id);
	}

end:
	uio->uio_offset = next_pos;
	pathrelse(&path_to_entry);
	reiserfs_check_path(&path_to_entry);
out:
	if (error && cookies != NULL) {
		free(cookies, M_REISERFSCOOKIES);
	} else if (ap->a_ncookies != NULL && ap->a_cookies != NULL) {
		*ap->a_ncookies = ncookies;
		*ap->a_cookies  = cookies;
	}
	return (error);
}
Exemplo n.º 6
0
int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
			   filldir_t filldir, loff_t *pos)
{
	struct inode *inode = dentry->d_inode;
	struct cpu_key pos_key;	
	INITIALIZE_PATH(path_to_entry);
	struct buffer_head *bh;
	int item_num, entry_num;
	const struct reiserfs_key *rkey;
	struct item_head *ih, tmp_ih;
	int search_res;
	char *local_buf;
	loff_t next_pos;
	char small_buf[32];	
	struct reiserfs_dir_entry de;
	int ret = 0;

	reiserfs_write_lock(inode->i_sb);

	reiserfs_check_lock_depth(inode->i_sb, "readdir");

	make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
	next_pos = cpu_key_k_offset(&pos_key);

	path_to_entry.reada = PATH_READA;
	while (1) {
	      research:
		
		search_res =
		    search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
					&de);
		if (search_res == IO_ERROR) {
			
			
			ret = -EIO;
			goto out;
		}
		entry_num = de.de_entry_num;
		bh = de.de_bh;
		item_num = de.de_item_num;
		ih = de.de_ih;
		store_ih(&tmp_ih, ih);

		
		RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
		       "vs-9000: found item %h does not match to dir we readdir %K",
		       ih, &pos_key);
		RFALSE(item_num > B_NR_ITEMS(bh) - 1,
		       "vs-9005 item_num == %d, item amount == %d",
		       item_num, B_NR_ITEMS(bh));

		
		RFALSE(I_ENTRY_COUNT(ih) < entry_num,
		       "vs-9010: entry number is too big %d (%d)",
		       entry_num, I_ENTRY_COUNT(ih));

		if (search_res == POSITION_FOUND
		    || entry_num < I_ENTRY_COUNT(ih)) {
			
			struct reiserfs_de_head *deh =
			    B_I_DEH(bh, ih) + entry_num;

			for (; entry_num < I_ENTRY_COUNT(ih);
			     entry_num++, deh++) {
				int d_reclen;
				char *d_name;
				off_t d_off;
				ino_t d_ino;

				if (!de_visible(deh))
					
					continue;
				d_reclen = entry_length(bh, ih, entry_num);
				d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);

				if (d_reclen <= 0 ||
				    d_name + d_reclen > bh->b_data + bh->b_size) {
					pathrelse(&path_to_entry);
					ret = -EIO;
					goto out;
				}

				if (!d_name[d_reclen - 1])
					d_reclen = strlen(d_name);

				if (d_reclen >
				    REISERFS_MAX_NAME(inode->i_sb->
						      s_blocksize)) {
					
					continue;
				}

				
				if (is_privroot_deh(dentry, deh))
					continue;

				d_off = deh_offset(deh);
				*pos = d_off;
				d_ino = deh_objectid(deh);
				if (d_reclen <= 32) {
					local_buf = small_buf;
				} else {
					local_buf = kmalloc(d_reclen,
							    GFP_NOFS);
					if (!local_buf) {
						pathrelse(&path_to_entry);
						ret = -ENOMEM;
						goto out;
					}
					if (item_moved(&tmp_ih, &path_to_entry)) {
						kfree(local_buf);
						goto research;
					}
				}
				
				
				
				
				memcpy(local_buf, d_name, d_reclen);

				reiserfs_write_unlock(inode->i_sb);
				if (filldir
				    (dirent, local_buf, d_reclen, d_off, d_ino,
				     DT_UNKNOWN) < 0) {
					reiserfs_write_lock(inode->i_sb);
					if (local_buf != small_buf) {
						kfree(local_buf);
					}
					goto end;
				}
				reiserfs_write_lock(inode->i_sb);
				if (local_buf != small_buf) {
					kfree(local_buf);
				}
				
				next_pos = deh_offset(deh) + 1;

				if (item_moved(&tmp_ih, &path_to_entry)) {
					goto research;
				}
			}	
		}

		if (item_num != B_NR_ITEMS(bh) - 1)
			
			goto end;

		rkey = get_rkey(&path_to_entry, inode->i_sb);
		if (!comp_le_keys(rkey, &MIN_KEY)) {
			set_cpu_key_k_offset(&pos_key, next_pos);
			continue;
		}

		if (COMP_SHORT_KEYS(rkey, &pos_key)) {
			
			goto end;
		}

		
		set_cpu_key_k_offset(&pos_key,
				     le_key_k_offset(KEY_FORMAT_3_5, rkey));

	}			

end:
	*pos = next_pos;
	pathrelse(&path_to_entry);
	reiserfs_check_path(&path_to_entry);
out:
	reiserfs_write_unlock(inode->i_sb);
	return ret;
}
Exemplo n.º 7
0
int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
			   filldir_t filldir, loff_t *pos)
{
	struct inode *inode = dentry->d_inode;
	struct cpu_key pos_key;	/* key of current position in the directory (key of directory entry) */
	INITIALIZE_PATH(path_to_entry);
	struct buffer_head *bh;
	int item_num, entry_num;
	const struct reiserfs_key *rkey;
	struct item_head *ih, tmp_ih;
	int search_res;
	char *local_buf;
	loff_t next_pos;
	char small_buf[32];	/* avoid kmalloc if we can */
	struct reiserfs_dir_entry de;
	int ret = 0;

	reiserfs_write_lock(inode->i_sb);

	reiserfs_check_lock_depth(inode->i_sb, "readdir");

	/* form key for search the next directory entry using f_pos field of
	   file structure */
	make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
	next_pos = cpu_key_k_offset(&pos_key);

	path_to_entry.reada = PATH_READA;
	while (1) {
	      research:
		/* search the directory item, containing entry with specified key */
		search_res =
		    search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
					&de);
		if (search_res == IO_ERROR) {
			// FIXME: we could just skip part of directory which could
			// not be read
			ret = -EIO;
			goto out;
		}
		entry_num = de.de_entry_num;
		bh = de.de_bh;
		item_num = de.de_item_num;
		ih = de.de_ih;
		store_ih(&tmp_ih, ih);

		/* we must have found item, that is item of this directory, */
		RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
		       "vs-9000: found item %h does not match to dir we readdir %K",
		       ih, &pos_key);
		RFALSE(item_num > B_NR_ITEMS(bh) - 1,
		       "vs-9005 item_num == %d, item amount == %d",
		       item_num, B_NR_ITEMS(bh));

		/* and entry must be not more than number of entries in the item */
		RFALSE(I_ENTRY_COUNT(ih) < entry_num,
		       "vs-9010: entry number is too big %d (%d)",
		       entry_num, I_ENTRY_COUNT(ih));

		if (search_res == POSITION_FOUND
		    || entry_num < I_ENTRY_COUNT(ih)) {
			/* go through all entries in the directory item beginning from the entry, that has been found */
			struct reiserfs_de_head *deh =
			    B_I_DEH(bh, ih) + entry_num;

			for (; entry_num < I_ENTRY_COUNT(ih);
			     entry_num++, deh++) {
				int d_reclen;
				char *d_name;
				off_t d_off;
				ino_t d_ino;
				loff_t cur_pos = deh_offset(deh);

				if (!de_visible(deh))
					/* it is hidden entry */
					continue;
				d_reclen = entry_length(bh, ih, entry_num);
				d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);

				if (d_reclen <= 0 ||
				    d_name + d_reclen > bh->b_data + bh->b_size) {
					/* There is corrupted data in entry,
					 * We'd better stop here */
					pathrelse(&path_to_entry);
					ret = -EIO;
					goto out;
				}

				if (!d_name[d_reclen - 1])
					d_reclen = strlen(d_name);

				if (d_reclen >
				    REISERFS_MAX_NAME(inode->i_sb->
						      s_blocksize)) {
					/* too big to send back to VFS */
					continue;
				}

				/* Ignore the .reiserfs_priv entry */
				if (is_privroot_deh(dentry, deh))
					continue;

				d_off = deh_offset(deh);
				*pos = d_off;
				d_ino = deh_objectid(deh);
				if (d_reclen <= 32) {
					local_buf = small_buf;
				} else {
					local_buf = kmalloc(d_reclen,
							    GFP_NOFS);
					if (!local_buf) {
						pathrelse(&path_to_entry);
						ret = -ENOMEM;
						goto out;
					}
					if (item_moved(&tmp_ih, &path_to_entry)) {
						kfree(local_buf);
						goto research;
					}
				}
				// Note, that we copy name to user space via temporary
				// buffer (local_buf) because filldir will block if
				// user space buffer is swapped out. At that time
				// entry can move to somewhere else
				memcpy(local_buf, d_name, d_reclen);

				/*
				 * Since filldir might sleep, we can release
				 * the write lock here for other waiters
				 */
				reiserfs_write_unlock(inode->i_sb);
				if (filldir
				    (dirent, local_buf, d_reclen, d_off, d_ino,
				     DT_UNKNOWN) < 0) {
					reiserfs_write_lock(inode->i_sb);
					if (local_buf != small_buf) {
						kfree(local_buf);
					}
					goto end;
				}
				reiserfs_write_lock(inode->i_sb);
				if (local_buf != small_buf) {
					kfree(local_buf);
				}

				/* deh_offset(deh) may be invalid now. */
				next_pos = cur_pos + 1;

				if (item_moved(&tmp_ih, &path_to_entry)) {
					set_cpu_key_k_offset(&pos_key,
							     next_pos);
					goto research;
				}
			}	/* for */
		}

		if (item_num != B_NR_ITEMS(bh) - 1)
			// end of directory has been reached
			goto end;

		/* item we went through is last item of node. Using right
		   delimiting key check is it directory end */
		rkey = get_rkey(&path_to_entry, inode->i_sb);
		if (!comp_le_keys(rkey, &MIN_KEY)) {
			/* set pos_key to key, that is the smallest and greater
			   that key of the last entry in the item */
			set_cpu_key_k_offset(&pos_key, next_pos);
			continue;
		}

		if (COMP_SHORT_KEYS(rkey, &pos_key)) {
			// end of directory has been reached
			goto end;
		}

		/* directory continues in the right neighboring block */
		set_cpu_key_k_offset(&pos_key,
				     le_key_k_offset(KEY_FORMAT_3_5, rkey));

	}			/* while */

end:
	*pos = next_pos;
	pathrelse(&path_to_entry);
	reiserfs_check_path(&path_to_entry);
out:
	reiserfs_write_unlock(inode->i_sb);
	return ret;
}