stree.c

linux 内核源代码

		if (n_ret_value != REPEAT_SEARCH)
			break;

		PROC_INFO_INC(p_s_sb, cut_from_item_restarted);

		n_ret_value =
		    search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path);
		if (n_ret_value == POSITION_FOUND)
			continue;

		reiserfs_warning(p_s_sb,
				 "PAP-5610: reiserfs_cut_from_item: item %K not found",
				 p_s_item_key);
		unfix_nodes(&s_cut_balance);
		return (n_ret_value == IO_ERROR) ? -EIO : -ENOENT;
	}			/* while */

	// check fix_nodes results (IO_ERROR or NO_DISK_SPACE)
	if (n_ret_value != CARRY_ON) {
		if (n_is_inode_locked) {
			// FIXME: this seems to be not needed: we are always able
			// to cut item
			indirect_to_direct_roll_back(th, p_s_inode, p_s_path);
		}
		if (n_ret_value == NO_DISK_SPACE)
			reiserfs_warning(p_s_sb, "NO_DISK_SPACE");
		unfix_nodes(&s_cut_balance);
		return -EIO;
	}

	/* go ahead and perform balancing */

	RFALSE(c_mode == M_PASTE || c_mode == M_INSERT, "invalid mode");

	/* Calculate number of bytes that need to be cut from the item. */
	quota_cut_bytes =
	    (c_mode ==
	     M_DELETE) ? ih_item_len(get_ih(p_s_path)) : -s_cut_balance.
	    insert_size[0];
	if (retval2 == -1)
		n_ret_value = calc_deleted_bytes_number(&s_cut_balance, c_mode);
	else
		n_ret_value = retval2;

	/* For direct items, we only change the quota when deleting the last
	 ** item.
	 */
	p_le_ih = PATH_PITEM_HEAD(s_cut_balance.tb_path);
	if (!S_ISLNK(p_s_inode->i_mode) && is_direct_le_ih(p_le_ih)) {
		if (c_mode == M_DELETE &&
		    (le_ih_k_offset(p_le_ih) & (p_s_sb->s_blocksize - 1)) ==
		    1) {
			// FIXME: this is to keep 3.5 happy
			REISERFS_I(p_s_inode)->i_first_direct_byte = U32_MAX;
			quota_cut_bytes = p_s_sb->s_blocksize + UNFM_P_SIZE;
		} else {
			quota_cut_bytes = 0;
		}
	}
#ifdef CONFIG_REISERFS_CHECK
	if (n_is_inode_locked) {
		struct item_head *le_ih =
		    PATH_PITEM_HEAD(s_cut_balance.tb_path);
		/* we are going to complete indirect2direct conversion. Make
		   sure, that we exactly remove last unformatted node pointer
		   of the item */
		if (!is_indirect_le_ih(le_ih))
			reiserfs_panic(p_s_sb,
				       "vs-5652: reiserfs_cut_from_item: "
				       "item must be indirect %h", le_ih);

		if (c_mode == M_DELETE && ih_item_len(le_ih) != UNFM_P_SIZE)
			reiserfs_panic(p_s_sb,
				       "vs-5653: reiserfs_cut_from_item: "
				       "completing indirect2direct conversion indirect item %h "
				       "being deleted must be of 4 byte long",
				       le_ih);

		if (c_mode == M_CUT
		    && s_cut_balance.insert_size[0] != -UNFM_P_SIZE) {
			reiserfs_panic(p_s_sb,
				       "vs-5654: reiserfs_cut_from_item: "
				       "can not complete indirect2direct conversion of %h (CUT, insert_size==%d)",
				       le_ih, s_cut_balance.insert_size[0]);
		}
		/* it would be useful to make sure, that right neighboring
		   item is direct item of this file */
	}
#endif

	do_balance(&s_cut_balance, NULL, NULL, c_mode);
	if (n_is_inode_locked) {
		/* we've done an indirect->direct conversion.  when the data block
		 ** was freed, it was removed from the list of blocks that must
		 ** be flushed before the transaction commits, make sure to
		 ** unmap and invalidate it
		 */
		unmap_buffers(page, tail_pos);
		REISERFS_I(p_s_inode)->i_flags &= ~i_pack_on_close_mask;
	}
#ifdef REISERQUOTA_DEBUG
	reiserfs_debug(p_s_inode->i_sb, REISERFS_DEBUG_CODE,
		       "reiserquota cut_from_item(): freeing %u id=%u type=%c",
		       quota_cut_bytes, p_s_inode->i_uid, '?');
#endif
	DQUOT_FREE_SPACE_NODIRTY(p_s_inode, quota_cut_bytes);
	return n_ret_value;
}

static void truncate_directory(struct reiserfs_transaction_handle *th,
			       struct inode *inode)
{
	BUG_ON(!th->t_trans_id);
	if (inode->i_nlink)
		reiserfs_warning(inode->i_sb,
				 "vs-5655: truncate_directory: link count != 0");

	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), DOT_OFFSET);
	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_DIRENTRY);
	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
	reiserfs_update_sd(th, inode);
	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), SD_OFFSET);
	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_STAT_DATA);
}

/* Truncate file to the new size. Note, this must be called with a transaction
   already started */
int reiserfs_do_truncate(struct reiserfs_transaction_handle *th, struct inode *p_s_inode,	/* ->i_size contains new
												   size */
			 struct page *page,	/* up to date for last block */
			 int update_timestamps	/* when it is called by
						   file_release to convert
						   the tail - no timestamps
						   should be updated */
    )
{
	INITIALIZE_PATH(s_search_path);	/* Path to the current object item. */
	struct item_head *p_le_ih;	/* Pointer to an item header. */
	struct cpu_key s_item_key;	/* Key to search for a previous file item. */
	loff_t n_file_size,	/* Old file size. */
	 n_new_file_size;	/* New file size. */
	int n_deleted;		/* Number of deleted or truncated bytes. */
	int retval;
	int err = 0;

	BUG_ON(!th->t_trans_id);
	if (!
	    (S_ISREG(p_s_inode->i_mode) || S_ISDIR(p_s_inode->i_mode)
	     || S_ISLNK(p_s_inode->i_mode)))
		return 0;

	if (S_ISDIR(p_s_inode->i_mode)) {
		// deletion of directory - no need to update timestamps
		truncate_directory(th, p_s_inode);
		return 0;
	}

	/* Get new file size. */
	n_new_file_size = p_s_inode->i_size;

	// FIXME: note, that key type is unimportant here
	make_cpu_key(&s_item_key, p_s_inode, max_reiserfs_offset(p_s_inode),
		     TYPE_DIRECT, 3);

	retval =
	    search_for_position_by_key(p_s_inode->i_sb, &s_item_key,
				       &s_search_path);
	if (retval == IO_ERROR) {
		reiserfs_warning(p_s_inode->i_sb,
				 "vs-5657: reiserfs_do_truncate: "
				 "i/o failure occurred trying to truncate %K",
				 &s_item_key);
		err = -EIO;
		goto out;
	}
	if (retval == POSITION_FOUND || retval == FILE_NOT_FOUND) {
		reiserfs_warning(p_s_inode->i_sb,
				 "PAP-5660: reiserfs_do_truncate: "
				 "wrong result %d of search for %K", retval,
				 &s_item_key);

		err = -EIO;
		goto out;
	}

	s_search_path.pos_in_item--;

	/* Get real file size (total length of all file items) */
	p_le_ih = PATH_PITEM_HEAD(&s_search_path);
	if (is_statdata_le_ih(p_le_ih))
		n_file_size = 0;
	else {
		loff_t offset = le_ih_k_offset(p_le_ih);
		int bytes =
		    op_bytes_number(p_le_ih, p_s_inode->i_sb->s_blocksize);

		/* this may mismatch with real file size: if last direct item
		   had no padding zeros and last unformatted node had no free
		   space, this file would have this file size */
		n_file_size = offset + bytes - 1;
	}
	/*
	 * are we doing a full truncate or delete, if so
	 * kick in the reada code
	 */
	if (n_new_file_size == 0)
		s_search_path.reada = PATH_READA | PATH_READA_BACK;

	if (n_file_size == 0 || n_file_size < n_new_file_size) {
		goto update_and_out;
	}

	/* Update key to search for the last file item. */
	set_cpu_key_k_offset(&s_item_key, n_file_size);

	do {
		/* Cut or delete file item. */
		n_deleted =
		    reiserfs_cut_from_item(th, &s_search_path, &s_item_key,
					   p_s_inode, page, n_new_file_size);
		if (n_deleted < 0) {
			reiserfs_warning(p_s_inode->i_sb,
					 "vs-5665: reiserfs_do_truncate: reiserfs_cut_from_item failed");
			reiserfs_check_path(&s_search_path);
			return 0;
		}

		RFALSE(n_deleted > n_file_size,
		       "PAP-5670: reiserfs_cut_from_item: too many bytes deleted: deleted %d, file_size %lu, item_key %K",
		       n_deleted, n_file_size, &s_item_key);

		/* Change key to search the last file item. */
		n_file_size -= n_deleted;

		set_cpu_key_k_offset(&s_item_key, n_file_size);

		/* While there are bytes to truncate and previous file item is presented in the tree. */

		/*
		 ** This loop could take a really long time, and could log 
		 ** many more blocks than a transaction can hold.  So, we do a polite
		 ** journal end here, and if the transaction needs ending, we make
		 ** sure the file is consistent before ending the current trans
		 ** and starting a new one
		 */
		if (journal_transaction_should_end(th, 0) ||
		    reiserfs_transaction_free_space(th) <= JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD) {
			int orig_len_alloc = th->t_blocks_allocated;
			decrement_counters_in_path(&s_search_path);

			if (update_timestamps) {
				p_s_inode->i_mtime = p_s_inode->i_ctime =
				    CURRENT_TIME_SEC;
			}
			reiserfs_update_sd(th, p_s_inode);

			err = journal_end(th, p_s_inode->i_sb, orig_len_alloc);
			if (err)
				goto out;
			err = journal_begin(th, p_s_inode->i_sb,
					    JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD + JOURNAL_PER_BALANCE_CNT * 4) ;
			if (err)
				goto out;
			reiserfs_update_inode_transaction(p_s_inode);
		}
	} while (n_file_size > ROUND_UP(n_new_file_size) &&
		 search_for_position_by_key(p_s_inode->i_sb, &s_item_key,
					    &s_search_path) == POSITION_FOUND);

	RFALSE(n_file_size > ROUND_UP(n_new_file_size),
	       "PAP-5680: truncate did not finish: new_file_size %Ld, current %Ld, oid %d",
	       n_new_file_size, n_file_size, s_item_key.on_disk_key.k_objectid);

      update_and_out:
	if (update_timestamps) {
		// this is truncate, not file closing
		p_s_inode->i_mtime = p_s_inode->i_ctime = CURRENT_TIME_SEC;
	}
	reiserfs_update_sd(th, p_s_inode);

      out:
	pathrelse(&s_search_path);
	return err;
}

#ifdef CONFIG_REISERFS_CHECK
// this makes sure, that we __append__, not overwrite or add holes
static void check_research_for_paste(struct treepath *path,
				     const struct cpu_key *p_s_key)
{
	struct item_head *found_ih = get_ih(path);

	if (is_direct_le_ih(found_ih)) {
		if (le_ih_k_offset(found_ih) +
		    op_bytes_number(found_ih,
				    get_last_bh(path)->b_size) !=
		    cpu_key_k_offset(p_s_key)
		    || op_bytes_number(found_ih,
				       get_last_bh(path)->b_size) !=
		    pos_in_item(path))
			reiserfs_panic(NULL,
				       "PAP-5720: check_research_for_paste: "
				       "found direct item %h or position (%d) does not match to key %K",
				       found_ih, pos_in_item(path), p_s_key);
	}
	if (is_indirect_le_ih(found_ih)) {
		if (le_ih_k_offset(found_ih) +
		    op_bytes_number(found_ih,
				    get_last_bh(path)->b_size) !=
		    cpu_key_k_offset(p_s_key)
		    || I_UNFM_NUM(found_ih) != pos_in_item(path)
		    || get_ih_free_space(found_ih) != 0)
			reiserfs_panic(NULL,
				       "PAP-5730: check_research_for_paste: "
				       "found indirect item (%h) or position (%d) does not match to key (%K)",
				       found_ih, pos_in_item(path), p_s_key);
	}
}
#endif				/* config reiserfs check */

/* Paste bytes to the existing item. Returns bytes number pasted into the item. */
int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th, struct treepath *p_s_search_path,	/* Path to the pasted item.          */
			     const struct cpu_key *p_s_key,	/* Key to search for the needed item. */
			     struct inode *inode,	/* Inode item belongs to */
			     const char *p_c_body,	/* Pointer to the bytes to paste.    */
			     int n_pasted_size)
{				/* Size of pasted bytes.             */
	struct tree_balance s_paste_balance;
	int retval;
	int fs_gen;

	BUG_ON(!th->t_trans_id);

	fs_gen = get_generation(inode->i_sb);

#ifdef REISERQUOTA_DEBUG
	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
		       "reiserquota paste_into_item(): allocating %u id=%u type=%c",
		       n_pasted_size, inode->i_uid,
		       key2type(&(p_s_key->on_disk_key)));
#endif

	if (DQUOT_ALLOC_SPACE_NODIRTY(inode, n_pasted_size)) {
		pathrelse(p_s_search_path);
		return -EDQUOT;
	}
	init_tb_struct(th, &s_paste_balance, th->t_super, p_s_search_path,
		       n_pasted_size);
#ifdef DISPLACE_NEW_PACKING_LOCALITIES
	s_paste_balance.key = p_s_key->on_disk_key;
#endif

	/* DQUOT_* can schedule, must check before the fix_nodes */
	if (fs_changed(fs_gen, inode->i_sb)) {
		goto search_again;
	}

	while ((retval =
		fix_nodes(M_PASTE, &s_paste_balance, NULL,
			  p_c_body)) == REPEAT_SEARCH) {
	      search_again:
		/* file system changed while we were in the fix_nodes */
		PROC_INFO_INC(th->t_super, paste_into_item_restarted);
		retval =
		    search_for_position_by_key(th->t_super, p_s_key,
					       p_s_search_path);
		if (retval == IO_ERROR) {
			retval = -EIO;
			goto error_out;
		}
		if (retval == POSITION_FOUND) {
			reiserfs_warning(inode->i_sb,
					 "PAP-5710: reiserfs_paste_into_item: entry or pasted byte (%K) exists",
					 p_s_key);
			retval = -EEXIST;
			goto error_out;
		}
#ifdef CONFIG_REISERFS_CHECK
		check_research_for_paste(p_s_search_path, p_s_key);
#endif
	}

	/* Perform balancing after all resources are collected by fix_nodes, and
	   accessing them will not risk triggering schedule. */
	if (retval == CARRY_ON) {
		do_balance(&s_paste_balance, NULL /*ih */ , p_c_body, M_PASTE);
		return 0;
	}
	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
      error_out:
	/* this also releases the path */
	unfix_nodes(&s_paste_balance);
#ifdef REISERQUOTA_DEBUG
	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
		       "reiserquota paste_into_item(): freeing %u id=%u type=%c",
		       n_pasted_size, inode->i_uid,
		       key2type(&(p_s_key->on_disk_key)));
#endif
	DQUOT_FREE_SPACE_NODIRTY(inode, n_pasted_size);
	return retval;
}

/* Insert new item into the buffer at the path. */
int reiserfs_insert_item(struct reiserfs_transaction_handle *th, struct treepath *p_s_path,	/* Path to the inserteded item.         */
			 const struct cpu_key *key,