alloc.c

			   struct buffer_head *fe_bh,
			   struct ocfs2_truncate_context **tc)
{
	int status;
	unsigned int new_i_clusters;
	struct ocfs2_dinode *fe;
	struct ocfs2_extent_block *eb;
	struct buffer_head *last_eb_bh = NULL;

	mlog_entry_void();

	*tc = NULL;

	new_i_clusters = ocfs2_clusters_for_bytes(osb->sb,
						  i_size_read(inode));
	fe = (struct ocfs2_dinode *) fe_bh->b_data;

	mlog(0, "fe->i_clusters = %u, new_i_clusters = %u, fe->i_size ="
	     "%llu\n", le32_to_cpu(fe->i_clusters), new_i_clusters,
	     (unsigned long long)le64_to_cpu(fe->i_size));

	*tc = kzalloc(sizeof(struct ocfs2_truncate_context), GFP_KERNEL);
	if (!(*tc)) {
		status = -ENOMEM;
		mlog_errno(status);
		goto bail;
	}
	ocfs2_init_dealloc_ctxt(&(*tc)->tc_dealloc);

	if (fe->id2.i_list.l_tree_depth) {
		status = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
					  &last_eb_bh, OCFS2_BH_CACHED, inode);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}
		eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
		if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
			OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);

			brelse(last_eb_bh);
			status = -EIO;
			goto bail;
		}
	}

	(*tc)->tc_last_eb_bh = last_eb_bh;

	status = 0;
bail:
	if (status < 0) {
		if (*tc)
			ocfs2_free_truncate_context(*tc);
		*tc = NULL;
	}
	mlog_exit_void();
	return status;
}

/*
 * 'start' is inclusive, 'end' is not.
 */
int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
			  unsigned int start, unsigned int end, int trunc)
{
	int ret;
	unsigned int numbytes;
	handle_t *handle;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
	struct ocfs2_inline_data *idata = &di->id2.i_data;

	if (end > i_size_read(inode))
		end = i_size_read(inode);

	BUG_ON(start >= end);

	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
	    !(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) ||
	    !ocfs2_supports_inline_data(osb)) {
		ocfs2_error(inode->i_sb,
			    "Inline data flags for inode %llu don't agree! "
			    "Disk: 0x%x, Memory: 0x%x, Superblock: 0x%x\n",
			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
			    le16_to_cpu(di->i_dyn_features),
			    OCFS2_I(inode)->ip_dyn_features,
			    osb->s_feature_incompat);
		ret = -EROFS;
		goto out;
	}

	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_journal_access(handle, inode, di_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	numbytes = end - start;
	memset(idata->id_data + start, 0, numbytes);

	/*
	 * No need to worry about the data page here - it's been
	 * truncated already and inline data doesn't need it for
	 * pushing zero's to disk, so we'll let readpage pick it up
	 * later.
	 */
	if (trunc) {
		i_size_write(inode, start);
		di->i_size = cpu_to_le64(start);
	}

	inode->i_blocks = ocfs2_inode_sector_count(inode);
	inode->i_ctime = inode->i_mtime = CURRENT_TIME;

	di->i_ctime = di->i_mtime = cpu_to_le64(inode->i_ctime.tv_sec);
	di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);

	ocfs2_journal_dirty(handle, di_bh);

out_commit:
	ocfs2_commit_trans(osb, handle);

out:
	return ret;
}

static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc)
{
	/*
	 * The caller is responsible for completing deallocation
	 * before freeing the context.
	 */
	if (tc->tc_dealloc.c_first_suballocator != NULL)
		mlog(ML_NOTICE,
		     "Truncate completion has non-empty dealloc context\n");

	if (tc->tc_last_eb_bh)
		brelse(tc->tc_last_eb_bh);

	kfree(tc);
}