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Commit 202ee5fa authored by Tristan Ye's avatar Tristan Ye
Browse files

Ocfs2/move_extents: defrag a range of extent. 



It's a relatively complete function to accomplish defragmentation for entire
or partial extent, one journal handle was kept during the operation, it was
logically doing one more thing than ocfs2_move_extent() acutally, yes, it's
claiming the new clusters itself;-)

Signed-off-by: default avatarTristan Ye <tristan.ye@oracle.com>
parent 8f603e56

fs/ocfs2/move_extents.c

+136 −0
Original line number Diff line number Diff line
@@ -215,3 +215,139 @@ static int ocfs2_lock_allocators_move_extents(struct inode *inode, 


	return ret;

}



/*

 * Using one journal handle to guarantee the data consistency in case

 * crash happens anywhere.

 */

static int ocfs2_defrag_extent(struct ocfs2_move_extents_context *context,

			       u32 cpos, u32 phys_cpos, u32 len, int ext_flags)

{

	int ret, credits = 0, extra_blocks = 0;

	handle_t *handle;

	struct inode *inode = context->inode;

	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	struct inode *tl_inode = osb->osb_tl_inode;

	struct ocfs2_refcount_tree *ref_tree = NULL;

	u32 new_phys_cpos, new_len;

	u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);



	if ((ext_flags & OCFS2_EXT_REFCOUNTED) && len) {



		BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &

			 OCFS2_HAS_REFCOUNT_FL));



		BUG_ON(!context->refcount_loc);



		ret = ocfs2_lock_refcount_tree(osb, context->refcount_loc, 1,

					       &ref_tree, NULL);

		if (ret) {

			mlog_errno(ret);

			return ret;

		}



		ret = ocfs2_prepare_refcount_change_for_del(inode,

							context->refcount_loc,

							phys_blkno,

							len,

							&credits,

							&extra_blocks);

		if (ret) {

			mlog_errno(ret);

			goto out;

		}

	}



	ret = ocfs2_lock_allocators_move_extents(inode, &context->et, len, 1,

						 &context->meta_ac,

						 &context->data_ac,

						 extra_blocks, &credits);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	/*

	 * should be using allocation reservation strategy there?

	 *

	 * if (context->data_ac)

	 *	context->data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;

	 */



	mutex_lock(&tl_inode->i_mutex);



	if (ocfs2_truncate_log_needs_flush(osb)) {

		ret = __ocfs2_flush_truncate_log(osb);

		if (ret < 0) {

			mlog_errno(ret);

			goto out_unlock_mutex;

		}

	}



	handle = ocfs2_start_trans(osb, credits);

	if (IS_ERR(handle)) {

		ret = PTR_ERR(handle);

		mlog_errno(ret);

		goto out_unlock_mutex;

	}



	ret = __ocfs2_claim_clusters(handle, context->data_ac, 1, len,

				     &new_phys_cpos, &new_len);

	if (ret) {

		mlog_errno(ret);

		goto out_commit;

	}



	/*

	 * we're not quite patient here to make multiple attempts for claiming

	 * enough clusters, failure to claim clusters per-requested is not a

	 * disaster though, it can only mean partial range of defragmentation

	 * or extent movements gets gone, users anyway is able to have another

	 * try as they wish anytime, since they're going to be returned a

	 * '-ENOSPC' and completed length of this movement.

	 */

	if (new_len != len) {

		mlog(0, "len_claimed: %u, len: %u\n", new_len, len);

		context->range->me_flags &= ~OCFS2_MOVE_EXT_FL_COMPLETE;

		ret = -ENOSPC;

		goto out_commit;

	}



	mlog(0, "cpos: %u, phys_cpos: %u, new_phys_cpos: %u\n", cpos,

	     phys_cpos, new_phys_cpos);



	ret = __ocfs2_move_extent(handle, context, cpos, len, phys_cpos,

				  new_phys_cpos, ext_flags);

	if (ret)

		mlog_errno(ret);



	/*

	 * Here we should write the new page out first if we are

	 * in write-back mode.

	 */

	ret = ocfs2_cow_sync_writeback(inode->i_sb, context->inode, cpos, len);

	if (ret)

		mlog_errno(ret);



out_commit:

	ocfs2_commit_trans(osb, handle);



out_unlock_mutex:

	mutex_unlock(&tl_inode->i_mutex);



	if (context->data_ac) {

		ocfs2_free_alloc_context(context->data_ac);

		context->data_ac = NULL;

	}



	if (context->meta_ac) {

		ocfs2_free_alloc_context(context->meta_ac);

		context->meta_ac = NULL;

	}



out:

	if (ref_tree)

		ocfs2_unlock_refcount_tree(osb, ref_tree, 1);



	return ret;

}