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Commit 8f603e56 authored by Tristan Ye's avatar Tristan Ye
Browse files

Ocfs2/move_extents: move a range of extent. 



The moving range of __ocfs2_move_extent() was within one extent always, it
consists following parts:

1. Duplicates the clusters in pages to new_blkoffset, where extent to be moved.

2. Split the original extent with new extent, coalecse the nearby extents if possible.

3. Append old clusters to truncate log, or decrease_refcount if the extent was refcounted.

Signed-off-by: default avatarTristan Ye <tristan.ye@oracle.com>
parent de474ee8

fs/ocfs2/move_extents.c

+100 −0
Original line number Diff line number Diff line
@@ -55,6 +55,106 @@ struct ocfs2_move_extents_context { 
	struct ocfs2_cached_dealloc_ctxt dealloc;

};



static int __ocfs2_move_extent(handle_t *handle,

			       struct ocfs2_move_extents_context *context,

			       u32 cpos, u32 len, u32 p_cpos, u32 new_p_cpos,

			       int ext_flags)

{

	int ret = 0, index;

	struct inode *inode = context->inode;

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

	struct ocfs2_extent_rec *rec, replace_rec;

	struct ocfs2_path *path = NULL;

	struct ocfs2_extent_list *el;

	u64 ino = ocfs2_metadata_cache_owner(context->et.et_ci);

	u64 old_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cpos);



	ret = ocfs2_duplicate_clusters_by_page(handle, context->file, cpos,

					       p_cpos, new_p_cpos, len);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	memset(&replace_rec, 0, sizeof(replace_rec));

	replace_rec.e_cpos = cpu_to_le32(cpos);

	replace_rec.e_leaf_clusters = cpu_to_le16(len);

	replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(inode->i_sb,

								   new_p_cpos));



	path = ocfs2_new_path_from_et(&context->et);

	if (!path) {

		ret = -ENOMEM;

		mlog_errno(ret);

		goto out;

	}



	ret = ocfs2_find_path(INODE_CACHE(inode), path, cpos);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	el = path_leaf_el(path);



	index = ocfs2_search_extent_list(el, cpos);

	if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {

		ocfs2_error(inode->i_sb,

			    "Inode %llu has an extent at cpos %u which can no "

			    "longer be found.\n",

			    (unsigned long long)ino, cpos);

		ret = -EROFS;

		goto out;

	}



	rec = &el->l_recs[index];



	BUG_ON(ext_flags != rec->e_flags);

	/*

	 * after moving/defraging to new location, the extent is not going

	 * to be refcounted anymore.

	 */

	replace_rec.e_flags = ext_flags & ~OCFS2_EXT_REFCOUNTED;



	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),

				      context->et.et_root_bh,

				      OCFS2_JOURNAL_ACCESS_WRITE);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	ret = ocfs2_split_extent(handle, &context->et, path, index,

				 &replace_rec, context->meta_ac,

				 &context->dealloc);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	ocfs2_journal_dirty(handle, context->et.et_root_bh);



	context->new_phys_cpos = new_p_cpos;



	/*

	 * need I to append truncate log for old clusters?

	 */

	if (old_blkno) {

		if (ext_flags & OCFS2_EXT_REFCOUNTED)

			ret = ocfs2_decrease_refcount(inode, handle,

					ocfs2_blocks_to_clusters(osb->sb,

								 old_blkno),

					len, context->meta_ac,

					&context->dealloc, 1);

		else

			ret = ocfs2_truncate_log_append(osb, handle,

							old_blkno, len);

	}



out:

	return ret;

}



/*

 * lock allocators, and reserving appropriate number of bits for

 * meta blocks and data clusters.