On Thu, Aug 07, 2008 at 06:31:26AM +0800, Tao Ma wrote:
> The old ocfs2_do_extend_allocation is restrictly to be used in file
> extension. Now a new function named ocfs2_do_cluster_allocation will
> handle the issue of generic extend allocation and it is created in
> suballoc.c.
<snip>
> +int ocfs2_add_clusters_in_btree(struct ocfs2_super *osb,
> + struct inode *inode,
> + u32 *logical_offset,
> + u32 clusters_to_add,
> + int mark_unwritten,
> + struct buffer_head *root_bh,
> + struct ocfs2_extent_list *root_el,
> + handle_t *handle,
> + struct ocfs2_alloc_context *data_ac,
> + struct ocfs2_alloc_context *meta_ac,
> + enum ocfs2_alloc_restarted *reason_ret,
> + enum ocfs2_extent_tree_type type)
It seems to me that if you have root_bh and type, you can create
an ocfs2_extent_tree and calculate root_el from that. So you don't need
root_el in this function's arguments, and callers don't need to know how
to compute it.
Joel
> +{
> + int status = 0;
> + int free_extents;
> + enum ocfs2_alloc_restarted reason = RESTART_NONE;
> + u32 bit_off, num_bits;
> + u64 block;
> + u8 flags = 0;
> +
> + BUG_ON(!clusters_to_add);
> +
> + if (mark_unwritten)
> + flags = OCFS2_EXT_UNWRITTEN;
> +
> + free_extents = ocfs2_num_free_extents(osb, inode, root_bh, type);
> + if (free_extents < 0) {
> + status = free_extents;
> + mlog_errno(status);
> + goto leave;
> + }
> +
> + /* there are two cases which could cause us to EAGAIN in the
> + * we-need-more-metadata case:
> + * 1) we haven't reserved *any*
> + * 2) we are so fragmented, we've needed to add metadata too
> + * many times. */
> + if (!free_extents && !meta_ac) {
> + mlog(0, "we haven't reserved any metadata!\n");
> + status = -EAGAIN;
> + reason = RESTART_META;
> + goto leave;
> + } else if ((!free_extents)
> + && (ocfs2_alloc_context_bits_left(meta_ac)
> + < ocfs2_extend_meta_needed(root_el))) {
> + mlog(0, "filesystem is really fragmented...\n");
> + status = -EAGAIN;
> + reason = RESTART_META;
> + goto leave;
> + }
> +
> + status = __ocfs2_claim_clusters(osb, handle, data_ac, 1,
> + clusters_to_add, &bit_off, &num_bits);
> + if (status < 0) {
> + if (status != -ENOSPC)
> + mlog_errno(status);
> + goto leave;
> + }
> +
> + BUG_ON(num_bits > clusters_to_add);
> +
> + /* reserve our write early -- insert_extent may update the inode */
> + status = ocfs2_journal_access(handle, inode, root_bh,
> + OCFS2_JOURNAL_ACCESS_WRITE);
> + if (status < 0) {
> + mlog_errno(status);
> + goto leave;
> + }
> +
> + block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
> + mlog(0, "Allocating %u clusters at block %u for inode %llu\n",
> + num_bits, bit_off, (unsigned long long)OCFS2_I(inode)->ip_blkno);
> + status = ocfs2_insert_extent(osb, handle, inode, root_bh,
> + *logical_offset, block, num_bits,
> + flags, meta_ac, type);
> + if (status < 0) {
> + mlog_errno(status);
> + goto leave;
> + }
> +
> + status = ocfs2_journal_dirty(handle, root_bh);
> + if (status < 0) {
> + mlog_errno(status);
> + goto leave;
> + }
> +
> + clusters_to_add -= num_bits;
> + *logical_offset += num_bits;
> +
> + if (clusters_to_add) {
> + mlog(0, "need to alloc once more, wanted = %u\n",
> + clusters_to_add);
> + status = -EAGAIN;
> + reason = RESTART_TRANS;
> + }
> +
> +leave:
> + mlog_exit(status);
> + if (reason_ret)
> + *reason_ret = reason;
> + return status;
> +}
--
"You don't make the poor richer by making the rich poorer."
- Sir Winston Churchill
Joel Becker
Principal Software Developer
Oracle
E-mail: [EMAIL PROTECTED]
Phone: (650) 506-8127
_______________________________________________
Ocfs2-devel mailing list
[email protected]
http://oss.oracle.com/mailman/listinfo/ocfs2-devel
