On Wed, Aug 28, 2013 at 07:29:38PM +0200, David Sterba wrote: > On Fri, Aug 16, 2013 at 04:27:28PM +0800, Liu Bo wrote: > > Similar to ocfs2, btrfs also supports that extents can be shared by > > different inodes, and there are some userspace tools requesting > > for this kind of 'space shared infomation'.[1] > > > > ocfs2 uses flag FIEMAP_EXTENT_SHARED, so does btrfs. > > Looks ok to me. > > > + int ref_cnt = 0; > > I think using long is cleaner here, it always fits into (void*), int > does not.
Good point. > > > + /* > > + * As btrfs supports shared space, this information > > + * can be exported to userspace tools via > > + * flag FIEMAP_EXTENT_SHARED. > > + */ > > + ret = iterate_inodes_from_logical( > > + em->block_start, > > + BTRFS_I(inode)->root->fs_info, > > + path, count_ext_ref, &ref_cnt); > > + if (ret < 0) > > + goto out_free; > > + > > + if (ref_cnt > 1) > > + flags |= FIEMAP_EXTENT_SHARED; > > AFAICS, e2fsprogs filefrag does not yet know about FIEMAP_EXTENT_SHARED. With checking filefrag's code, it's easy to make filefrag aware of this flag. I'll make a patch for filefrag unless someone has already done it, thanks. -liubo -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
