From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:46885 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753336AbcE1DMl (ORCPT ); Fri, 27 May 2016 23:12:41 -0400 Date: Fri, 27 May 2016 20:14:12 -0700 From: Liu Bo To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org, dsterba@suse.cz, David Sterba Subject: Re: [PATCH v3 15/22] btrfs-progs: convert: Introduce new function to create converted image Message-ID: <20160528031412.GB31255@localhost.localdomain> Reply-To: bo.li.liu@oracle.com References: <1454043812-7893-1-git-send-email-quwenruo@cn.fujitsu.com> <1454043812-7893-16-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1454043812-7893-16-git-send-email-quwenruo@cn.fujitsu.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Jan 29, 2016 at 01:03:25PM +0800, Qu Wenruo wrote: > Use new function, create_convert_image_v2() to create snapshot of old > filesystem. > > Unlike old function which is called after copying all inodes, this > function need to be called before copying inodes. > > Signed-off-by: Qu Wenruo > Signed-off-by: David Sterba > --- > btrfs-convert.c | 184 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 184 insertions(+) > > diff --git a/btrfs-convert.c b/btrfs-convert.c > index 102953a..16e2309 100644 > --- a/btrfs-convert.c > +++ b/btrfs-convert.c > @@ -1412,6 +1412,7 @@ static int create_image_file_range(struct btrfs_trans_handle *trans, > fail: > return ret; > } > + > /* > * Create the fs image file. > */ > @@ -1605,6 +1606,189 @@ fail: > return ret; > } > > +static int create_image_file_range_v2(struct btrfs_trans_handle *trans, > + struct btrfs_root *root, > + struct cache_tree *used, > + struct btrfs_inode_item *inode, > + u64 ino, u64 bytenr, u64 *ret_len, > + int datacsum) > +{ > + struct cache_extent *cache; > + struct btrfs_block_group_cache *bg_cache; > + u64 len = *ret_len; > + u64 disk_bytenr; > + int ret; > + > + BUG_ON(bytenr != round_down(bytenr, root->sectorsize)); > + BUG_ON(len != round_down(len, root->sectorsize)); > + len = min_t(u64, len, BTRFS_MAX_EXTENT_SIZE); > + > + cache = search_cache_extent(used, bytenr); > + if (cache) { > + if (cache->start <= bytenr) { > + /* > + * |///////Used///////| > + * |<--insert--->| > + * bytenr > + */ > + len = min_t(u64, len, cache->start + cache->size - > + bytenr); > + disk_bytenr = bytenr; > + } else { > + /* > + * |//Used//| > + * |<-insert-->| > + * bytenr > + */ > + len = min(len, cache->start - bytenr); > + disk_bytenr = 0; > + datacsum = 0; > + } > + } else { > + /* > + * |//Used//| |EOF > + * |<-insert-->| > + * bytenr > + */ > + disk_bytenr = 0; > + datacsum = 0; > + } > + > + if (disk_bytenr) { > + /* Check if the range is in a data block group */ > + bg_cache = btrfs_lookup_block_group(root->fs_info, bytenr); > + if (!bg_cache) > + return -ENOENT; > + if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_DATA)) > + return -EINVAL; > + > + /* The extent should never cross block group boundary */ > + len = min_t(u64, len, bg_cache->key.objectid + > + bg_cache->key.offset - bytenr); > + } > + > + BUG_ON(len != round_down(len, root->sectorsize)); > + ret = btrfs_record_file_extent(trans, root, ino, inode, bytenr, > + disk_bytenr, len); > + if (ret < 0) > + return ret; > + > + if (datacsum) > + ret = csum_disk_extent(trans, root, bytenr, len); > + *ret_len = len; > + return ret; > +} > + > +static int wipe_reserved_ranges(struct cache_tree *tree, u64 min_stripe_size, > + int ensure_size); > + > +/* > + * Create the fs image file of old filesystem. > + * > + * This is completely fs independent as we have cctx->used, only > + * need to create file extents point to all the posistions. s/posistions/positions/g > + * TODO: Add handler for reserved ranges in next patch > + */ > +static int create_image_v2(struct btrfs_root *root, > + struct btrfs_mkfs_config *cfg, > + struct btrfs_convert_context *cctx, > + u64 size, char *name, int datacsum) > +{ > + struct btrfs_inode_item buf; > + struct btrfs_trans_handle *trans; > + struct btrfs_path *path = NULL; > + struct btrfs_key key; > + struct cache_extent *cache; > + struct cache_tree used_tmp; > + u64 cur; > + u64 ino; > + int ret; > + > + trans = btrfs_start_transaction(root, 1); > + if (!trans) > + return -ENOMEM; > + > + cache_tree_init(&used_tmp); > + > + ret = btrfs_find_free_objectid(trans, root, BTRFS_FIRST_FREE_OBJECTID, > + &ino); > + if (ret < 0) > + goto out; > + ret = btrfs_new_inode(trans, root, ino, 0600 | S_IFREG); > + if (ret < 0) > + goto out; > + ret = btrfs_add_link(trans, root, ino, BTRFS_FIRST_FREE_OBJECTID, name, > + strlen(name), BTRFS_FT_REG_FILE, NULL, 1); > + if (ret < 0) > + goto out; > + > + path = btrfs_alloc_path(); > + if (!path) { > + ret = -ENOMEM; > + goto out; > + } > + key.objectid = ino; > + key.type = BTRFS_INODE_ITEM_KEY; > + key.offset = 0; > + > + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); > + if (ret) { > + ret = (ret > 0 ? -ENOENT : ret); > + goto out; > + } > + read_extent_buffer(path->nodes[0], &buf, > + btrfs_item_ptr_offset(path->nodes[0], path->slots[0]), > + sizeof(buf)); > + btrfs_release_path(path); It seems unnecessary to search for inode_item, inode_item is initialized by fill_inode_item(), so fill_inode_item(...&buf...) is fine. > + > + /* > + * Create a new used space cache, which doesn't contain the reserved > + * range > + */ > + for (cache = first_cache_extent(&cctx->used); cache; > + cache = next_cache_extent(cache)) { > + ret = add_cache_extent(&used_tmp, cache->start, cache->size); > + if (ret < 0) > + goto out; > + } It's not clear why we need used_tmp. Thanks, -liubo > + ret = wipe_reserved_ranges(&used_tmp, 0, 0); > + if (ret < 0) > + goto out; > + > + /* > + * Start from 1M, as 0~1M is reserved, and create_image_file_range_v2() > + * can't handle bytenr 0(will consider it as a hole) > + */ > + cur = 1024 * 1024; > + while (cur < size) { > + u64 len = size - cur; > + > + ret = create_image_file_range_v2(trans, root, &used_tmp, > + &buf, ino, cur, &len, datacsum); > + if (ret < 0) > + goto out; > + cur += len; > + } > + > + key.objectid = ino; > + key.type = BTRFS_INODE_ITEM_KEY; > + key.offset = 0; > + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); > + if (ret) { > + ret = (ret > 0 ? -ENOENT : ret); > + goto out; > + } > + btrfs_set_stack_inode_size(&buf, cfg->num_bytes); > + write_extent_buffer(path->nodes[0], &buf, > + btrfs_item_ptr_offset(path->nodes[0], path->slots[0]), > + sizeof(buf)); > +out: > + free_extent_cache_tree(&used_tmp); > + btrfs_free_path(path); > + btrfs_commit_transaction(trans, root); > + return ret; > +} > + > static struct btrfs_root * link_subvol(struct btrfs_root *root, > const char *base, u64 root_objectid) > { > -- > 2.7.0 > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html