On tue, 30 Jul 2013 12:08:17 +0100, Filipe David Borba Manana wrote: > After reading all device items from the chunk tree, don't > exit the loop and then navigate down the tree again to find > the chunk items. Instead just read all device items and > chunk items with a single tree search. This is possible > because all device items are found before any chunk item in > the chunks tree. > > This is a port of the corresponding kernel patch to keep both > kernel and btrfs-progs identical: > > https://patchwork.kernel.org/patch/2835529/ > > Signed-off-by: Filipe David Borba Manana <fdmanana@xxxxxxxxx> > --- > > V2: Simplified logic inside the loop > (suggested by Josef Bacik on irc). > V3: Updated comment to comply with kernel coding style. Reviewed-by: Miao Xie <miaox@xxxxxxxxxxxxxx> > > volumes.c | 28 ++++++++++------------------ > 1 file changed, 10 insertions(+), 18 deletions(-) > > diff --git a/volumes.c b/volumes.c > index 0ff2283..0cb3505 100644 > --- a/volumes.c > +++ b/volumes.c > @@ -1718,14 +1718,15 @@ int btrfs_read_chunk_tree(struct btrfs_root *root) > if (!path) > return -ENOMEM; > > - /* first we search for all of the device items, and then we > - * read in all of the chunk items. This way we can create chunk > - * mappings that reference all of the devices that are afound > + /* > + * Read all device items, and then all the chunk items. All > + * device items are found before any chunk item (their object id > + * is smaller than the lowest possible object id for a chunk > + * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID). > */ > key.objectid = BTRFS_DEV_ITEMS_OBJECTID; > key.offset = 0; > key.type = 0; > -again: > ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > while(1) { > leaf = path->nodes[0]; > @@ -1739,16 +1740,12 @@ again: > break; > } > btrfs_item_key_to_cpu(leaf, &found_key, slot); > - if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { > - if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) > - break; > - if (found_key.type == BTRFS_DEV_ITEM_KEY) { > - struct btrfs_dev_item *dev_item; > - dev_item = btrfs_item_ptr(leaf, slot, > + if (found_key.type == BTRFS_DEV_ITEM_KEY) { > + struct btrfs_dev_item *dev_item; > + dev_item = btrfs_item_ptr(leaf, slot, > struct btrfs_dev_item); > - ret = read_one_dev(root, leaf, dev_item); > - BUG_ON(ret); > - } > + ret = read_one_dev(root, leaf, dev_item); > + BUG_ON(ret); > } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { > struct btrfs_chunk *chunk; > chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); > @@ -1757,11 +1754,6 @@ again: > } > path->slots[0]++; > } > - if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { > - key.objectid = 0; > - btrfs_release_path(root, path); > - goto again; > - } > > ret = 0; > error: > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
