From: Filipe David Borba Manana Date: Wed, 5 Feb 2014 16:48:56 +0000 (+0000) Subject: Btrfs: make some tree searches in send.c more efficient X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=dff6d0adbe998927f72fc8d9ceee8ff72b124328;p=linux-beck.git Btrfs: make some tree searches in send.c more efficient We have this pattern where we do search for a contiguous group of items in a tree and everytime we find an item, we process it, then we release our path, increment the offset of the search key, do another full tree search and repeat these steps until a tree search can't find more items we're interested in. Instead of doing these full tree searches after processing each item, just process the next item/slot in our leaf and don't release the path. Since all these trees are read only and we always use the commit root for a search and skip node/leaf locks, we're not affecting concurrency on the trees. Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik --- diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 89fefbd955f3..a2621e7aaa5c 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -2501,17 +2501,26 @@ static int did_create_dir(struct send_ctx *sctx, u64 dir) key.objectid = dir; key.type = BTRFS_DIR_INDEX_KEY; key.offset = 0; + ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0); + if (ret < 0) + goto out; + while (1) { - ret = btrfs_search_slot_for_read(sctx->send_root, &key, path, - 1, 0); - if (ret < 0) - goto out; - if (!ret) { - eb = path->nodes[0]; - slot = path->slots[0]; - btrfs_item_key_to_cpu(eb, &found_key, slot); + eb = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(sctx->send_root, path); + if (ret < 0) { + goto out; + } else if (ret > 0) { + ret = 0; + break; + } + continue; } - if (ret || found_key.objectid != key.objectid || + + btrfs_item_key_to_cpu(eb, &found_key, slot); + if (found_key.objectid != key.objectid || found_key.type != key.type) { ret = 0; goto out; @@ -2526,8 +2535,7 @@ static int did_create_dir(struct send_ctx *sctx, u64 dir) goto out; } - key.offset = found_key.offset + 1; - btrfs_release_path(path); + path->slots[0]++; } out: @@ -2693,19 +2701,24 @@ static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress) key.objectid = dir; key.type = BTRFS_DIR_INDEX_KEY; key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; while (1) { - ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); - if (ret < 0) - goto out; - if (!ret) { - btrfs_item_key_to_cpu(path->nodes[0], &found_key, - path->slots[0]); + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + else if (ret > 0) + break; + continue; } - if (ret || found_key.objectid != key.objectid || - found_key.type != key.type) { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + if (found_key.objectid != key.objectid || + found_key.type != key.type) break; - } di = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_dir_item); @@ -2716,8 +2729,7 @@ static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress) goto out; } - btrfs_release_path(path); - key.offset = found_key.offset + 1; + path->slots[0]++; } ret = 1; @@ -3620,15 +3632,22 @@ static int process_all_refs(struct send_ctx *sctx, key.objectid = sctx->cmp_key->objectid; key.type = BTRFS_INODE_REF_KEY; key.offset = 0; - while (1) { - ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); - if (ret < 0) - goto out; - if (ret) - break; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + while (1) { eb = path->nodes[0]; slot = path->slots[0]; + if (slot >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + else if (ret > 0) + break; + continue; + } + btrfs_item_key_to_cpu(eb, &found_key, slot); if (found_key.objectid != key.objectid || @@ -3637,11 +3656,10 @@ static int process_all_refs(struct send_ctx *sctx, break; ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx); - btrfs_release_path(path); if (ret < 0) goto out; - key.offset = found_key.offset + 1; + path->slots[0]++; } btrfs_release_path(path); @@ -3922,19 +3940,25 @@ static int process_all_new_xattrs(struct send_ctx *sctx) key.objectid = sctx->cmp_key->objectid; key.type = BTRFS_XATTR_ITEM_KEY; key.offset = 0; - while (1) { - ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); - if (ret < 0) - goto out; - if (ret) { - ret = 0; - goto out; - } + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + while (1) { eb = path->nodes[0]; slot = path->slots[0]; - btrfs_item_key_to_cpu(eb, &found_key, slot); + if (slot >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) { + goto out; + } else if (ret > 0) { + ret = 0; + break; + } + continue; + } + btrfs_item_key_to_cpu(eb, &found_key, slot); if (found_key.objectid != key.objectid || found_key.type != key.type) { ret = 0; @@ -3946,8 +3970,7 @@ static int process_all_new_xattrs(struct send_ctx *sctx) if (ret < 0) goto out; - btrfs_release_path(path); - key.offset = found_key.offset + 1; + path->slots[0]++; } out: