From: Theodore Ts'o Subject: [PATCH 2/3] libext2fs: ext2fs_extents_fix_parents() should not modify the handle location Date: Thu, 20 Dec 2012 18:43:42 -0500 Message-ID: <1356047023-28367-2-git-send-email-tytso@mit.edu> References: <20121220234229.GA22476@thunk.org> <1356047023-28367-1-git-send-email-tytso@mit.edu> Cc: forrestl@synology.com, Theodore Ts'o To: Ext4 Developers List Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:39633 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745Ab2LTXnp (ORCPT ); Thu, 20 Dec 2012 18:43:45 -0500 In-Reply-To: <1356047023-28367-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: Previously, ext2fs_extent_fix_parents() would only avoid modifying the cursor location associated with the extent handle the cursor was pointed at a leaf node in the extent tree. This is because it saved the starting logical block number of the current extent, but not the "level" of the extent (where level 0 is the leaf node, level 1 is the interior node which points at blocks containing leaf nodes, etc.) Fix ext2fs_extent_fix_parents() so it is guaranteed to not change the current extent in the handle even if the current extent is not at the bottom of the tree. Also add a fix_extent command to the tst_extents program to make it easier to test this function. Signed-off-by: "Theodore Ts'o" --- lib/ext2fs/extent.c | 25 ++++++++++++++++++++++++- lib/ext2fs/extent_dbg.ct | 3 +++ 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c index 95a0a86..c6716bc 100644 --- a/lib/ext2fs/extent.c +++ b/lib/ext2fs/extent.c @@ -709,9 +709,11 @@ errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle, errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle) { int retval = 0; + int orig_height; blk64_t start; struct extent_path *path; struct ext2fs_extent extent; + struct ext2_extent_info info; EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE); @@ -732,6 +734,10 @@ errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle) /* modified node's start block */ start = extent.e_lblk; + if ((retval = ext2fs_extent_get_info(handle, &info))) + return retval; + orig_height = info.max_depth - info.curr_level; + /* traverse up until index not first, or startblk matches, or top */ while (handle->level > 0 && (path->left == path->entries - 1)) { @@ -750,7 +756,7 @@ errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle) } /* put handle back to where we started */ - retval = ext2fs_extent_goto(handle, start); + retval = extent_goto(handle, orig_height, start); done: return retval; } @@ -1943,6 +1949,23 @@ void do_print_all(int argc, char **argv) } } +void do_fix_parents(int argc, char **argv) +{ + struct ext2fs_extent extent; + struct ext2_extent_info info; + errcode_t retval; + + if (common_extent_args_process(argc, argv, 1, 1, "fix_parents", "", + CHECK_FS_RW)) + return; + + retval = ext2fs_extent_fix_parents(current_handle); + if (retval) { + com_err(argv[0], retval, 0); + return; + } +} + void do_info(int argc, char **argv) { struct ext2fs_extent extent; diff --git a/lib/ext2fs/extent_dbg.ct b/lib/ext2fs/extent_dbg.ct index d0571f4..c1d8033 100644 --- a/lib/ext2fs/extent_dbg.ct +++ b/lib/ext2fs/extent_dbg.ct @@ -55,6 +55,9 @@ request do_insert_node, "Insert node", request do_split_node, "Split node", split_node, split; +request do_fix_parents, "Fix parents", + fix_parents, fixp; + request do_set_bmap, "Set block mapping", set_bmap; -- 1.7.12.rc0.22.gcdd159b