From: Eric Sandeen Subject: Re: [PATCH] resize2fs: move bitmaps if shrinking would orphan them Date: Fri, 21 Jun 2013 09:13:17 -0500 Message-ID: <51C45F7D.1030208@redhat.com> References: <51C0FA44.3030600@redhat.com> <51C10B41.9020103@redhat.com> <20130621024707.GC10730@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: ext4 development , Leonardo Menezes Vaz To: "Theodore Ts'o" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43943 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422693Ab3FUONU (ORCPT ); Fri, 21 Jun 2013 10:13:20 -0400 In-Reply-To: <20130621024707.GC10730@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 6/20/13 9:47 PM, Theodore Ts'o wrote: > On Tue, Jun 18, 2013 at 08:37:05PM -0500, Eric Sandeen wrote: >> It is possible to have a flex_bg filesystem with block groups >> which have inode & block bitmaps at some point well past the >> start of the group. >> >> If an offline shrink puts the new size somewhere between >> the start of the block group and the (old) location of >> the bitmaps, they can be left beyond the end of the filesystem, >> i.e. result in fs corruption. >> >> Check each remaining block group for whether its bitmaps >> are beyond the end of the new filesystem, and reallocate >> them in a new location if needed. >> >> Signed-off-by: Eric Sandeen > > Looks good, thanks for the patch. I made a few minor changes to fix > up some extra whitespace and a minor optimization. Great, thanks for the review. > - Ted > > diff --git a/resize/resize2fs.c b/resize/resize2fs.c > index 28131c2..204b10a 100644 > --- a/resize/resize2fs.c > +++ b/resize/resize2fs.c > @@ -889,7 +889,7 @@ static errcode_t blocks_to_move(ext2_resize_t rfs) > * bitmaps which are beyond the end of the new filesystem. > */ > new_size = ext2fs_blocks_count(fs->super); > - if (ext2fs_blocks_count(fs->super) < ext2fs_blocks_count(old_fs->super)) { > + if (new_size < ext2fs_blocks_count(old_fs->super)) { thanks, I think I *meant* to do that > for (g = 0; g < fs->group_desc_count; g++) { > /* > * ext2fs_allocate_group_table re-allocates bitmaps > @@ -900,13 +900,13 @@ static errcode_t blocks_to_move(ext2_resize_t rfs) > retval = ext2fs_allocate_group_table(fs, g, 0); > if (retval) > return retval; > - } ^ whoops sorry > + } > if (ext2fs_inode_bitmap_loc(fs, g) >= new_size) { > ext2fs_inode_bitmap_loc_set(fs, g, 0); > retval = ext2fs_allocate_group_table(fs, g, 0); > if (retval) > return retval; > - } ^ whoops sorry^2! > + } > } > } > >