From: Theodore Ts'o <tytso@mit.edu>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [PATCH 20/49] libext2fs: fix parents when modifying extents
Date: Fri, 14 Mar 2014 10:01:58 -0400 [thread overview]
Message-ID: <20140314140158.GP8282@thunk.org> (raw)
In-Reply-To: <20140311065605.30585.47791.stgit@birch.djwong.org>
On Mon, Mar 10, 2014 at 11:56:05PM -0700, Darrick J. Wong wrote:
> In ext2fs_extent_set_bmap() and ext2fs_punch_extent(), fix the parents
> when altering either end of an extent so that the parent nodes reflect
> the added mapping.
Can you say more about what bug/symptom this fixes?
> There's a slight complication to using fix_parents: if there are two
> mappings to an lblk in the tree, the value of handle->path->curr can
> point to either extent afterwards), which is documented in a comment.
It's horribly wrong to map an lblk with two extents. So the question
is at what places should we complain if we notice this. In the ideal
world we would never allow an extent tree to be mutated in such a way
that it is invalid like this, but I am worried about the overhead
costs of always checking. But if there are places where it wouldn't
take much effort to check, we should probably do so and return an
error. (If the extent tree is already invalid, I suppose we should
allow error out the operation, since this would affect e2fsck and
debugfs. I'm talking about checks to make sure that libext2fs or its
callers don't accidentally make things worse.)
- Ted
P.S. I suppose the one possible valid use case for making an invalid
extent tree is a developer making an invalid extent tree for
regression testing, so maybe there should be an exemption for debugfs.
next prev parent reply other threads:[~2014-03-14 14:02 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-11 6:53 [PATCH 00/49] e2fsprogs patchbomb 3/14 Darrick J. Wong
2014-03-11 6:54 ` [PATCH 01/49] create_inode: clean up return mess in do_write_internal Darrick J. Wong
2014-03-11 20:30 ` Andreas Dilger
2014-03-11 20:41 ` Darrick J. Wong
2014-03-11 21:08 ` Theodore Ts'o
2014-03-12 3:24 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 02/49] create_inode: minor cleanups Darrick J. Wong
2014-03-11 20:31 ` Andreas Dilger
2014-03-12 3:25 ` Theodore Ts'o
2014-03-12 3:27 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 03/49] create_inode: whitespace fixes Darrick J. Wong
2014-03-12 3:27 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 04/49] create_inode: move debugfs internal state back to debugfs Darrick J. Wong
2014-03-12 3:31 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 05/49] create_inode: handle hard link inum mappings per populate_fs invocation Darrick J. Wong
2014-03-12 3:46 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 06/49] libext2fs: support modifying arbitrary extended attributes (v5) Darrick J. Wong
2014-03-12 3:51 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 07/49] debugfs: create commands to edit extended attributes Darrick J. Wong
2014-03-12 3:51 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 08/49] e2fsck: don't rehash inline directories Darrick J. Wong
2014-03-13 3:52 ` Theodore Ts'o
2014-03-13 5:38 ` Darrick J. Wong
2014-03-13 12:13 ` Theodore Ts'o
2014-03-11 6:54 ` [PATCH 09/49] libext2fs: don't fail when doing a strict rewrite of inline data Darrick J. Wong
2014-03-14 13:19 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 10/49] libext2fs: fix iblocks correctly when expanding an inline_data file Darrick J. Wong
2014-03-12 16:38 ` Andreas Dilger
2014-03-12 17:01 ` Darrick J. Wong
2014-03-14 13:25 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 11/49] e2fsck: zero errcode when checking inline data blocks Darrick J. Wong
2014-03-14 13:26 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 12/49] libext2fs: during inlinedata expand, don't corrupt inode Darrick J. Wong
2014-03-14 13:29 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 13/49] libext2fs: repair side effects when iterating dirents in inline dirs Darrick J. Wong
2014-03-14 13:30 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 14/49] resize2fs: add inline dirs for remapping Darrick J. Wong
2014-03-14 13:31 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 15/49] all: Introduce cppcheck static checking for make C=1 Darrick J. Wong
2014-03-14 13:33 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 16/49] misc: cppcheck cleanups Darrick J. Wong
2014-03-14 13:34 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 17/49] libext2fs: fix 64bit overflow in ext2fs_block_alloc_stats_range Darrick J. Wong
2014-03-14 13:35 ` Theodore Ts'o
2014-03-11 6:55 ` [PATCH 18/49] misc: fix header complaints and resource leaks in e2fsprogs Darrick J. Wong
2014-03-14 13:39 ` Theodore Ts'o
2014-03-14 13:53 ` Theodore Ts'o
2014-03-14 19:23 ` Darrick J. Wong
2014-03-11 6:55 ` [PATCH 19/49] libext2fs: fix memory leak when drastically shrinking extent tree depth Darrick J. Wong
2014-03-14 13:56 ` Theodore Ts'o
2014-03-11 6:56 ` [PATCH 20/49] libext2fs: fix parents when modifying extents Darrick J. Wong
2014-03-14 14:01 ` Theodore Ts'o [this message]
2014-03-14 20:13 ` Darrick J. Wong
2014-03-15 15:46 ` Theodore Ts'o
2014-03-17 16:59 ` Darrick J. Wong
2014-03-11 6:56 ` [PATCH 21/49] e2fsck: print runs of duplicate blocks instead of all of them Darrick J. Wong
2014-03-15 16:19 ` Theodore Ts'o
2014-03-11 6:56 ` [PATCH 22/49] e2fsck: verify checksums after checking everything else Darrick J. Wong
2014-03-11 6:56 ` [PATCH 23/49] e2fsck: fix the extended attribute checksum error message Darrick J. Wong
2014-03-11 6:56 ` [PATCH 24/49] e2fsck: insert a missing dirent tail for checksums if possible Darrick J. Wong
2014-03-11 6:56 ` [PATCH 25/49] e2fsck: write dir blocks after new inode when reconstructing root/lost+found Darrick J. Wong
2014-03-11 6:56 ` [PATCH 26/49] tests: add test for corrupted checksummed root directory block Darrick J. Wong
2014-03-11 6:56 ` [PATCH 27/49] dumpe2fs: add switch to disable checksum verification Darrick J. Wong
2014-03-11 6:56 ` [PATCH 28/49] mke2fs: set block_validity as a default mount option Darrick J. Wong
2014-03-11 6:57 ` [PATCH 29/49] libext2fs: support allocating uninit blocks in bmap2() Darrick J. Wong
2014-03-11 6:57 ` [PATCH 30/49] libext2fs: file IO routines should handle uninit blocks Darrick J. Wong
2014-03-11 6:57 ` [PATCH 31/49] resize2fs: convert fs to and from 64bit mode Darrick J. Wong
2014-03-11 6:57 ` [PATCH 32/49] resize2fs: when toggling 64bit, don't free in-use bg data clusters Darrick J. Wong
2014-03-11 6:57 ` [PATCH 33/49] resize2fs: adjust reserved_gdt_blocks when changing group descriptor size Darrick J. Wong
2014-03-11 6:57 ` [PATCH 34/49] libext2fs: have UNIX IO manager use pread/pwrite Darrick J. Wong
2014-03-11 6:57 ` [PATCH 35/49] ext2fs: add readahead method to improve scanning Darrick J. Wong
2014-03-17 22:07 ` Andreas Dilger
2014-03-11 6:57 ` [PATCH 36/49] libext2fs: allow clients to read-ahead metadata Darrick J. Wong
2014-03-17 23:11 ` Andreas Dilger
2014-03-11 6:57 ` [PATCH 37/49] e2fsck: read-ahead metadata during passes 1, 2, and 4 Darrick J. Wong
2014-03-17 23:10 ` Andreas Dilger
2014-03-18 4:42 ` Darrick J. Wong
2014-03-18 6:50 ` Darrick J. Wong
2014-03-11 6:58 ` [PATCH 38/49] libext2fs: when appending to a file, don't split an index block in equal halves Darrick J. Wong
2014-03-11 6:58 ` [PATCH 39/49] libext2fs: find inode goal when allocating blocks Darrick J. Wong
2014-03-11 6:58 ` [PATCH 40/49] libext2fs: find a range of empty blocks Darrick J. Wong
2014-03-11 6:58 ` [PATCH 41/49] libext2fs: provide a function to set inode size Darrick J. Wong
2014-03-11 6:58 ` [PATCH 42/49] libext2fs: implement fallocate Darrick J. Wong
2014-03-11 6:58 ` [PATCH 44/49] fuse2fs: translate ACL structures Darrick J. Wong
2014-03-11 6:58 ` [PATCH 45/49] fuse2fs: handle 64-bit dates correctly Darrick J. Wong
2014-03-11 6:58 ` [PATCH 46/49] fuse2fs: implement fallocate Darrick J. Wong
2014-03-11 6:59 ` [PATCH 48/49] tests: enable using fuse2fs with metadata checksum test Darrick J. Wong
2014-03-11 6:59 ` [PATCH 49/49] tests: test date handling Darrick J. Wong
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