From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [PATCH 11/18] libext2/fsck: correctly preserve fs flags when modifying ignore-csum-error flag
Date: Mon, 28 Jul 2014 01:06:17 -0700 [thread overview]
Message-ID: <20140728080617.GM8628@birch.djwong.org> (raw)
In-Reply-To: <20140727232746.GZ6725@thunk.org>
On Sun, Jul 27, 2014 at 07:27:46PM -0400, Theodore Ts'o wrote:
> On Fri, Jul 25, 2014 at 05:34:47PM -0700, Darrick J. Wong wrote:
> > nor is it correct
> > to assume that we can unconditionally set (or clear) the "ignore csum
> > error" flag bit.
>
> For functions inside e2fsck, why is this true? All of the places
> where we are are EXT2_FLAG_IGNORE_CSUM_ERRORS are places where we set
> it, and then clear it after an ext2 call. So as near as I can tell it
> shouldn't matter.
>
> I can understand why we need to be careful for functions inside
> libext2fs, but in that particular case, none of the downstream
> functions of ext2fs_read_inode_full() modify fs->flags.
>
> So I'm really puzzled what problem this patch actually solves. Was
> this a theoretical concern, or was there something I missed?
It's mostly a theoretical concern -- rather than having to decide where it's ok
to set the flag and unset it later vs. where we have to set the flag and then
restore it to the previous value, I'd rather just be careful every time, so
that the next time I read through this code I'll know that IGNORE_CSUM_ERRORS
is always put back to its previous value and the other flags are left alone, no
matter how much e2fsck or libext2fs might get refactored.
One of those sites where we modify IGNORE_CSUM_ERRORS actually would
incorrectly clobber the other flag bits that were set inside the library (I
think it's the write_dir_block4 in pass2.c), so I decided to fix all of the
sites.
--D
>
> - Ted
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2014-07-28 8:06 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-26 0:33 [PATCH 00/18] e2fsprogs patchbomb 7/14, part 2 Darrick J. Wong
2014-07-26 0:33 ` [PATCH 01/18] e2fsck: reserve blocks for root/lost+found directory repair Darrick J. Wong
2014-07-26 19:47 ` Theodore Ts'o
2014-07-28 7:27 ` Darrick J. Wong
2014-07-26 0:33 ` [PATCH 02/18] e2fsck: fix merge error in "clear uninit flag on directory extents" Darrick J. Wong
2014-07-26 20:04 ` Theodore Ts'o
2014-07-26 0:33 ` [PATCH 03/18] e2fsck: perform implied cluster allocations when filling a directory hole Darrick J. Wong
2014-07-26 20:08 ` Theodore Ts'o
2014-07-26 0:34 ` [PATCH 04/18] e2fsck: fix rule-violating lblk->pblk mappings on bigalloc filesystems Darrick J. Wong
2014-07-26 6:02 ` Andreas Dilger
2014-07-26 20:27 ` Theodore Ts'o
2014-07-28 8:28 ` Darrick J. Wong
2014-07-28 17:55 ` Darrick J. Wong
2014-07-28 19:32 ` Theodore Ts'o
2014-07-26 0:34 ` [PATCH 05/18] e2fsck: during pass1b delete_file, only free a cluster once Darrick J. Wong
2014-07-26 20:30 ` Theodore Ts'o
2014-07-26 0:34 ` [PATCH 06/18] dumpe2fs: add switch to disable checksum verification Darrick J. Wong
2014-07-26 20:58 ` Theodore Ts'o
2014-07-28 7:48 ` Darrick J. Wong
2014-07-26 0:34 ` [PATCH 07/18] e2fsck: verify checksums after checking everything else Darrick J. Wong
2014-07-26 20:53 ` Theodore Ts'o
2014-07-28 8:27 ` Darrick J. Wong
2014-07-26 0:34 ` [PATCH 08/18] e2fsck: fix the various checksum error messages Darrick J. Wong
2014-07-26 21:09 ` Theodore Ts'o
2014-07-28 7:57 ` Darrick J. Wong
2014-07-26 0:34 ` [PATCH 09/18] e2fsck: insert a missing dirent tail for checksums if possible Darrick J. Wong
2014-07-26 21:13 ` Theodore Ts'o
2014-07-26 0:34 ` [PATCH 10/18] e2fsck: write dir blocks after new inode when reconstructing root/lost+found Darrick J. Wong
2014-07-26 21:18 ` Theodore Ts'o
2014-07-26 0:34 ` [PATCH 11/18] libext2/fsck: correctly preserve fs flags when modifying ignore-csum-error flag Darrick J. Wong
2014-07-27 23:27 ` Theodore Ts'o
2014-07-28 8:06 ` Darrick J. Wong [this message]
2014-07-26 0:34 ` [PATCH 12/18] e2fsck: toggle checksum verification error reporting appropriately Darrick J. Wong
2014-07-27 23:37 ` Theodore Ts'o
2014-07-28 7:38 ` Darrick J. Wong
2014-07-28 11:41 ` Theodore Ts'o
2014-07-26 0:34 ` [PATCH 13/18] libext2fs: Don't cache inodes that fail checksum verification Darrick J. Wong
2014-07-26 0:35 ` [PATCH 14/18] e2fsck: always recheck an inode checksum failure Darrick J. Wong
2014-07-26 0:35 ` [PATCH 15/18] e2fsck: clear badblocks inode when checksum fails Darrick J. Wong
2014-07-27 23:42 ` Theodore Ts'o
2014-07-26 0:35 ` [PATCH 16/18] e2fsck: leave room for checksum structure when salvaging a directory Darrick J. Wong
2014-07-27 23:45 ` Theodore Ts'o
2014-07-26 0:35 ` [PATCH 17/18] e2fsck: make insert_dirent_tail more robust Darrick J. Wong
2014-07-27 23:48 ` Theodore Ts'o
2014-07-26 0:35 ` [PATCH 18/18] e2fsck: don't offer to fix the checksum of fixed extents Darrick J. Wong
2014-07-27 23:52 ` Theodore Ts'o
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140728080617.GM8628@birch.djwong.org \
--to=darrick.wong@oracle.com \
--cc=linux-ext4@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).