[PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal

[PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal

[Darrick J. Wong]

When we're removing the internal journal (broken journal, turning it
off, or adding an external journal), zero s_jnl_blocks so that they
can't be picked up by accident later.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: TR Reardon <thomas_reardon@hotmail.com>
---
 e2fsck/journal.c       |    1 +
 lib/ext2fs/mkjournal.c |    1 +
 misc/tune2fs.c         |    1 +
 3 files changed, 3 insertions(+)


diff --git a/e2fsck/journal.c b/e2fsck/journal.c
index 16bd757..d12e317 100644
--- a/e2fsck/journal.c
+++ b/e2fsck/journal.c
@@ -549,6 +549,7 @@ static errcode_t e2fsck_journal_fix_bad_inode(e2fsck_t ctx,
 				       "filesystem is now ext2 only ***\n\n");
 			sb->s_feature_compat &= ~EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 			sb->s_journal_inum = 0;
+			memset(sb->s_jnl_blocks, 0, sizeof(sb->s_jnl_blocks));
 			ctx->flags |= E2F_FLAG_JOURNAL_INODE;
 			ctx->fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 			e2fsck_clear_recover(ctx, 1);
diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index 85f86bf..0a7cd18 100644
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -490,6 +490,7 @@ errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
 	fs->super->s_journal_dev = st.st_rdev;
 	memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
 	       sizeof(fs->super->s_journal_uuid));
+	memset(fs->super->s_jnl_blocks, 0, sizeof(fs->super->s_jnl_blocks));
 	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 	ext2fs_mark_super_dirty(fs);
 	return 0;
diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index c22c8fd..7292ab1 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -377,6 +377,7 @@ static errcode_t remove_journal_inode(ext2_filsys fs)
 		return retval;
 	}
 	fs->super->s_journal_inum = 0;
+	memset(fs->super->s_jnl_blocks, 0, sizeof(fs->super->s_jnl_blocks));
 	ext2fs_mark_super_dirty(fs);
 
 	return 0;

Re: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal

[Theodore Ts'o]

On Mon, Sep 08, 2014 at 04:12:35PM -0700, Darrick J. Wong wrote:
> When we're removing the internal journal (broken journal, turning it
> off, or adding an external journal), zero s_jnl_blocks so that they
> can't be picked up by accident later.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Cc: TR Reardon <thomas_reardon@hotmail.com>

Applied, thanks.

					- Ted

Re: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal

[Darrick J. Wong]

[cc linux-ext4]

On Fri, Sep 12, 2014 at 10:09:55AM -0400, TR Reardon wrote:
> Note that this only works (zeroes out) when removing inode journal.  Removing
> an existing journal_dev leaves s_jnl_blocks untouched.  To be absolutely
> clean, perhaps it should be wiped in all removal cases?

s_jnl_blocks shouldn't be set if an external journal is in use.

(Unless it is somehow?)

--D

> 
> --- Original Message ---
> 
> From: "Theodore Ts'o" <tytso@mit.edu>
> Sent: September 11, 2014 12:44 PM
> To: "Darrick J. Wong" <darrick.wong@oracle.com>
> Cc: linux-ext4@vger.kernel.org, "TR Reardon" <thomas_reardon@hotmail.com>
> Subject: Re: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal
> 
> On Mon, Sep 08, 2014 at 04:12:35PM -0700, Darrick J. Wong wrote:
> > When we're removing the internal journal (broken journal, turning it
> > off, or adding an external journal), zero s_jnl_blocks so that they
> > can't be picked up by accident later.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > Cc: TR Reardon <thomas_reardon@hotmail.com>
> 
> Applied, thanks.
> 
>                                         - 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

RE: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal

[TR Reardon]

If the change from journal_inode to journal_dev is/was made prior to the recent change, the s_jnl_blocks will have whatever it last had.  So if it started with journal_inode and then switched to journal_dev (again, prior to your fix) or no journal, the s_jnl_blocks will have the old journal_inode info, and adding/removing journal_dev does no clear it out.  For a new fs with created only with journal_dev, there is no issue.  I'm just arguing that *adding* journal_dev should also zero this out.

+Reardon


----------------------------------------
> Date: Fri, 12 Sep 2014 09:43:42 -0700
> From: darrick.wong@oracle.com
> To: thomas_reardon@hotmail.com
> CC: linux-ext4@vger.kernel.org
> Subject: Re: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal
>
> [cc linux-ext4]
>
> On Fri, Sep 12, 2014 at 10:09:55AM -0400, TR Reardon wrote:
>> Note that this only works (zeroes out) when removing inode journal. Removing
>> an existing journal_dev leaves s_jnl_blocks untouched. To be absolutely
>> clean, perhaps it should be wiped in all removal cases?
>
> s_jnl_blocks shouldn't be set if an external journal is in use.
>
> (Unless it is somehow?)
>
> --D

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Re: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal

[Darrick J. Wong]

On Fri, Sep 12, 2014 at 03:06:23PM -0400, TR Reardon wrote:
> If the change from journal_inode to journal_dev is/was made prior to the
> recent change, the s_jnl_blocks will have whatever it last had.  So if it
> started with journal_inode and then switched to journal_dev (again, prior to
> your fix) or no journal, the s_jnl_blocks will have the old journal_inode
> info, and adding/removing journal_dev does no clear it out.  For a new fs
> with created only with journal_dev, there is no issue.  I'm just arguing that
> *adding* journal_dev should also zero this out.

You would also want to zero out s_jnl_blocks if creating a journal on a mounted
FS, since there's no way to find the block map/ETB blocks; the best we can do
is hope the user runs e2fsck, which will fix it.

--D
> 
> +Reardon
> 
> 
> ----------------------------------------
> > Date: Fri, 12 Sep 2014 09:43:42 -0700
> > From: darrick.wong@oracle.com
> > To: thomas_reardon@hotmail.com
> > CC: linux-ext4@vger.kernel.org
> > Subject: Re: [PATCH 09/25] misc: zero s_jnl_blocks when removing internal journal
> >
> > [cc linux-ext4]
> >
> > On Fri, Sep 12, 2014 at 10:09:55AM -0400, TR Reardon wrote:
> >> Note that this only works (zeroes out) when removing inode journal. Removing
> >> an existing journal_dev leaves s_jnl_blocks untouched. To be absolutely
> >> clean, perhaps it should be wiped in all removal cases?
> >
> > s_jnl_blocks shouldn't be set if an external journal is in use.
> >
> > (Unless it is somehow?)
> >
> > --D
> 
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