[PATCH] xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

[PATCH] xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

[Eric Sandeen]

Commit e0607266 xfsprogs: add crc format support to repair

added a 2nd assignment to l_sectBBsize:

	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;

which is incorrect; sb_logsectlog is log2 of the sector size,
in bytes; l_sectBBsize is the size of the log sector in
512-byte units.

So for a 4k sector size log, we were assigning 4096 rather
than 8.  This broke xlog_find_tail, and caused xfs_repair
to think that a log was dirty even when it was clean:

"ERROR: The filesystem has valuable metadata changes in a log"

(xfs_logprint didn't have this error, so xfs_logprint -t
agreed that the filesystem really was clean).

Just remove the incorrect assignment; it was already properly
assigned about 12 lines prior:

        log.l_sectBBsize  = BTOBB(x.lbsize);

and things work again.

(This worked accidentally for 512-sector devices, because
we special-case those and set sb_logsectlog to "0" rather
than 9, so l_sectBBsize came out to "1" (as in 1 sector),
as it should have).

Reporteed-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

diff --git a/repair/phase2.c b/repair/phase2.c
index a62854e..2817fed 100644
--- a/repair/phase2.c
+++ b/repair/phase2.c
@@ -64,7 +64,6 @@ zero_log(xfs_mount_t *mp)
 		ASSERT(mp->m_sb.sb_logsectlog >= BBSHIFT);
 	}
 	log.l_sectbb_mask = (1 << log.l_sectbb_log) - 1;
-	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;
 
 	if ((error = xlog_find_tail(&log, &head_blk, &tail_blk))) {
 		do_warn(_("zero_log: cannot find log head/tail "

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Re: [PATCH] xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

[Carlos Maiolino]

This looks good to me,

Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

On Mon, Oct 07, 2013 at 12:35:16PM -0500, Eric Sandeen wrote:
> Commit e0607266 xfsprogs: add crc format support to repair
> 
> added a 2nd assignment to l_sectBBsize:
> 
> 	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;
> 
> which is incorrect; sb_logsectlog is log2 of the sector size,
> in bytes; l_sectBBsize is the size of the log sector in
> 512-byte units.
> 
> So for a 4k sector size log, we were assigning 4096 rather
> than 8.  This broke xlog_find_tail, and caused xfs_repair
> to think that a log was dirty even when it was clean:
> 
> "ERROR: The filesystem has valuable metadata changes in a log"
> 
> (xfs_logprint didn't have this error, so xfs_logprint -t
> agreed that the filesystem really was clean).
> 
> Just remove the incorrect assignment; it was already properly
> assigned about 12 lines prior:
> 
>         log.l_sectBBsize  = BTOBB(x.lbsize);
> 
> and things work again.
> 
> (This worked accidentally for 512-sector devices, because
> we special-case those and set sb_logsectlog to "0" rather
> than 9, so l_sectBBsize came out to "1" (as in 1 sector),
> as it should have).
> 
> Reporteed-by: Markus Trippelsdorf <markus@trippelsdorf.de>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> diff --git a/repair/phase2.c b/repair/phase2.c
> index a62854e..2817fed 100644
> --- a/repair/phase2.c
> +++ b/repair/phase2.c
> @@ -64,7 +64,6 @@ zero_log(xfs_mount_t *mp)
>  		ASSERT(mp->m_sb.sb_logsectlog >= BBSHIFT);
>  	}
>  	log.l_sectbb_mask = (1 << log.l_sectbb_log) - 1;
> -	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;
>  
>  	if ((error = xlog_find_tail(&log, &head_blk, &tail_blk))) {
>  		do_warn(_("zero_log: cannot find log head/tail "
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

-- 
Carlos

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Re: [PATCH] xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

[Dave Chinner]

On Mon, Oct 07, 2013 at 12:35:16PM -0500, Eric Sandeen wrote:
> Commit e0607266 xfsprogs: add crc format support to repair
> 
> added a 2nd assignment to l_sectBBsize:
> 
> 	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;
> 
> which is incorrect; sb_logsectlog is log2 of the sector size,
> in bytes; l_sectBBsize is the size of the log sector in
> 512-byte units.

Yes, that is wrong. It looks like a hunk of code I didn't cleanup
properly when I did some patch reordering and rebasing. IIRC, the
above patch was written before I realised that all of xfsprogs
failed to handle log sector sizes != 512 bytes properly, and that
the log CRC code required that to work correctly. Hence a generic
fix to the problem was added in commit:

999f0b9 xfsprogs: updata libxlog to current kernel code

Which fixed repair, db and logprint. That is where this code:

> Just remove the incorrect assignment; it was already properly
> assigned about 12 lines prior:
> 
>         log.l_sectBBsize  = BTOBB(x.lbsize);
> 
> and things work again.

came from.

Basically, I didn't clean all the random fix fragments out of the
repair patch, and so I broke log secotr size != 512 byte cases for
repair again....

> Reporteed-by: Markus Trippelsdorf <markus@trippelsdorf.de>

Reported-by the reportee. ;)

> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> diff --git a/repair/phase2.c b/repair/phase2.c
> index a62854e..2817fed 100644
> --- a/repair/phase2.c
> +++ b/repair/phase2.c
> @@ -64,7 +64,6 @@ zero_log(xfs_mount_t *mp)
>  		ASSERT(mp->m_sb.sb_logsectlog >= BBSHIFT);
>  	}
>  	log.l_sectbb_mask = (1 << log.l_sectbb_log) - 1;
> -	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;
>  
>  	if ((error = xlog_find_tail(&log, &head_blk, &tail_blk))) {
>  		do_warn(_("zero_log: cannot find log head/tail "

Looks good,

Reviewed-by: Dave Chinner <dchinner@redhat.com>
-- 
Dave Chinner
david@fromorbit.com

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Re: [PATCH] xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

[Rich Johnston]

This has been committed.

Thanks
--Rich

commit 5425725c56bccb9a91847cb74cfdadc8b44fecf7
Author: Eric Sandeen <sandeen@redhat.com>
Date:   Mon Oct 7 17:35:16 2013 +0000

     xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

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