[PATCH] xfs_db: modify bad_features2 when modifying features2

[PATCH] xfs_db: modify bad_features2 when modifying features2

[Eric Sandeen]

The "attr1" command in xfs_db, for example, only modifies the features2
field; when mounted, the kernel will find a mismatch between features2
and bad_features2, and attr2 gets turned back on.

I think the simplest fix is to modify do_version to modify both fields,
but not if there is an existing mismatch that should be investigated
first.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/db/sb.c b/db/sb.c
index 7c61b15..961a939 100644
--- a/db/sb.c
+++ b/db/sb.c
@@ -556,6 +556,12 @@ do_version(xfs_agnumber_t agno, __uint16_t version, __uint32_t features)
 	if (!get_sb(agno, &tsb))
 		return 0;
 
+	if (xfs_sb_has_mismatched_features2(&tsb)) {
+		dbprintf(_("Superblock has mismatched features2 fields, "
+			   "skipping modification\n"));
+		return 0;
+	}
+
 	if ((version & XFS_SB_VERSION_LOGV2BIT) &&
 					!xfs_sb_version_haslogv2(&tsb)) {
 		tsb.sb_logsunit = 1;
@@ -564,7 +570,8 @@ do_version(xfs_agnumber_t agno, __uint16_t version, __uint32_t features)
 
 	tsb.sb_versionnum = version;
 	tsb.sb_features2 = features;
-	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2;
+	tsb.sb_bad_features2 = features;
+	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
 	libxfs_sb_to_disk(iocur_top->data, &tsb, fields);
 	write_cur();
 	return 1;

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_db: modify bad_features2 when modifying features2

[Christoph Hellwig]

On Tue, Dec 01, 2009 at 01:17:55PM -0600, Eric Sandeen wrote:
> +	if (xfs_sb_has_mismatched_features2(&tsb)) {
> +		dbprintf(_("Superblock has mismatched features2 fields, "
> +			   "skipping modification\n"));
> +		return 0;
> +	}

However I'm not sure if this one is an all that good idea.  It'll make
all version updates fail if we have a mismatched features2.  That way
people can't use xfs_db to fix it up which seems odd.

To me just printing the warning but not aborting would be the best way
to inform the user about it.

> +
>  	if ((version & XFS_SB_VERSION_LOGV2BIT) &&
>  					!xfs_sb_version_haslogv2(&tsb)) {
>  		tsb.sb_logsunit = 1;
> @@ -564,7 +570,8 @@ do_version(xfs_agnumber_t agno, __uint16_t version, __uint32_t features)
>  
>  	tsb.sb_versionnum = version;
>  	tsb.sb_features2 = features;
> -	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2;
> +	tsb.sb_bad_features2 = features;
> +	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;

This one looks good to me.

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_db: modify bad_features2 when modifying features2

[Eric Sandeen]

Christoph Hellwig wrote:
> On Tue, Dec 01, 2009 at 01:17:55PM -0600, Eric Sandeen wrote:
>> +	if (xfs_sb_has_mismatched_features2(&tsb)) {
>> +		dbprintf(_("Superblock has mismatched features2 fields, "
>> +			   "skipping modification\n"));
>> +		return 0;
>> +	}
> 
> However I'm not sure if this one is an all that good idea.  It'll make
> all version updates fail if we have a mismatched features2.  That way
> people can't use xfs_db to fix it up which seems odd.
> 
> To me just printing the warning but not aborting would be the best way
> to inform the user about it.

hm yeah I suppose so.

I wonder if we should catch it somehow on the feature-set shortcuts
like "attr1" but allow it for explicit value sets ...

?

-Eric

> 
>> +
>>  	if ((version & XFS_SB_VERSION_LOGV2BIT) &&
>>  					!xfs_sb_version_haslogv2(&tsb)) {
>>  		tsb.sb_logsunit = 1;
>> @@ -564,7 +570,8 @@ do_version(xfs_agnumber_t agno, __uint16_t version, __uint32_t features)
>>  
>>  	tsb.sb_versionnum = version;
>>  	tsb.sb_features2 = features;
>> -	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2;
>> +	tsb.sb_bad_features2 = features;
>> +	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
> 
> This one looks good to me.
> 

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_db: modify bad_features2 when modifying features2

[Eric Sandeen]

Eric Sandeen wrote:
> Christoph Hellwig wrote:
>> On Tue, Dec 01, 2009 at 01:17:55PM -0600, Eric Sandeen wrote:
>>> +	if (xfs_sb_has_mismatched_features2(&tsb)) {
>>> +		dbprintf(_("Superblock has mismatched features2 fields, "
>>> +			   "skipping modification\n"));
>>> +		return 0;
>>> +	}
>> However I'm not sure if this one is an all that good idea.  It'll make
>> all version updates fail if we have a mismatched features2.  That way
>> people can't use xfs_db to fix it up which seems odd.
>>
>> To me just printing the warning but not aborting would be the best way
>> to inform the user about it.
> 
> hm yeah I suppose so.
> 
> I wonder if we should catch it somehow on the feature-set shortcuts
> like "attr1" but allow it for explicit value sets ...

actually:

"version" prints version
"version <featurename>" adds that feature
"version <value> <value>" prints the names for the values but doesn't change anything

... so you can still modify mismatched values by writing to the superblocks
directly although that's a little tedious.  But that shouldn't really happen
too often.

I'm just wary of automatically overwriting the mismatch w/o errors... it seems
like some intervention might be necessary.

Or, since the kernel does this already (fixes up mismatches) maybe we should
just put the same algorithms into xfs_db but that's getting tricky.  :)

Maybe for a later date ...

-Eric

> ?
> 
> -Eric
> 
>>> +
>>>  	if ((version & XFS_SB_VERSION_LOGV2BIT) &&
>>>  					!xfs_sb_version_haslogv2(&tsb)) {
>>>  		tsb.sb_logsunit = 1;
>>> @@ -564,7 +570,8 @@ do_version(xfs_agnumber_t agno, __uint16_t version, __uint32_t features)
>>>  
>>>  	tsb.sb_versionnum = version;
>>>  	tsb.sb_features2 = features;
>>> -	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2;
>>> +	tsb.sb_bad_features2 = features;
>>> +	fields |= XFS_SB_VERSIONNUM | XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
>> This one looks good to me.
>>
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
> 

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs