From: Eric Sandeen <sandeen@redhat.com>
Subject: Re: [PATCH] e2fsck: ignore differing NEEDS_RECOVERY flag on backup
 sbs
Date: Thu, 26 Mar 2009 11:31:41 -0500
Message-ID: <49CBADED.7040909@redhat.com>
References: <49281F18.7080404@redhat.com>
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To: ext4 development <linux-ext4@vger.kernel.org>
In-Reply-To: <49281F18.7080404@redhat.com>
Sender: linux-ext4-owner@vger.kernel.org

Eric Sandeen wrote:
> This is for RH bugzilla 471925 -  Complete scan of filesystems expanded online
> 
> When we resize online, the primary superblock gets copied to all
> the backups, and of course since we're mounted the NEEDS_RECOVERY
> flag is set.  A subsequent fsck will find the backups have the
> NEEDS_RECOVERY flag set while the primary does not, and this
> forces a full fsck pass.
> 
> I think this flag can be safely ignored in the flag comparisons.

ping on this?  Andreas wondered about masking the flag when sb backups
are written, but I think that only needs to be done in kernelspace; from
reading code & testing offline resize, I don't think userspace needs
further changes.

-Eric

> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> Index: e2fsprogs/e2fsck/super.c
> ===================================================================
> --- e2fsprogs.orig/e2fsck/super.c	2008-11-22 07:54:47.000000000 -0600
> +++ e2fsprogs/e2fsck/super.c	2008-11-22 08:59:45.953060973 -0600
> @@ -860,7 +860,8 @@ void check_super_block(e2fsck_t ctx)
>   * try to discourage it in the future.  In particular, for the newer
>   * ext4 files, especially EXT4_FEATURE_RO_COMPAT_DIR_NLINK and
>   * EXT3_FEATURE_INCOMPAT_EXTENTS.  So some of these may go away in the
> - * future.
> + * future.  EXT3_FEATURE_INCOMPAT_RECOVER may also get set when
> + * copying the primary superblock during online resize.
>   *
>   * The kernel will set EXT2_FEATURE_COMPAT_EXT_ATTR, but
>   * unfortunately, we shouldn't ignore it since if it's not set in the
> @@ -869,7 +870,8 @@ void check_super_block(e2fsck_t ctx)
>   */
>  #define FEATURE_RO_COMPAT_IGNORE	(EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
>  					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK)
> -#define FEATURE_INCOMPAT_IGNORE		(EXT3_FEATURE_INCOMPAT_EXTENTS)
> +#define FEATURE_INCOMPAT_IGNORE		(EXT3_FEATURE_INCOMPAT_EXTENTS| \
> +					 EXT3_FEATURE_INCOMPAT_RECOVER)
>  
>  int check_backup_super_block(e2fsck_t ctx)
>  {
> 
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