ACK w/cmt: [Trusty][SRU][PATCH] xfs: avoid false quotacheck after unclean shutdown

[Chris J Arges]

Backport mainly involved in moved file. Minor nitpicks about changes in
code formatting inlined.

Acked-by: <chris.j.arges at canonical.com>

On 06/04/2015 03:43 AM, Seyeong Kim wrote:
> From: Eric Sandeen <sandeen at sandeen.net>
> 
> BugLink: http://bugs.launchpad.net/bugs/1461730
> 
> The commit
> 
> 83e782e xfs: Remove incore use of XFS_OQUOTA_ENFD and XFS_OQUOTA_CHKD
> 
> added a new function xfs_sb_quota_from_disk() which swaps
> on-disk XFS_OQUOTA_* flags for in-core XFS_GQUOTA_* and XFS_PQUOTA_*
> flags after the superblock is read.
> 
> However, if log recovery is required, the superblock is read again,
> and the modified in-core flags are re-read from disk, so we have
> XFS_OQUOTA_* flags in memory again.  This causes the
> XFS_QM_NEED_QUOTACHECK() test to be true, because the XFS_OQUOTA_CHKD
> is still set, and not XFS_GQUOTA_CHKD or XFS_PQUOTA_CHKD.
> 
> Change xfs_sb_from_disk to call xfs_sb_quota_from disk and always
> convert the disk flags to in-memory flags.
> 
> Add a lower-level function which can be called with "false" to
> not convert the flags, so that the sb verifier can verify
> exactly what was on disk, per Brian Foster's suggestion.
> 
> Reported-by: Cyril B. <cbay at excellency.fr>
> Signed-off-by: Eric Sandeen <sandeen at redhat.com>
> 
> (backported from commit 5ef828c4152726f56751c78ea844f08d2b2a4fa3)
> Signed-off-by: Seyeong Kim <seyeong.kim at canonical.com>
> 
> Conflicts:
> 	fs/xfs/libxfs/xfs_sb.c
> 	fs/xfs/xfs_mount.c
> ---
>  fs/xfs/xfs_mount.c |  1 -
>  fs/xfs/xfs_sb.c    | 26 ++++++++++++++++++++++----
>  2 files changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 02df7b4..e853572 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -314,7 +314,6 @@ reread:
>  	 * Initialize the mount structure from the superblock.
>  	 */
>  	xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
> -	xfs_sb_quota_from_disk(&mp->m_sb);
>  
>  	/*
>  	 * We must be able to do sector-sized and sector-aligned IO.
> diff --git a/fs/xfs/xfs_sb.c b/fs/xfs/xfs_sb.c
> index b7c9aea..6301f33 100644
> --- a/fs/xfs/xfs_sb.c
> +++ b/fs/xfs/xfs_sb.c
> @@ -398,10 +398,13 @@ xfs_sb_quota_from_disk(struct xfs_sb *sbp)
>  	}
>  }
>  
> -void
> -xfs_sb_from_disk(
> +
> +
> +static void
> +__xfs_sb_from_disk(
>  	struct xfs_sb	*to,
> -	xfs_dsb_t	*from)
> +	xfs_dsb_t	*from,
> +	bool	convert_xquota)

In this case you are applying the patch to a different file. A minor
comment here is to ensure you match the changes exactly by the previous
patch. (Not add extra spaces, and match indentation.)


>  {
>  	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
>  	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
> @@ -457,6 +460,17 @@ xfs_sb_from_disk(
>  	to->sb_pad = 0;
>  	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
>  	to->sb_lsn = be64_to_cpu(from->sb_lsn);
> +	/* Convert on-disk flags to in-memory flags? */
> +	if (convert_xquota)
> +		xfs_sb_quota_from_disk(to);
> +}
> +
> +void
> +xfs_sb_from_disk(
> +	struct xfs_sb   *to,
> +	xfs_dsb_t       *from)
> +{
> +	__xfs_sb_from_disk(to, from, true);
>  }
>  
>  static inline void
> @@ -572,7 +586,11 @@ xfs_sb_verify(
>  	struct xfs_mount *mp = bp->b_target->bt_mount;
>  	struct xfs_sb	sb;
>  
> -	xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp));
> +	/*
> +	* Use call variant which doesn't convert quota flags from disk
> +	* format, because xfs_mount_validate_sb checks the on-disk flags.
> +	*/
> +	__xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
>  
>  	/*
>  	 * Only check the in progress field for the primary superblock as
>