Re: [PATCH 1/3] xfs: clear MS_ACTIVE after finishing log recovery

[Brian Foster <bfoster@redhat.com>]

On Mon, Aug 14, 2017 at 03:07:03PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Way back when we established inode block-map redo log items, it was
> discovered that we needed to prevent the VFS from evicting inodes during
> log recovery because any given inode might be have bmap redo items to
> replay even if the inode has no link count and is ultimately deleted,
> and any eviction of an unlinked inode causes the inode to be truncated
> and freed too early.
> 
> To make this possible, we set MS_ACTIVE so that inodes would not be torn
> down immediately upon release.  Unfortunately, this also results in the
> quota inodes not being released at all if a later part of the mount
> process should fail, because we never reclaim the inodes.  So, set
> MS_ACTIVE right before we do the last part of log recovery and clear it
> immediately after we finish the log recovery so that everything
> will be torn down properly if we abort the mount.
> 
> Fixes: 17c12bcd30 ("xfs: when replaying bmap operations, don't let unlinked inodes get reaped")
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/xfs_log.c   |   11 +++++++++++
>  fs/xfs/xfs_mount.c |   10 ----------
>  2 files changed, 11 insertions(+), 10 deletions(-)
> 
> 
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 0053bcf..4ebd0ba 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -749,9 +749,20 @@ xfs_log_mount_finish(
>  		return 0;
>  	}
>  
> +	/*
> +	 * During the second phase of log recovery, we need iget and
> +	 * iput to behave like they do for an active filesystem.
> +	 * xfs_fs_drop_inode needs to be able to prevent the deletion
> +	 * of inodes before we're done replaying log items on those
> +	 * inodes.  Turn it off immediately after recovery finishes
> +	 * so that we don't leak the quota inodes if subsequent mount
> +	 * activities fail.
> +	 */
> +	mp->m_super->s_flags |= MS_ACTIVE;
>  	error = xlog_recover_finish(mp->m_log);
>  	if (!error)
>  		xfs_log_work_queue(mp);
> +	mp->m_super->s_flags &= ~MS_ACTIVE;
>  
>  	return error;
>  }
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 40d4e8b..151a82db 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -945,15 +945,6 @@ xfs_mountfs(
>  	}
>  
>  	/*
> -	 * During the second phase of log recovery, we need iget and
> -	 * iput to behave like they do for an active filesystem.
> -	 * xfs_fs_drop_inode needs to be able to prevent the deletion
> -	 * of inodes before we're done replaying log items on those
> -	 * inodes.
> -	 */
> -	mp->m_super->s_flags |= MS_ACTIVE;
> -
> -	/*
>  	 * Finish recovering the file system.  This part needed to be delayed
>  	 * until after the root and real-time bitmap inodes were consistently
>  	 * read in.
> @@ -1028,7 +1019,6 @@ xfs_mountfs(
>   out_quota:
>  	xfs_qm_unmount_quotas(mp);
>   out_rtunmount:
> -	mp->m_super->s_flags &= ~MS_ACTIVE;
>  	xfs_rtunmount_inodes(mp);
>   out_rele_rip:
>  	IRELE(rip);
> 
> --
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