[PATCH 1/1] xfs: log the inode in ->write_inode calls for kupdate

[Hans-Peter Jansen]

On Sunday 18 December 2011, 16:49:55 Christoph Hellwig wrote:
> If the writeback code writes back an inode because it has expired we
> currently use the non-blockin ->write_inode path.  This means any
> inode that is pinned is skipped.  With delayed logging and a workload
> that has very little log traffic otherwise it is very likely that an
> inode that gets constantly written to is always pinned, and thus we
> keep refusing to write it.  The VM writeback code at that point
> redirties it and doesn't try to write it again for another 30
> seconds.  This means under certain scenarious time based metadata
> writeback never happens.

Wouldn't this qualify as STABLE material then?

> Fix this by calling into xfs_log_inode for kupdate in addition to
> data integrity syncs, and thus transfer the inode to the log ASAP.
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
>
> Index: xfs/fs/xfs/xfs_super.c
> ===================================================================
> --- xfs.orig/fs/xfs/xfs_super.c	2011-12-14 05:33:07.193262189 -0800
> +++ xfs/fs/xfs/xfs_super.c	2011-12-14 05:38:56.108038623 -0800
> @@ -905,7 +884,7 @@ xfs_fs_write_inode(
>  	if (!ip->i_update_core)
>  		return 0;
>
> -	if (wbc->sync_mode == WB_SYNC_ALL) {
> +	if (wbc->sync_mode == WB_SYNC_ALL || wbc->for_kupdate) {
>  		/*
>  		 * Make sure the inode has made it it into the log.  Instead
>  		 * of forcing it all the way to stable storage using a
>