Re: [PATCH] writeback: remove .nonblocking and .encountered_congestion

[Jan Kara <jack@suse.cz>]

On Thu 05-05-11 21:30:02, Wu Fengguang wrote:
> [allyesconfig compile tested]
> [it modifies 3 filesystems all at once, is it OK?]
> 
> Remove two unused struct writeback_control fields:
> 
> 	.encountered_congestion	(completley unused)
> 	.nonblocking		(never set, checked/showed in XFS,NFS/btrfs)
> 
> Proposed-by: Christoph Hellwig <hch@infradead.org>
> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
  Yep. Makes sense.
Reviewed-by: Jan Kara <jack@suse.cz>
  BTW: I've noticed you removed ->for_background check from
nfs_write_inode(). That's OK because for_background => WB_SYNC_NONE but I
guess you should mention it in the changelog.

								Honza
> ---
>  fs/nfs/write.c               |    3 +--
>  fs/xfs/linux-2.6/xfs_aops.c  |    2 +-
>  include/linux/writeback.h    |    2 --
>  include/trace/events/btrfs.h |    6 ++----
>  4 files changed, 4 insertions(+), 9 deletions(-)
> 
> --- linux-next.orig/fs/xfs/linux-2.6/xfs_aops.c	2011-05-05 21:10:01.000000000 +0800
> +++ linux-next/fs/xfs/linux-2.6/xfs_aops.c	2011-05-05 21:10:37.000000000 +0800
> @@ -970,7 +970,7 @@ xfs_vm_writepage(
>  	offset = page_offset(page);
>  	type = IO_OVERWRITE;
>  
> -	if (wbc->sync_mode == WB_SYNC_NONE && wbc->nonblocking)
> +	if (wbc->sync_mode == WB_SYNC_NONE)
>  		nonblocking = 1;
>  
>  	do {
> --- linux-next.orig/include/trace/events/btrfs.h	2011-05-05 21:07:31.000000000 +0800
> +++ linux-next/include/trace/events/btrfs.h	2011-05-05 21:09:47.000000000 +0800
> @@ -284,7 +284,6 @@ DECLARE_EVENT_CLASS(btrfs__writepage,
>  		__field(	long,   pages_skipped		)
>  		__field(	loff_t, range_start		)
>  		__field(	loff_t, range_end		)
> -		__field(	char,   nonblocking		)
>  		__field(	char,   for_kupdate		)
>  		__field(	char,   for_reclaim		)
>  		__field(	char,   range_cyclic		)
> @@ -299,7 +298,6 @@ DECLARE_EVENT_CLASS(btrfs__writepage,
>  		__entry->pages_skipped	= wbc->pages_skipped;
>  		__entry->range_start	= wbc->range_start;
>  		__entry->range_end	= wbc->range_end;
> -		__entry->nonblocking	= wbc->nonblocking;
>  		__entry->for_kupdate	= wbc->for_kupdate;
>  		__entry->for_reclaim	= wbc->for_reclaim;
>  		__entry->range_cyclic	= wbc->range_cyclic;
> @@ -310,13 +308,13 @@ DECLARE_EVENT_CLASS(btrfs__writepage,
>  
>  	TP_printk("root = %llu(%s), ino = %lu, page_index = %lu, "
>  		  "nr_to_write = %ld, pages_skipped = %ld, range_start = %llu, "
> -		  "range_end = %llu, nonblocking = %d, for_kupdate = %d, "
> +		  "range_end = %llu, for_kupdate = %d, "
>  		  "for_reclaim = %d, range_cyclic = %d, writeback_index = %lu",
>  		  show_root_type(__entry->root_objectid),
>  		  (unsigned long)__entry->ino, __entry->index,
>  		  __entry->nr_to_write, __entry->pages_skipped,
>  		  __entry->range_start, __entry->range_end,
> -		  __entry->nonblocking, __entry->for_kupdate,
> +		  __entry->for_kupdate,
>  		  __entry->for_reclaim, __entry->range_cyclic,
>  		  (unsigned long)__entry->writeback_index)
>  );
> --- linux-next.orig/fs/nfs/write.c	2011-05-05 21:10:52.000000000 +0800
> +++ linux-next/fs/nfs/write.c	2011-05-05 21:11:19.000000000 +0800
> @@ -1564,8 +1564,7 @@ int nfs_write_inode(struct inode *inode,
>  		int status;
>  		bool sync = true;
>  
> -		if (wbc->sync_mode == WB_SYNC_NONE || wbc->nonblocking ||
> -		    wbc->for_background)
> +		if (wbc->sync_mode == WB_SYNC_NONE)
>  			sync = false;
>  
>  		status = pnfs_layoutcommit_inode(inode, sync);
> --- linux-next.orig/include/linux/writeback.h	2011-05-05 21:07:16.000000000 +0800
> +++ linux-next/include/linux/writeback.h	2011-05-05 21:13:20.000000000 +0800
> @@ -36,8 +36,6 @@ struct writeback_control {
>  	loff_t range_start;
>  	loff_t range_end;
>  
> -	unsigned nonblocking:1;		/* Don't get stuck on request queues */
> -	unsigned encountered_congestion:1; /* An output: a queue is full */
>  	unsigned for_kupdate:1;		/* A kupdate writeback */
>  	unsigned for_background:1;	/* A background writeback */
>  	unsigned tagged_sync:1;		/* do livelock prevention for sync */
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR