Re: [PATCH 02/11] writeback: get rid of wbc->for_writepages

[Jan Kara <jack@suse.cz>]

On Tue 15-09-09 20:16:48, Jens Axboe wrote:
> It's only set, it's never checked. Kill it.
  Acked-by: Jan Kara <jack@suse.cz>

							Honza

> 
> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
> ---
>  fs/afs/write.c              |    1 -
>  fs/btrfs/ordered-data.c     |    1 -
>  fs/jbd2/commit.c            |    1 -
>  fs/nfs/write.c              |    1 -
>  include/linux/writeback.h   |    1 -
>  include/trace/events/ext4.h |    6 ++----
>  mm/page-writeback.c         |    2 --
>  7 files changed, 2 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/afs/write.c b/fs/afs/write.c
> index c2e7a7f..c63a3c8 100644
> --- a/fs/afs/write.c
> +++ b/fs/afs/write.c
> @@ -712,7 +712,6 @@ int afs_writeback_all(struct afs_vnode *vnode)
>  		.bdi		= mapping->backing_dev_info,
>  		.sync_mode	= WB_SYNC_ALL,
>  		.nr_to_write	= LONG_MAX,
> -		.for_writepages = 1,
>  		.range_cyclic	= 1,
>  	};
>  	int ret;
> diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
> index d6f0806..7b2f401 100644
> --- a/fs/btrfs/ordered-data.c
> +++ b/fs/btrfs/ordered-data.c
> @@ -740,7 +740,6 @@ int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
>  		.nr_to_write = mapping->nrpages * 2,
>  		.range_start = start,
>  		.range_end = end,
> -		.for_writepages = 1,
>  	};
>  	return btrfs_writepages(mapping, &wbc);
>  }
> diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
> index 7b4088b..0df600e 100644
> --- a/fs/jbd2/commit.c
> +++ b/fs/jbd2/commit.c
> @@ -220,7 +220,6 @@ static int journal_submit_inode_data_buffers(struct address_space *mapping)
>  		.nr_to_write = mapping->nrpages * 2,
>  		.range_start = 0,
>  		.range_end = i_size_read(mapping->host),
> -		.for_writepages = 1,
>  	};
>  
>  	ret = generic_writepages(mapping, &wbc);
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index 120acad..53eb26c 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -1490,7 +1490,6 @@ static int nfs_write_mapping(struct address_space *mapping, int how)
>  		.nr_to_write = LONG_MAX,
>  		.range_start = 0,
>  		.range_end = LLONG_MAX,
> -		.for_writepages = 1,
>  	};
>  
>  	return __nfs_write_mapping(mapping, &wbc, how);
> diff --git a/include/linux/writeback.h b/include/linux/writeback.h
> index d347632..48a054e 100644
> --- a/include/linux/writeback.h
> +++ b/include/linux/writeback.h
> @@ -50,7 +50,6 @@ struct writeback_control {
>  	unsigned encountered_congestion:1; /* An output: a queue is full */
>  	unsigned for_kupdate:1;		/* A kupdate writeback */
>  	unsigned for_reclaim:1;		/* Invoked from the page allocator */
> -	unsigned for_writepages:1;	/* This is a writepages() call */
>  	unsigned range_cyclic:1;	/* range_start is cyclic */
>  	unsigned more_io:1;		/* more io to be dispatched */
>  	/*
> diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
> index 7d8b5bc..8d433c4 100644
> --- a/include/trace/events/ext4.h
> +++ b/include/trace/events/ext4.h
> @@ -227,7 +227,6 @@ TRACE_EVENT(ext4_da_writepages,
>  		__field(	char,	nonblocking		)
>  		__field(	char,	for_kupdate		)
>  		__field(	char,	for_reclaim		)
> -		__field(	char,	for_writepages		)
>  		__field(	char,	range_cyclic		)
>  	),
>  
> @@ -241,16 +240,15 @@ TRACE_EVENT(ext4_da_writepages,
>  		__entry->nonblocking	= wbc->nonblocking;
>  		__entry->for_kupdate	= wbc->for_kupdate;
>  		__entry->for_reclaim	= wbc->for_reclaim;
> -		__entry->for_writepages	= wbc->for_writepages;
>  		__entry->range_cyclic	= wbc->range_cyclic;
>  	),
>  
> -	TP_printk("dev %s ino %lu nr_t_write %ld pages_skipped %ld range_start %llu range_end %llu nonblocking %d for_kupdate %d for_reclaim %d for_writepages %d range_cyclic %d",
> +	TP_printk("dev %s ino %lu nr_t_write %ld pages_skipped %ld range_start %llu range_end %llu nonblocking %d for_kupdate %d for_reclaim %d range_cyclic %d",
>  		  jbd2_dev_to_name(__entry->dev), __entry->ino, __entry->nr_to_write,
>  		  __entry->pages_skipped, __entry->range_start,
>  		  __entry->range_end, __entry->nonblocking,
>  		  __entry->for_kupdate, __entry->for_reclaim,
> -		  __entry->for_writepages, __entry->range_cyclic)
> +		  __entry->range_cyclic)
>  );
>  
>  TRACE_EVENT(ext4_da_writepages_result,
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 25e7770..64c01d0 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -1019,12 +1019,10 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
>  
>  	if (wbc->nr_to_write <= 0)
>  		return 0;
> -	wbc->for_writepages = 1;
>  	if (mapping->a_ops->writepages)
>  		ret = mapping->a_ops->writepages(mapping, wbc);
>  	else
>  		ret = generic_writepages(mapping, wbc);
> -	wbc->for_writepages = 0;
>  	return ret;
>  }
>  
> -- 
> 1.6.4.1.207.g68ea
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR