Commit ad4ae1c7 authored Jun 01, 2020 by Matthew Wilcox (Oracle) Committed by Linus Torvalds Jun 02, 2020

mm: move readahead nr_pages check into read_pages



Simplify the callers by moving the check for nr_pages and the BUG_ON
into read_pages().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-5-willy@infradead.org


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a1ef8566

mm/readahead.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -119,6 +119,9 @@ static void read_pages(struct address_space mapping, struct file filp,
		struct blk_plug plug;
		unsigned page_idx;

		if (!nr_pages)
		return;

		blk_start_plug(&plug);

		if (mapping->a_ops->readpages) {
		@@ -138,6 +141,8 @@ static void read_pages(struct address_space mapping, struct file filp,

		out:
		blk_finish_plug(&plug);

		BUG_ON(!list_empty(pages));
		}

		/*
		@@ -180,7 +185,6 @@ void __do_page_cache_readahead(struct address_space *mapping,
		* contiguous pages before continuing with the next
		* batch.
		*/
		if (nr_pages)
		read_pages(mapping, filp, &page_pool, nr_pages,
		gfp_mask);
		nr_pages = 0;
		@@ -202,9 +206,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
		* uptodate then the caller will launch readpage again, and
		* will then handle the error.
		*/
		if (nr_pages)
		read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask);
		BUG_ON(!list_empty(&page_pool));
		}

		/*

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