From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm: remove 'page_offset' from readahead loop Replace the page_offset variable with 'index + i'. Link: http://lkml.kernel.org/r/20200414150233.24495-10-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> Cc: Chao Yu <yuchao0@xxxxxxxxxx> Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx> Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Cc: Dave Chinner <dchinner@xxxxxxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: Gao Xiang <gaoxiang25@xxxxxxxxxx> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Cc: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Cc: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> Cc: Miklos Szeredi <mszeredi@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/readahead.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/mm/readahead.c~mm-remove-page_offset-from-readahead-loop +++ a/mm/readahead.c @@ -180,12 +180,10 @@ void __do_page_cache_readahead(struct ad * Preallocate as many pages as we will need. */ for (i = 0; i < nr_to_read; i++) { - pgoff_t page_offset = index + i; - - if (page_offset > end_index) + if (index + i > end_index) break; - page = xa_load(&mapping->i_pages, page_offset); + page = xa_load(&mapping->i_pages, index + i); if (page && !xa_is_value(page)) { /* * Page already present? Kick off the current batch of @@ -199,7 +197,7 @@ void __do_page_cache_readahead(struct ad page = __page_cache_alloc(gfp_mask); if (!page) break; - page->index = page_offset; + page->index = index + i; list_add(&page->lru, &page_pool); if (i == nr_to_read - lookahead_size) SetPageReadahead(page); _
