+ mm-filemap-restructure-filemap_get_pages.patch added to -mm tree

+ mm-filemap-restructure-filemap_get_pages.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/filemap: restructure filemap_get_pages
has been added to the -mm tree.  Its filename is
     mm-filemap-restructure-filemap_get_pages.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-restructure-filemap_get_pages.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-restructure-filemap_get_pages.patch

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm/filemap: restructure filemap_get_pages

Remove the got_pages label, remove indentation, rename find_page to retry,
simplify error handling.

Link: https://lkml.kernel.org/r/20210122160140.223228-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/filemap.c |   71 +++++++++++++++++++------------------------------
 1 file changed, 28 insertions(+), 43 deletions(-)

--- a/mm/filemap.c~mm-filemap-restructure-filemap_get_pages
+++ a/mm/filemap.c
@@ -2342,70 +2342,55 @@ static int filemap_get_pages(struct kioc
 	struct file_ra_state *ra = &filp->f_ra;
 	pgoff_t index = iocb->ki_pos >> PAGE_SHIFT;
 	pgoff_t last_index;
+	struct page *page;
 	int err = 0;
 
 	last_index = DIV_ROUND_UP(iocb->ki_pos + iter->count, PAGE_SIZE);
-find_page:
+retry:
 	if (fatal_signal_pending(current))
 		return -EINTR;
 
 	filemap_get_read_batch(mapping, index, last_index, pvec);
-	if (pvec->nr)
-		goto got_pages;
-
-	if (iocb->ki_flags & IOCB_NOIO)
-		return -EAGAIN;
-
-	page_cache_sync_readahead(mapping, ra, filp, index, last_index - index);
-
-	filemap_get_read_batch(mapping, index, last_index, pvec);
+	if (!pagevec_count(pvec)) {
+		if (iocb->ki_flags & IOCB_NOIO)
+			return -EAGAIN;
+		page_cache_sync_readahead(mapping, ra, filp, index,
+				last_index - index);
+		filemap_get_read_batch(mapping, index, last_index, pvec);
+	}
 	if (!pagevec_count(pvec)) {
 		if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_WAITQ))
 			return -EAGAIN;
 		err = filemap_create_page(filp, mapping,
 				iocb->ki_pos >> PAGE_SHIFT, pvec);
 		if (err == AOP_TRUNCATED_PAGE)
-			goto find_page;
+			goto retry;
 		return err;
 	}
-got_pages:
-	{
-		struct page *page = pvec->pages[pvec->nr - 1];
-
-		if (PageReadahead(page)) {
-			err = filemap_readahead(iocb, filp, mapping, page,
-					last_index);
-			if (err) {
-				put_page(page);
-				pvec->nr--;
-				goto err;
-			}
-		}
 
-		if (!PageUptodate(page)) {
-			if ((iocb->ki_flags & IOCB_WAITQ) &&
-			    pagevec_count(pvec) > 1)
-				iocb->ki_flags |= IOCB_NOWAIT;
-			err = filemap_update_page(iocb, mapping, iter, page);
-			if (err) {
-				if (err < 0)
-					put_page(page);
-				pvec->nr--;
-			}
-		}
+	page = pvec->pages[pagevec_count(pvec) - 1];
+	if (PageReadahead(page)) {
+		err = filemap_readahead(iocb, filp, mapping, page, last_index);
+		if (err)
+			goto err;
+	}
+	if (!PageUptodate(page)) {
+		if ((iocb->ki_flags & IOCB_WAITQ) && pagevec_count(pvec) > 1)
+			iocb->ki_flags |= IOCB_NOWAIT;
+		err = filemap_update_page(iocb, mapping, iter, page);
+		if (err)
+			goto err;
 	}
 
+	return 0;
 err:
-	if (likely(pvec->nr))
+	if (err < 0)
+		put_page(page);
+	if (likely(--pvec->nr))
 		return 0;
 	if (err == AOP_TRUNCATED_PAGE)
-		goto find_page;
-	if (err)
-		return err;
-	/*
-	 * No pages and no error means we raced and should retry:
-	 */
-	goto find_page;
+		goto retry;
+	return err;
 }
 
 /**
_

Patches currently in -mm which might be from willy@infradead.org are

mm-debug-improve-memcg-debugging.patch
mm-filemap-rename-generic_file_buffered_read-subfunctions.patch
mm-filemap-remove-dynamically-allocated-array-from-filemap_read.patch
mm-filemap-convert-filemap_get_pages-to-take-a-pagevec.patch
mm-filemap-use-head-pages-in-generic_file_buffered_read.patch
mm-filemap-pass-a-sleep-state-to-put_and_wait_on_page_locked.patch
mm-filemap-support-readpage-splitting-a-page.patch
mm-filemap-inline-__wait_on_page_locked_async-into-caller.patch
mm-filemap-dont-call-readpage-if-iocb_waitq-is-set.patch
mm-filemap-change-filemap_read_page-calling-conventions.patch
mm-filemap-change-filemap_create_page-calling-conventions.patch
mm-filemap-convert-filemap_update_page-to-return-an-errno.patch
mm-filemap-move-the-iocb-checks-into-filemap_update_page.patch
mm-filemap-add-filemap_range_uptodate.patch
mm-filemap-split-filemap_readahead-out-of-filemap_get_pages.patch
mm-filemap-restructure-filemap_get_pages.patch
mm-filemap-dont-relock-the-page-after-calling-readpage.patch
mm-make-pagecache-tagged-lookups-return-only-head-pages.patch
mm-shmem-use-pagevec_lookup-in-shmem_unlock_mapping.patch
mm-swap-optimise-get_shadow_from_swap_cache.patch
mm-add-fgp_entry.patch
mm-filemap-rename-find_get_entry-to-mapping_get_entry.patch
mm-filemap-add-helper-for-finding-pages.patch
mm-filemap-add-helper-for-finding-pages-fix.patch
mm-filemap-add-mapping_seek_hole_data.patch
mm-filemap-add-mapping_seek_hole_data-fix.patch
iomap-use-mapping_seek_hole_data.patch
mm-add-and-use-find_lock_entries.patch
mm-add-and-use-find_lock_entries-fix.patch
mm-add-an-end-parameter-to-find_get_entries.patch
mm-add-an-end-parameter-to-pagevec_lookup_entries.patch
mm-remove-nr_entries-parameter-from-pagevec_lookup_entries.patch
mm-pass-pvec-directly-to-find_get_entries.patch
mm-remove-pagevec_lookup_entries.patch