Commit 50b7d8568008 for kernel

commit 50b7d85680086126d7bd91dae81d57d4cb1ab6b7
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date:   Thu Oct 15 20:13:04 2020 -0700

    ramfs: fix nommu mmap with gaps in the page cache

    ramfs needs to check that pages are both physically contiguous and
    contiguous in the file.  If the page cache happens to have, eg, page A for
    index 0 of the file, no page for index 1, and page A+1 for index 2, then
    an mmap of the first two pages of the file will succeed when it should
    fail.

    Fixes: 642fb4d1f1dd ("[PATCH] NOMMU: Provide shared-writable mmap support on ramfs")
    Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Cc: David Howells <dhowells@redhat.com>
    Link: https://lkml.kernel.org/r/20200914122239.GO6583@casper.infradead.org
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 414695454956..355523f4a4bf 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -224,7 +224,7 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
 	if (!pages)
 		goto out_free;

-	nr = find_get_pages(inode->i_mapping, &pgoff, lpages, pages);
+	nr = find_get_pages_contig(inode->i_mapping, pgoff, lpages, pages);
 	if (nr != lpages)
 		goto out_free_pages; /* leave if some pages were missing */