From 66d9282523b3228183b14d9f812872dd2620704d Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 28 Jun 2021 16:02:19 +0100 Subject: [PATCH] mm/page_alloc: Correct return value of populated elements if bulk array is populated Dave Jones reported the following This made it into 5.13 final, and completely breaks NFSD for me (Serving tcp v3 mounts). Existing mounts on clients hang, as do new mounts from new clients. Rebooting the server back to rc7 everything recovers. The commit b3b64ebd3822 ("mm/page_alloc: do bulk array bounds check after checking populated elements") returns the wrong value if the array is already populated which is interpreted as an allocation failure. Dave reported this fixes his problem and it also passed a test running dbench over NFS. Fixes: b3b64ebd3822 ("mm/page_alloc: do bulk array bounds check after checking populated elements") Reported-and-tested-by: Dave Jones Signed-off-by: Mel Gorman Cc: [5.13+] Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ef2265f86b91..04220581579c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5058,7 +5058,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, /* Already populated array? */ if (unlikely(page_array && nr_pages - nr_populated == 0)) - return 0; + return nr_populated; /* Use the single page allocator for one page. */ if (nr_pages - nr_populated == 1)