From: John Hubbard Date: Fri, 5 Nov 2021 20:37:16 +0000 (-0700) Subject: mm/gup: further simplify __gup_device_huge() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=20b7fee738d65e50ca00e325ae27ee3efaa819f6;p=linux.git mm/gup: further simplify __gup_device_huge() Commit 6401c4eb57f9 ("mm: gup: fix potential pgmap refcnt leak in __gup_device_huge()") simplified the return paths, but didn't go quite far enough, as discussed in [1]. Remove the "ret" variable entirely, because there is enough information already available to provide the return value. [1] https://lore.kernel.org/r/CAHk-=wgQTRX=5SkCmS+zfmpqubGHGJvXX_HgnPG8JSpHKHBMeg@mail.gmail.com Link: https://lkml.kernel.org/r/20210904004224.86391-1-jhubbard@nvidia.com Signed-off-by: John Hubbard Suggested-by: Linus Torvalds Reviewed-by: Jan Kara Cc: Miaohe Lin Cc: Claudio Imbrenda Cc: Kirill A. Shutemov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/gup.c b/mm/gup.c index 886d6148d3d03..48c7a5a1e85ba 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2228,7 +2228,6 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, { int nr_start = *nr; struct dev_pagemap *pgmap = NULL; - int ret = 1; do { struct page *page = pfn_to_page(pfn); @@ -2236,14 +2235,12 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, pgmap = get_dev_pagemap(pfn, pgmap); if (unlikely(!pgmap)) { undo_dev_pagemap(nr, nr_start, flags, pages); - ret = 0; break; } SetPageReferenced(page); pages[*nr] = page; if (unlikely(!try_grab_page(page, flags))) { undo_dev_pagemap(nr, nr_start, flags, pages); - ret = 0; break; } (*nr)++; @@ -2251,7 +2248,7 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, } while (addr += PAGE_SIZE, addr != end); put_dev_pagemap(pgmap); - return ret; + return addr == end; } static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,