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authorJohn Hubbard <jhubbard@nvidia.com>2021-11-05 21:37:16 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-06 21:30:34 +0100
commit20b7fee738d65e50ca00e325ae27ee3efaa819f6 (patch)
tree84677ddddabc70db5a909a82c12c16b1fe1c8861 /mm/gup.c
parentmm: move more expensive part of XA setup out of mapping check (diff)
downloadlinux-20b7fee738d65e50ca00e325ae27ee3efaa819f6.tar.xz
linux-20b7fee738d65e50ca00e325ae27ee3efaa819f6.zip
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 <jhubbard@nvidia.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/mm/gup.c b/mm/gup.c
index 886d6148d3d0..48c7a5a1e85b 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,