From: John Hubbard <jhubbard@xxxxxxxxxx> Subject: mm/gup: move try_get_compound_head() to top, fix minor issues An upcoming patch uses try_get_compound_head() more widely, so move it to the top of gup.c. Also fix a tiny spelling error and a checkpatch.pl warning. Link: http://lkml.kernel.org/r/20200107224558.2362728-3-jhubbard@xxxxxxxxxx Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Cc: Björn Töpel <bjorn.topel@xxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Jerome Glisse <jglisse@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> Cc: Leon Romanovsky <leonro@xxxxxxxxxxxx> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/gup.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) --- a/mm/gup.c~mm-gup-move-try_get_compound_head-to-top-fix-minor-issues +++ a/mm/gup.c @@ -29,6 +29,21 @@ struct follow_page_context { unsigned int page_mask; }; +/* + * Return the compound head page with ref appropriately incremented, + * or NULL if that failed. + */ +static inline struct page *try_get_compound_head(struct page *page, int refs) +{ + struct page *head = compound_head(page); + + if (WARN_ON_ONCE(page_ref_count(head) < 0)) + return NULL; + if (unlikely(!page_cache_add_speculative(head, refs))) + return NULL; + return head; +} + /** * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages * @pages: array of pages to be maybe marked dirty, and definitely released. @@ -1807,20 +1822,6 @@ static void __maybe_unused undo_dev_page } } -/* - * Return the compund head page with ref appropriately incremented, - * or NULL if that failed. - */ -static inline struct page *try_get_compound_head(struct page *page, int refs) -{ - struct page *head = compound_head(page); - if (WARN_ON_ONCE(page_ref_count(head) < 0)) - return NULL; - if (unlikely(!page_cache_add_speculative(head, refs))) - return NULL; - return head; -} - #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, unsigned int flags, struct page **pages, int *nr) _
