From: Ira Weiny <ira.weiny@xxxxxxxxx> Now that there is a mechanism for users to safely take LONGTERM pins on FS DAX pages. Remove the FS DAX exclusion from GUP with FOLL_LONGTERM. Special processing remains in effect for CONFIG_CMA --- mm/gup.c | 65 ++++++-------------------------------------------------- 1 file changed, 6 insertions(+), 59 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 1ee17f2339f7..cf6863422cb9 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1324,26 +1324,6 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, } EXPORT_SYMBOL(get_user_pages_remote); -#if defined(CONFIG_FS_DAX) || defined (CONFIG_CMA) -static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) -{ - long i; - struct vm_area_struct *vma_prev = NULL; - - for (i = 0; i < nr_pages; i++) { - struct vm_area_struct *vma = vmas[i]; - - if (vma == vma_prev) - continue; - - vma_prev = vma; - - if (vma_is_fsdax(vma)) - return true; - } - return false; -} - #ifdef CONFIG_CMA static struct page *new_non_cma_page(struct page *page, unsigned long private) { @@ -1474,18 +1454,6 @@ static long check_and_migrate_cma_pages(struct task_struct *tsk, return nr_pages; } -#else -static long check_and_migrate_cma_pages(struct task_struct *tsk, - struct mm_struct *mm, - unsigned long start, - unsigned long nr_pages, - struct page **pages, - struct vm_area_struct **vmas, - unsigned int gup_flags) -{ - return nr_pages; -} -#endif /* * __gup_longterm_locked() is a wrapper for __get_user_pages_locked which @@ -1499,49 +1467,28 @@ static long __gup_longterm_locked(struct task_struct *tsk, struct vm_area_struct **vmas, unsigned int gup_flags) { - struct vm_area_struct **vmas_tmp = vmas; unsigned long flags = 0; - long rc, i; + long rc; - if (gup_flags & FOLL_LONGTERM) { - if (!pages) - return -EINVAL; - - if (!vmas_tmp) { - vmas_tmp = kcalloc(nr_pages, - sizeof(struct vm_area_struct *), - GFP_KERNEL); - if (!vmas_tmp) - return -ENOMEM; - } + if (flags & FOLL_LONGTERM) flags = memalloc_nocma_save(); - } rc = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, - vmas_tmp, NULL, gup_flags); + vmas, NULL, gup_flags); if (gup_flags & FOLL_LONGTERM) { memalloc_nocma_restore(flags); if (rc < 0) goto out; - if (check_dax_vmas(vmas_tmp, rc)) { - for (i = 0; i < rc; i++) - put_page(pages[i]); - rc = -EOPNOTSUPP; - goto out; - } - rc = check_and_migrate_cma_pages(tsk, mm, start, rc, pages, - vmas_tmp, gup_flags); + vmas, gup_flags); } out: - if (vmas_tmp != vmas) - kfree(vmas_tmp); return rc; } -#else /* !CONFIG_FS_DAX && !CONFIG_CMA */ +#else /* !CONFIG_CMA */ static __always_inline long __gup_longterm_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, @@ -1553,7 +1500,7 @@ static __always_inline long __gup_longterm_locked(struct task_struct *tsk, return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, NULL, flags); } -#endif /* CONFIG_FS_DAX || CONFIG_CMA */ +#endif /* CONFIG_CMA */ /* * This is the same as get_user_pages_remote(), just with a -- 2.20.1