From f5cc4eef9987d0b517364d01e290d6438e47ee5d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 5 Mar 2012 14:14:20 -0500 Subject: VM: make zap_page_range() callers that act on a single VMA use separate helper ... and not rely on ->vm_next being there for them... Signed-off-by: Al Viro --- mm/memory.c | 113 +++++++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 74 insertions(+), 39 deletions(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index 016c67587ef4..8ab09188360a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1307,6 +1307,47 @@ static void unmap_page_range(struct mmu_gather *tlb, mem_cgroup_uncharge_end(); } + +static void unmap_single_vma(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long start_addr, + unsigned long end_addr, unsigned long *nr_accounted, + struct zap_details *details) +{ + unsigned long start = max(vma->vm_start, start_addr); + unsigned long end; + + if (start >= vma->vm_end) + return; + end = min(vma->vm_end, end_addr); + if (end <= vma->vm_start) + return; + + if (vma->vm_flags & VM_ACCOUNT) + *nr_accounted += (end - start) >> PAGE_SHIFT; + + if (unlikely(is_pfn_mapping(vma))) + untrack_pfn_vma(vma, 0, 0); + + if (start != end) { + if (unlikely(is_vm_hugetlb_page(vma))) { + /* + * It is undesirable to test vma->vm_file as it + * should be non-null for valid hugetlb area. + * However, vm_file will be NULL in the error + * cleanup path of do_mmap_pgoff. When + * hugetlbfs ->mmap method fails, + * do_mmap_pgoff() nullifies vma->vm_file + * before calling this function to clean up. + * Since no pte has actually been setup, it is + * safe to do nothing in this case. + */ + if (vma->vm_file) + unmap_hugepage_range(vma, start, end, NULL); + } else + unmap_page_range(tlb, vma, start, end, details); + } +} + /** * unmap_vmas - unmap a range of memory covered by a list of vma's * @tlb: address of the caller's struct mmu_gather @@ -1332,46 +1373,12 @@ void unmap_vmas(struct mmu_gather *tlb, unsigned long end_addr, unsigned long *nr_accounted, struct zap_details *details) { - unsigned long start = start_addr; struct mm_struct *mm = vma->vm_mm; mmu_notifier_invalidate_range_start(mm, start_addr, end_addr); - for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) { - unsigned long end; - - start = max(vma->vm_start, start_addr); - if (start >= vma->vm_end) - continue; - end = min(vma->vm_end, end_addr); - if (end <= vma->vm_start) - continue; - - if (vma->vm_flags & VM_ACCOUNT) - *nr_accounted += (end - start) >> PAGE_SHIFT; - - if (unlikely(is_pfn_mapping(vma))) - untrack_pfn_vma(vma, 0, 0); - - if (start != end) { - if (unlikely(is_vm_hugetlb_page(vma))) { - /* - * It is undesirable to test vma->vm_file as it - * should be non-null for valid hugetlb area. - * However, vm_file will be NULL in the error - * cleanup path of do_mmap_pgoff. When - * hugetlbfs ->mmap method fails, - * do_mmap_pgoff() nullifies vma->vm_file - * before calling this function to clean up. - * Since no pte has actually been setup, it is - * safe to do nothing in this case. - */ - if (vma->vm_file) - unmap_hugepage_range(vma, start, end, NULL); - } else - unmap_page_range(tlb, vma, start, end, details); - } - } - + for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) + unmap_single_vma(tlb, vma, start_addr, end_addr, nr_accounted, + details); mmu_notifier_invalidate_range_end(mm, start_addr, end_addr); } @@ -1381,6 +1388,8 @@ void unmap_vmas(struct mmu_gather *tlb, * @address: starting address of pages to zap * @size: number of bytes to zap * @details: details of nonlinear truncation or shared cache invalidation + * + * Caller must protect the VMA list */ void zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *details) @@ -1397,6 +1406,32 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long address, tlb_finish_mmu(&tlb, address, end); } +/** + * zap_page_range_single - remove user pages in a given range + * @vma: vm_area_struct holding the applicable pages + * @address: starting address of pages to zap + * @size: number of bytes to zap + * @details: details of nonlinear truncation or shared cache invalidation + * + * The range must fit into one VMA. + */ +static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address, + unsigned long size, struct zap_details *details) +{ + struct mm_struct *mm = vma->vm_mm; + struct mmu_gather tlb; + unsigned long end = address + size; + unsigned long nr_accounted = 0; + + lru_add_drain(); + tlb_gather_mmu(&tlb, mm, 0); + update_hiwater_rss(mm); + mmu_notifier_invalidate_range_start(mm, address, end); + unmap_single_vma(&tlb, vma, address, end, &nr_accounted, details); + mmu_notifier_invalidate_range_end(mm, address, end); + tlb_finish_mmu(&tlb, address, end); +} + /** * zap_vma_ptes - remove ptes mapping the vma * @vma: vm_area_struct holding ptes to be zapped @@ -1415,7 +1450,7 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, if (address < vma->vm_start || address + size > vma->vm_end || !(vma->vm_flags & VM_PFNMAP)) return -1; - zap_page_range(vma, address, size, NULL); + zap_page_range_single(vma, address, size, NULL); return 0; } EXPORT_SYMBOL_GPL(zap_vma_ptes); @@ -2762,7 +2797,7 @@ static void unmap_mapping_range_vma(struct vm_area_struct *vma, unsigned long start_addr, unsigned long end_addr, struct zap_details *details) { - zap_page_range(vma, start_addr, end_addr - start_addr, details); + zap_page_range_single(vma, start_addr, end_addr - start_addr, details); } static inline void unmap_mapping_range_tree(struct prio_tree_root *root, -- cgit v1.2.3-55-g7522