Add orig_pte field to vm_fault structure to allow ->page_mkwrite handlers to fully handle the fault. This also allows us to save some passing of extra arguments around.
Reviewed-by: Ross Zwisler <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Signed-off-by: Jan Kara <[email protected]> --- include/linux/mm.h | 4 +-- mm/internal.h | 2 +- mm/khugepaged.c | 7 ++--- mm/memory.c | 82 +++++++++++++++++++++++++++--------------------------- 4 files changed, 47 insertions(+), 48 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index df3958437473..5cc679b874eb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -298,8 +298,8 @@ struct vm_fault { pgoff_t pgoff; /* Logical page offset based on vma */ unsigned long address; /* Faulting virtual address */ pmd_t *pmd; /* Pointer to pmd entry matching - * the 'address' - */ + * the 'address' */ + pte_t orig_pte; /* Value of PTE at the time of fault */ struct page *cow_page; /* Handler may choose to COW */ struct page *page; /* ->fault handlers should return a diff --git a/mm/internal.h b/mm/internal.h index 093b1eacc91b..44d68895a9b9 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -36,7 +36,7 @@ /* Do not use these with a slab allocator */ #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) -int do_swap_page(struct vm_fault *vmf, pte_t orig_pte); +int do_swap_page(struct vm_fault *vmf); void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long floor, unsigned long ceiling); diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d7df06383b10..1f20f25fe029 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -873,7 +873,6 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int referenced) { - pte_t pteval; int swapped_in = 0, ret = 0; struct vm_fault vmf = { .vma = vma, @@ -891,11 +890,11 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, vmf.pte = pte_offset_map(pmd, address); for (; vmf.address < address + HPAGE_PMD_NR*PAGE_SIZE; vmf.pte++, vmf.address += PAGE_SIZE) { - pteval = *vmf.pte; - if (!is_swap_pte(pteval)) + vmf.orig_pte = *vmf.pte; + if (!is_swap_pte(vmf.orig_pte)) continue; swapped_in++; - ret = do_swap_page(&vmf, pteval); + ret = do_swap_page(&vmf); /* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */ if (ret & VM_FAULT_RETRY) { diff --git a/mm/memory.c b/mm/memory.c index 372722e07659..e95e0231b746 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2074,8 +2074,8 @@ static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page, * case, all we need to do here is to mark the page as writable and update * any related book-keeping. */ -static inline int wp_page_reuse(struct vm_fault *vmf, pte_t orig_pte, - struct page *page, int page_mkwrite, int dirty_shared) +static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page, + int page_mkwrite, int dirty_shared) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; @@ -2088,8 +2088,8 @@ static inline int wp_page_reuse(struct vm_fault *vmf, pte_t orig_pte, if (page) page_cpupid_xchg_last(page, (1 << LAST_CPUPID_SHIFT) - 1); - flush_cache_page(vma, vmf->address, pte_pfn(orig_pte)); - entry = pte_mkyoung(orig_pte); + flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); + entry = pte_mkyoung(vmf->orig_pte); entry = maybe_mkwrite(pte_mkdirty(entry), vma); if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1)) update_mmu_cache(vma, vmf->address, vmf->pte); @@ -2139,8 +2139,7 @@ static inline int wp_page_reuse(struct vm_fault *vmf, pte_t orig_pte, * held to the old page, as well as updating the rmap. * - In any case, unlock the PTL and drop the reference we took to the old page. */ -static int wp_page_copy(struct vm_fault *vmf, pte_t orig_pte, - struct page *old_page) +static int wp_page_copy(struct vm_fault *vmf, struct page *old_page) { struct vm_area_struct *vma = vmf->vma; struct mm_struct *mm = vma->vm_mm; @@ -2154,7 +2153,7 @@ static int wp_page_copy(struct vm_fault *vmf, pte_t orig_pte, if (unlikely(anon_vma_prepare(vma))) goto oom; - if (is_zero_pfn(pte_pfn(orig_pte))) { + if (is_zero_pfn(pte_pfn(vmf->orig_pte))) { new_page = alloc_zeroed_user_highpage_movable(vma, vmf->address); if (!new_page) @@ -2178,7 +2177,7 @@ static int wp_page_copy(struct vm_fault *vmf, pte_t orig_pte, * Re-check the pte - we dropped the lock */ vmf->pte = pte_offset_map_lock(mm, vmf->pmd, vmf->address, &vmf->ptl); - if (likely(pte_same(*vmf->pte, orig_pte))) { + if (likely(pte_same(*vmf->pte, vmf->orig_pte))) { if (old_page) { if (!PageAnon(old_page)) { dec_mm_counter_fast(mm, @@ -2188,7 +2187,7 @@ static int wp_page_copy(struct vm_fault *vmf, pte_t orig_pte, } else { inc_mm_counter_fast(mm, MM_ANONPAGES); } - flush_cache_page(vma, vmf->address, pte_pfn(orig_pte)); + flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = mk_pte(new_page, vma->vm_page_prot); entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* @@ -2272,7 +2271,7 @@ static int wp_page_copy(struct vm_fault *vmf, pte_t orig_pte, * Handle write page faults for VM_MIXEDMAP or VM_PFNMAP for a VM_SHARED * mapping */ -static int wp_pfn_shared(struct vm_fault *vmf, pte_t orig_pte) +static int wp_pfn_shared(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; @@ -2290,16 +2289,15 @@ static int wp_pfn_shared(struct vm_fault *vmf, pte_t orig_pte) * We might have raced with another page fault while we * released the pte_offset_map_lock. */ - if (!pte_same(*vmf->pte, orig_pte)) { + if (!pte_same(*vmf->pte, vmf->orig_pte)) { pte_unmap_unlock(vmf->pte, vmf->ptl); return 0; } } - return wp_page_reuse(vmf, orig_pte, NULL, 0, 0); + return wp_page_reuse(vmf, NULL, 0, 0); } -static int wp_page_shared(struct vm_fault *vmf, pte_t orig_pte, - struct page *old_page) +static int wp_page_shared(struct vm_fault *vmf, struct page *old_page) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; @@ -2325,7 +2323,7 @@ static int wp_page_shared(struct vm_fault *vmf, pte_t orig_pte, */ vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (!pte_same(*vmf->pte, orig_pte)) { + if (!pte_same(*vmf->pte, vmf->orig_pte)) { unlock_page(old_page); pte_unmap_unlock(vmf->pte, vmf->ptl); put_page(old_page); @@ -2334,7 +2332,7 @@ static int wp_page_shared(struct vm_fault *vmf, pte_t orig_pte, page_mkwrite = 1; } - return wp_page_reuse(vmf, orig_pte, old_page, page_mkwrite, 1); + return wp_page_reuse(vmf, old_page, page_mkwrite, 1); } /* @@ -2355,13 +2353,13 @@ static int wp_page_shared(struct vm_fault *vmf, pte_t orig_pte, * but allow concurrent faults), with pte both mapped and locked. * We return with mmap_sem still held, but pte unmapped and unlocked. */ -static int do_wp_page(struct vm_fault *vmf, pte_t orig_pte) +static int do_wp_page(struct vm_fault *vmf) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; struct page *old_page; - old_page = vm_normal_page(vma, vmf->address, orig_pte); + old_page = vm_normal_page(vma, vmf->address, vmf->orig_pte); if (!old_page) { /* * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a @@ -2372,10 +2370,10 @@ static int do_wp_page(struct vm_fault *vmf, pte_t orig_pte) */ if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED)) - return wp_pfn_shared(vmf, orig_pte); + return wp_pfn_shared(vmf); pte_unmap_unlock(vmf->pte, vmf->ptl); - return wp_page_copy(vmf, orig_pte, old_page); + return wp_page_copy(vmf, old_page); } /* @@ -2390,7 +2388,7 @@ static int do_wp_page(struct vm_fault *vmf, pte_t orig_pte) lock_page(old_page); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (!pte_same(*vmf->pte, orig_pte)) { + if (!pte_same(*vmf->pte, vmf->orig_pte)) { unlock_page(old_page); pte_unmap_unlock(vmf->pte, vmf->ptl); put_page(old_page); @@ -2410,12 +2408,12 @@ static int do_wp_page(struct vm_fault *vmf, pte_t orig_pte) page_move_anon_rmap(old_page, vma); } unlock_page(old_page); - return wp_page_reuse(vmf, orig_pte, old_page, 0, 0); + return wp_page_reuse(vmf, old_page, 0, 0); } unlock_page(old_page); } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED))) { - return wp_page_shared(vmf, orig_pte, old_page); + return wp_page_shared(vmf, old_page); } /* @@ -2424,7 +2422,7 @@ static int do_wp_page(struct vm_fault *vmf, pte_t orig_pte) get_page(old_page); pte_unmap_unlock(vmf->pte, vmf->ptl); - return wp_page_copy(vmf, orig_pte, old_page); + return wp_page_copy(vmf, old_page); } static void unmap_mapping_range_vma(struct vm_area_struct *vma, @@ -2512,7 +2510,7 @@ EXPORT_SYMBOL(unmap_mapping_range); * We return with the mmap_sem locked or unlocked in the same cases * as does filemap_fault(). */ -int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) +int do_swap_page(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct page *page, *swapcache; @@ -2523,10 +2521,10 @@ int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) int exclusive = 0; int ret = 0; - if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, orig_pte)) + if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte)) goto out; - entry = pte_to_swp_entry(orig_pte); + entry = pte_to_swp_entry(vmf->orig_pte); if (unlikely(non_swap_entry(entry))) { if (is_migration_entry(entry)) { migration_entry_wait(vma->vm_mm, vmf->pmd, @@ -2534,7 +2532,7 @@ int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) } else if (is_hwpoison_entry(entry)) { ret = VM_FAULT_HWPOISON; } else { - print_bad_pte(vma, vmf->address, orig_pte, NULL); + print_bad_pte(vma, vmf->address, vmf->orig_pte, NULL); ret = VM_FAULT_SIGBUS; } goto out; @@ -2551,7 +2549,7 @@ int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) */ vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (likely(pte_same(*vmf->pte, orig_pte))) + if (likely(pte_same(*vmf->pte, vmf->orig_pte))) ret = VM_FAULT_OOM; delayacct_clear_flag(DELAYACCT_PF_SWAPIN); goto unlock; @@ -2608,7 +2606,7 @@ int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) */ vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (unlikely(!pte_same(*vmf->pte, orig_pte))) + if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) goto out_nomap; if (unlikely(!PageUptodate(page))) { @@ -2636,9 +2634,10 @@ int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) exclusive = RMAP_EXCLUSIVE; } flush_icache_page(vma, page); - if (pte_swp_soft_dirty(orig_pte)) + if (pte_swp_soft_dirty(vmf->orig_pte)) pte = pte_mksoft_dirty(pte); set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte); + vmf->orig_pte = pte; if (page == swapcache) { do_page_add_anon_rmap(page, vma, vmf->address, exclusive); mem_cgroup_commit_charge(page, memcg, true, false); @@ -2668,7 +2667,7 @@ int do_swap_page(struct vm_fault *vmf, pte_t orig_pte) } if (vmf->flags & FAULT_FLAG_WRITE) { - ret |= do_wp_page(vmf, pte); + ret |= do_wp_page(vmf); if (ret & VM_FAULT_ERROR) ret &= VM_FAULT_ERROR; goto out; @@ -3328,7 +3327,7 @@ static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, return mpol_misplaced(page, vma, addr); } -static int do_numa_page(struct vm_fault *vmf, pte_t pte) +static int do_numa_page(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct page *page = NULL; @@ -3336,6 +3335,7 @@ static int do_numa_page(struct vm_fault *vmf, pte_t pte) int last_cpupid; int target_nid; bool migrated = false; + pte_t pte = vmf->orig_pte; bool was_writable = pte_write(pte); int flags = 0; @@ -3486,8 +3486,7 @@ static int handle_pte_fault(struct vm_fault *vmf) * So now it's safe to run pte_offset_map(). */ vmf->pte = pte_offset_map(vmf->pmd, vmf->address); - - entry = *vmf->pte; + vmf->orig_pte = *vmf->pte; /* * some architectures can have larger ptes than wordsize, @@ -3498,7 +3497,7 @@ static int handle_pte_fault(struct vm_fault *vmf) * ptl lock held. So here a barrier will do. */ barrier(); - if (pte_none(entry)) { + if (pte_none(vmf->orig_pte)) { pte_unmap(vmf->pte); vmf->pte = NULL; } @@ -3511,19 +3510,20 @@ static int handle_pte_fault(struct vm_fault *vmf) return do_fault(vmf); } - if (!pte_present(entry)) - return do_swap_page(vmf, entry); + if (!pte_present(vmf->orig_pte)) + return do_swap_page(vmf); - if (pte_protnone(entry) && vma_is_accessible(vmf->vma)) - return do_numa_page(vmf, entry); + if (pte_protnone(vmf->orig_pte) && vma_is_accessible(vmf->vma)) + return do_numa_page(vmf); vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); spin_lock(vmf->ptl); + entry = vmf->orig_pte; if (unlikely(!pte_same(*vmf->pte, entry))) goto unlock; if (vmf->flags & FAULT_FLAG_WRITE) { if (!pte_write(entry)) - return do_wp_page(vmf, entry); + return do_wp_page(vmf); entry = pte_mkdirty(entry); } entry = pte_mkyoung(entry); -- 2.6.6 _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
