Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, swap: fix race between swap count continuation operations
  mm/huge_memory.c: deposit page table when copying a PMD migration entry
  initramfs: fix initramfs rebuilds w/ compression after disabling
  fs/hugetlbfs/inode.c: fix hwpoison reserve accounting
  ocfs2: fstrim: Fix start offset of first cluster group during fstrim
  mm, /proc/pid/pagemap: fix soft dirty marking for PMD migration entry
  userfaultfd: hugetlbfs: prevent UFFDIO_COPY to fill beyond the end of i_size

8 files changed, 86 insertions, 20 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 59073e9f01a4..ed113ea17aff 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -842,9 +842,12 @@ static int hugetlbfs_error_remove_page(struct address_space *mapping,
 				struct page *page)
 {
 	struct inode *inode = mapping->host;
+	pgoff_t index = page->index;
 
 	remove_huge_page(page);
-	hugetlb_fix_reserve_counts(inode);
+	if (unlikely(hugetlb_unreserve_pages(inode, index, index + 1, 1)))
+		hugetlb_fix_reserve_counts(inode);
+
 	return 0;
 }
 
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index a177eae3aa1a..addd7c5f2d3e 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -7304,13 +7304,24 @@ out:
 
 static int ocfs2_trim_extent(struct super_block *sb,
 			     struct ocfs2_group_desc *gd,
-			     u32 start, u32 count)
+			     u64 group, u32 start, u32 count)
 {
 	u64 discard, bcount;
+	struct ocfs2_super *osb = OCFS2_SB(sb);
 
 	bcount = ocfs2_clusters_to_blocks(sb, count);
-	discard = le64_to_cpu(gd->bg_blkno) +
-			ocfs2_clusters_to_blocks(sb, start);
+	discard = ocfs2_clusters_to_blocks(sb, start);
+
+	/*
+	 * For the first cluster group, the gd->bg_blkno is not at the start
+	 * of the group, but at an offset from the start. If we add it while
+	 * calculating discard for first group, we will wrongly start fstrim a
+	 * few blocks after the desried start block and the range can cross
+	 * over into the next cluster group. So, add it only if this is not
+	 * the first cluster group.
+	 */
+	if (group != osb->first_cluster_group_blkno)
+		discard += le64_to_cpu(gd->bg_blkno);
 
 	trace_ocfs2_trim_extent(sb, (unsigned long long)discard, bcount);
 
@@ -7318,7 +7329,7 @@ static int ocfs2_trim_extent(struct super_block *sb,
 }
 
 static int ocfs2_trim_group(struct super_block *sb,
-			    struct ocfs2_group_desc *gd,
+			    struct ocfs2_group_desc *gd, u64 group,
 			    u32 start, u32 max, u32 minbits)
 {
 	int ret = 0, count = 0, next;
@@ -7337,7 +7348,7 @@ static int ocfs2_trim_group(struct super_block *sb,
 		next = ocfs2_find_next_bit(bitmap, max, start);
 
 		if ((next - start) >= minbits) {
-			ret = ocfs2_trim_extent(sb, gd,
+			ret = ocfs2_trim_extent(sb, gd, group,
 						start, next - start);
 			if (ret < 0) {
 				mlog_errno(ret);
@@ -7435,7 +7446,8 @@ int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
 		}
 
 		gd = (struct ocfs2_group_desc *)gd_bh->b_data;
-		cnt = ocfs2_trim_group(sb, gd, first_bit, last_bit, minlen);
+		cnt = ocfs2_trim_group(sb, gd, group,
+				       first_bit, last_bit, minlen);
 		brelse(gd_bh);
 		gd_bh = NULL;
 		if (cnt < 0) {
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 280282b05bc7..6744bd706ecf 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1311,13 +1311,15 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
 		pmd_t pmd = *pmdp;
 		struct page *page = NULL;
 
-		if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd))
+		if (vma->vm_flags & VM_SOFTDIRTY)
 			flags |= PM_SOFT_DIRTY;
 
 		if (pmd_present(pmd)) {
 			page = pmd_page(pmd);
 
 			flags |= PM_PRESENT;
+			if (pmd_soft_dirty(pmd))
+				flags |= PM_SOFT_DIRTY;
 			if (pm->show_pfn)
 				frame = pmd_pfn(pmd) +
 					((addr & ~PMD_MASK) >> PAGE_SHIFT);
@@ -1329,6 +1331,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
 			frame = swp_type(entry) |
 				(swp_offset(entry) << MAX_SWAPFILES_SHIFT);
 			flags |= PM_SWAP;
+			if (pmd_swp_soft_dirty(pmd))
+				flags |= PM_SOFT_DIRTY;
 			VM_BUG_ON(!is_pmd_migration_entry(pmd));
 			page = migration_entry_to_page(entry);
 		}
diff --git a/include/linux/swap.h b/include/linux/swap.h
index b489bd77bbdc..f02fb5db8914 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -266,6 +266,10 @@ struct swap_info_struct {
 					 * both locks need hold, hold swap_lock
 					 * first.
 					 */
+	spinlock_t cont_lock;		/*
+					 * protect swap count continuation page
+					 * list.
+					 */
 	struct work_struct discard_work; /* discard worker */
 	struct swap_cluster_list discard_clusters; /* discard clusters list */
 };
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 269b5df58543..1981ed697dab 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -941,6 +941,9 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 				pmd = pmd_swp_mksoft_dirty(pmd);
 			set_pmd_at(src_mm, addr, src_pmd, pmd);
 		}
+		add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
+		atomic_long_inc(&dst_mm->nr_ptes);
+		pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
 		set_pmd_at(dst_mm, addr, dst_pmd, pmd);
 		ret = 0;
 		goto out_unlock;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 424b0ef08a60..2d2ff5e8bf2b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3984,6 +3984,9 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    unsigned long src_addr,
 			    struct page **pagep)
 {
+	struct address_space *mapping;
+	pgoff_t idx;
+	unsigned long size;
 	int vm_shared = dst_vma->vm_flags & VM_SHARED;
 	struct hstate *h = hstate_vma(dst_vma);
 	pte_t _dst_pte;
@@ -4021,13 +4024,24 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 	__SetPageUptodate(page);
 	set_page_huge_active(page);
 
+	mapping = dst_vma->vm_file->f_mapping;
+	idx = vma_hugecache_offset(h, dst_vma, dst_addr);
+
 	/*
 	 * If shared, add to page cache
 	 */
 	if (vm_shared) {
-		struct address_space *mapping = dst_vma->vm_file->f_mapping;
-		pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);
+		size = i_size_read(mapping->host) >> huge_page_shift(h);
+		ret = -EFAULT;
+		if (idx >= size)
+			goto out_release_nounlock;
 
+		/*
+		 * Serialization between remove_inode_hugepages() and
+		 * huge_add_to_page_cache() below happens through the
+		 * hugetlb_fault_mutex_table that here must be hold by
+		 * the caller.
+		 */
 		ret = huge_add_to_page_cache(page, mapping, idx);
 		if (ret)
 			goto out_release_nounlock;
@@ -4036,6 +4050,20 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 	ptl = huge_pte_lockptr(h, dst_mm, dst_pte);
 	spin_lock(ptl);
 
+	/*
+	 * Recheck the i_size after holding PT lock to make sure not
+	 * to leave any page mapped (as page_mapped()) beyond the end
+	 * of the i_size (remove_inode_hugepages() is strict about
+	 * enforcing that). If we bail out here, we'll also leave a
+	 * page in the radix tree in the vm_shared case beyond the end
+	 * of the i_size, but remove_inode_hugepages() will take care
+	 * of it as soon as we drop the hugetlb_fault_mutex_table.
+	 */
+	size = i_size_read(mapping->host) >> huge_page_shift(h);
+	ret = -EFAULT;
+	if (idx >= size)
+		goto out_release_unlock;
+
 	ret = -EEXIST;
 	if (!huge_pte_none(huge_ptep_get(dst_pte)))
 		goto out_release_unlock;
diff --git a/mm/swapfile.c b/mm/swapfile.c
index bf91dc9e7a79..e47a21e64764 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2869,6 +2869,7 @@ static struct swap_info_struct *alloc_swap_info(void)
 	p->flags = SWP_USED;
 	spin_unlock(&swap_lock);
 	spin_lock_init(&p->lock);
+	spin_lock_init(&p->cont_lock);
 
 	return p;
 }
@@ -3545,6 +3546,7 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask)
 	head = vmalloc_to_page(si->swap_map + offset);
 	offset &= ~PAGE_MASK;
 
+	spin_lock(&si->cont_lock);
 	/*
 	 * Page allocation does not initialize the page's lru field,
 	 * but it does always reset its private field.
@@ -3564,7 +3566,7 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask)
 		 * a continuation page, free our allocation and use this one.
 		 */
 		if (!(count & COUNT_CONTINUED))
-			goto out;
+			goto out_unlock_cont;
 
 		map = kmap_atomic(list_page) + offset;
 		count = *map;
@@ -3575,11 +3577,13 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask)
 		 * free our allocation and use this one.
 		 */
 		if ((count & ~COUNT_CONTINUED) != SWAP_CONT_MAX)
-			goto out;
+			goto out_unlock_cont;
 	}
 
 	list_add_tail(&page->lru, &head->lru);
 	page = NULL;			/* now it's attached, don't free it */
+out_unlock_cont:
+	spin_unlock(&si->cont_lock);
 out:
 	unlock_cluster(ci);
 	spin_unlock(&si->lock);
@@ -3604,6 +3608,7 @@ static bool swap_count_continued(struct swap_info_struct *si,
 	struct page *head;
 	struct page *page;
 	unsigned char *map;
+	bool ret;
 
 	head = vmalloc_to_page(si->swap_map + offset);
 	if (page_private(head) != SWP_CONTINUED) {
@@ -3611,6 +3616,7 @@ static bool swap_count_continued(struct swap_info_struct *si,
 		return false;		/* need to add count continuation */
 	}
 
+	spin_lock(&si->cont_lock);
 	offset &= ~PAGE_MASK;
 	page = list_entry(head->lru.next, struct page, lru);
 	map = kmap_atomic(page) + offset;
@@ -3631,8 +3637,10 @@ static bool swap_count_continued(struct swap_info_struct *si,
 		if (*map == SWAP_CONT_MAX) {
 			kunmap_atomic(map);
 			page = list_entry(page->lru.next, struct page, lru);
-			if (page == head)
-				return false;	/* add count continuation */
+			if (page == head) {
+				ret = false;	/* add count continuation */
+				goto out;
+			}
 			map = kmap_atomic(page) + offset;
 init_map:		*map = 0;		/* we didn't zero the page */
 		}
@@ -3645,7 +3653,7 @@ init_map:		*map = 0;		/* we didn't zero the page */
 			kunmap_atomic(map);
 			page = list_entry(page->lru.prev, struct page, lru);
 		}
-		return true;			/* incremented */
+		ret = true;			/* incremented */
 
 	} else {				/* decrementing */
 		/*
@@ -3671,8 +3679,11 @@ init_map:		*map = 0;		/* we didn't zero the page */
 			kunmap_atomic(map);
 			page = list_entry(page->lru.prev, struct page, lru);
 		}
-		return count == COUNT_CONTINUED;
+		ret = count == COUNT_CONTINUED;
 	}
+out:
+	spin_unlock(&si->cont_lock);
+	return ret;
 }
 
 /*
diff --git a/usr/Makefile b/usr/Makefile
index 34a9fcd0f537..237a028693ce 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -8,6 +8,7 @@ PHONY += klibcdirs
 
 suffix_y = $(subst $\",,$(CONFIG_INITRAMFS_COMPRESSION))
 datafile_y = initramfs_data.cpio$(suffix_y)
+datafile_d_y = .$(datafile_y).d
 AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/$(datafile_y)"
 
 
@@ -30,12 +31,12 @@ ramfs-args  := \
         $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
         $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
 
-# .initramfs_data.cpio.d is used to identify all files included
+# $(datafile_d_y) is used to identify all files included
 # in initramfs and to detect if any files are added/removed.
 # Removed files are identified by directory timestamp being updated
 # The dependency list is generated by gen_initramfs.sh -l
-ifneq ($(wildcard $(obj)/.initramfs_data.cpio.d),)
-	include $(obj)/.initramfs_data.cpio.d
+ifneq ($(wildcard $(obj)/$(datafile_d_y)),)
+	include $(obj)/$(datafile_d_y)
 endif
 
 quiet_cmd_initfs = GEN     $@
@@ -53,5 +54,5 @@ $(deps_initramfs): klibcdirs
 # 3) If gen_init_cpio are newer than initramfs_data.cpio
 # 4) arguments to gen_initramfs.sh changes
 $(obj)/$(datafile_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
-	$(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.d
+	$(Q)$(initramfs) -l $(ramfs-input) > $(obj)/$(datafile_d_y)
 	$(call if_changed,initfs)