Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...

9 files changed, 26 insertions, 18 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 76ce0cc3ee4e..1f32da13d39e 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -323,13 +323,16 @@ static void aio_free_ring(struct kioctx *ctx)
 	}
 }
 
-static int aio_ring_mremap(struct vm_area_struct *vma)
+static int aio_ring_mremap(struct vm_area_struct *vma, unsigned long flags)
 {
 	struct file *file = vma->vm_file;
 	struct mm_struct *mm = vma->vm_mm;
 	struct kioctx_table *table;
 	int i, res = -EINVAL;
 
+	if (flags & MREMAP_DONTUNMAP)
+		return -EINVAL;
+
 	spin_lock(&mm->ioctx_lock);
 	rcu_read_lock();
 	table = rcu_dereference(mm->ioctx_table);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index f42967b738eb..e5aab265dff1 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -323,7 +323,7 @@ static ssize_t ntfs_prepare_file_for_write(struct kiocb *iocb,
 	unsigned long flags;
 	struct file *file = iocb->ki_filp;
 	struct inode *vi = file_inode(file);
-	ntfs_inode *base_ni, *ni = NTFS_I(vi);
+	ntfs_inode *ni = NTFS_I(vi);
 	ntfs_volume *vol = ni->vol;
 
 	ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
@@ -365,9 +365,6 @@ static ssize_t ntfs_prepare_file_for_write(struct kiocb *iocb,
 		err = -EOPNOTSUPP;
 		goto out;
 	}
-	base_ni = ni;
-	if (NInoAttr(ni))
-		base_ni = ni->ext.base_ntfs_ino;
 	err = file_remove_privs(file);
 	if (unlikely(err))
 		goto out;
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index caf563981532..f7e4cbc26eaf 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -2347,7 +2347,6 @@ int ntfs_truncate(struct inode *vi)
 	ATTR_RECORD *a;
 	const char *te = "  Leaving file length out of sync with i_size.";
 	int err, mp_size, size_change, alloc_change;
-	u32 attr_len;
 
 	ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
 	BUG_ON(NInoAttr(ni));
@@ -2721,7 +2720,6 @@ do_non_resident_truncate:
 	 * this cannot fail since we are making the attribute smaller thus by
 	 * definition there is enough space to do so.
 	 */
-	attr_len = le32_to_cpu(a->length);
 	err = ntfs_attr_record_resize(m, a, mp_size +
 			le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
 	BUG_ON(err);
diff --git a/fs/ntfs/logfile.c b/fs/ntfs/logfile.c
index a0c40f1be7ac..bc1bf217b38e 100644
--- a/fs/ntfs/logfile.c
+++ b/fs/ntfs/logfile.c
@@ -478,7 +478,7 @@ bool ntfs_check_logfile(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
 	u8 *kaddr = NULL;
 	RESTART_PAGE_HEADER *rstr1_ph = NULL;
 	RESTART_PAGE_HEADER *rstr2_ph = NULL;
-	int log_page_size, log_page_mask, err;
+	int log_page_size, err;
 	bool logfile_is_empty = true;
 	u8 log_page_bits;
 
@@ -501,7 +501,6 @@ bool ntfs_check_logfile(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
 		log_page_size = DefaultLogPageSize;
 	else
 		log_page_size = PAGE_SIZE;
-	log_page_mask = log_page_size - 1;
 	/*
 	 * Use ntfs_ffs() instead of ffs() to enable the compiler to
 	 * optimize log_page_size and log_page_bits into constants.
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index 79a231719460..3bd8119bed5e 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -1198,7 +1198,6 @@ static int o2net_process_message(struct o2net_sock_container *sc,
 			msglog(hdr, "bad magic\n");
 			ret = -EINVAL;
 			goto out;
-			break;
 	}
 
 	/* find a handler for it */
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index c46bf7f581a1..2a237ab00453 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1088,8 +1088,8 @@ static int ocfs2_check_if_ancestor(struct ocfs2_super *osb,
 		child_inode_no = parent_inode_no;
 
 		if (++i >= MAX_LOOKUP_TIMES) {
-			mlog(ML_NOTICE, "max lookup times reached, filesystem "
-					"may have nested directories, "
+			mlog_ratelimited(ML_NOTICE, "max lookup times reached, "
+					"filesystem may have nested directories, "
 					"src inode: %llu, dest inode: %llu.\n",
 					(unsigned long long)src_inode_no,
 					(unsigned long long)dest_inode_no);
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index e502414b3556..4d2e64e9016c 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -193,8 +193,6 @@ kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
 		return 1;
 
 	p = pfn_to_page(pfn);
-	if (!memmap_valid_within(pfn, p, page_zone(p)))
-		return 1;
 
 	ent = kmalloc(sizeof(*ent), GFP_KERNEL);
 	if (!ent)
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 887a5532e449..d6fc74619625 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -107,7 +107,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 		   global_node_page_state(NR_KERNEL_SCS_KB));
 #endif
 	show_val_kb(m, "PageTables:     ",
-		    global_zone_page_state(NR_PAGETABLE));
+		    global_node_page_state(NR_PAGETABLE));
 
 	show_val_kb(m, "NFS_Unstable:   ", 0);
 	show_val_kb(m, "Bounce:         ",
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 000b457ad087..894cc28142e7 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -28,7 +28,7 @@
 #include <linux/security.h>
 #include <linux/hugetlb.h>
 
-int sysctl_unprivileged_userfaultfd __read_mostly = 1;
+int sysctl_unprivileged_userfaultfd __read_mostly;
 
 static struct kmem_cache *userfaultfd_ctx_cachep __read_mostly;
 
@@ -405,6 +405,13 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 
 	if (ctx->features & UFFD_FEATURE_SIGBUS)
 		goto out;
+	if ((vmf->flags & FAULT_FLAG_USER) == 0 &&
+	    ctx->flags & UFFD_USER_MODE_ONLY) {
+		printk_once(KERN_WARNING "uffd: Set unprivileged_userfaultfd "
+			"sysctl knob to 1 if kernel faults must be handled "
+			"without obtaining CAP_SYS_PTRACE capability\n");
+		goto out;
+	}
 
 	/*
 	 * If it's already released don't get it. This avoids to loop
@@ -1959,16 +1966,23 @@ SYSCALL_DEFINE1(userfaultfd, int, flags)
 	struct userfaultfd_ctx *ctx;
 	int fd;
 
-	if (!sysctl_unprivileged_userfaultfd && !capable(CAP_SYS_PTRACE))
+	if (!sysctl_unprivileged_userfaultfd &&
+	    (flags & UFFD_USER_MODE_ONLY) == 0 &&
+	    !capable(CAP_SYS_PTRACE)) {
+		printk_once(KERN_WARNING "uffd: Set unprivileged_userfaultfd "
+			"sysctl knob to 1 if kernel faults must be handled "
+			"without obtaining CAP_SYS_PTRACE capability\n");
 		return -EPERM;
+	}
 
 	BUG_ON(!current->mm);
 
 	/* Check the UFFD_* constants for consistency.  */
+	BUILD_BUG_ON(UFFD_USER_MODE_ONLY & UFFD_SHARED_FCNTL_FLAGS);
 	BUILD_BUG_ON(UFFD_CLOEXEC != O_CLOEXEC);
 	BUILD_BUG_ON(UFFD_NONBLOCK != O_NONBLOCK);
 
-	if (flags & ~UFFD_SHARED_FCNTL_FLAGS)
+	if (flags & ~(UFFD_SHARED_FCNTL_FLAGS | UFFD_USER_MODE_ONLY))
 		return -EINVAL;
 
 	ctx = kmem_cache_alloc(userfaultfd_ctx_cachep, GFP_KERNEL);