Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:
 "Incoming:

   - a small number of updates to scripts/, ocfs2 and fs/buffer.c

   - most of MM

  I still have quite a lot of material (mostly not MM) staged after
  linux-next due to -next dependencies. I'll send those across next week
  as the preprequisites get merged up"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits)
  mm/page_io.c: annotate refault stalls from swap_readpage
  mm/Kconfig: fix trivial help text punctuation
  mm/Kconfig: fix indentation
  mm/memory_hotplug.c: remove __online_page_set_limits()
  mm: fix typos in comments when calling __SetPageUptodate()
  mm: fix struct member name in function comments
  mm/shmem.c: cast the type of unmap_start to u64
  mm: shmem: use proper gfp flags for shmem_writepage()
  mm/shmem.c: make array 'values' static const, makes object smaller
  userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK
  fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()
  userfaultfd: wrap the common dst_vma check into an inlined function
  userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb()
  userfaultfd: use vma_pagesize for all huge page size calculation
  mm/madvise.c: use PAGE_ALIGN[ED] for range checking
  mm/madvise.c: replace with page_size() in madvise_inject_error()
  mm/mmap.c: make vma_merge() comment more easy to understand
  mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops
  autonuma: reduce cache footprint when scanning page tables
  autonuma: fix watermark checking in migrate_balanced_pgdat()
  ...

3 files changed, 16 insertions, 29 deletions

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 84c4e1f72cbd..799b43191dea 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -19,15 +19,12 @@
 #include <linux/memory.h>
 #include <linux/memory_hotplug.h>
 #include <linux/mm.h>
-#include <linux/mutex.h>
 #include <linux/stat.h>
 #include <linux/slab.h>
 
 #include <linux/atomic.h>
 #include <linux/uaccess.h>
 
-static DEFINE_MUTEX(mem_sysfs_mutex);
-
 #define MEMORY_CLASS_NAME	"memory"
 
 #define to_memory_block(dev) container_of(dev, struct memory_block, dev)
@@ -538,12 +535,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
 	if (kstrtoull(buf, 0, &pfn) < 0)
 		return -EINVAL;
 	pfn >>= PAGE_SHIFT;
-	if (!pfn_valid(pfn))
-		return -ENXIO;
-	/* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
-	if (!pfn_to_online_page(pfn))
-		return -EIO;
-	ret = soft_offline_page(pfn_to_page(pfn), 0);
+	ret = soft_offline_page(pfn, 0);
 	return ret == 0 ? count : ret;
 }
 
@@ -705,6 +697,8 @@ static void unregister_memory(struct memory_block *memory)
  * Create memory block devices for the given memory area. Start and size
  * have to be aligned to memory block granularity. Memory block devices
  * will be initialized as offline.
+ *
+ * Called under device_hotplug_lock.
  */
 int create_memory_block_devices(unsigned long start, unsigned long size)
 {
@@ -718,7 +712,6 @@ int create_memory_block_devices(unsigned long start, unsigned long size)
 			 !IS_ALIGNED(size, memory_block_size_bytes())))
 		return -EINVAL;
 
-	mutex_lock(&mem_sysfs_mutex);
 	for (block_id = start_block_id; block_id != end_block_id; block_id++) {
 		ret = init_memory_block(&mem, block_id, MEM_OFFLINE);
 		if (ret)
@@ -730,11 +723,12 @@ int create_memory_block_devices(unsigned long start, unsigned long size)
 		for (block_id = start_block_id; block_id != end_block_id;
 		     block_id++) {
 			mem = find_memory_block_by_id(block_id);
+			if (WARN_ON_ONCE(!mem))
+				continue;
 			mem->section_count = 0;
 			unregister_memory(mem);
 		}
 	}
-	mutex_unlock(&mem_sysfs_mutex);
 	return ret;
 }
 
@@ -742,6 +736,8 @@ int create_memory_block_devices(unsigned long start, unsigned long size)
  * Remove memory block devices for the given memory area. Start and size
  * have to be aligned to memory block granularity. Memory block devices
  * have to be offline.
+ *
+ * Called under device_hotplug_lock.
  */
 void remove_memory_block_devices(unsigned long start, unsigned long size)
 {
@@ -754,7 +750,6 @@ void remove_memory_block_devices(unsigned long start, unsigned long size)
 			 !IS_ALIGNED(size, memory_block_size_bytes())))
 		return;
 
-	mutex_lock(&mem_sysfs_mutex);
 	for (block_id = start_block_id; block_id != end_block_id; block_id++) {
 		mem = find_memory_block_by_id(block_id);
 		if (WARN_ON_ONCE(!mem))
@@ -763,7 +758,6 @@ void remove_memory_block_devices(unsigned long start, unsigned long size)
 		unregister_memory_block_under_nodes(mem);
 		unregister_memory(mem);
 	}
-	mutex_unlock(&mem_sysfs_mutex);
 }
 
 /* return true if the memory block is offlined, otherwise, return false */
@@ -797,12 +791,13 @@ static const struct attribute_group *memory_root_attr_groups[] = {
 };
 
 /*
- * Initialize the sysfs support for memory devices...
+ * Initialize the sysfs support for memory devices. At the time this function
+ * is called, we cannot have concurrent creation/deletion of memory block
+ * devices, the device_hotplug_lock is not needed.
  */
 void __init memory_dev_init(void)
 {
 	int ret;
-	int err;
 	unsigned long block_sz, nr;
 
 	/* Validate the configured memory block size */
@@ -813,24 +808,19 @@ void __init memory_dev_init(void)
 
 	ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
 	if (ret)
-		goto out;
+		panic("%s() failed to register subsystem: %d\n", __func__, ret);
 
 	/*
 	 * Create entries for memory sections that were found
 	 * during boot and have been initialized
 	 */
-	mutex_lock(&mem_sysfs_mutex);
 	for (nr = 0; nr <= __highest_present_section_nr;
 	     nr += sections_per_block) {
-		err = add_memory_block(nr);
-		if (!ret)
-			ret = err;
+		ret = add_memory_block(nr);
+		if (ret)
+			panic("%s() failed to add memory block: %d\n", __func__,
+			      ret);
 	}
-	mutex_unlock(&mem_sysfs_mutex);
-
-out:
-	if (ret)
-		panic("%s() failed: %d\n", __func__, ret);
 }
 
 /**
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 7f4cf4fc805e..b155d0052981 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -682,9 +682,7 @@ static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
 		__ClearPageOffline(pg);
 
 	/* This frame is currently backed; online the page. */
-	__online_page_set_limits(pg);
-	__online_page_increment_counters(pg);
-	__online_page_free(pg);
+	generic_online_page(pg, 0);
 
 	lockdep_assert_held(&dm_device.ha_lock);
 	dm_device.num_pages_onlined++;
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 5bae515c8e25..4f2e78a5e4db 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -374,7 +374,6 @@ static void xen_online_page(struct page *page, unsigned int order)
 	mutex_lock(&balloon_mutex);
 	for (i = 0; i < size; i++) {
 		p = pfn_to_page(start_pfn + i);
-		__online_page_set_limits(p);
 		balloon_append(p);
 	}
 	mutex_unlock(&balloon_mutex);