1 files changed, 38 insertions, 24 deletions

diff --git a/fs/dax.c b/fs/dax.c
index a7f77e1fa18c..57bb70b4af70 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -23,6 +23,7 @@
 #include <linux/memcontrol.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
+#include <linux/pmem.h>
 #include <linux/sched.h>
 #include <linux/uio.h>
 #include <linux/vmstat.h>
@@ -34,7 +35,7 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size)
 
 	might_sleep();
 	do {
-		void *addr;
+		void __pmem *addr;
 		unsigned long pfn;
 		long count;
 
@@ -46,10 +47,7 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size)
 			unsigned pgsz = PAGE_SIZE - offset_in_page(addr);
 			if (pgsz > count)
 				pgsz = count;
-			if (pgsz < PAGE_SIZE)
-				memset(addr, 0, pgsz);
-			else
-				clear_page(addr);
+			clear_pmem(addr, pgsz);
 			addr += pgsz;
 			size -= pgsz;
 			count -= pgsz;
@@ -59,26 +57,29 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size)
 		}
 	} while (size);
 
+	wmb_pmem();
 	return 0;
 }
 EXPORT_SYMBOL_GPL(dax_clear_blocks);
 
-static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits)
+static long dax_get_addr(struct buffer_head *bh, void __pmem **addr,
+		unsigned blkbits)
 {
 	unsigned long pfn;
 	sector_t sector = bh->b_blocknr << (blkbits - 9);
 	return bdev_direct_access(bh->b_bdev, sector, addr, &pfn, bh->b_size);
 }
 
-static void dax_new_buf(void *addr, unsigned size, unsigned first, loff_t pos,
-			loff_t end)
+/* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */
+static void dax_new_buf(void __pmem *addr, unsigned size, unsigned first,
+		loff_t pos, loff_t end)
 {
 	loff_t final = end - pos + first; /* The final byte of the buffer */
 
 	if (first > 0)
-		memset(addr, 0, first);
+		clear_pmem(addr, first);
 	if (final < size)
-		memset(addr + final, 0, size - final);
+		clear_pmem(addr + final, size - final);
 }
 
 static bool buffer_written(struct buffer_head *bh)
@@ -106,14 +107,15 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 	loff_t pos = start;
 	loff_t max = start;
 	loff_t bh_max = start;
-	void *addr;
+	void __pmem *addr;
 	bool hole = false;
+	bool need_wmb = false;
 
 	if (iov_iter_rw(iter) != WRITE)
 		end = min(end, i_size_read(inode));
 
 	while (pos < end) {
-		unsigned len;
+		size_t len;
 		if (pos == max) {
 			unsigned blkbits = inode->i_blkbits;
 			sector_t block = pos >> blkbits;
@@ -145,19 +147,23 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 				retval = dax_get_addr(bh, &addr, blkbits);
 				if (retval < 0)
 					break;
-				if (buffer_unwritten(bh) || buffer_new(bh))
+				if (buffer_unwritten(bh) || buffer_new(bh)) {
 					dax_new_buf(addr, retval, first, pos,
 									end);
+					need_wmb = true;
+				}
 				addr += first;
 				size = retval - first;
 			}
 			max = min(pos + size, end);
 		}
 
-		if (iov_iter_rw(iter) == WRITE)
-			len = copy_from_iter_nocache(addr, max - pos, iter);
-		else if (!hole)
-			len = copy_to_iter(addr, max - pos, iter);
+		if (iov_iter_rw(iter) == WRITE) {
+			len = copy_from_iter_pmem(addr, max - pos, iter);
+			need_wmb = true;
+		} else if (!hole)
+			len = copy_to_iter((void __force *)addr, max - pos,
+					iter);
 		else
 			len = iov_iter_zero(max - pos, iter);
 
@@ -168,6 +174,9 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 		addr += len;
 	}
 
+	if (need_wmb)
+		wmb_pmem();
+
 	return (pos == start) ? retval : pos - start;
 }
 
@@ -260,11 +269,13 @@ static int dax_load_hole(struct address_space *mapping, struct page *page,
 static int copy_user_bh(struct page *to, struct buffer_head *bh,
 			unsigned blkbits, unsigned long vaddr)
 {
-	void *vfrom, *vto;
+	void __pmem *vfrom;
+	void *vto;
+
 	if (dax_get_addr(bh, &vfrom, blkbits) < 0)
 		return -EIO;
 	vto = kmap_atomic(to);
-	copy_user_page(vto, vfrom, vaddr, to);
+	copy_user_page(vto, (void __force *)vfrom, vaddr, to);
 	kunmap_atomic(vto);
 	return 0;
 }
@@ -275,7 +286,7 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh,
 	struct address_space *mapping = inode->i_mapping;
 	sector_t sector = bh->b_blocknr << (inode->i_blkbits - 9);
 	unsigned long vaddr = (unsigned long)vmf->virtual_address;
-	void *addr;
+	void __pmem *addr;
 	unsigned long pfn;
 	pgoff_t size;
 	int error;
@@ -303,8 +314,10 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh,
 		goto out;
 	}
 
-	if (buffer_unwritten(bh) || buffer_new(bh))
-		clear_page(addr);
+	if (buffer_unwritten(bh) || buffer_new(bh)) {
+		clear_pmem(addr, PAGE_SIZE);
+		wmb_pmem();
+	}
 
 	error = vm_insert_mixed(vma, vaddr, pfn);
 
@@ -548,11 +561,12 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length,
 	if (err < 0)
 		return err;
 	if (buffer_written(&bh)) {
-		void *addr;
+		void __pmem *addr;
 		err = dax_get_addr(&bh, &addr, inode->i_blkbits);
 		if (err < 0)
 			return err;
-		memset(addr + offset, 0, length);
+		clear_pmem(addr + offset, length);
+		wmb_pmem();
 	}
 
 	return 0;