[PATCH 05/17] fs/btrfs: Convert to memzero_page()

[ira.weiny@intel.com]

From: Ira Weiny <ira.weiny@intel.com>

Remove the kmap/memset()/kunmap pattern and use the new memzero_page()
call where possible.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 fs/btrfs/inode.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index da58c58ef9aa..b0bcf9493236 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -590,17 +590,12 @@ static noinline int compress_file_range(struct async_chunk *async_chunk)
 		if (!ret) {
 			unsigned long offset = offset_in_page(total_compressed);
 			struct page *page = pages[nr_pages - 1];
-			char *kaddr;
 
 			/* zero the tail end of the last page, we might be
 			 * sending it down to disk
 			 */
-			if (offset) {
-				kaddr = kmap_atomic(page);
-				memset(kaddr + offset, 0,
-				       PAGE_SIZE - offset);
-				kunmap_atomic(kaddr);
-			}
+			if (offset)
+				memzero_page(page, offset, PAGE_SIZE - offset);
 			will_compress = 1;
 		}
 	}
@@ -6485,11 +6480,8 @@ static noinline int uncompress_inline(struct btrfs_path *path,
 	 * cover that region here.
 	 */
 
-	if (max_size + pg_offset < PAGE_SIZE) {
-		char *map = kmap(page);
-		memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
-		kunmap(page);
-	}
+	if (max_size + pg_offset < PAGE_SIZE)
+		memzero_page(page, pg_offset + max_size, PAGE_SIZE - max_size - pg_offset);
 	kfree(tmp);
 	return ret;
 }
@@ -8245,7 +8237,6 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
 	struct btrfs_ordered_extent *ordered;
 	struct extent_state *cached_state = NULL;
 	struct extent_changeset *data_reserved = NULL;
-	char *kaddr;
 	unsigned long zero_start;
 	loff_t size;
 	vm_fault_t ret;
@@ -8352,10 +8343,8 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
 		zero_start = PAGE_SIZE;
 
 	if (zero_start != PAGE_SIZE) {
-		kaddr = kmap(page);
-		memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
+		memzero_page(page, zero_start, PAGE_SIZE - zero_start);
 		flush_dcache_page(page);
-		kunmap(page);
 	}
 	ClearPageChecked(page);
 	set_page_dirty(page);
-- 
2.28.0.rc0.12.gb6a658bd00c9