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

[ira . weiny]

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

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

Cc: Chris Mason <c...@fb.com>
Cc: Josef Bacik <jo...@toxicpanda.com>
Cc: David Sterba <dste...@suse.com>
Signed-off-by: Ira Weiny <ira.we...@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