[PATCH] zero_user_page conversion

Eric Sandeen
2007-06-20T22:08:49Z

Use zero_user_page() in cifs, ocfs2, ext4, and gfs2 where possible.

Compile tested, reviews welcome.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Index: linux-2.6.22-rc4-mm2/fs/cifs/inode.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/fs/cifs/inode.c
+++ linux-2.6.22-rc4-mm2/fs/cifs/inode.c
@@ -1334,17 +1334,13 @@ static int cifs_truncate_page(struct add
pgoff_t index = from >> PAGE_CACHE_SHIFT;
unsigned offset = from & (PAGE_CACHE_SIZE - 1);
struct page *page;
- char *kaddr;
int rc = 0;

page = grab_cache_page(mapping, index);
if (!page)
return -ENOMEM;

- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_page(page, offset, PAGE_CACHE_SIZE - offset, KM_USER0);
unlock_page(page);
page_cache_release(page);
return rc;
Index: linux-2.6.22-rc4-mm2/fs/ext4/inode.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/fs/ext4/inode.c
+++ linux-2.6.22-rc4-mm2/fs/ext4/inode.c
@@ -1830,7 +1830,6 @@ int ext4_block_truncate_page(handle_t *h
struct inode *inode = mapping->host;
struct buffer_head *bh;
int err = 0;
- void *kaddr;

if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) &&
test_opt(inode->i_sb, EXTENTS) &&
@@ -1847,10 +1846,7 @@ int ext4_block_truncate_page(handle_t *h
*/
if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
ext4_should_writeback_data(inode) && PageUptodate(page)) {
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, 0, length);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_page(page, offset, length, KM_USER0);
set_page_dirty(page);
goto unlock;
}
@@ -1903,10 +1899,7 @@ int ext4_block_truncate_page(handle_t *h
goto unlock;
}

- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, 0, length);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_page(page, offset, length, KM_USER0);

BUFFER_TRACE(bh, "zeroed end of block");

Index: linux-2.6.22-rc4-mm2/fs/gfs2/ops_address.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/fs/gfs2/ops_address.c
+++ linux-2.6.22-rc4-mm2/fs/gfs2/ops_address.c
@@ -207,10 +207,7 @@ static int stuffed_readpage(struct gfs2_
* so we need to supply one here. It doesn't happen often.
*/
if (unlikely(page->index)) {
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr, 0, PAGE_CACHE_SIZE);
- kunmap_atomic(kaddr, KM_USER0);
- flush_dcache_page(page);
+ zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
SetPageUptodate(page);
return 0;
}
Index: linux-2.6.22-rc4-mm2/fs/ocfs2/aops.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/fs/ocfs2/aops.c
+++ linux-2.6.22-rc4-mm2/fs/ocfs2/aops.c
@@ -739,18 +739,13 @@ int ocfs2_map_page_blocks(struct page *p
bh = head;
block_start = 0;
do {
- void *kaddr;
-
block_end = block_start + bsize;
if (block_end <= from)
goto next_bh;
if (block_start >= to)
break;

- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr+block_start, 0, bh->b_size);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_page(page, block_start, bh->b_size, KM_USER0);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);

@@ -895,15 +890,11 @@ static void ocfs2_zero_new_buffers(struc
if (block_end > from && block_start < to) {
if (!PageUptodate(page)) {
unsigned start, end;
- void *kaddr;

start = max(from, block_start);
end = min(to, block_end);

- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr+start, 0, end - start);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_page(page, start, end - start, KM_USER0);
set_buffer_uptodate(bh);
}