[PATCHv6 27/37] ext4: handle huge pages in __ext4_block_zero_page_range()

Kirill A. Shutemov
2017-01-26T11:58:09Z

As the function handles zeroing range only within one block, the
required changes are trivial, just remove assuption on page size.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
fs/ext4/inode.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index a25be1cf4506..7e65a5b78cf1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3785,7 +3785,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
struct address_space *mapping, loff_t from, loff_t length)
{
ext4_fsblk_t index = from >> PAGE_SHIFT;
- unsigned offset = from & (PAGE_SIZE-1);
+ unsigned offset;
unsigned blocksize, pos;
ext4_lblk_t iblock;
struct inode *inode = mapping->host;
@@ -3798,6 +3798,9 @@ static int __ext4_block_zero_page_range(handle_t *handle,
if (!page)
return -ENOMEM;

+ page = compound_head(page);
+ offset = from & ~hpage_mask(page);
+
blocksize = inode->i_sb->s_blocksize;

iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
@@ -3853,7 +3856,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
if (err)
goto unlock;
}
- zero_user(page, offset, length);
+ zero_user(page + offset / PAGE_SIZE, offset % PAGE_SIZE, length);
BUFFER_TRACE(bh, "zeroed end of block");

if (ext4_should_journal_data(inode)) {