[PATCHv6 26/37] ext4: handle huge pages in ext4_page_mkwrite()

Kirill A. Shutemov
2017-01-26T11:58:08Z

Trivial: remove assumption on page size.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
fs/ext4/inode.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8d1b5e63cb15..a25be1cf4506 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5778,7 +5778,7 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)

int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
- struct page *page = vmf->page;
+ struct page *page = compound_head(vmf->page);
loff_t size;
unsigned long len;
int ret;
@@ -5814,10 +5814,10 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
goto out;
}

- if (page->index == size >> PAGE_SHIFT)
- len = size & ~PAGE_MASK;
- else
- len = PAGE_SIZE;
+ len = hpage_size(page);
+ if (page->index + hpage_nr_pages(page) - 1 == size >> PAGE_SHIFT)
+ len = size & ~hpage_mask(page);
+
/*
* Return if we have all the buffers mapped. This avoids the need to do
* journal_start/journal_stop which can block and take a long time
@@ -5848,7 +5848,8 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
ret = block_page_mkwrite(vma, vmf, get_block);
if (!ret && ext4_should_journal_data(inode)) {
if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_SIZE, NULL, do_journal_get_write_access)) {
+ hpage_size(page), NULL,
+ do_journal_get_write_access)) {
unlock_page(page);
ret = VM_FAULT_SIGBUS;
ext4_journal_stop(handle);