Use the "page has been truncated" logic in page_mkwrite_check_truncate instead of reimplementing it here. Other than with the existing code, fail with -EFAULT / VM_FAULT_NOPAGE when page_offset(page) == size here as well, as should be expected. Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> --- fs/buffer.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index b8d28370cfd7..31a9a02878a2 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2499,23 +2499,13 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, struct page *page = vmf->page; struct inode *inode = file_inode(vma->vm_file); unsigned long end; - loff_t size; int ret; lock_page(page); - size = i_size_read(inode); - if ((page->mapping != inode->i_mapping) || - (page_offset(page) > size)) { - /* We overload EFAULT to mean page got truncated */ - ret = -EFAULT; + ret = page_mkwrite_check_truncate(page, inode); + if (ret < 0) goto out_unlock; - } - - /* page is wholly or partially inside EOF */ - if (((page->index + 1) << PAGE_SHIFT) > size) - end = size & ~PAGE_MASK; - else - end = PAGE_SIZE; + end = ret; ret = __block_write_begin(page, 0, end, get_block); if (!ret) -- 2.24.1