Am Mi., 7. Juni 2023 um 00:48 Uhr schrieb Matthew Wilcox (Oracle)
<willy@xxxxxxxxxxxxx>:
> If any page in a folio is dirtied, dirty the entire folio. Removes a
> number of hidden calls to compound_head() and references to page->mapping
> and page->index.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> fs/buffer.c | 27 +++++++++++++--------------
> 1 file changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index d8c2c000676b..f34ed29b1085 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -2564,38 +2564,37 @@ EXPORT_SYMBOL(block_commit_write);
> int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
> get_block_t get_block)
> {
> - struct page *page = vmf->page;
> + struct folio *folio = page_folio(vmf->page);
> struct inode *inode = file_inode(vma->vm_file);
> unsigned long end;
> loff_t size;
> int ret;
>
> - lock_page(page);
> + folio_lock(folio);
> size = i_size_read(inode);
> - if ((page->mapping != inode->i_mapping) ||
> - (page_offset(page) > size)) {
> + if ((folio->mapping != inode->i_mapping) ||
> + (folio_pos(folio) > size)) {
This should probably also be 'folio_pos(folio) >= size', but this was
wrong before this patch already.
> /* We overload EFAULT to mean page got truncated */
> ret = -EFAULT;
> 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 = folio_size(folio);
> + /* folio is wholly or partially inside EOF */
> + if (folio_pos(folio) + end > size)
> + end = size - folio_pos(folio);
>
> - ret = __block_write_begin(page, 0, end, get_block);
> + ret = __block_write_begin_int(folio, 0, end, get_block, NULL);
> if (!ret)
> - ret = block_commit_write(page, 0, end);
> + ret = block_commit_write(&folio->page, 0, end);
>
> if (unlikely(ret < 0))
> goto out_unlock;
> - set_page_dirty(page);
> - wait_for_stable_page(page);
> + folio_set_dirty(folio);
> + folio_wait_stable(folio);
> return 0;
> out_unlock:
> - unlock_page(page);
> + folio_unlock(folio);
> return ret;
> }
> EXPORT_SYMBOL(block_page_mkwrite);
> --
> 2.39.2
>
Thanks,
Andreas
