Re: [PATCH 15/15] ubifs: Convert populate_page() to take a folio

Zhihao Cheng
2024-01-22T12:22:49Z

在 2024/1/21 7:08, Matthew Wilcox (Oracle) 写道:
> Both callers now have a folio, so pass it in. This function contains
> several assumptions that folios are not large.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> fs/ubifs/file.c | 41 +++++++++++++++++++++--------------------
> 1 file changed, 21 insertions(+), 20 deletions(-)
>

Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>

> diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
> index dec5258b4f38..fbbd07390959 100644
> --- a/fs/ubifs/file.c
> +++ b/fs/ubifs/file.c
> @@ -592,35 +592,35 @@ static int ubifs_write_end(struct file *file, struct address_space *mapping,
> /**
> * populate_page - copy data nodes into a page for bulk-read.
> * @c: UBIFS file-system description object
> - * @page: page
> + * @folio: folio
> * @bu: bulk-read information
> * @n: next zbranch slot
> *
> * Returns: %0 on success and a negative error code on failure.
> */
> -static int populate_page(struct ubifs_info *c, struct page *page,
> +static int populate_page(struct ubifs_info *c, struct folio *folio,
> struct bu_info *bu, int *n)
> {
> int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0;
> - struct inode *inode = page->mapping->host;
> + struct inode *inode = folio->mapping->host;
> loff_t i_size = i_size_read(inode);
> unsigned int page_block;
> void *addr, *zaddr;
> pgoff_t end_index;
>
> dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
> - inode->i_ino, page->index, i_size, page->flags);
> + inode->i_ino, folio->index, i_size, folio->flags);
>
> - addr = zaddr = kmap(page);
> + addr = zaddr = kmap_local_folio(folio, 0);
>
> end_index = (i_size - 1) >> PAGE_SHIFT;
> - if (!i_size || page->index > end_index) {
> + if (!i_size || folio->index > end_index) {
> hole = 1;
> - memset(addr, 0, PAGE_SIZE);
> + addr = folio_zero_tail(folio, 0, addr);
> goto out_hole;
> }
>
> - page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
> + page_block = folio->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
> while (1) {
> int err, len, out_len, dlen;
>
> @@ -669,9 +669,13 @@ static int populate_page(struct ubifs_info *c, struct page *page,
> break;
> addr += UBIFS_BLOCK_SIZE;
> page_block += 1;
> + if (folio_test_highmem(folio) && (offset_in_page(addr) == 0)) {
> + kunmap_local(addr - UBIFS_BLOCK_SIZE);
> + addr = kmap_local_folio(folio, i * UBIFS_BLOCK_SIZE);
> + }
> }
>
> - if (end_index == page->index) {
> + if (end_index == folio->index) {
> int len = i_size & (PAGE_SIZE - 1);
>
> if (len && len < read)
> @@ -680,22 +684,19 @@ static int populate_page(struct ubifs_info *c, struct page *page,
>
> out_hole:
> if (hole) {
> - SetPageChecked(page);
> + folio_set_checked(folio);
> dbg_gen("hole");
> }
>
> - SetPageUptodate(page);
> - ClearPageError(page);
> - flush_dcache_page(page);
> - kunmap(page);
> + folio_mark_uptodate(folio);
> + flush_dcache_folio(folio);
> + kunmap_local(addr);
> *n = nn;
> return 0;
>
> out_err:
> - ClearPageUptodate(page);
> - SetPageError(page);
> - flush_dcache_page(page);
> - kunmap(page);
> + flush_dcache_folio(folio);
> + kunmap_local(addr);
> ubifs_err(c, "bad data node (block %u, inode %lu)",
> page_block, inode->i_ino);
> return -EINVAL;
> @@ -763,7 +764,7 @@ static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
> goto out_warn;
> }
>
> - err = populate_page(c, &folio1->page, bu, &n);
> + err = populate_page(c, folio1, bu, &n);
> if (err)
> goto out_warn;
>
> @@ -787,7 +788,7 @@ static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
> if (IS_ERR(folio))
> break;
> if (!folio_test_uptodate(folio))
> - err = populate_page(c, &folio->page, bu, &n);
> + err = populate_page(c, folio, bu, &n);
> folio_unlock(folio);
> folio_put(folio);
> if (err)