On 2024/5/31 11:29, Matthew Wilcox (Oracle) wrote:
> Nobody checks the error flag any more, so setting it accomplishes
> nothing. Remove the obsolete parts of this comment; it hasn't
> been true since errseq_t was used to track writeback errors in 2017.
>
> Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> Cc: linux-mm@xxxxxxxxx
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Acked-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Thanks.
.
> ---
> mm/memory-failure.c | 29 -----------------------------
> 1 file changed, 29 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index ac030061eda0..78fdf5ee8421 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1112,7 +1112,6 @@ static int me_pagecache_dirty(struct page_state *ps, struct page *p)
> struct folio *folio = page_folio(p);
> struct address_space *mapping = folio_mapping(folio);
>
> - SetPageError(p);
> /* TBD: print more information about the file. */
> if (mapping) {
> /*
> @@ -1120,34 +1119,6 @@ static int me_pagecache_dirty(struct page_state *ps, struct page *p)
> * who check the mapping.
> * This way the application knows that something went
> * wrong with its dirty file data.
> - *
> - * There's one open issue:
> - *
> - * The EIO will be only reported on the next IO
> - * operation and then cleared through the IO map.
> - * Normally Linux has two mechanisms to pass IO error
> - * first through the AS_EIO flag in the address space
> - * and then through the PageError flag in the page.
> - * Since we drop pages on memory failure handling the
> - * only mechanism open to use is through AS_AIO.
> - *
> - * This has the disadvantage that it gets cleared on
> - * the first operation that returns an error, while
> - * the PageError bit is more sticky and only cleared
> - * when the page is reread or dropped. If an
> - * application assumes it will always get error on
> - * fsync, but does other operations on the fd before
> - * and the page is dropped between then the error
> - * will not be properly reported.
> - *
> - * This can already happen even without hwpoisoned
> - * pages: first on metadata IO errors (which only
> - * report through AS_EIO) or when the page is dropped
> - * at the wrong time.
> - *
> - * So right now we assume that the application DTRT on
> - * the first EIO, but we're not worse than other parts
> - * of the kernel.
> */
> mapping_set_error(mapping, -EIO);
> }
>
