Re: [PATCH] iomap: Do not use GFP_NORETRY to allocate BIOs

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Mon, Mar 23, 2020 at 06:12:44AM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> If we use GFP_NORETRY, we have to be able to handle failures, and it's
> tricky to handle failure here.  Other implementations of ->readpages
> do not attempt to handle BIO allocation failures, so this is no worse.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

This fixes the regression I saw, though I see what looks like a new
patch forming further down in this thread, so please let me know if
you'd prefer I take this change, the other one, or both.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/iomap/buffered-io.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 417115bfaf6b..2336642d7390 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -307,8 +307,6 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
>  		if (ctx->bio)
>  			submit_bio(ctx->bio);
>  
> -		if (ctx->is_readahead) /* same as readahead_gfp_mask */
> -			gfp |= __GFP_NORETRY | __GFP_NOWARN;
>  		ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs));
>  		ctx->bio->bi_opf = REQ_OP_READ;
>  		if (ctx->is_readahead)
> -- 
> 2.25.1
>