fs: do not pass __GFP_HIGHMEM to bio_alloc in do_mpage_readpage

The mpage bio alloc cleanup accidentally removed clearing ~GFP_KERNEL
bits from the mask passed to bio_alloc.  Fix this up in a slightly
less obsfucated way that mirrors what iomap does in its readpage code.

Fixes: 77c436d ("mpage: pass the operation to bio_alloc")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Link: https://lore.kernel.org/r/20220323153952.1418560-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

fs/mpage.c

@@ -148,13 +148,11 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
 	int op = REQ_OP_READ;
 	unsigned nblocks;
 	unsigned relative_block;
-	gfp_t gfp;
+	gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
 
 	if (args->is_readahead) {
 		op |= REQ_RAHEAD;
-		gfp = readahead_gfp_mask(page->mapping);
-	} else {
-		gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
+		gfp |= __GFP_NORETRY | __GFP_NOWARN;
 	}
 
 	if (page_has_buffers(page))