On Sun, Jun 16, 2019 at 09:38:10PM +0530, Chandan Rajendra wrote:
> This commit adds code to make do_mpage_readpage() to be "read callbacks"
> aware i.e. for files requiring decryption, do_mpage_readpage() now
> sets up the read callbacks state machine when allocating a bio and later
> starts execution of the state machine after file data is read from the
> underlying disk.
>
> Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxx>
> ---
> fs/mpage.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/fs/mpage.c b/fs/mpage.c
> index 436a85260394..611ad122fc92 100644
> --- a/fs/mpage.c
> +++ b/fs/mpage.c
> @@ -30,6 +30,7 @@
> #include <linux/backing-dev.h>
> #include <linux/pagevec.h>
> #include <linux/cleancache.h>
> +#include <linux/read_callbacks.h>
> #include "internal.h"
>
> /*
> @@ -49,6 +50,8 @@ static void mpage_end_io(struct bio *bio)
> struct bio_vec *bv;
> struct bvec_iter_all iter_all;
>
> + if (read_callbacks_end_bio(bio))
> + return;
> bio_for_each_segment_all(bv, bio, iter_all) {
> struct page *page = bv->bv_page;
> page_endio(page, bio_op(bio),
> @@ -309,6 +312,12 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
> gfp);
> if (args->bio == NULL)
> goto confused;
> +
> + if (read_callbacks_setup(inode, args->bio, NULL)) {
> + bio_put(args->bio);
> + args->bio = NULL;
> + goto confused;
> + }
> }
>
> length = first_hole << blkbits;
> @@ -330,7 +339,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
> confused:
> if (args->bio)
> args->bio = mpage_bio_submit(REQ_OP_READ, op_flags, args->bio);
> - if (!PageUptodate(page))
> + if (!PageUptodate(page) && !PageError(page))
> block_read_full_page(page, args->get_block);
> else
> unlock_page(page);
> --
> 2.19.1
Why is the !PageError() check needed here?
- Eric
