orangefs: use folios in orangefs_readahead

orangefs: use folios in orangefs_readahead

Patch series "remove page_endio()", v3.

It was decided to remove the page_endio() as per the previous RFC
discussion[1] of this series and move that functionality into the caller
itself.  One of the side benefit of doing that is the callers have been
modified to directly work on folios as page_endio() already worked on
folios.

As Christoph is doing ZRAM cleanups[4] which will get rid of page_endio()
function usage, I removed the final patch that removes page_endio()[5].  I
will send it separately after rc-1 once the zram cleanups are merged.

mpage changes were tested with a simple boot testing and running a fio
workload on ext2 filesystem.  orangefs was tested by Mike Marshall (No
code changes since he tested).

This patch (of 3):

Convert orangefs_readahead() from using struct page to struct folio.  This
conversion removes the call to page_endio() which is soon to be removed,
and simplifies the final page handling.

The page error flags is not required to be set in the error case as
orangefs doesn't depend on them.

Link: https://lkml.kernel.org/r/20230411122920.30134-1-p.raghav@samsung.com
Link: https://lkml.kernel.org/r/20230411122920.30134-2-p.raghav@samsung.com
Link: https://lore.kernel.org/linux-mm/ZBHcl8Pz2ULb4RGD@infradead.org/
Link: https://lore.kernel.org/linux-mm/20230322135013.197076-1-p.raghav@samsung.com/
Link: https://lore.kernel.org/linux-mm/8adb0770-6124-e11f-2551-6582db27ed32@samsung.com/
Link: https://lore.kernel.org/linux-block/20230404150536.2142108-1-hch@lst.de/T/#t
Link: https://lore.kernel.org/lkml/20230403132221.94921-6-p.raghav@samsung.com/
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mike Marshall <hubcap@omnibond.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Martin Brandenburg <martin@omnibond.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>