Patch "brd: Fix discard request processing" has been added to the 4.4-stable tree

Patch "brd: Fix discard request processing" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    brd: Fix discard request processing

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     brd-fix-discard-request-processing.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 5e4298be45e83ecdffaabb370eea9396889b07f1 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Tue, 15 Dec 2015 16:38:22 +0100
Subject: brd: Fix discard request processing

From: Bart Van Assche <bart.vanassche@sandisk.com>

commit 5e4298be45e83ecdffaabb370eea9396889b07f1 upstream.

Avoid that discard requests with size => PAGE_SIZE fail with
-EIO. Refuse discard requests if the discard size is not a
multiple of the page size.

Fixes: 2dbe54957636 ("brd: Refuse improperly aligned discard requests")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Jan Kara <jack@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Elliot <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/block/brd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -338,7 +338,7 @@ static blk_qc_t brd_make_request(struct
 
 	if (unlikely(bio->bi_rw & REQ_DISCARD)) {
 		if (sector & ((PAGE_SIZE >> SECTOR_SHIFT) - 1) ||
-		    bio->bi_iter.bi_size & PAGE_MASK)
+		    bio->bi_iter.bi_size & ~PAGE_MASK)
 			goto io_error;
 		discard_from_brd(brd, sector, bio->bi_iter.bi_size);
 		goto out;


Patches currently in stable-queue which might be from bart.vanassche@sandisk.com are

queue-4.4/ib-srpt-simplify-srpt_handle_tsk_mgmt.patch
queue-4.4/sd-fix-discard-granularity-when-lbprz-1.patch
queue-4.4/brd-fix-discard-request-processing.patch