linux-kernel - [PATCH 4.9 57/69] nbd: fix 64-bit division

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Message-Id: <20170419141619.263541821@linuxfoundation.org>
Date:   Wed, 19 Apr 2017 16:43:13 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Jens Axboe <axboe@...com>,
        Ben Hutchings <ben@...adent.org.uk>
Subject: [PATCH 4.9 57/69] nbd: fix 64-bit division

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jens Axboe <axboe@...com>

commit e88f72cb9f54f6d244e55f629fe5e2f34ca6f9ed upstream.

We have this:

ERROR: "__aeabi_ldivmod" [drivers/block/nbd.ko] undefined!
ERROR: "__divdi3" [drivers/block/nbd.ko] undefined!
nbd.c:(.text+0x247c72): undefined reference to `__divdi3'

due to a recent commit, that did 64-bit division. Use the proper
divider function so that 32-bit compiles don't break.

Fixes: ef77b515243b ("nbd: use loff_t for blocksize and nbd_set_size args")
Signed-off-by: Jens Axboe <axboe@...com>
Cc: Ben Hutchings <ben@...adent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

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

--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -648,7 +648,7 @@ static int __nbd_ioctl(struct block_devi
 
 	case NBD_SET_SIZE:
 		return nbd_size_set(nbd, bdev, nbd->blksize,
-				    arg / nbd->blksize);
+					div_s64(arg, nbd->blksize));
 
 	case NBD_SET_SIZE_BLOCKS:
 		return nbd_size_set(nbd, bdev, nbd->blksize, arg);