This is a note to let you know that I've just added the patch titled s390/dcssblk: fix device size calculation in dcssblk_direct_access() 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: s390-dcssblk-fix-device-size-calculation-in-dcssblk_direct_access.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@xxxxxxxxxxxxxxx> know about it. >From a63f53e34db8b49675448d03ae324f6c5bc04fe6 Mon Sep 17 00:00:00 2001 From: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> Date: Mon, 30 Jan 2017 15:52:14 +0100 Subject: s390/dcssblk: fix device size calculation in dcssblk_direct_access() From: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> commit a63f53e34db8b49675448d03ae324f6c5bc04fe6 upstream. Since commit dd22f551 "block: Change direct_access calling convention", the device size calculation in dcssblk_direct_access() is off-by-one. This results in bdev_direct_access() always returning -ENXIO because the returned value is not page aligned. Fix this by adding 1 to the dev_sz calculation. Fixes: dd22f551 ("block: Change direct_access calling convention") Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/s390/block/dcssblk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -892,7 +892,7 @@ dcssblk_direct_access (struct block_devi dev_info = bdev->bd_disk->private_data; if (!dev_info) return -ENODEV; - dev_sz = dev_info->end - dev_info->start; + dev_sz = dev_info->end - dev_info->start + 1; offset = secnum * 512; addr = (void *) (dev_info->start + offset); *pfn = virt_to_phys(addr) >> PAGE_SHIFT; Patches currently in stable-queue which might be from gerald.schaefer@xxxxxxxxxx are queue-4.4/s390-dcssblk-fix-device-size-calculation-in-dcssblk_direct_access.patch