4.10-stable review patch. If anyone has any objections, please let me know. ------------------ 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; *kaddr = (void *) dev_info->start + offset; *pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), PFN_DEV);