Commit fc8ebd01 authored Aug 15, 2018 by Maciej S. Szmigiero Committed by Jens Axboe Aug 16, 2018

block, bfq: return nbytes and not zero from struct cftype .write() method



The value that struct cftype .write() method returns is then directly
returned to userspace as the value returned by write() syscall, so it
should be the number of bytes actually written (or consumed) and not zero.

Returning zero from write() syscall makes programs like /bin/echo or bash
spin.

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Fixes: e21b7a0b ("block, bfq: add full hierarchical scheduling and cgroups support")
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent f8121648

block/bfq-cgroup.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -913,7 +913,8 @@ static ssize_t bfq_io_set_weight(struct kernfs_open_file *of,
		if (ret)
		return ret;

		return bfq_io_set_weight_legacy(of_css(of), NULL, weight);
		ret = bfq_io_set_weight_legacy(of_css(of), NULL, weight);
		return ret ?: nbytes;
		}

		#ifdef CONFIG_DEBUG_BLK_CGROUP