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  1. 03 Mar, 2016 10 commits
  3. 29 Feb, 2016 5 commits
  5. 15 Feb, 2016 1 commit
    • Markus Pargmann's avatar
      nbd: Create size change events for userspace · 37091fdd
      Markus Pargmann authored 
      The userspace needs to know when nbd devices are ready for use.
Currently no events are created for the userspace which doesn't work for
systemd.

See the discussion here: https://github.com/systemd/systemd/pull/358

This patch uses a central point to setup the nbd-internal sizes. A ioctl
to set a size does not lead to a visible size change. The size of the
block device will be kept at 0 until nbd is connected. As soon as it
connects, the size will be changed to the real value and a uevent is
created. When disconnecting, the blockdevice is set to 0 size and
another uevent is generated.
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
      37091fdd
  7. 10 Feb, 2016 5 commits
  9. 09 Feb, 2016 3 commits
  11. 05 Feb, 2016 5 commits
    • Dan Streetman's avatar
      nbd: ratelimit error msgs after socket close · da6ccaaa
      Dan Streetman authored 
      Make the "Attempted send on closed socket" error messages generated in
nbd_request_handler() ratelimited.

When the nbd socket is shutdown, the nbd_request_handler() function emits
an error message for every request remaining in its queue.  If the queue
is large, this will spam a large amount of messages to the log.  There's
no need for a separate error message for each request, so this patch
ratelimits it.

In the specific case this was found, the system was virtual and the error
messages were logged to the serial port, which overwhelmed it.

Fixes: 4d48a542 ("nbd: fix I/O hang on disconnected nbds")
Signed-off-by: default avatarDan Streetman <dan.streetman@canonical.com>
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
      da6ccaaa
    • Markus Pargmann's avatar
      nbd: Move flag parsing to a function · d02cf531
      Markus Pargmann authored 
      nbd changes properties of the blockdevice depending on flags that were
received. This patch moves this flag parsing into a separate function
nbd_parse_flags().
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
      d02cf531
    • Markus Pargmann's avatar
      nbd: Cleanup reset of nbd and bdev after a disconnect · 0e4f0f6f
      Markus Pargmann authored 
      Group all variables that are reset after a disconnect into reset
functions. This patch adds two of these functions, nbd_reset() and
nbd_bdev_reset().
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
      0e4f0f6f
    • Markus Pargmann's avatar
      nbd: Timeouts are not user requested disconnects · 1f7b5cf1
      Markus Pargmann authored 
      It may be useful to know in the client that a connection timed out. The
current code returns success for a timeout.

This patch reports the error code -ETIMEDOUT for a timeout.
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
      1f7b5cf1
    • Markus Pargmann's avatar
      nbd: Remove signal usage · 23272a67
      Markus Pargmann authored 
      As discussed on the mailing list, the usage of signals for timeout
handling has a lot of potential issues. The nbd driver used for some
time signals for timeouts. These signals where able to get the threads
out of the blocking socket operations.

This patch removes all signal usage and uses a socket shutdown instead.
The socket descriptor itself is cleared later when the whole nbd device
is closed.

The tasks_lock is removed as we do not depend on this anymore. Instead
a new lock for the socket is introduced so we can safely work with the
socket in the timeout handler outside of the two main threads.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      23272a67
  13. 04 Feb, 2016 4 commits
    • Jan Kara's avatar
      cfq-iosched: Allow parent cgroup to preempt its child · 3984aa55
      Jan Kara authored 
      Currently we don't allow sync workload of one cgroup to preempt sync
workload of any other cgroup. This is because we want to achieve service
separation between cgroups. However in cases where cgroup preempting is
ancestor of the current cgroup, there is no need of separation and
idling introduces unnecessary overhead. This hurts for example the case
when workload is isolated within a cgroup but journalling threads are in
root cgroup. Simple way to demostrate the issue is using:

dbench4 -c /usr/share/dbench4/client.txt -t 10 -D /mnt 1

on ext4 filesystem on plain SATA drive (mounted with barrier=0 to make
difference more visible). When all processes are in the root cgroup,
reported throughput is 153.132 MB/sec. When dbench process gets its own
blkio cgroup, reported throughput drops to 26.1006 MB/sec.

Fix the problem by making check in cfq_should_preempt() more benevolent
and allow preemption by ancestor cgroup. This improves the throughput
reported by dbench4 to 48.9106 MB/sec.
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJan Kara <jack@suse.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      3984aa55
    • Jan Kara's avatar
      cfq-iosched: Allow sync noidle workloads to preempt each other · a257ae3e
      Jan Kara authored 
      The original idea with preemption of sync noidle queues (introduced in
commit 718eee05 "cfq-iosched: fairness for sync no-idle queues") was
that we service all sync noidle queues together, we don't idle on any of
the queues individually and we idle only if there is no sync noidle
queue to be served. This intention also matches the original test:

	if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD
	   && new_cfqq->service_tree == cfqq->service_tree)
		return true;

However since at that time cfqq->service_tree was not set for idling
queues, this test was unreliable and was replaced in commit e4a22919
"cfq-iosched: fix no-idle preemption logic" by:

	if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
	    cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
	    new_cfqq->service_tree->count == 1)
		return true;

That was a reliable test but was actually doing something different -
now we preempt sync noidle queue only if the new queue is the only one
busy in the service tree.

These days cfq queue is kept in service tree even if it is idling and
thus the original check would be safe again. But since we actually check
that cfq queues are in the same cgroup, of the same priority class and
workload type (sync noidle), we know that new_cfqq is fine to preempt
cfqq. So just remove the service tree check.
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJan Kara <jack@suse.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      a257ae3e
    • Jan Kara's avatar
      cfq-iosched: Reorder checks in cfq_should_preempt() · 6c80731c
      Jan Kara authored 
      Move check for preemption by rt class up. There is no functional change
but it makes arguing about conditions simpler since we can be sure both
cfq queues are from the same ioprio class.
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJan Kara <jack@suse.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      6c80731c
    • Jan Kara's avatar
      cfq-iosched: Don't group_idle if cfqq has big thinktime · e795421e
      Jan Kara authored 
      There is no point in idling on a cfq group if the only cfq queue that is
there has too big thinktime.
Signed-off-by: default avatarJan Kara <jack@suse.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      e795421e
  15. 03 Feb, 2016 1 commit
    • Markus Pargmann's avatar
      nbd: Fix debugfs error handling · 27ea43fe
      Markus Pargmann authored 
      Static checker complains about the implemented error handling. It is
indeed wrong. We don't care about the return values of created debugfs
files.

We only have to check the return values of created dirs for NULL
pointer. If we use a null pointer as parent directory for files, this
may lead to debugfs files in wrong places.
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
      27ea43fe
  17. 01 Feb, 2016 6 commits
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