fs/9p: adjust sscanf parameters accordingly to the variable types

Signed-off-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
9P: fix return value in v9fs_fid_xattr_set

v9fs_fid_xattr_set is supposed to return 0 on success.

This corrects the behaviour introduced in commit
bdd5c28dcb8330b9074404cc92a0b83aae5606a
"9p: fix return value in case in v9fs_fid_xattr_set()"

(The function returns a negative error on error, as expected)

Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Don't trigger congestion wait on dirty-but-not-writeout pages

shrink_inactive_list() used to wait 0.1s to avoid congestion when all
the pages that were isolated from the inactive list were dirty but not
under active writeback.  That makes no real sense, and apparently causes
major interactivity issues under some loads since 3.11.

The ostensible reason for it was to wait for kswapd to start writing
pages, but that seems questionable as well, since the congestion wait
code seems to trigger for kswapd itself as well.  Also, the logic behind
delaying anything when we haven't actually started writeback is not
clear - it only delays actually starting that writeback.

We'll still trigger the congestion waiting if

 (a) the process is kswapd, and we hit pages flagged for immediate
     reclaim

 (b) the process is not kswapd, and the zone backing dev writeback is
     actually congested.

This probably needs to be revisited, but as it is this fixes a reported
regression.

Reported-by: Felipe Contreras <felipe.contreras@gmail.com>
Pinpointed-by: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
numa,sched: fix load_to_imbalanced logic inversion

This function is supposed to return true if the new load imbalance is
worse than the old one.  It didn't.  I can only hope brown paper bags
are in style.

Now things converge much better on both the 4 node and 8 node systems.

I am not sure why this did not seem to impact specjbb performance on the
4 node system, which is the system I have full-time access to.

This bug was introduced recently, with commit e63da03639cc ("sched/numa:
Allow task switch if load imbalance improves")

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'for-linus-3.16-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

Pull 9p fixes from Eric Van Hensbergen:
 "Two bug fixes, one in xattr error path and the other in parsing
  major/minor numbers from devices"

* tag 'for-linus-3.16-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9P: fix return value in v9fs_fid_xattr_set
  fs/9p: adjust sscanf parameters accordingly to the variable types