Skip to content

L
linux
Switch branch/tag
  1. 09 Jan, 2014 15 commits
  3. 08 Jan, 2014 18 commits
  5. 07 Jan, 2014 7 commits
    • David S. Miller's avatar
      Merge branch 'tipc' · 8752b5ca
      David S. Miller authored 
      Jon Maloy says:

====================
tipc: link setup and failover improvements

This series consists of four unrelated commits with different purposes.

- Commit #1 is purely cosmetic and pedagogic, hopefully making the
  failover/tunneling logics slightly easier to understand.
- Commit #2 fixes a bug that has always been in the code, but was not
  discovered until very recently.
- Commit #3 fixes a non-fatal race issue in the neighbour discovery
  code.
- Commit #4 removes an unnecessary indirection step during link
  startup.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8752b5ca
    • Jon Paul Maloy's avatar
      tipc: make link start event synchronous · 581465fa
      Jon Paul Maloy authored 
      When a link is created we delay the start event by launching it
to be executed later in a tasklet. As we hold all the
necessary locks at the moment of creation, and there is no risk
of deadlock or contention, this delay serves no purpose in the
current code.

We remove this obsolete indirection step, and the associated function
link_start(). At the same time, we rename the function tipc_link_stop()
to the more appropriate tipc_link_purge_queues().
Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      581465fa
    • Ying Xue's avatar
      tipc: introduce new spinlock to protect struct link_req · f9a2c80b
      Ying Xue authored 
      Currently, only 'bearer_lock' is used to protect struct link_req in
the function disc_timeout(). This is unsafe, since the member fields
'num_nodes' and 'timer_intv' might be accessed by below three different
threads simultaneously, none of them grabbing bearer_lock in the
critical region:

link_activate()
  tipc_bearer_add_dest()
    tipc_disc_add_dest()
      req->num_nodes++;

tipc_link_reset()
  tipc_bearer_remove_dest()
    tipc_disc_remove_dest()
      req->num_nodes--
      disc_update()
        read req->num_nodes
	write req->timer_intv

disc_timeout()
  read req->num_nodes
  read/write req->timer_intv

Without lock protection, the only symptom of a race is that discovery
messages occasionally may not be sent out. This is not fatal, since such
messages are best-effort anyway. On the other hand, since discovery
messages are not time critical, adding a protecting lock brings no
serious overhead either. So we add a new, dedicated spinlock in
order to guarantee absolute data consistency in link_req objects.
This also helps reduce the overall role of the bearer_lock, which
we want to remove completely in a later commit series.
Signed-off-by: default avatarYing Xue <ying.xue@windriver.com>
Reviewed-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f9a2c80b
    • Jon Paul Maloy's avatar
      tipc: remove 'has_redundant_link' flag from STATE link protocol messages · b9d4c339
      Jon Paul Maloy authored 
      The flag 'has_redundant_link' is defined only in RESET and ACTIVATE
protocol messages. Due to an ambiguity in the protocol specification it
is currently also transferred in STATE messages. Its value is used to
initialize a link state variable, 'permit_changeover', which is used
to inhibit futile link failover attempts when it is known that the
peer node has no working links at the moment, although the local node
may still think it has one.

The fact that 'has_redundant_link' incorrectly is read from STATE
messages has the effect that 'permit_changeover' sometimes gets a wrong
value, and permanently blocks any links from being re-established. Such
failures can only occur in in dual-link systems, and are extremely rare.
This bug seems to have always been present in the code.

Furthermore, since commit b4b56102
("tipc: Ensure both nodes recognize loss of contact between them"),
the 'permit_changeover' field serves no purpose any more. The task of
enforcing 'lost contact' cycles at both peer endpoints is now taken
by a new mechanism, using the flags WAIT_NODE_DOWN and WAIT_PEER_DOWN
in struct tipc_node to abort unnecessary failover attempts.

We therefore remove the 'has_redundant_link' flag from STATE messages,
as well as the now redundant 'permit_changeover' variable.
Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
Reviewed-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b9d4c339
    • Jon Paul Maloy's avatar
      tipc: rename functions related to link failover and improve comments · 170b3927
      Jon Paul Maloy authored 
      The functionality related to link addition and failover is unnecessarily
hard to understand and maintain. We try to improve this by renaming
some of the functions, at the same time adding or improving the
explanatory comments around them. Names such as "tipc_rcv()" etc. also
align better with what is used in other networking components.

The changes in this commit are purely cosmetic, no functional changes
are made.
Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: default avatarYing Xue <ying.xue@windriver.com>
Reviewed-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      170b3927
    • Daniel Borkmann's avatar
      net: skbuff: const-ify casts in skb_queue_* functions · fd44b93c
      Daniel Borkmann authored 
      We should const-ify comparisons on skb_queue_* inline helper
functions as their parameters are const as well, so lets not
drop that.
Suggested-by: default avatarBrad Spengler <spender@grsecurity.net>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      fd44b93c
    • Daniel Borkmann's avatar
      net: xfrm: xfrm_policy: fix inline not at beginning of declaration · be7928d2
      Daniel Borkmann authored 
      Fix three warnings related to:

  net/xfrm/xfrm_policy.c:1644:1: warning: 'inline' is not at beginning of declaration [-Wold-style-declaration]
  net/xfrm/xfrm_policy.c:1656:1: warning: 'inline' is not at beginning of declaration [-Wold-style-declaration]
  net/xfrm/xfrm_policy.c:1668:1: warning: 'inline' is not at beginning of declaration [-Wold-style-declaration]

Just removing the inline keyword is sufficient as the compiler will
decide on its own about inlining or not.
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      be7928d2
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7