Commit Graph

346 Commits

Author SHA1 Message Date
Alexey Dobriyan 08009a7602 net: make kmem caches as __ro_after_init
All kmem caches aren't reallocated once set up.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26 15:11:48 -05:00
Alexey Dobriyan 96890d6252 net: delete /proc THIS_MODULE references
/proc has been ignoring struct file_operations::owner field for 10 years.
Specifically, it started with commit 786d7e1612
("Fix rmmod/read/write races in /proc entries"). Notice the chunk where
inode->i_fop is initialized with proxy struct file_operations for
regular files:

	-               if (de->proc_fops)
	-                       inode->i_fop = de->proc_fops;
	+               if (de->proc_fops) {
	+                       if (S_ISREG(inode->i_mode))
	+                               inode->i_fop = &proc_reg_file_ops;
	+                       else
	+                               inode->i_fop = de->proc_fops;
	+               }

VFS stopped pinning module at this point.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 15:01:33 -05:00
David Ahern 6c31e5a91f net: Add extack to fib_notifier_info
Add extack to fib_notifier_info and plumb through stack to
call_fib_rule_notifiers, call_fib_entry_notifiers and
call_fib6_entry_notifiers. This allows notifer handlers to
return messages to user.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01 11:50:43 +09:00
David Ahern 6eba87c781 net: ipv4: Change fib notifiers to take a fib_alias
All of the notifier data (fib_info, tos, type and table id) are
contained in the fib_alias. Pass it to the notifier instead of
each data separately shortening the argument list by 3.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:29:26 +01:00
Xin Long 5f9ae3d9e7 ipv4: do metrics match when looking up and deleting a route
Now when ipv4 route inserts a fib_info, it memcmp fib_metrics.
It means ipv4 route identifies one route also with metrics.

But when removing a route, it tries to find the route without
caring about the metrics. It will cause that the route with
right metrics can't be removed.

Thomas noticed this issue when doing the testing:

1. add:
   # ip route append 192.168.7.0/24 dev v window 1000
   # ip route append 192.168.7.0/24 dev v window 1001
   # ip route append 192.168.7.0/24 dev v window 1002
   # ip route append 192.168.7.0/24 dev v window 1003
2. delete:
   # ip route delete 192.168.7.0/24 dev v window 1002
3. show:
     192.168.7.0/24 proto boot scope link window 1001
     192.168.7.0/24 proto boot scope link window 1002
     192.168.7.0/24 proto boot scope link window 1003

The one with window 1002 wasn't deleted but the first one was.

This patch is to do metrics match when looking up and deleting
one route.

Reported-by: Thomas Haller <thaller@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-23 20:37:10 -07:00
Ido Schimmel 04b1d4e50e net: core: Make the FIB notification chain generic
The FIB notification chain is currently soley used by IPv4 code.
However, we're going to introduce IPv6 FIB offload support, which
requires these notification as well.

As explained in commit c3852ef7f2 ("ipv4: fib: Replay events when
registering FIB notifier"), upon registration to the chain, the callee
receives a full dump of the FIB tables and rules by traversing all the
net namespaces. The integrity of the dump is ensured by a per-namespace
sequence counter that is incremented whenever a change to the tables or
rules occurs.

In order to allow more address families to use the chain, each family is
expected to register its fib_notifier_ops in its pernet init. These
operations allow the common code to read the family's sequence counter
as well as dump its tables and rules in the given net namespace.

Additionally, a 'family' parameter is added to sent notifications, so
that listeners could distinguish between the different families.

Implement the common code that allows listeners to register to the chain
and for address families to register their fib_notifier_ops. Subsequent
patches will implement these operations in IPv6.

In the future, ipmr and ip6mr will be extended to provide these
notifications as well.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:35:59 -07:00
Reshetova, Elena 0029c0deb5 net, ipv4: convert fib_info.fib_clntref from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04 01:29:04 -07:00
David Ahern 9ae2872748 net: add extack arg to lwtunnel build state
Pass extack arg down to lwtunnel_build_state and the build_state callbacks.
Add messages for failures in lwtunnel_build_state, and add the extarg to
nla_parse where possible in the build_state callbacks.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:32 -04:00
David Ahern 7805599895 net: ipv4: Add extack message for invalid prefix or length
Add extack error message for invalid prefix length and invalid prefix.
Example of the latter is a route spec containing 172.16.100.1/24, where
the /24 mask means the lower 8-bits should be 0. Amazing how easy that
one is to overlook when an EINVAL is returned.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:31 -04:00
David Ahern ba277e8e05 net: ipv4: refactor key and length checks
fib_table_insert and fib_table_delete have the same checks on the prefix
and length. Refactor into a helper. Avoids duplicate extack messages in
the next patch.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:31 -04:00
David Ahern 6ffd903415 net: ipv4: Save trie prefix to fib lookup result
Prefix is needed for returning matching route spec on get route request.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-26 14:12:50 -04:00
David Ahern 6d8422a175 net: ipv4: Plumb extack through route add functions
Plumb extack argument down to route add functions.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-22 12:12:19 -04:00
David Ahern f6c5775ff0 net: Improve handling of failures on link and route dumps
In general, rtnetlink dumps do not anticipate failure to dump a single
object (e.g., link or route) on a single pass. As both route and link
objects have grown via more attributes, that is no longer a given.

netlink dumps can handle a failure if the dump function returns an
error; specifically, netlink_dump adds the return code to the response
if it is <= 0 so userspace is notified of the failure. The missing
piece is the rtnetlink dump functions returning the error.

Fix route and link dump functions to return the errors if no object is
added to an skb (detected by skb->len != 0). IPv6 route dumps
(rt6_dump_route) already return the error; this patch updates IPv4 and
link dumps. Other dump functions may need to be ajusted as well.

Reported-by: Jan Moskyto Matejka <mq@ucw.cz>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-16 14:54:11 -04:00
Ido Schimmel d05f7a7dd4 ipv4: fib: Remove redundant argument
We always pass the same event type to fib_notify() and
fib_rules_notify(), so we can safely drop this argument.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 09:45:09 -08:00
Ido Schimmel c0243892cb ipv4: fib: Move FIB notification code to a separate file
Most of the code concerned with the FIB notification chain currently
resides in fib_trie.c, but this isn't really appropriate, as the FIB
notification chain is also used for FIB rules.

Therefore, it makes sense to move the common FIB notification code to a
separate file and have it export the relevant functions, which can be
invoked by its different users (e.g., fib_trie.c, fib_rules.c).

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 09:45:09 -08:00
Alexey Dobriyan 5b5e0928f7 lib/vsprintf.c: remove %Z support
Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.

Use BUILD_BUG_ON in a couple ATM drivers.

In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement.  Hopefully this patch inspires
someone else to trim vsprintf.c more.

Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:47 -08:00
Ido Schimmel 2f3a5272e5 ipv4: fib: Add events for FIB replace and append
The FIB notification chain currently uses the NLM_F_{REPLACE,APPEND}
flags to signal routes being replaced or appended.

Instead of using netlink flags for in-kernel notifications we can simply
introduce two new events in the FIB notification chain. This has the
added advantage of making the API cleaner, thereby making it clear that
these events should be supported by listeners of the notification chain.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-10 11:32:13 -05:00
Ido Schimmel 5b7d616dbc ipv4: fib: Send notification before deleting FIB alias
When a FIB alias is replaced following NLM_F_REPLACE, the ENTRY_ADD
notification is sent after the reference on the previous FIB info was
dropped. This is problematic as potential listeners might need to access
it in their notification blocks.

Solve this by sending the notification prior to the deletion of the
replaced FIB alias. This is consistent with ENTRY_DEL notifications.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-10 11:32:12 -05:00
Ido Schimmel 42d5aa76ec ipv4: fib: Send deletion notification with actual FIB alias type
When a FIB alias is removed, a notification is sent using the type
passed from user space - can be RTN_UNSPEC - instead of the actual type
of the removed alias. This is problematic for listeners of the FIB
notification chain, as several FIB aliases can exist with matching
parameters, but the type.

Solve this by passing the actual type of the removed FIB alias.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-10 11:32:12 -05:00
Ido Schimmel 58e3bdd597 ipv4: fib: Only flush FIB aliases belonging to currently flushed table
In case the MAIN table is flushed and its trie is shared with the LOCAL
table, then we might be flushing FIB aliases belonging to the latter.
This can lead to FIB_ENTRY_DEL notifications sent with the wrong table
ID.

The above doesn't affect current listeners, as the table ID is ignored
during entry deletion, but this will change later in the patchset.

When flushing a particular table, skip any aliases belonging to a
different one.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Patrick McHardy <kaber@trash.net>
Reviewed-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-10 11:32:12 -05:00
Linus Torvalds 7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
David S. Miller c63d352f05 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-06 21:33:19 -05:00
Alexander Duyck a52ca62c4a ipv4: Drop suffix update from resize code
It has been reported that update_suffix can be expensive when it is called
on a large node in which most of the suffix lengths are the same.  The time
required to add 200K entries had increased from around 3 seconds to almost
49 seconds.

In order to address this we need to move the code for updating the suffix
out of resize and instead just have it handled in the cases where we are
pushing a node that increases the suffix length, or will decrease the
suffix length.

Fixes: 5405afd1a3 ("fib_trie: Add tracking value for suffix length")
Reported-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: Robert Shearman <rshearma@brocade.com>
Tested-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05 13:15:58 -05:00
Alexander Duyck 1a239173cc ipv4: Drop leaf from suffix pull/push functions
It wasn't necessary to pass a leaf in when doing the suffix updates so just
drop it.  Instead just pass the suffix and work with that.

Since we dropped the leaf there is no need to include that in the name so
the names are updated to node_push_suffix and node_pull_suffix.

Finally I noticed that the logic for pulling the suffix length back
actually had some issues.  Specifically it would stop prematurely if there
was a longer suffix, but it was not as long as the original suffix.  I
updated the code to address that in node_pull_suffix.

Fixes: 5405afd1a3 ("fib_trie: Add tracking value for suffix length")
Suggested-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: Robert Shearman <rshearma@brocade.com>
Tested-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05 13:15:58 -05:00
Ido Schimmel c3852ef7f2 ipv4: fib: Replay events when registering FIB notifier
Commit b90eb75494 ("fib: introduce FIB notification infrastructure")
introduced a new notification chain to notify listeners (f.e., switchdev
drivers) about addition and deletion of routes.

However, upon registration to the chain the FIB tables can already be
populated, which means potential listeners will have an incomplete view
of the tables.

Solve that by dumping the FIB tables and replaying the events to the
passed notification block. The dump itself is done using RCU in order
not to starve consumers that need RTNL to make progress.

The integrity of the dump is ensured by reading the FIB change sequence
counter before and after the dump under RTNL. This allows us to avoid
the problematic situation in which the dumping process sends a ENTRY_ADD
notification following ENTRY_DEL generated by another process holding
RTNL.

Callers of the registration function may pass a callback that is
executed in case the dump was inconsistent with current FIB tables.

The number of retries until a consistent dump is achieved is set to a
fixed number to prevent callers from looping for long periods of time.
In case current limit proves to be problematic in the future, it can be
easily converted to be configurable using a sysctl.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 19:29:35 -05:00
Ido Schimmel cacaad11f4 ipv4: fib: Allow for consistent FIB dumping
The next patch will enable listeners of the FIB notification chain to
request a dump of the FIB tables. However, since RTNL isn't taken during
the dump, it's possible for the FIB tables to change mid-dump, which
will result in inconsistency between the listener's table and the
kernel's.

Allow listeners to know about changes that occurred mid-dump, by adding
a change sequence counter to each net namespace. The counter is
incremented just before a notification is sent in the FIB chain.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 19:29:35 -05:00
Ido Schimmel d3f706f68e ipv4: fib: Convert FIB notification chain to be atomic
In order not to hold RTNL for long periods of time we're going to dump
the FIB tables using RCU.

Convert the FIB notification chain to be atomic, as we can't block in
RCU critical sections.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 19:29:35 -05:00
Alexander Duyck 3114cdfe66 ipv4: Fix memory leak in exception case for splitting tries
Fix a small memory leak that can occur where we leak a fib_alias in the
event of us not being able to insert it into the local table.

Fixes: 0ddcf43d5d ("ipv4: FIB Local/MAIN table collapse")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16 13:24:50 -05:00
Alexander Duyck 3b7093346b ipv4: Restore fib_trie_flush_external function and fix call ordering
The patch that removed the FIB offload infrastructure was a bit too
aggressive and also removed code needed to clean up us splitting the table
if additional rules were added.  Specifically the function
fib_trie_flush_external was called at the end of a new rule being added to
flush the foreign trie entries from the main trie.

I updated the code so that we only call fib_trie_flush_external on the main
table so that we flush the entries for local from main.  This way we don't
call it for every rule change which is what was happening previously.

Fixes: 347e3b28c1 ("switchdev: remove FIB offload infrastructure")
Reported-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16 13:24:50 -05:00
Alexander Duyck fd0285a39b fib_trie: Correct /proc/net/route off by one error
The display of /proc/net/route has had a couple issues due to the fact that
when I originally rewrote most of fib_trie I made it so that the iterator
was tracking the next value to use instead of the current.

In addition it had an off by 1 error where I was tracking the first piece
of data as position 0, even though in reality that belonged to the
SEQ_START_TOKEN.

This patch updates the code so the iterator tracks the last reported
position and key instead of the next expected position and key.  In
addition it shifts things so that all of the leaves start at 1 instead of
trying to report leaves starting with offset 0 as being valid.  With these
two issues addressed this should resolve any off by one errors that were
present in the display of /proc/net/route.

Fixes: 25b97c016b ("ipv4: off-by-one in continuation handling in /proc/net/route")
Cc: Andy Whitcroft <apw@canonical.com>
Reported-by: Jason Baron <jbaron@akamai.com>
Tested-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-07 20:40:27 -05:00
Jiri Pirko 347e3b28c1 switchdev: remove FIB offload infrastructure
Since this is now taken care of by FIB notifier, remove the code, with
all unused dependencies.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-28 04:48:00 -04:00
Jiri Pirko b90eb75494 fib: introduce FIB notification infrastructure
This allows to pass information about added/deleted FIB entries/rules to
whoever is interested. This is done in a very similar way as devinet
notifies address additions/removals.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-28 04:48:00 -04:00
Guillaume Nault b93e1fa710 ipv4: fix value of ->nlmsg_flags reported in RTM_NEWROUTE events
fib_table_insert() inconsistently fills the nlmsg_flags field in its
notification messages.

Since commit b8f5583135 ("[RTNETLINK]: Fix sending netlink message
when replace route."), the netlink message has its nlmsg_flags set to
NLM_F_REPLACE if the route replaced a preexisting one.

Then commit a2bb6d7d6f ("ipv4: include NLM_F_APPEND flag in append
route notifications") started setting nlmsg_flags to NLM_F_APPEND if
the route matched a preexisting one but was appended.

In other cases (exclusive creation or prepend), nlmsg_flags is 0.

This patch sets ->nlmsg_flags in all situations, preserving the
semantic of the NLM_F_* bits:

  * NLM_F_CREATE: a new fib entry has been created for this route.
  * NLM_F_EXCL: no other fib entry existed for this route.
  * NLM_F_REPLACE: this route has overwritten a preexisting fib entry.
  * NLM_F_APPEND: the new fib entry was added after other entries for
    the same route.

As a result, the possible flag combination can now be reported
(iproute2's terminology into parentheses):

  * NLM_F_CREATE | NLM_F_EXCL: route didn't exist, exclusive creation
    ("add").
  * NLM_F_CREATE | NLM_F_APPEND: route did already exist, new route
    added after preexisting ones ("append").
  * NLM_F_CREATE: route did already exist, new route added before
    preexisting ones ("prepend").
  * NLM_F_REPLACE: route did already exist, new route replaced the
    first preexisting one ("change").

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-09 16:50:23 -07:00
Xunlei Pang 98a384eca9 fib_trie: Fix the description of pos and bits
1) Fix one typo: s/tn/tp/
2) Fix the description about the "u" bits.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 23:51:23 -07:00
David Forster 94d9f1c590 ipv4: panic in leaf_walk_rcu due to stale node pointer
Panic occurs when issuing "cat /proc/net/route" whilst
populating FIB with > 1M routes.

Use of cached node pointer in fib_route_get_idx is unsafe.

 BUG: unable to handle kernel paging request at ffffc90001630024
 IP: [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 PGD 11b08d067 PUD 11b08e067 PMD dac4b067 PTE 0
 Oops: 0000 [#1] SMP
 Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscac
 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep virti
 acpi_cpufreq button parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd
tio_ring virtio floppy uhci_hcd ehci_hcd usbcore usb_common libata scsi_mod
 CPU: 1 PID: 785 Comm: cat Not tainted 4.2.0-rc8+ #4
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 task: ffff8800da1c0bc0 ti: ffff88011a05c000 task.ti: ffff88011a05c000
 RIP: 0010:[<ffffffff814cf6a0>]  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 RSP: 0018:ffff88011a05fda0  EFLAGS: 00010202
 RAX: ffff8800d8a40c00 RBX: ffff8800da4af940 RCX: ffff88011a05ff20
 RDX: ffffc90001630020 RSI: 0000000001013531 RDI: ffff8800da4af950
 RBP: 0000000000000000 R08: ffff8800da1f9a00 R09: 0000000000000000
 R10: ffff8800db45b7e4 R11: 0000000000000246 R12: ffff8800da4af950
 R13: ffff8800d97a74c0 R14: 0000000000000000 R15: ffff8800d97a7480
 FS:  00007fd3970e0700(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffffc90001630024 CR3: 000000011a7e4000 CR4: 00000000000006e0
 Stack:
  ffffffff814d00d3 0000000000000000 ffff88011a05ff20 ffff8800da1f9a00
  ffffffff811dd8b9 0000000000000800 0000000000020000 00007fd396f35000
  ffffffff811f8714 0000000000003431 ffffffff8138dce0 0000000000000f80
 Call Trace:
  [<ffffffff814d00d3>] ? fib_route_seq_start+0x93/0xc0
  [<ffffffff811dd8b9>] ? seq_read+0x149/0x380
  [<ffffffff811f8714>] ? fsnotify+0x3b4/0x500
  [<ffffffff8138dce0>] ? process_echoes+0x70/0x70
  [<ffffffff8121cfa7>] ? proc_reg_read+0x47/0x70
  [<ffffffff811bb823>] ? __vfs_read+0x23/0xd0
  [<ffffffff811bbd42>] ? rw_verify_area+0x52/0xf0
  [<ffffffff811bbe61>] ? vfs_read+0x81/0x120
  [<ffffffff811bcbc2>] ? SyS_read+0x42/0xa0
  [<ffffffff81549ab2>] ? entry_SYSCALL_64_fastpath+0x16/0x75
 Code: 48 85 c0 75 d8 f3 c3 31 c0 c3 f3 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00
a 04 89 f0 33 02 44 89 c9 48 d3 e8 0f b6 4a 05 49 89
 RIP  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
  RSP <ffff88011a05fda0>
 CR2: ffffc90001630024

Signed-off-by: Dave Forster <dforster@brocade.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-06 00:10:05 -04:00
Linus Torvalds 34229b2774 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "This looks like a lot but it's a mixture of regression fixes as well
  as fixes for longer standing issues.

   1) Fix on-channel cancellation in mac80211, from Johannes Berg.

   2) Handle CHECKSUM_COMPLETE properly in xt_TCPMSS netfilter xtables
      module, from Eric Dumazet.

   3) Avoid infinite loop in UDP SO_REUSEPORT logic, also from Eric
      Dumazet.

   4) Avoid a NULL deref if we try to set SO_REUSEPORT after a socket is
      bound, from Craig Gallek.

   5) GRO key comparisons don't take lightweight tunnels into account,
      from Jesse Gross.

   6) Fix struct pid leak via SCM credentials in AF_UNIX, from Eric
      Dumazet.

   7) We need to set the rtnl_link_ops of ipv6 SIT tunnels before we
      register them, otherwise the NEWLINK netlink message is missing
      the proper attributes.  From Thadeu Lima de Souza Cascardo.

   8) Several Spectrum chip bug fixes for mlxsw switch driver, from Ido
      Schimmel

   9) Handle fragments properly in ipv4 easly socket demux, from Eric
      Dumazet.

  10) Don't ignore the ifindex key specifier on ipv6 output route
      lookups, from Paolo Abeni"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (128 commits)
  tcp: avoid cwnd undo after receiving ECN
  irda: fix a potential use-after-free in ircomm_param_request
  net: tg3: avoid uninitialized variable warning
  net: nb8800: avoid uninitialized variable warning
  net: vxge: avoid unused function warnings
  net: bgmac: clarify CONFIG_BCMA dependency
  net: hp100: remove unnecessary #ifdefs
  net: davinci_cpdma: use dma_addr_t for DMA address
  ipv6/udp: use sticky pktinfo egress ifindex on connect()
  ipv6: enforce flowi6_oif usage in ip6_dst_lookup_tail()
  netlink: not trim skb for mmaped socket when dump
  vxlan: fix a out of bounds access in __vxlan_find_mac
  net: dsa: mv88e6xxx: fix port VLAN maps
  fib_trie: Fix shift by 32 in fib_table_lookup
  net: moxart: use correct accessors for DMA memory
  ipv4: ipconfig: avoid unused ic_proto_used symbol
  bnxt_en: Fix crash in bnxt_free_tx_skbs() during tx timeout.
  bnxt_en: Exclude rx_drop_pkts hw counter from the stack's rx_dropped counter.
  bnxt_en: Ring free response from close path should use completion ring
  net_sched: drr: check for NULL pointer in drr_dequeue
  ...
2016-02-01 15:56:08 -08:00
Alexander Duyck a5829f536b fib_trie: Fix shift by 32 in fib_table_lookup
The fib_table_lookup function had a shift by 32 that triggered a UBSAN
warning.  This was due to the fact that I had placed the shift first and
then followed it with the check for the suffix length to ignore the
undefined behavior.  If we reorder this so that we verify the suffix is
less than 32 before shifting the value we can avoid the issue.

Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-29 19:41:00 -08:00
Tetsuo Handa 1d5cfdb076 tree wide: use kvfree() than conditional kfree()/vfree()
There are many locations that do

  if (memory_was_allocated_by_vmalloc)
    vfree(ptr);
  else
    kfree(ptr);

but kvfree() can handle both kmalloc()ed memory and vmalloc()ed memory
using is_vmalloc_addr().  Unless callers have special reasons, we can
replace this branch with kvfree().  Please check and reply if you found
problems.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Jan Kara <jack@suse.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Boris Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-22 17:02:18 -08:00
Alexander Duyck c2229fe143 fib_trie: leaf_walk_rcu should not compute key if key is less than pn->key
We were computing the child index in cases where the key value we were
looking for was actually less than the base key of the tnode.  As a result
we were getting incorrect index values that would cause us to skip over
some children.

To fix this I have added a test that will force us to use child index 0 if
the key we are looking for is less than the key of the current tnode.

Fixes: 8be33e955c ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf")
Reported-by: Brian Rak <brak@gameservers.com>
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-27 18:14:51 -07:00
David Ahern 58189ca7b2 net: Fix vti use case with oif in dst lookups
Steffen reported that the recent change to add oif to dst lookups breaks
the VTI use case. The problem is that with the oif set in the flow struct
the comparison to the nh_oif is triggered. Fix by splitting the
FLOWI_FLAG_VRFSRC into 2 flags -- one that triggers the vrf device cache
bypass (FLOWI_FLAG_VRFSRC) and another telling the lookup to not compare
nh oif (FLOWI_FLAG_SKIP_NH_OIF).

Fixes: 42a7b32b73 ("xfrm: Add oif to dst lookups")

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 16:36:34 -07:00
David Ahern f6d3c19274 net: FIB tracepoints
A few useful tracepoints developing VRF driver.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-29 13:05:16 -07:00
David S. Miller dc25b25897 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/qmi_wwan.c

Overlapping additions of new device IDs to qmi_wwan.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-21 11:44:04 -07:00
David Ahern 613d09b30f net: Use VRF device index for lookups on TX
As with ingress use the index of VRF master device for route lookups on
egress. However, the oif should only be used to direct the lookups to a
specific table. Routes in the table are not based on the VRF device but
rather interfaces that are part of the VRF so do not consider the oif for
lookups within the table. The FLOWI_FLAG_VRFSRC is used to control this
latter part.

Signed-off-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-13 22:43:20 -07:00
Andy Whitcroft 25b97c016b ipv4: off-by-one in continuation handling in /proc/net/route
When generating /proc/net/route we emit a header followed by a line for
each route.  When a short read is performed we will restart this process
based on the open file descriptor.  When calculating the start point we
fail to take into account that the 0th entry is the header.  This leads
us to skip the first entry when doing a continuation read.

This can be easily seen with the comparison below:

  while read l; do echo "$l"; done </proc/net/route >A
  cat /proc/net/route >B
  diff -bu A B | grep '^[+-]'

On my example machine I have approximatly 10KB of route output.  There we
see the very first non-title element is lost in the while read case,
and an entry around the 8K mark in the cat case:

  +wlan0 00000000 02021EAC 0003 0 0 400 00000000 0 0 0
  -tun1  00C0AC0A 00000000 0001 0 0 950 00C0FFFF 0 0 0

Fix up the off-by-one when reaquiring position on continuation.

Fixes: 8be33e955c ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf")
BugLink: http://bugs.launchpad.net/bugs/1483440
Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-13 21:16:29 -07:00
Alexander Duyck 1513069edc fib_trie: Drop unnecessary calls to leaf_pull_suffix
It was reported that update_suffix was taking a long time on systems where
a large number of leaves were attached to a single node.  As it turns out
fib_table_flush was calling update_suffix for each leaf that didn't have all
of the aliases stripped from it.  As a result, on this large node removing
one leaf would result in us calling update_suffix for every other leaf on
the node.

The fix is to just remove the calls to leaf_pull_suffix since they are
redundant as we already have a call in resize that will go through and
update the suffix length for the node before we exit out of
fib_table_flush or fib_table_flush_external.

Reported-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27 14:29:11 -07:00
Julian Anastasov 2392debc2b ipv4: consider TOS in fib_select_default
fib_select_default considers alternative routes only when
res->fi is for the first alias in res->fa_head. In the
common case this can happen only when the initial lookup
matches the first alias with highest TOS value. This
prevents the alternative routes to require specific TOS.

This patch solves the problem as follows:

- routes that require specific TOS should be returned by
fib_select_default only when TOS matches, as already done
in fib_table_lookup. This rule implies that depending on the
TOS we can have many different lists of alternative gateways
and we have to keep the last used gateway (fa_default) in first
alias for the TOS instead of using single tb_default value.

- as the aliases are ordered by many keys (TOS desc,
fib_priority asc), we restrict the possible results to
routes with matching TOS and lowest metric (fib_priority)
and routes that match any TOS, again with lowest metric.

For example, packet with TOS 8 can not use gw3 (not lowest
metric), gw4 (different TOS) and gw6 (not lowest metric),
all other gateways can be used:

tos 8 via gw1 metric 2 <--- res->fa_head and res->fi
tos 8 via gw2 metric 2
tos 8 via gw3 metric 3
tos 4 via gw4
tos 0 via gw5
tos 0 via gw6 metric 1

Reported-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-24 22:46:11 -07:00
Andy Gospodarek 0eeb075fad net: ipv4 sysctl option to ignore routes when nexthop link is down
This feature is only enabled with the new per-interface or ipv4 global
sysctls called 'ignore_routes_with_linkdown'.

net.ipv4.conf.all.ignore_routes_with_linkdown = 0
net.ipv4.conf.default.ignore_routes_with_linkdown = 0
net.ipv4.conf.lo.ignore_routes_with_linkdown = 0
...

When the above sysctls are set, will report to userspace that a route is
dead and will no longer resolve to this nexthop when performing a fib
lookup.  This will signal to userspace that the route will not be
selected.  The signalling of a RTNH_F_DEAD is only passed to userspace
if the sysctl is enabled and link is down.  This was done as without it
the netlink listeners would have no idea whether or not a nexthop would
be selected.   The kernel only sets RTNH_F_DEAD internally if the
interface has IFF_UP cleared.

With the new sysctl set, the following behavior can be observed
(interface p8p1 is link-down):

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1 dead linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1 dead linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2
90.0.0.1 via 70.0.0.2 dev p7p1  src 70.0.0.1
    cache
local 80.0.0.1 dev lo  src 80.0.0.1
    cache <local>
80.0.0.2 via 10.0.5.2 dev p9p1  src 10.0.5.15
    cache

While the route does remain in the table (so it can be modified if
needed rather than being wiped away as it would be if IFF_UP was
cleared), the proper next-hop is chosen automatically when the link is
down.  Now interface p8p1 is linked-up:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2
192.168.56.0/24 dev p2p1  proto kernel  scope link  src 192.168.56.2
90.0.0.1 via 80.0.0.2 dev p8p1  src 80.0.0.1
    cache
local 80.0.0.1 dev lo  src 80.0.0.1
    cache <local>
80.0.0.2 dev p8p1  src 80.0.0.1
    cache

and the output changes to what one would expect.

If the sysctl is not set, the following output would be expected when
p8p1 is down:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1 linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1 linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2

Since the dead flag does not appear, there should be no expectation that
the kernel would skip using this route due to link being down.

v2: Split kernel changes into 2 patches, this actually makes a
behavioral change if the sysctl is set.  Also took suggestion from Alex
to simplify code by only checking sysctl during fib lookup and
suggestion from Scott to add a per-interface sysctl.

v3: Code clean-ups to make it more readable and efficient as well as a
reverse path check fix.

v4: Drop binary sysctl

v5: Whitespace fixups from Dave

v6: Style changes from Dave and checkpatch suggestions

v7: One more checkpatch fixup

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24 02:15:54 -07:00
Roopa Prabhu a2bb6d7d6f ipv4: include NLM_F_APPEND flag in append route notifications
This patch adds NLM_F_APPEND flag to struct nlmsg_hdr->nlmsg_flags
in newroute notifications if the route add was an append.
(This is similar to how NLM_F_REPLACE is already part of new
route replace notifications today)

This helps userspace determine if the route add operation was
an append.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-21 10:23:04 -07:00
Firo Yang f38b24c905 fib_trie: coding style: Use pointer after check
As Alexander Duyck pointed out that:
struct tnode {
        ...
        struct key_vector kv[1];
}
The kv[1] member of struct tnode is an arry that refernced by
a null pointer will not crash the system, like this:
struct tnode *p = NULL;
struct key_vector *kv = p->kv;
As such p->kv doesn't actually dereference anything, it is simply a
means for getting the offset to the array from the pointer p.

This patch make the code more regular to avoid making people feel
odd when they look at the code.

Signed-off-by: Firo Yang <firogm@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-07 23:45:40 -07:00
David S. Miller ffa915d071 ipv4: Fix fib_trie.c build, missing linux/vmalloc.h include.
We used to get this indirectly I supposed, but no longer do.

Either way, an explicit include should have been done in the
first place.

   net/ipv4/fib_trie.c: In function '__node_free_rcu':
>> net/ipv4/fib_trie.c:293:3: error: implicit declaration of function 'vfree' [-Werror=implicit-function-declaration]
      vfree(n);
      ^
   net/ipv4/fib_trie.c: In function 'tnode_alloc':
>> net/ipv4/fib_trie.c:312:3: error: implicit declaration of function 'vzalloc' [-Werror=implicit-function-declaration]
      return vzalloc(size);
      ^
>> net/ipv4/fib_trie.c:312:3: warning: return makes pointer from integer without a cast
   cc1: some warnings being treated as errors

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-27 00:19:03 -04:00
David S. Miller 36583eb54d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/cadence/macb.c
	drivers/net/phy/phy.c
	include/linux/skbuff.h
	net/ipv4/tcp.c
	net/switchdev/switchdev.c

Switchdev was a case of RTNH_H_{EXTERNAL --> OFFLOAD}
renaming overlapping with net-next changes of various
sorts.

phy.c was a case of two changes, one adding a local
variable to a function whilst the second was removing
one.

tcp.c overlapped a deadlock fix with the addition of new tcp_info
statistic values.

macb.c involved the addition of two zyncq device entries.

skbuff.h involved adding back ipv4_daddr to nf_bridge_info
whilst net-next changes put two other existing members of
that struct into a union.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-23 01:22:35 -04:00
Michal Kubeček d4e64c2909 ipv4: fill in table id when replacing a route
When replacing an IPv4 route, tb_id member of the new fib_alias
structure is not set in the replace code path so that the new route is
ignored.

Fixes: 0ddcf43d5d ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-22 14:33:17 -04:00
Roopa Prabhu eea39946a1 rename RTNH_F_EXTERNAL to RTNH_F_OFFLOAD
RTNH_F_EXTERNAL today is printed as "offload" in iproute2 output.

This patch renames the flag to be consistent with what the user sees.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-14 22:45:39 -04:00
Jiri Pirko ebb9a03a59 switchdev: s/netdev_switch_/switchdev_/ and s/NETDEV_SWITCH_/SWITCHDEV_/
Turned out that "switchdev" sticks. So just unify all related terms to use
this prefix.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-12 18:43:52 -04:00
Ian Morris 00db41243e ipv4: coding style: comparison for inequality with NULL
The ipv4 code uses a mixture of coding styles. In some instances check
for non-NULL pointer is done as x != NULL and sometimes as x. x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-03 12:11:15 -04:00
Ian Morris 51456b2914 ipv4: coding style: comparison for equality with NULL
The ipv4 code uses a mixture of coding styles. In some instances check
for NULL pointer is done as x == NULL and sometimes as !x. !x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-03 12:11:15 -04:00
Alexander Duyck b6f15f828d fib_trie: Fix regression in handling of inflate/halve failure
When I updated the code to address a possible null pointer dereference in
resize I ended up reverting an exception handling fix for the suffix length
in the event that inflate or halve failed.  This change is meant to correct
that by reverting the earlier fix and instead simply getting the parent
again after inflate has been completed to avoid the possible null pointer
issue.

Fixes: ddb4b9a13 ("fib_trie: Address possible NULL pointer dereference in resize")
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 16:58:32 -04:00
Alexander Duyck 0b65bd97ba fib_trie: Provide a deterministic order for fib_alias w/ tables merged
This change makes it so that we should always have a deterministic ordering
for the main and local aliases within the merged table when two leaves
overlap.

So for example if we have a leaf with a key of 192.168.254.0.  If we
previously added two aliases with a prefix length of 24 from both local and
main the first entry would be first and the second would be second.  When I
was coding this I had added a WARN_ON should such a situation occur as I
wasn't sure how likely it would be.  However this WARN_ON has been
triggered so this is something that should be addressed.

With this patch the ordering of the aliases is as follows.  First they are
sorted on prefix length, then on their table ID, then tos, and finally
priority.  This way what we end up doing is essentially interleaving the
two tables on what used to be leaf_info structure boundaries.

Fixes: 0ddcf43d5 ("ipv4: FIB Local/MAIN table collapse")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 18:26:51 -04:00
Alexander Duyck 654eff4516 fib_trie: Only display main table in /proc/net/route
When we merged the tries for local and main I had overlooked the iterator
for /proc/net/route.  As a result it was outputting both local and main
when the two tries were merged.

This patch resolves that by only providing output for aliases that are
actually in the main trie.  As a result we should go back to the original
behavior which I assume will be necessary to maintain legacy support.

Fixes: 0ddcf43d5 ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 21:24:32 -04:00
Alexander Duyck 0ddcf43d5d ipv4: FIB Local/MAIN table collapse
This patch is meant to collapse local and main into one by converting
tb_data from an array to a pointer.  Doing this allows us to point the
local table into the main while maintaining the same variables in the
table.

As such the tb_data was converted from an array to a pointer, and a new
array called data is added in order to still provide an object for tb_data
to point to.

In order to track the origin of the fib aliases a tb_id value was added in
a hole that existed on 64b systems.  Using this we can also reverse the
merge in the event that custom FIB rules are enabled.

With this patch I am seeing an improvement of 20ns to 30ns for routing
lookups as long as custom rules are not enabled, with custom rules enabled
we fall back to split tables and the original behavior.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 16:22:14 -04:00
Alexander Duyck ddb4b9a132 fib_trie: Address possible NULL pointer dereference in resize
If the inflate call failed it would return NULL.  As a result tp would be
set to NULL and cause use to trigger a NULL pointer dereference in
should_halve if the inflate failed on the first attempt.

In order to prevent this we should decrement max_work before we actually
attempt to inflate as this will force us to exit before attempting to halve
a node we should have inflated.  In order to keep things symmetric between
inflate and halve I went ahead and also moved the decrement of max_work for
the halve case as well so we take care of that before we actually attempt
to halve the tnode.

Fixes: 88bae714 ("fib_trie: Add key vector to root, return parent key_vector in resize")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-10 18:36:56 -04:00
Alexander Duyck 3ec320dd5c fib_trie: Correctly handle case of key == 0 in leaf_walk_rcu
In the case of a trie that had no tnodes with a key of 0 the initial
look-up would fail resulting in an out-of-bounds cindex on the first tnode.
This resulted in an entire trie being skipped.

In order resolve this I have updated the cindex logic in the initial
look-up so that if the key is zero we will always traverse the child zero
path.

Fixes: 8be33e95 ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Tested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-10 16:13:55 -04:00
Scott Feldman f8f2147150 switchdev: add netlink flags to IPv4 FIB add op
Pass in the netlink flags (NLM_F_*) into switchdev driver for IPv4 FIB add op
to allow driver to 1) optimize hardware updates, 2) handle ip route prepend
and append commands correctly.

Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Suggested-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-09 23:56:52 -04:00
Alexander Duyck 88bae7149a fib_trie: Add key vector to root, return parent key_vector in resize
This change makes it so that the root of the trie contains a key_vector, by
doing this we make room to essentially collapse the entire trie by at least
one cache line as we can store the information about the tnode or leaf that
is pointed to in the root.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:28 -05:00
Alexander Duyck f23e59fbd7 fib_trie: Move parent from key_vector to tnode
This change pulls the parent pointer from the key_vector and places it in
the tnode structure.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:28 -05:00
Alexander Duyck 6e22d174ba fib_trie: Pull empty_children and full_children into tnode
This pulls the information about the child array out of the key_vector and
places it in the tnode since that is where it is needed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:28 -05:00
Alexander Duyck 56ca2adf6a fib_trie: Move rcu from key_vector to tnode, add accessors.
RCU is only needed once for the entire node, not once per key_vector so we
can pull that out and move it to the tnode structure.

In addition add accessors to be used inside the RCU functions so that we
can more easily get from the key vector to either the tnode or the trie
pointers.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:28 -05:00
Alexander Duyck dc35dbeda3 fib_trie: Add tnode struct as a container for fields not needed in key_vector
This change pulls the fields not explicitly needed in the key_vector and
placed them in the new tnode structure.  By doing this we will eventually
be able to reduce the key_vector down to 16 bytes on 64 bit systems, and
12 bytes on 32 bit systems.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:28 -05:00
Alexander Duyck 2e1ac88a48 fib_trie: Rename tnode_child_length to child_length
We are now checking the length of a key_vector instead of a tnode so it
makes sense to probably just rename this to child_length since it would
probably even be applicable to a leaf.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:28 -05:00
Alexander Duyck 754baf8dec fib_trie: replace tnode_get_child functions with get_child macros
I am replacing the tnode_get_child call with get_child since we are
techically pulling the child out of a key_vector now and not a tnode.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:27 -05:00
Alexander Duyck 35c6edac19 fib_trie: Rename tnode to key_vector
Rename the tnode to key_vector.  The key_vector will be the eventual
container for all of the information needed by either a leaf or a tnode.
The final result should be much smaller than the 40 bytes currently needed
for either one.

This also updates the trie struct so that it contains an array of size 1 of
tnode pointers.  This is to bring the structure more inline with how an
actual tnode itself is configured.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:27 -05:00
Alexander Duyck 8d8e810ca8 fib_trie: Return pointer to tnode pointer in resize/inflate/halve
Resize related functions now all return a pointer to the pointer that
references the object that was resized.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:27 -05:00
Alexander Duyck 72be72607a fib_trie: Minor cleanups to fib_table_flush_external
This change just does a couple of minor cleanups on
fib_table_flush_external.  Specifically it addresses the fact that resize
was being called even though nothing was being removed from the table, and
it drops an unecessary indent since we could just call continue on the
inverse of the fi && flag check.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:49:27 -05:00
David S. Miller 23375a0fd5 ipv4: Fix unused variable warnings in fib_table_flush_external.
net/ipv4/fib_trie.c: In function ‘fib_table_flush_external’:
net/ipv4/fib_trie.c:1572:6: warning: unused variable ‘found’ [-Wunused-variable]
  int found = 0;
      ^
net/ipv4/fib_trie.c:1571:16: warning: unused variable ‘slen’ [-Wunused-variable]
  unsigned char slen;
                ^

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 00:38:35 -05:00
Scott Feldman 8e05fd7166 fib: hook IPv4 fib for hardware offload
Call into the switchdev driver any time an IPv4 fib entry is
added/modified/deleted from the kernel's FIB.  The switchdev driver may or
may not install the route to the offload device.  In the case where the
driver tries to install the route and something goes wrong (device's routing
table is full, etc), then all of the offloaded routes will be flushed from the
device, route forwarding falls back to the kernel, and no more routes are
offloading.

We can refine this logic later.  For now, use the simplist model of offloading
routes up to the point of failure, and then on failure, undo everything and
mark IPv4 offloading disabled.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 00:24:58 -05:00
Scott Feldman 104616e74e switchdev: don't support custom ip rules, for now
Keep switchdev FIB offload model simple for now and don't allow custom ip
rules.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 00:24:58 -05:00
Alexander Duyck 1de3d87bcd fib_trie: Prevent allocating tnode if bits is too big for size_t
This patch adds code to prevent us from attempting to allocate a tnode with
a size larger than what can be represented by size_t.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Alexander Duyck 71e8b67d0f fib_trie: Update last spot w/ idx >> n->bits code and explanation
This change updates the fib_table_lookup function so that it is in sync
with the fib_find_node function in terms of the explanation for the index
check based on the bits value.

I have also updated it from doing a mask to just doing a compare as I have
found that seems to provide more options to the compiler as I have seen it
turn this into a shift of the value and test under some circumstances.

In addition I addressed one minor issue in which we kept computing the key
^ n->key when checking the fib aliases.  I pulled the xor out of the loop
in order to reduce the number of memory reads in the lookup.  As a result
we should save a couple cycles since the xor is only done once much earlier
in the lookup.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Alexander Duyck a7e5353123 fib_trie: Make fib_table rcu safe
The fib_table was wrapped in several places with an
rcu_read_lock/rcu_read_unlock however after looking over the code I found
several spots where the tables were being accessed as just standard
pointers without any protections.  This change fixes that so that all of
the proper protections are in place when accessing the table to take RCU
replacement or removal of the table into account.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Alexander Duyck 41b489fd6c fib_trie: move leaf and tnode to occupy the same spot in the key vector
If we are going to compact the leaf and tnode we first need to make sure
the fields are all in the same place.  In that regard I am moving the leaf
pointer which represents the fib_alias hash list to occupy what is
currently the first key_vector pointer.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Alexander Duyck d5d6487cb8 fib_trie: Update insert and delete to make use of tp from find_node
This change makes it so that the insert and delete functions make use of
the tnode pointer returned in the fib_find_node call.  By doing this we
will not have to rely on the parent pointer in the leaf which will be going
away soon.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Alexander Duyck d4a975e83f fib_trie: Fib find node should return parent
This change makes it so that the parent pointer is returned by reference in
fib_find_node.  By doing this I can use it to find the parent node when I
am performing an insertion and I don't have to look for it again in
fib_insert_node.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:17 -05:00
Alexander Duyck 8be33e955c fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf
This change makes it so that leaf_walk_rcu takes a tnode and a key instead
of the trie and a leaf.

The main idea behind this is to avoid using the leaf parent pointer as that
can have additional overhead in the future as I am trying to reduce the
size of a leaf down to 16 bytes on 64b systems and 12b on 32b systems.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:17 -05:00
Alexander Duyck 7289e6ddb6 fib_trie: Only resize tnodes once instead of on each leaf removal in fib_table_flush
This change makes it so that we only call resize on the tnodes, instead of
from each of the leaves.  By doing this we can significantly reduce the
amount of time spent resizing as we can update all of the leaves in the
tnode first before we make any determinations about resizing.  As a result
we can simply free the tnode in the case that all of the leaves from a
given tnode are flushed instead of resizing with each leaf removed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:17 -05:00
Alexander Duyck 79e5ad2ceb fib_trie: Remove leaf_info
At this point the leaf_info hash is redundant.  By adding the suffix length
to the fib_alias hash list we no longer have need of leaf_info as we can
determine the prefix length from fa_slen.  So we can compress things by
dropping the leaf_info structure from fib_trie and instead directly connect
the leaves to the fib_alias hash list.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27 16:37:07 -05:00
Alexander Duyck 9b6ebad5c3 fib_trie: Add slen to fib alias
Make use of an empty spot in the alias to store the suffix length so that
we don't need to pull that information from the leaf_info structure.

This patch also makes a slight change to the user statistics.  Instead of
incrementing semantic_match_miss once per leaf_info miss we now just
increment it once per leaf if a match was not found.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27 16:37:07 -05:00
Alexander Duyck 5786ec6054 fib_trie: Replace plen with slen in leaf_info
This replaces the prefix length variable in the leaf_info structure with a
suffix length value, or host identifier length in bits.  By doing this it
makes it easier to sort out since the tnodes and leaf are carrying this
value as well since it is compatible with the ->pos field in tnodes.

I also cleaned up one spot that had some list manipulation that could be
simplified.  I basically updated it so that we just use hlist_add_head_rcu
instead of calling hlist_add_before_rcu on the first node in the list.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27 16:37:06 -05:00
Alexander Duyck 56315f9e6e fib_trie: Convert fib_alias to hlist from list
There isn't any advantage to having it as a list and by making it an hlist
we make the fib_alias more compatible with the list_info in terms of the
type of list used.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27 16:37:06 -05:00
Alexander Duyck 64c6272351 fib_trie: Various clean-ups for handling slen
While doing further work on the fib_trie I noted a few items.

First I was using calls that were far more complicated than they needed to
be for determining when to push/pull the suffix length.  I have updated the
code to reflect the simplier logic.

The second issue is that I realised we weren't necessarily handling the
case of a leaf_info struct surviving a flush.  I have updated the logic so
that now we will call pull_suffix in the event of having a leaf info value
left in the leaf after flushing it.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:16 -08:00
Alexander Duyck 02525368f4 fib_trie: Move fib_find_alias to file where it is used
The function fib_find_alias is only accessed by functions in fib_trie.c as
such it makes sense to relocate it and cast it as static so that the
compiler can take advantage of optimizations it can do to it as a local
function.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:16 -08:00
Alexander Duyck 30cfe7c9c8 fib_trie: Use empty_children instead of counting empty nodes in stats collection
It doesn't make much sense to count the pointers ourselves when
empty_children already has a count for the number of NULL pointers stored
in the tnode.  As such save ourselves the cycles and just use
empty_children.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:16 -08:00
Alexander Duyck 95f60ea3e9 fib_trie: Add collapse() and should_collapse() to resize
This patch really does two things.

First it pulls the logic for determining if we should collapse one node out
of the tree and the actual code doing the collapse into a separate pair of
functions.  This helps to make the changes to these areas more readable.

Second it encodes the upper 32b of the empty_children value onto the
full_children value in the case of bits == KEYLENGTH.  By doing this we are
able to handle the case of a 32b node where empty_children would appear to
be 0 when it was actually 1ul << 32.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:16 -08:00
Alexander Duyck a80e89d4c6 fib_trie: Fall back to slen update on inflate/halve failure
This change corrects an issue where if inflate or halve fails we were
exiting the resize function without at least updating the slen for the
node.  To correct this I have moved the update of max_size into the while
loop so that it is only decremented on a successful call to either inflate
or halve.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:16 -08:00
Alexander Duyck 69fa57b1e4 fib_trie: Fix RCU bug and merge similar bits of inflate/halve
This patch addresses two issues.

The first issue is the fact that I believe I had the RCU freeing sequence
slightly out of order.  As a result we could get into an issue if a caller
went into a child of a child of the new node, then backtraced into the to be
freed parent, and then attempted to access a child of a child that may have
been consumed in a resize of one of the new nodes children.  To resolve this I
have moved the resize after we have freed the oldtnode.  The only side effect
of this is that we will now be calling resize on more nodes in the case of
inflate due to the fact that we don't have a good way to test to see if a
full_tnode on the new node was there before or after the allocation.  This
should have minimal impact however since the node should already be
correctly size so it is just the cost of calling should_inflate that we
will be taking on the node which is only a couple of cycles.

The second issue is the fact that inflate and halve were essentially doing
the same thing after the new node was added to the trie replacing the old
one.  As such it wasn't really necessary to keep the code in both functions
so I have split it out into two other functions, called replace and
update_children.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:15 -08:00
Alexander Duyck b3832117b4 fib_trie: Use index & (~0ul << n->bits) instead of index >> n->bits
In doing performance testing and analysis of the changes I recently found
that by shifting the index I had created an unnecessary dependency.

I have updated the code so that we instead shift a mask by bits and then
just test against that as that should save us about 2 CPU cycles since we
can generate the mask while the key and pos are being processed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-25 14:47:15 -08:00
Alexander Duyck 5405afd1a3 fib_trie: Add tracking value for suffix length
This change adds a tracking value for the maximum suffix length of all
prefixes stored in any given tnode.  With this value we can determine if we
need to backtrace or not based on if the suffix is greater than the pos
value.

By doing this we can reduce the CPU overhead for lookups in the local table
as many of the prefixes there are 32b long and have a suffix length of 0
meaning we can immediately backtrace to the root node without needing to
test any of the nodes between it and where we ended up.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-31 18:25:55 -05:00
Alexander Duyck 21d1f11db0 fib_trie: Remove checks for index >= tnode_child_length from tnode_get_child
For some reason the compiler doesn't seem to understand that when we are in
a loop that runs from tnode_child_length - 1 to 0 we don't expect the value
of tn->bits to change.  As such every call to tnode_get_child was rerunning
tnode_chile_length which ended up consuming quite a bit of space in the
resultant assembly code.

I have gone though and verified that in all cases where tnode_get_child
is used we are either winding though a fixed loop from tnode_child_length -
1 to 0, or are in a fastpath case where we are verifying the value by
either checking for any remaining bits after shifting index by bits and
testing for leaf, or by using tnode_child_length.

size net/ipv4/fib_trie.o
Before:
   text	   data	    bss	    dec	    hex	filename
  15506	    376	      8	  15890	   3e12	net/ipv4/fib_trie.o

After:
   text	   data	    bss	    dec	    hex	filename
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Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-31 18:25:55 -05:00
Alexander Duyck 12c081a5c8 fib_trie: inflate/halve nodes in a more RCU friendly way
This change pulls the node_set_parent functionality out of put_child_reorg
and instead leaves that to the function to take care of as well.  By doing
this we can fully construct the new cluster of tnodes and all of the
pointers out of it before we start routing pointers into it.

I am suspecting this will likely fix some concurency issues though I don't
have a good test to show as such.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-31 18:25:55 -05:00
Alexander Duyck fc86a93b46 fib_trie: Push tnode flushing down to inflate/halve
This change pushes the tnode freeing down into the inflate and halve
functions.  It makes more sense here as we have a better grasp of what is
going on and when a given cluster of nodes is ready to be freed.

I believe this may address a bug in the freeing logic as well.  For some
reason if the freelist got to a certain size we would call
synchronize_rcu().  I'm assuming that what they meant to do is call
synchronize_rcu() after they had handed off that much memory via
call_rcu().  As such that is what I have updated the behavior to be.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-31 18:25:55 -05:00
Alexander Duyck ff181ed876 fib_trie: Push assignment of child to parent down into inflate/halve
This change makes it so that the assignment of the tnode to the parent is
handled directly within whatever function is currently handling the node be
it inflate, halve, or resize.  By doing this we can avoid some of the need
to set NULL pointers in the tree while we are resizing the subnodes.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-31 18:25:55 -05:00