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  1. 22 3月, 2019 3 次提交
    • N
      rhashtable: rename rht_for_each*continue as *from. · f7ad68bf
      由 NeilBrown 提交于 
      The pattern set by list.h is that for_each..continue()
iterators start at the next entry after the given one,
while for_each..from() iterators start at the given
entry.

The rht_for_each*continue() iterators are documented as though the
start at the 'next' entry, but actually start at the given entry,
and they are used expecting that behaviour.
So fix the documentation and change the names to *from for consistency
with list.h
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NMiguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f7ad68bf
    • N
      rhashtable: don't hold lock on first table throughout insertion. · 4feb7c7a
      由 NeilBrown 提交于 
      rhashtable_try_insert() currently holds a lock on the bucket in
the first table, while also locking buckets in subsequent tables.
This is unnecessary and looks like a hold-over from some earlier
version of the implementation.

As insert and remove always lock a bucket in each table in turn, and
as insert only inserts in the final table, there cannot be any races
that are not covered by simply locking a bucket in each table in turn.

When an insert call reaches that last table it can be sure that there
is no matchinf entry in any other table as it has searched them all, and
insertion never happens anywhere but in the last table.  The fact that
code tests for the existence of future_tbl while holding a lock on
the relevant bucket ensures that two threads inserting the same key
will make compatible decisions about which is the "last" table.

This simplifies the code and allows the ->rehash field to be
discarded.

We still need a way to ensure that a dead bucket_table is never
re-linked by rhashtable_walk_stop().  This can be achieved by calling
call_rcu() inside the locked region, and checking with
rcu_head_after_call_rcu() in rhashtable_walk_stop() to see if the
bucket table is empty and dead.
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4feb7c7a
    • H
      rhashtable: Still do rehash when we get EEXIST · 408f13ef
      由 Herbert Xu 提交于 
      As it stands if a shrink is delayed because of an outstanding
rehash, we will go into a rescheduling loop without ever doing
the rehash.

This patch fixes this by still carrying out the rehash and then
rescheduling so that we can shrink after the completion of the
rehash should it still be necessary.

The return value of EEXIST captures this case and other cases
(e.g., another thread expanded/rehashed the table at the same
time) where we should still proceed with the rehash.

Fixes: da20420f ("rhashtable: Add nested tables")
Reported-by: NJosh Elsasser <jelsasser@appneta.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Tested-by: NJosh Elsasser <jelsasser@appneta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      408f13ef
  3. 22 2月, 2019 1 次提交
  5. 04 12月, 2018 1 次提交
    • N
      rhashtable: detect when object movement between tables might have invalidated a lookup · 82208d0d
      由 NeilBrown 提交于 
      Some users of rhashtables might need to move an object from one table
to another -  this appears to be the reason for the incomplete usage
of NULLS markers.

To support these, we store a unique NULLS_MARKER at the end of
each chain, and when a search fails to find a match, we check
if the NULLS marker found was the expected one.  If not, the search
may not have examined all objects in the target bucket, so it is
repeated.

The unique NULLS_MARKER is derived from the address of the
head of the chain.  As this cannot be derived at load-time the
static rhnull in rht_bucket_nested() needs to be initialised
at run time.

Any caller of a lookup function must still be prepared for the
possibility that the object returned is in a different table - it
might have been there for some time.

Note that this does NOT provide support for other uses of
NULLS_MARKERs such as allocating with SLAB_TYPESAFE_BY_RCU or changing
the key of an object and re-inserting it in the same table.
These could only be done safely if new objects were inserted
at the *start* of a hash chain, and that is not currently the case.
Signed-off-by: NNeilBrown <neilb@suse.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      82208d0d
  7. 23 8月, 2018 2 次提交
  9. 21 8月, 2018 1 次提交
  11. 19 7月, 2018 1 次提交
  13. 10 7月, 2018 1 次提交
    • T
      rhashtable: add restart routine in rhashtable_free_and_destroy() · 0026129c
      由 Taehee Yoo 提交于 
      rhashtable_free_and_destroy() cancels re-hash deferred work
then walks and destroys elements. at this moment, some elements can be
still in future_tbl. that elements are not destroyed.

test case:
nft_rhash_destroy() calls rhashtable_free_and_destroy() to destroy
all elements of sets before destroying sets and chains.
But rhashtable_free_and_destroy() doesn't destroy elements of future_tbl.
so that splat occurred.

test script:
   %cat test.nft
   table ip aa {
	   map map1 {
		   type ipv4_addr : verdict;
		   elements = {
			   0 : jump a0,
			   1 : jump a0,
			   2 : jump a0,
			   3 : jump a0,
			   4 : jump a0,
			   5 : jump a0,
			   6 : jump a0,
			   7 : jump a0,
			   8 : jump a0,
			   9 : jump a0,
		}
	   }
	   chain a0 {
	   }
   }
   flush ruleset
   table ip aa {
	   map map1 {
		   type ipv4_addr : verdict;
		   elements = {
			   0 : jump a0,
			   1 : jump a0,
			   2 : jump a0,
			   3 : jump a0,
			   4 : jump a0,
			   5 : jump a0,
			   6 : jump a0,
			   7 : jump a0,
			   8 : jump a0,
			   9 : jump a0,
		   }
	   }
	   chain a0 {
	   }
   }
   flush ruleset

   %while :; do nft -f test.nft; done

Splat looks like:
[  200.795603] kernel BUG at net/netfilter/nf_tables_api.c:1363!
[  200.806944] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  200.812253] CPU: 1 PID: 1582 Comm: nft Not tainted 4.17.0+ #24
[  200.820297] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[  200.830309] RIP: 0010:nf_tables_chain_destroy.isra.34+0x62/0x240 [nf_tables]
[  200.838317] Code: 43 50 85 c0 74 26 48 8b 45 00 48 8b 4d 08 ba 54 05 00 00 48 c7 c6 60 6d 29 c0 48 c7 c7 c0 65 29 c0 4c 8b 40 08 e8 58 e5 fd f8 <0f> 0b 48 89 da 48 b8 00 00 00 00 00 fc ff
[  200.860366] RSP: 0000:ffff880118dbf4d0 EFLAGS: 00010282
[  200.866354] RAX: 0000000000000061 RBX: ffff88010cdeaf08 RCX: 0000000000000000
[  200.874355] RDX: 0000000000000061 RSI: 0000000000000008 RDI: ffffed00231b7e90
[  200.882361] RBP: ffff880118dbf4e8 R08: ffffed002373bcfb R09: ffffed002373bcfa
[  200.890354] R10: 0000000000000000 R11: ffffed002373bcfb R12: dead000000000200
[  200.898356] R13: dead000000000100 R14: ffffffffbb62af38 R15: dffffc0000000000
[  200.906354] FS:  00007fefc31fd700(0000) GS:ffff88011b800000(0000) knlGS:0000000000000000
[  200.915533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  200.922355] CR2: 0000557f1c8e9128 CR3: 0000000106880000 CR4: 00000000001006e0
[  200.930353] Call Trace:
[  200.932351]  ? nf_tables_commit+0x26f6/0x2c60 [nf_tables]
[  200.939525]  ? nf_tables_setelem_notify.constprop.49+0x1a0/0x1a0 [nf_tables]
[  200.947525]  ? nf_tables_delchain+0x6e0/0x6e0 [nf_tables]
[  200.952383]  ? nft_add_set_elem+0x1700/0x1700 [nf_tables]
[  200.959532]  ? nla_parse+0xab/0x230
[  200.963529]  ? nfnetlink_rcv_batch+0xd06/0x10d0 [nfnetlink]
[  200.968384]  ? nfnetlink_net_init+0x130/0x130 [nfnetlink]
[  200.975525]  ? debug_show_all_locks+0x290/0x290
[  200.980363]  ? debug_show_all_locks+0x290/0x290
[  200.986356]  ? sched_clock_cpu+0x132/0x170
[  200.990352]  ? find_held_lock+0x39/0x1b0
[  200.994355]  ? sched_clock_local+0x10d/0x130
[  200.999531]  ? memset+0x1f/0x40

V2:
 - free all tables requested by Herbert Xu
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0026129c
  15. 03 7月, 2018 1 次提交
  17. 22 6月, 2018 6 次提交
  19. 25 4月, 2018 3 次提交
  21. 01 4月, 2018 1 次提交
  23. 07 3月, 2018 1 次提交
  25. 11 12月, 2017 3 次提交
    • T
      rhashtable: Call library function alloc_bucket_locks · 64e0cd0d
      由 Tom Herbert 提交于 
      To allocate the array of bucket locks for the hash table we now
call library function alloc_bucket_spinlocks. This function is
based on the old alloc_bucket_locks in rhashtable and should
produce the same effect.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      64e0cd0d
    • T
      rhashtable: Add rhastable_walk_peek · 2db54b47
      由 Tom Herbert 提交于 
      This function is like rhashtable_walk_next except that it only returns
the current element in the inter and does not advance the iter.

This patch also creates __rhashtable_walk_find_next. It finds the next
element in the table when the entry cached in iter is NULL or at the end
of a slot. __rhashtable_walk_find_next is called from
rhashtable_walk_next and rhastable_walk_peek.

end_of_table is an added field to the iter structure. This indicates
that the end of table was reached (walker.tbl being NULL is not a
sufficient condition for end of table).
Signed-off-by: NTom Herbert <tom@quantonium.net>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2db54b47
    • T
      rhashtable: Change rhashtable_walk_start to return void · 97a6ec4a
      由 Tom Herbert 提交于 
      Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

       ret = rhashtable_walk_start(rhiter);
       if (ret && ret != -EAGAIN)
               goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      97a6ec4a
  27. 20 9月, 2017 1 次提交
  29. 11 7月, 2017 1 次提交
  31. 20 6月, 2017 1 次提交
  33. 09 5月, 2017 1 次提交
  35. 02 5月, 2017 1 次提交
  37. 28 4月, 2017 1 次提交
  39. 27 4月, 2017 2 次提交
  41. 19 4月, 2017 1 次提交
  43. 02 3月, 2017 1 次提交
  45. 27 2月, 2017 2 次提交
  47. 18 2月, 2017 1 次提交
    • H
      rhashtable: Add nested tables · da20420f
      由 Herbert Xu 提交于 
      This patch adds code that handles GFP_ATOMIC kmalloc failure on
insertion.  As we cannot use vmalloc, we solve it by making our
hash table nested.  That is, we allocate single pages at each level
and reach our desired table size by nesting them.

When a nested table is created, only a single page is allocated
at the top-level.  Lower levels are allocated on demand during
insertion.  Therefore for each insertion to succeed, only two
(non-consecutive) pages are needed.

After a nested table is created, a rehash will be scheduled in
order to switch to a vmalloced table as soon as possible.  Also,
the rehash code will never rehash into a nested table.  If we
detect a nested table during a rehash, the rehash will be aborted
and a new rehash will be scheduled.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      da20420f
  49. 16 2月, 2017 1 次提交
  51. 14 2月, 2017 1 次提交
    • H
      rhashtable: Add nested tables · 40137906
      由 Herbert Xu 提交于 
      This patch adds code that handles GFP_ATOMIC kmalloc failure on
insertion.  As we cannot use vmalloc, we solve it by making our
hash table nested.  That is, we allocate single pages at each level
and reach our desired table size by nesting them.

When a nested table is created, only a single page is allocated
at the top-level.  Lower levels are allocated on demand during
insertion.  Therefore for each insertion to succeed, only two
(non-consecutive) pages are needed.

After a nested table is created, a rehash will be scheduled in
order to switch to a vmalloced table as soon as possible.  Also,
the rehash code will never rehash into a nested table.  If we
detect a nested table during a rehash, the rehash will be aborted
and a new rehash will be scheduled.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      40137906