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2015-12-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-7/+11
Conflicts: drivers/net/geneve.c Here we had an overlapping change, where in 'net' the extraneous stats bump was being removed whilst in 'net-next' the final argument to udp_tunnel6_xmit_skb() was being changed. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16rhashtable: add function to replace an elementTom Herbert1-0/+82
Add the rhashtable_replace_fast function. This replaces one object in the table with another atomically. The hashes of the new and old objects must be equal. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-04rhashtable: Prevent spurious EBUSY errors on insertionHerbert Xu1-7/+11
Thomas and Phil observed that under stress rhashtable insertion sometimes failed with EBUSY, even though this error should only ever been seen when we're under attack and our hash chain length has grown to an unacceptable level, even after a rehash. It turns out that the logic for detecting whether there is an existing rehash is faulty. In particular, when two threads both try to grow the same table at the same time, one of them may see the newly grown table and thus erroneously conclude that it had been rehashed. This is what leads to the EBUSY error. This patch fixes this by remembering the current last table we used during insertion so that rhashtable_insert_rehash can detect when another thread has also done a resize/rehash. When this is detected we will give up our resize/rehash and simply retry the insertion with the new table. Reported-by: Thomas Graf <tgraf@suug.ch> Reported-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Phil Sutter <phil@nwl.cc> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-17rhashtable: Add cap on number of elements in hash tableHerbert Xu1-0/+19
We currently have no limit on the number of elements in a hash table. This is a problem because some users (tipc) set a ceiling on the maximum table size and when that is reached the hash table may degenerate. Others may encounter OOM when growing and if we allow insertions when that happens the hash table perofrmance may also suffer. This patch adds a new paramater insecure_max_entries which becomes the cap on the table. If unset it defaults to max_size * 2. If it is also zero it means that there is no cap on the number of elements in the table. However, the table will grow whenever the utilisation hits 100% and if that growth fails, you will get ENOMEM on insertion. As allowing oversubscription is potentially dangerous, the name contains the word insecure. Note that the cap is not a hard limit. This is done for performance reasons as enforcing a hard limit will result in use of atomic ops that are heavier than the ones we currently use. The reasoning is that we're only guarding against a gross over- subscription of the table, rather than a small breach of the limit. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-24rhashtable: don't attempt to grow when at max_sizeJohannes Berg1-1/+2
The conversion of mac80211's station table to rhashtable had a bug that I found by accident in code review, that hadn't been found as rhashtable apparently managed to have a maximum hash chain length of one (!) in all our testing. In order to test the bug and verify the fix I set my rhashtable's max_size very low (4) in order to force getting hash collisions. At that point, rhashtable WARNed in rhashtable_insert_rehash() but didn't actually reject the hash table insertion. This caused it to lose insertions - my master list of stations would have 9 entries, but the rhashtable only had 5. This may warrant a deeper look, but that WARN_ON() just shouldn't happen. Fix this by not returning true from rht_grow_above_100() when the rhashtable's max_size has been reached - in this case the user is explicitly configuring it to be at most that big, so even if it's now above 100% it shouldn't attempt to resize. This fixes the "lost insertion" issue and consequently allows my code to display its error (and verify my fix for it.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25rhashtable: provide len to obj_hashfnPatrick McHardy1-2/+4
nftables sets will be converted to use so called setextensions, moving the key to a non-fixed position. To hash it, the obj_hashfn must be used, however it so far doesn't receive the length parameter. Pass the key length to obj_hashfn() and convert existing users. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-25rhashtable: Add rhashtable_free_and_destroy()Thomas Graf1-2/+3
rhashtable_destroy() variant which stops rehashes, iterates over the table and calls a callback to release resources. Avoids need for nft_hash to embed rhashtable internals and allows to get rid of the being_destroyed flag. It also saves a 2nd mutex lock upon destruction. Also fixes an RCU lockdep splash on nft set destruction due to calling rht_for_each_entry_safe() without holding bucket locks. Open code this loop as we need know that no mutations may occur in parallel. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25rhashtable: Disable automatic shrinking by defaultThomas Graf1-2/+5
Introduce a new bool automatic_shrinking to require the user to explicitly opt-in to automatic shrinking of tables. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25rhashtable: Mark internal/private inline functions as suchThomas Graf1-0/+2
Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25rhashtable: Use 'unsigned int' consistentlyThomas Graf1-7/+7
Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25rhashtable: Extend RCU read lock into rhashtable_insert_rehash()Thomas Graf1-1/+1
rhashtable_insert_rehash() requires RCU locks to be held in order to access ht->tbl and traverse to the last table. Fixes: ccd57b1bd324 ("rhashtable: Add immediate rehash during insertion") Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24rhashtable: Fix sleeping inside RCU critical section in walk_stopHerbert Xu1-0/+2
The commit 963ecbd41a1026d99ec7537c050867428c397b89 ("rhashtable: Fix use-after-free in rhashtable_walk_stop") fixed a real bug but created another one because we may end up sleeping inside an RCU critical section. This patch fixes it properly by replacing the mutex with a spin lock that specifically protects the walker lists. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24rhashtable: Add immediate rehash during insertionHerbert Xu1-5/+37
This patch reintroduces immediate rehash during insertion. If we find during insertion that the table is full or the chain length exceeds a set limit (currently 16 but may be disabled with insecure_elasticity) then we will force an immediate rehash. The rehash will contain an expansion if the table utilisation exceeds 75%. If this rehash fails then the insertion will fail. Otherwise the insertion will be reattempted in the new hash table. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24rhashtable: Add multiple rehash supportHerbert Xu1-12/+14
This patch adds the missing bits to allow multiple rehashes. The read-side as well as remove already handle this correctly. So it's only the rehasher and insertion that need modification to handle this. Note that this patch doesn't actually enable it so for now rehashing is still only performed by the worker thread. This patch also disables the explicit expand/shrink interface because the table is meant to expand and shrink automatically, and continuing to export these interfaces unnecessarily complicates the life of the rehasher since the rehash process is now composed of two parts. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24rhashtable: Allow hashfn to be unsetHerbert Xu1-6/+27
Since every current rhashtable user uses jhash as their hash function, the fact that jhash is an inline function causes each user to generate a copy of its code. This function provides a solution to this problem by allowing hashfn to be unset. In which case rhashtable will automatically set it to jhash. Furthermore, if the key length is a multiple of 4, we will switch over to jhash2. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24rhashtable: Eliminate unnecessary branch in rht_key_hashfnHerbert Xu1-2/+6
When rht_key_hashfn is called from rhashtable itself and params is equal to ht->p, there is no point in checking params.key_len and falling back to ht->p.key_len. For some reason gcc couldn't figure out that params is the same as ht->p. So let's help it by only checking params.key_len when it's a constant. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-21rhashtable: Fix undeclared EEXIST build error on ia64Herbert Xu1-0/+1
We need to include linux/errno.h in rhashtable.h since it doesn't always get included otherwise. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20rhashtable: Rip out obsolete out-of-line interfaceHerbert Xu1-16/+3
Now that all rhashtable users have been converted over to the inline interface, this patch removes the unused out-of-line interface. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20rhashtable: Allow hash/comparison functions to be inlinedHerbert Xu1-0/+386
This patch deals with the complaint that we make indirect function calls on the fast paths unnecessarily in rhashtable. We resolve it by moving the fast paths into inline functions that take struct rhashtable_param (which obviously must be the same set of parameters supplied to rhashtable_init) as an argument. The only remaining indirect call is to obj_hashfn (or key_hashfn it obj_hashfn is unset) on the rehash as well as the insert-during- rehash slow path. This patch also extends the support of vairable-length keys to include those where the key is fixed but scattered in the object. For example, in netlink we want to key off the namespace and the portid but they're not next to each other. This patch does this by directly using the object hash function as the indicator of whether the key is accessible or not. It also adds a new function obj_cmpfn to compare a key against an object. This means that the caller no longer needs to supply explicit compare functions. All this is done in a backwards compatible manner so no existing users are affected until they convert to the new interface. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20rhashtable: Make rhashtable_init params argument constHerbert Xu1-1/+2
This patch marks the rhashtable_init params argument const as there is no reason to modify it since we will always make a copy of it in the rhashtable. This patch also fixes a bug where we don't actually round up the value of min_size unless it is less than HASH_MIN_SIZE. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18rhashtable: Remove max_shift and min_shiftHerbert Xu1-4/+0
Now that nobody uses max_shift and min_shift, we can safely remove them. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18rhashtable: Introduce max_size/min_sizeHerbert Xu1-0/+4
This patch adds the parameters max_size and min_size which are meant to replace max_shift and min_shift. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18rhashtable: Remove shift from bucket_tableHerbert Xu1-2/+0
Keeping both size and shift is silly. We only need one. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-15rhashtable: Move future_tbl into struct bucket_tableHerbert Xu1-2/+3
This patch moves future_tbl to open up the possibility of having multiple rehashes on the same table. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-15rhashtable: Add rehash counter to bucket_tableHerbert Xu1-1/+3
This patch adds a rehash counter to bucket_table to indicate the last bucket that has been rehashed. This serves two purposes: 1. Any bucket that has been rehashed can never gain a new object. 2. If the rehash counter reaches the size of the table, the table will forever remain empty. This patch also downsizes bucket_table->size to an unsigned int since we do not support sizes greater than 32 bits yet. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-15rhashtable: Free bucket tables asynchronously after rehashHerbert Xu1-0/+2
There is in fact no need to wait for an RCU grace period in the rehash function, since all insertions are guaranteed to go into the new table through spin locks. This patch uses call_rcu to free the old/rehashed table at our leisure. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-15rhashtable: Fix walker behaviour during rehashHerbert Xu1-4/+4
Previously whenever the walker encountered a resize it simply snaps back to the beginning and starts again. However, this only works if the rehash started and completed while the walker was idle. If the walker attempts to restart while the rehash is still ongoing, we may miss objects that we shouldn't have. This patch fixes this by making the walker walk the old table followed by the new table just like all other readers. If a rehash is detected we will still signal our caller of the fact so they can prepare for duplicates but we will simply continue the walk onto the new table after the old one is finished either by us or by the rehasher. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-13rhashtable: kill ht->shift atomic operationsDaniel Borkmann1-3/+3
Commit c0c09bfdc415 ("rhashtable: avoid unnecessary wakeup for worker queue") changed ht->shift to be atomic, which is actually unnecessary. Instead of leaving the current shift in the core rhashtable structure, it can be cached inside the individual bucket tables. There, it will only be initialized once during a new table allocation in the shrink/expansion slow path, and from then onward it stays immutable for the rest of the bucket table liftime. That allows shift to be non-atomic. The patch also moves hash_rnd management into the table setup. The rhashtable structure now consumes 3 instead of 4 cachelines. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Ying Xue <ying.xue@windriver.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11rhashtable: Move hash_rnd into bucket_tableHerbert Xu1-2/+2
Currently hash_rnd is a parameter that users can set. However, no existing users set this parameter. It is also something that people are unlikely to want to set directly since it's just a random number. In preparation for allowing the reseeding/rehashing of rhashtable, this patch moves hash_rnd into bucket_table so that it's now an internal state rather than a parameter. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-28rhashtable: remove indirection for grow/shrink decision functionsDaniel Borkmann1-13/+0
Currently, all real users of rhashtable default their grow and shrink decision functions to rht_grow_above_75() and rht_shrink_below_30(), so that there's currently no need to have this explicitly selectable. It can/should be generic and private inside rhashtable until a real use case pops up. Since we can make this private, we'll save us this additional indirection layer and can improve insertion/deletion time as well. Reference: http://patchwork.ozlabs.org/patch/443040/ Suggested-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-22rhashtable: ensure cache line alignment on bucket_tableEric Dumazet1-4/+5
struct bucket_table contains mostly read fields : size, locks_mask, locks. Make sure these are not sharing a cache line with buckets[] Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05rhashtable: Introduce rhashtable_walk_*Herbert Xu1-0/+35
Some existing rhashtable users get too intimate with it by walking the buckets directly. This prevents us from easily changing the internals of rhashtable. This patch adds the helpers rhashtable_walk_init/exit/start/next/stop which will replace these custom walkers. They are meant to be usable for both procfs seq_file walks as well as walking by a netlink dump. The iterator structure should fit inside a netlink dump cb structure, with at least one element to spare. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-26rhashtable: fix rht_for_each_entry_safe() endless loopPatrick McHardy1-1/+3
"next" is not updated, causing an endless loop for buckets with more than one element. Fixes: 88d6ed15acff ("rhashtable: Convert bucket iterators to take table and index") Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-16rhashtable: Fix race in rhashtable_destroy() and use regular work_structYing Xue1-1/+1
When we put our declared work task in the global workqueue with schedule_delayed_work(), its delay parameter is always zero. Therefore, we should define a regular work in rhashtable structure instead of a delayed work. By the way, we add a condition to check whether resizing functions are NULL before cancelling the work, avoiding to cancel an uninitialized work. Lastly, while we wait for all work items we submitted before to run to completion with cancel_delayed_work(), ht->mutex has been taken in rhashtable_destroy(). Moreover, cancel_delayed_work() doesn't return until all work items are accomplished, and when work items are scheduled, the work's function - rht_deferred_worker() will be called. However, as rht_deferred_worker() also needs to acquire the lock, deadlock might happen at the moment as the lock is already held before. So if the cancel work function is moved out of the lock covered scope, this will avoid the deadlock. Fixes: 97defe1 ("rhashtable: Per bucket locks & deferred expansion/shrinking") Signed-off-by: Ying Xue <ying.xue@windriver.com> Cc: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-13rhashtable: add a note for grow and shrink decision functionsYing Xue1-0/+4
As commit c0c09bfdc415 ("rhashtable: avoid unnecessary wakeup for worker queue") moves condition statements of verifying whether hash table size exceeds its maximum threshold or reaches its minimum threshold from resizing functions to resizing decision functions, we should add a note in rhashtable.h to indicate the implementation of what the grow and shrink decision function must enforce min/max shift, otherwise, it's failed to take min/max shift's set watermarks into effect. Signed-off-by: Ying Xue <ying.xue@windriver.com> Cc: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-13rhashtable: involve rhashtable_lookup_compare_insert routineYing Xue1-0/+5
Introduce a new function called rhashtable_lookup_compare_insert() which is very similar to rhashtable_lookup_insert(). But the former makes use of users' given compare function to look for an object, and then inserts it into hash table if found. As the entire process of search and insertion is under protection of per bucket lock, this can help users to avoid the involvement of extra lock. Signed-off-by: Ying Xue <ying.xue@windriver.com> Cc: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-09rhashtable: avoid unnecessary wakeup for worker queueYing Xue1-1/+1
Move condition statements of verifying whether hash table size exceeds its maximum threshold or reaches its minimum threshold from resizing functions to resizing decision functions, avoiding unnecessary wakeup for worker queue thread. Signed-off-by: Ying Xue <ying.xue@windriver.com> Cc: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-09rhashtable: involve rhashtable_lookup_insert routineYing Xue1-0/+1
Involve a new function called rhashtable_lookup_insert() which makes lookup and insertion atomic under bucket lock protection, helping us avoid to introduce an extra lock when we search and insert an object into hash table. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-05rhashtable: fix missing headerYing Xue1-0/+1
Fixup below build error: include/linux/rhashtable.h: At top level: include/linux/rhashtable.h:118:34: error: field ‘mutex’ has incomplete type Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Supports for nulls markerThomas Graf1-10/+47
In order to allow for wider usage of rhashtable, use a special nulls marker to terminate each chain. The reason for not using the existing nulls_list is that the prev pointer usage would not be valid as entries can be linked in two different buckets at the same time. The 4 nulls base bits can be set through the rhashtable_params structure like this: struct rhashtable_params params = { [...] .nulls_base = (1U << RHT_BASE_SHIFT), }; This reduces the hash length from 32 bits to 27 bits. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Per bucket locks & deferred expansion/shrinkingThomas Graf1-11/+26
Introduces an array of spinlocks to protect bucket mutations. The number of spinlocks per CPU is configurable and selected based on the hash of the bucket. This allows for parallel insertions and removals of entries which do not share a lock. The patch also defers expansion and shrinking to a worker queue which allows insertion and removal from atomic context. Insertions and deletions may occur in parallel to it and are only held up briefly while the particular bucket is linked or unzipped. Mutations of the bucket table pointer is protected by a new mutex, read access is RCU protected. In the event of an expansion or shrinking, the new bucket table allocated is exposed as a so called future table as soon as the resize process starts. Lookups, deletions, and insertions will briefly use both tables. The future table becomes the main table after an RCU grace period and initial linking of the old to the new table was performed. Optimization of the chains to make use of the new number of buckets follows only the new table is in use. The side effect of this is that during that RCU grace period, a bucket traversal using any rht_for_each() variant on the main table will not see any insertions performed during the RCU grace period which would at that point land in the future table. The lookup will see them as it searches both tables if needed. Having multiple insertions and removals occur in parallel requires nelems to become an atomic counter. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03nft_hash: Remove rhashtable_remove_pprev()Thomas Graf1-2/+0
The removal function of nft_hash currently stores a reference to the previous element during lookup which is used to optimize removal later on. This was possible because a lock is held throughout calling rhashtable_lookup() and rhashtable_remove(). With the introdution of deferred table resizing in parallel to lookups and insertions, the nftables lock will no longer synchronize all table mutations and the stored pprev may become invalid. Removing this optimization makes removal slightly more expensive on average but allows taking the resize cost out of the insert and remove path. Signed-off-by: Thomas Graf <tgraf@suug.ch> Cc: netfilter-devel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Convert bucket iterators to take table and indexThomas Graf1-57/+116
This patch is in preparation to introduce per bucket spinlocks. It extends all iterator macros to take the bucket table and bucket index. It also introduces a new rht_dereference_bucket() to handle protected accesses to buckets. It introduces a barrier() to the RCU iterators to the prevent the compiler from caching the first element. The lockdep verifier is introduced as stub which always succeeds and properly implement in the next patch when the locks are introduced. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Do hashing inside of rhashtable_lookup_compare()Thomas Graf1-4/+1
Hash the key inside of rhashtable_lookup_compare() like rhashtable_lookup() does. This allows to simplify the hashing functions and keep them private. Signed-off-by: Thomas Graf <tgraf@suug.ch> Cc: netfilter-devel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13rhashtable: Drop gfp_flags arg in insert/remove functionsThomas Graf1-5/+5
Reallocation is only required for shrinking and expanding and both rely on a mutex for synchronization and callers of rhashtable_init() are in non atomic context. Therefore, no reason to continue passing allocation hints through the API. Instead, use GFP_KERNEL and add __GFP_NOWARN | __GFP_NORETRY to allow for silent fall back to vzalloc() without the OOM killer jumping in as pointed out by Eric Dumazet and Eric W. Biederman. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13rhashtable: Add parent argument to mutex_is_heldHerbert Xu1-1/+2
Currently mutex_is_held can only test locks in the that are global since it takes no arguments. This prevents rhashtable from being used in places where locks are lock, e.g., per-namespace locks. This patch adds a parent field to mutex_is_held and rhashtable_params so that local locks can be used (and tested). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13rhashtable: Move mutex_is_held under PROVE_LOCKINGHerbert Xu1-0/+2
The rhashtable function mutex_is_held is only used when PROVE_LOCKING is enabled. This patch makes the mutex_is_held field in rhashtable optional depending on PROVE_LOCKING. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04lib/rhashtable: allow user to set the minimum shifts of shrinkingYing Xue1-0/+2
Although rhashtable library allows user to specify a quiet big size for user's created hash table, the table may be shrunk to a very small size - HASH_MIN_SIZE(4) after object is removed from the table at the first time. Subsequently, even if the total amount of objects saved in the table is quite lower than user's initial setting in a long time, the hash table size is still dynamically adjusted by rhashtable_shrink() or rhashtable_expand() each time object is inserted or removed from the table. However, as synchronize_rcu() has to be called when table is shrunk or expanded by the two functions, we should permit user to set the minimum table size through configuring the minimum number of shifts according to user specific requirement, avoiding these expensive actions of shrinking or expanding because of calling synchronize_rcu(). Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-15rhashtable: fix annotations for rht_for_each_entry_rcu()Thomas Graf1-8/+4
Call rcu_deference_raw() directly from within rht_for_each_entry_rcu() as list_for_each_entry_rcu() does. Fixes the following sparse warnings: net/netlink/af_netlink.c:2906:25: expected struct rhash_head const *__mptr net/netlink/af_netlink.c:2906:25: got struct rhash_head [noderef] <asn:4>*<noident> Fixes: e341694e3eb57fc ("netlink: Convert netlink_lookup() to use RCU protected hash table") Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-15rhashtable: unexport and make rht_obj() staticThomas Graf1-1/+0
No need to export rht_obj(), all inner to outer object translations occur internally. It was intended to be used with rht_for_each() which now primarily serves as the iterator for rhashtable_remove_pprev() to effectively flush and free the full table. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>