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author | Herbert Xu <herbert@gondor.apana.org.au> | 2016-08-18 08:50:56 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-08-19 21:40:24 (GMT) |
commit | 246779dd090bd1b74d2652b3a6ca7759f593b27a (patch) | |
tree | 63526206a69c1ec56bc8490839504095ab0428f9 /lib | |
parent | 363dc396a5030ca82aa3e1a55b7d72965f968849 (diff) | |
download | linux-246779dd090bd1b74d2652b3a6ca7759f593b27a.tar.xz |
rhashtable: Remove GFP flag from rhashtable_walk_init
The commit 8f6fd83c6c5ec66a4a70c728535ddcdfef4f3697 ("rhashtable:
accept GFP flags in rhashtable_walk_init") added a GFP flag argument
to rhashtable_walk_init because some users wish to use the walker
in an unsleepable context.
In fact we don't need to allocate memory in rhashtable_walk_init
at all. The walker is always paired with an iterator so we could
just stash ourselves there.
This patch does that by introducing a new enter function to replace
the existing init function. This way we don't have to churn all
the existing users again.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/rhashtable.c | 46 |
1 files changed, 18 insertions, 28 deletions
diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 5ba520b..97e3cf0 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -489,10 +489,9 @@ exit: EXPORT_SYMBOL_GPL(rhashtable_insert_slow); /** - * rhashtable_walk_init - Initialise an iterator + * rhashtable_walk_enter - Initialise an iterator * @ht: Table to walk over * @iter: Hash table Iterator - * @gfp: GFP flags for allocations * * This function prepares a hash table walk. * @@ -507,30 +506,22 @@ EXPORT_SYMBOL_GPL(rhashtable_insert_slow); * This function may sleep so you must not call it from interrupt * context or with spin locks held. * - * You must call rhashtable_walk_exit if this function returns - * successfully. + * You must call rhashtable_walk_exit after this function returns. */ -int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter, - gfp_t gfp) +void rhashtable_walk_enter(struct rhashtable *ht, struct rhashtable_iter *iter) { iter->ht = ht; iter->p = NULL; iter->slot = 0; iter->skip = 0; - iter->walker = kmalloc(sizeof(*iter->walker), gfp); - if (!iter->walker) - return -ENOMEM; - spin_lock(&ht->lock); - iter->walker->tbl = + iter->walker.tbl = rcu_dereference_protected(ht->tbl, lockdep_is_held(&ht->lock)); - list_add(&iter->walker->list, &iter->walker->tbl->walkers); + list_add(&iter->walker.list, &iter->walker.tbl->walkers); spin_unlock(&ht->lock); - - return 0; } -EXPORT_SYMBOL_GPL(rhashtable_walk_init); +EXPORT_SYMBOL_GPL(rhashtable_walk_enter); /** * rhashtable_walk_exit - Free an iterator @@ -541,10 +532,9 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_init); void rhashtable_walk_exit(struct rhashtable_iter *iter) { spin_lock(&iter->ht->lock); - if (iter->walker->tbl) - list_del(&iter->walker->list); + if (iter->walker.tbl) + list_del(&iter->walker.list); spin_unlock(&iter->ht->lock); - kfree(iter->walker); } EXPORT_SYMBOL_GPL(rhashtable_walk_exit); @@ -570,12 +560,12 @@ int rhashtable_walk_start(struct rhashtable_iter *iter) rcu_read_lock(); spin_lock(&ht->lock); - if (iter->walker->tbl) - list_del(&iter->walker->list); + if (iter->walker.tbl) + list_del(&iter->walker.list); spin_unlock(&ht->lock); - if (!iter->walker->tbl) { - iter->walker->tbl = rht_dereference_rcu(ht->tbl, ht); + if (!iter->walker.tbl) { + iter->walker.tbl = rht_dereference_rcu(ht->tbl, ht); return -EAGAIN; } @@ -597,7 +587,7 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_start); */ void *rhashtable_walk_next(struct rhashtable_iter *iter) { - struct bucket_table *tbl = iter->walker->tbl; + struct bucket_table *tbl = iter->walker.tbl; struct rhashtable *ht = iter->ht; struct rhash_head *p = iter->p; @@ -630,8 +620,8 @@ next: /* Ensure we see any new tables. */ smp_rmb(); - iter->walker->tbl = rht_dereference_rcu(tbl->future_tbl, ht); - if (iter->walker->tbl) { + iter->walker.tbl = rht_dereference_rcu(tbl->future_tbl, ht); + if (iter->walker.tbl) { iter->slot = 0; iter->skip = 0; return ERR_PTR(-EAGAIN); @@ -651,7 +641,7 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU) { struct rhashtable *ht; - struct bucket_table *tbl = iter->walker->tbl; + struct bucket_table *tbl = iter->walker.tbl; if (!tbl) goto out; @@ -660,9 +650,9 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter) spin_lock(&ht->lock); if (tbl->rehash < tbl->size) - list_add(&iter->walker->list, &tbl->walkers); + list_add(&iter->walker.list, &tbl->walkers); else - iter->walker->tbl = NULL; + iter->walker.tbl = NULL; spin_unlock(&ht->lock); iter->p = NULL; |