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authorTejun Heo <tj@kernel.org>2022-12-06 11:36:32 -1000
committerDavid S. Miller <davem@davemloft.net>2022-12-09 10:42:56 +0000
commite47877c7aa821c413b45e05f804819579bdfa1a3 (patch)
tree281f4a159cd9d5ddfa0c940636a72868e8c19cff /lib
parentb602d00384bdfb8874cc4dcb298fc87cc369630b (diff)
downloadlinux-e47877c7aa821c413b45e05f804819579bdfa1a3.tar.bz2
rhashtable: Allow rhashtable to be used from irq-safe contexts
rhashtable currently only does bh-safe synchronization making it impossible to use from irq-safe contexts. Switch it to use irq-safe synchronization to remove the restriction. v2: Update the lock functions to return the ulong flags value and unlock functions to take the value directly instead of passing around the pointer. Suggested by Linus. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: David Vernet <dvernet@meta.com> Acked-by: Josh Don <joshdon@google.com> Acked-by: Hao Luo <haoluo@google.com> Acked-by: Barret Rhoden <brho@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib')
-rw-r--r--lib/rhashtable.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index e12bbfb240b8..6ae2ba8e06a2 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -231,6 +231,7 @@ static int rhashtable_rehash_one(struct rhashtable *ht,
struct rhash_head *head, *next, *entry;
struct rhash_head __rcu **pprev = NULL;
unsigned int new_hash;
+ unsigned long flags;
if (new_tbl->nest)
goto out;
@@ -253,13 +254,14 @@ static int rhashtable_rehash_one(struct rhashtable *ht,
new_hash = head_hashfn(ht, new_tbl, entry);
- rht_lock_nested(new_tbl, &new_tbl->buckets[new_hash], SINGLE_DEPTH_NESTING);
+ flags = rht_lock_nested(new_tbl, &new_tbl->buckets[new_hash],
+ SINGLE_DEPTH_NESTING);
head = rht_ptr(new_tbl->buckets + new_hash, new_tbl, new_hash);
RCU_INIT_POINTER(entry->next, head);
- rht_assign_unlock(new_tbl, &new_tbl->buckets[new_hash], entry);
+ rht_assign_unlock(new_tbl, &new_tbl->buckets[new_hash], entry, flags);
if (pprev)
rcu_assign_pointer(*pprev, next);
@@ -276,18 +278,19 @@ static int rhashtable_rehash_chain(struct rhashtable *ht,
{
struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht);
struct rhash_lock_head __rcu **bkt = rht_bucket_var(old_tbl, old_hash);
+ unsigned long flags;
int err;
if (!bkt)
return 0;
- rht_lock(old_tbl, bkt);
+ flags = rht_lock(old_tbl, bkt);
while (!(err = rhashtable_rehash_one(ht, bkt, old_hash)))
;
if (err == -ENOENT)
err = 0;
- rht_unlock(old_tbl, bkt);
+ rht_unlock(old_tbl, bkt, flags);
return err;
}
@@ -590,6 +593,7 @@ static void *rhashtable_try_insert(struct rhashtable *ht, const void *key,
struct bucket_table *new_tbl;
struct bucket_table *tbl;
struct rhash_lock_head __rcu **bkt;
+ unsigned long flags;
unsigned int hash;
void *data;
@@ -607,7 +611,7 @@ static void *rhashtable_try_insert(struct rhashtable *ht, const void *key,
new_tbl = rht_dereference_rcu(tbl->future_tbl, ht);
data = ERR_PTR(-EAGAIN);
} else {
- rht_lock(tbl, bkt);
+ flags = rht_lock(tbl, bkt);
data = rhashtable_lookup_one(ht, bkt, tbl,
hash, key, obj);
new_tbl = rhashtable_insert_one(ht, bkt, tbl,
@@ -615,7 +619,7 @@ static void *rhashtable_try_insert(struct rhashtable *ht, const void *key,
if (PTR_ERR(new_tbl) != -EEXIST)
data = ERR_CAST(new_tbl);
- rht_unlock(tbl, bkt);
+ rht_unlock(tbl, bkt, flags);
}
} while (!IS_ERR_OR_NULL(new_tbl));