From e47877c7aa821c413b45e05f804819579bdfa1a3 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 6 Dec 2022 11:36:32 -1000 Subject: 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 Reviewed-by: David Vernet Acked-by: Josh Don Acked-by: Hao Luo Acked-by: Barret Rhoden Cc: Linus Torvalds Signed-off-by: David S. Miller --- lib/rhashtable.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'lib/rhashtable.c') 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)); -- cgit v1.2.3