In certain cases, the 802.11 mesh pathtable code wants to
iterate over all of the entries in the forwarding table from
the receive path, which is inside an RCU read-side critical
section. Enable walks inside atomic sections by allowing
GFP_ATOMIC allocations for the walker state.
Change all existing callsites to pass in GFP_KERNEL.
Cc: Thomas Graf <tgraf@xxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Acked-by: Thomas Graf <tgraf@xxxxxxx>
Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx>
---
(-RFC, +Thomas's Ack)
include/linux/rhashtable.h | 3 ++-
lib/rhashtable.c | 6 ++++--
net/ipv6/ila/ila_xlat.c | 3 ++-
net/netfilter/nft_hash.c | 4 ++--
net/netlink/af_netlink.c | 3 ++-
net/sctp/proc.c | 3 ++-
6 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 63bd7601b6de..3eef0802a0cd 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -346,7 +346,8 @@ struct bucket_table *rhashtable_insert_slow(struct rhashtable *ht,
struct bucket_table *old_tbl);
int rhashtable_insert_rehash(struct rhashtable *ht, struct bucket_table *tbl);
-int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter);
+int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter,
+ gfp_t gfp);
void rhashtable_walk_exit(struct rhashtable_iter *iter);
int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU);
void *rhashtable_walk_next(struct rhashtable_iter *iter);
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index cc808707d1cf..5d845ffd7982 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -487,6 +487,7 @@ EXPORT_SYMBOL_GPL(rhashtable_insert_slow);
* rhashtable_walk_init - Initialise an iterator
* @ht: Table to walk over
* @iter: Hash table Iterator
+ * @gfp: GFP flags for allocations
*
* This function prepares a hash table walk.
*
@@ -504,14 +505,15 @@ EXPORT_SYMBOL_GPL(rhashtable_insert_slow);
* You must call rhashtable_walk_exit if this function returns
* successfully.
*/
-int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter)
+int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter,
+ gfp_t gfp)
{
iter->ht = ht;
iter->p = NULL;
iter->slot = 0;
iter->skip = 0;
- iter->walker = kmalloc(sizeof(*iter->walker), GFP_KERNEL);
+ iter->walker = kmalloc(sizeof(*iter->walker), gfp);
if (!iter->walker)
return -ENOMEM;
diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 295ca29a23c3..0b03533453e4 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -501,7 +501,8 @@ static int ila_nl_dump_start(struct netlink_callback *cb)
struct ila_net *ilan = net_generic(net, ila_net_id);
struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args;
- return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter);
+ return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter,
+ GFP_KERNEL);
}
static int ila_nl_dump_done(struct netlink_callback *cb)
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index 3f9d45d3d9b7..6fa016564f90 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -192,7 +192,7 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
int err;
- err = rhashtable_walk_init(&priv->ht, &hti);
+ err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
iter->err = err;
if (err)
return;
@@ -248,7 +248,7 @@ static void nft_hash_gc(struct work_struct *work)
priv = container_of(work, struct nft_hash, gc_work.work);
set = nft_set_container_of(priv);
- err = rhashtable_walk_init(&priv->ht, &hti);
+ err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
if (err)
goto schedule;
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index c8416792cce0..6e0cbdeb21d3 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2335,7 +2335,8 @@ static int netlink_walk_start(struct nl_seq_iter *iter)
{
int err;
- err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti);
+ err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti,
+ GFP_KERNEL);
if (err) {
iter->link = MAX_LINKS;
return err;
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index cfc3c7101a38..c5991e5e5daf 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -319,7 +319,8 @@ static int sctp_transport_walk_start(struct seq_file *seq)
struct sctp_ht_iter *iter = seq->private;
int err;
- err = rhashtable_walk_init(&sctp_transport_hashtable, &iter->hti);
+ err = rhashtable_walk_init(&sctp_transport_hashtable, &iter->hti,
+ GFP_KERNEL);
if (err)
return err;
--
2.6.1
--
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