Remove the code that resets the walker table. The walker table should
only be initialized in the walk init function or when a future table is
encountered. If the walker table is NULL this is the indication that
the walk has completed and this information can be used to break a
multi-call walk in the table (e.g. successive calls to nelink_dump
that are dumping elements of an rhashtable).
This also allows us to change rhashtable_walk_start to return void
since the only error it was returning was -EAGAIN for a table change.
This patch changes all the callers of rhashtable_walk_start to expect
void which eliminates logic needed to check the return value for a
rare condition. Note that -EAGAIN will be returned in a call
to rhashtable_walk_next which seems to always follow the start
of the walk so there should be no behavioral change in doing this.
Signed-off-by: Tom Herbert <t...@quantonium.net>
---
drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c | 6 +---
.../net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c | 7 ++---
fs/gfs2/glock.c | 8 ++---
include/linux/rhashtable.h | 2 +-
include/net/sctp/sctp.h | 2 +-
lib/rhashtable.c | 18 ++----------
lib/test_rhashtable.c | 6 +---
net/ipv6/ila/ila_xlat.c | 4 +--
net/ipv6/seg6.c | 4 +--
net/mac80211/mesh_pathtbl.c | 34 +++++++---------------
net/netfilter/nft_set_hash.c | 10 ++-----
net/netlink/af_netlink.c | 5 ++--
net/netlink/diag.c | 8 ++---
net/sctp/proc.c | 6 +---
net/sctp/socket.c | 19 +++---------
net/tipc/socket.c | 6 ++--
16 files changed, 37 insertions(+), 108 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c
b/drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c
index d5031f436f83..df6a57087848 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c
@@ -1416,11 +1416,7 @@ bnxt_tc_flow_stats_batch_prep(struct bnxt *bp,
void *flow_node;
int rc, i;
- rc = rhashtable_walk_start(iter);
- if (rc && rc != -EAGAIN) {
- i = 0;
- goto done;
- }
+ rhashtable_walk_start(iter);
rc = 0;
for (i = 0; i < BNXT_FLOW_STATS_BATCH_MAX; i++) {
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c
b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c
index d4a548a6a55c..6d7a10d0c45e 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c
@@ -765,9 +765,7 @@ static void ch_flower_stats_handler(struct work_struct
*work)
rhashtable_walk_enter(&adap->flower_tbl, &iter);
do {
- flower_entry = ERR_PTR(rhashtable_walk_start(&iter));
- if (IS_ERR(flower_entry))
- goto walk_stop;
+ rhashtable_walk_start(&iter);
while ((flower_entry = rhashtable_walk_next(&iter)) &&
!IS_ERR(flower_entry)) {
@@ -786,8 +784,9 @@ static void ch_flower_stats_handler(struct work_struct
*work)
spin_unlock(&flower_entry->lock);
}
}
-walk_stop:
+
rhashtable_walk_stop(&iter);
+
} while (flower_entry == ERR_PTR(-EAGAIN));
rhashtable_walk_exit(&iter);
mod_timer(&adap->flower_stats_timer, jiffies + STATS_CHECK_PERIOD);
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 11066d8647d2..20d1b6e2d829 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1549,16 +1549,13 @@ static void glock_hash_walk(glock_examiner examiner,
const struct gfs2_sbd *sdp)
rhashtable_walk_enter(&gl_hash_table, &iter);
do {
- gl = ERR_PTR(rhashtable_walk_start(&iter));
- if (IS_ERR(gl))
- goto walk_stop;
+ rhashtable_walk_start(&iter);
while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl))
if (gl->gl_name.ln_sbd == sdp &&
lockref_get_not_dead(&gl->gl_lockref))
examiner(gl);
-walk_stop:
rhashtable_walk_stop(&iter);
} while (cond_resched(), gl == ERR_PTR(-EAGAIN));
@@ -1947,8 +1944,7 @@ static void *gfs2_glock_seq_start(struct seq_file *seq,
loff_t *pos)
loff_t n = *pos;
rhashtable_walk_enter(&gl_hash_table, &gi->hti);
- if (rhashtable_walk_start(&gi->hti) != 0)
- return NULL;
+ rhashtable_walk_start(&gi->hti);
do {
gfs2_glock_iter_next(gi);
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 361c08e35dbc..4c976bf320a8 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -378,7 +378,7 @@ void *rhashtable_insert_slow(struct rhashtable *ht, const
void *key,
void rhashtable_walk_enter(struct rhashtable *ht,
struct rhashtable_iter *iter);
void rhashtable_walk_exit(struct rhashtable_iter *iter);
-int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU);
+void rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU);
void *rhashtable_walk_next(struct rhashtable_iter *iter);
void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU);
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 906a9c0efa71..6f79415f6634 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -116,7 +116,7 @@ extern struct percpu_counter sctp_sockets_allocated;
int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
-int sctp_transport_walk_start(struct rhashtable_iter *iter);
+void sctp_transport_walk_start(struct rhashtable_iter *iter);
void sctp_transport_walk_stop(struct rhashtable_iter *iter);
struct sctp_transport *sctp_transport_get_next(struct net *net,
struct rhashtable_iter *iter);
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index ddd7dde87c3c..eeddfb3199cd 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -736,16 +736,9 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_exit);
* @iter: Hash table iterator
*
* Start a hash table walk at the current iterator position. Note that we take
- * the RCU lock in all cases including when we return an error. So you must
- * always call rhashtable_walk_stop to clean up.
- *
- * Returns zero if successful.
- *
- * Returns -EAGAIN if resize event occured. Note that the iterator
- * will rewind back to the beginning and you may use it immediately
- * by calling rhashtable_walk_next.
+ * the RCU lock so you must always call rhashtable_walk_stop to clean up.
*/
-int rhashtable_walk_start(struct rhashtable_iter *iter)
+void rhashtable_walk_start(struct rhashtable_iter *iter)
__acquires(RCU)
{
struct rhashtable *ht = iter->ht;
@@ -756,13 +749,6 @@ int rhashtable_walk_start(struct rhashtable_iter *iter)
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);
- return -EAGAIN;
- }
-
- return 0;
}
EXPORT_SYMBOL_GPL(rhashtable_walk_start);
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index 8e83cbdc049c..76d3667fdea2 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -162,11 +162,7 @@ static void test_bucket_stats(struct rhashtable *ht,
unsigned int entries)
return;
}
- err = rhashtable_walk_start(&hti);
- if (err && err != -EAGAIN) {
- pr_warn("Test failed: iterator failed: %d\n", err);
- return;
- }
+ rhashtable_walk_start(&hti);
while ((pos = rhashtable_walk_next(&hti))) {
if (PTR_ERR(pos) == -EAGAIN) {
diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 6eb5e68f112a..44c39c5f0638 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -512,9 +512,7 @@ static int ila_nl_dump(struct sk_buff *skb, struct
netlink_callback *cb)
struct ila_map *ila;
int ret;
- ret = rhashtable_walk_start(rhiter);
- if (ret && ret != -EAGAIN)
- goto done;
+ rhashtable_walk_start(rhiter);
for (;;) {
ila = rhashtable_walk_next(rhiter);
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index c81407770956..7f5621d09571 100644
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -306,9 +306,7 @@ static int seg6_genl_dumphmac(struct sk_buff *skb, struct
netlink_callback *cb)
struct seg6_hmac_info *hinfo;
int ret;
- ret = rhashtable_walk_start(iter);
- if (ret && ret != -EAGAIN)
- goto done;
+ rhashtable_walk_start(iter);
for (;;) {
hinfo = rhashtable_walk_next(iter);
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 86c8dfef56a4..a5125624a76d 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -257,9 +257,7 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
if (ret)
return NULL;
- ret = rhashtable_walk_start(&iter);
- if (ret && ret != -EAGAIN)
- goto err;
+ rhashtable_walk_start(&iter);
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -269,7 +267,6 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
if (i++ == idx)
break;
}
-err:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
@@ -513,9 +510,7 @@ void mesh_plink_broken(struct sta_info *sta)
if (ret)
return;
- ret = rhashtable_walk_start(&iter);
- if (ret && ret != -EAGAIN)
- goto out;
+ rhashtable_walk_start(&iter);
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -535,7 +530,6 @@ void mesh_plink_broken(struct sta_info *sta)
WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
}
}
-out:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
@@ -584,9 +578,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
if (ret)
return;
- ret = rhashtable_walk_start(&iter);
- if (ret && ret != -EAGAIN)
- goto out;
+ rhashtable_walk_start(&iter);
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -597,7 +589,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
if (rcu_access_pointer(mpath->next_hop) == sta)
__mesh_path_del(tbl, mpath);
}
-out:
+
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
@@ -614,9 +606,7 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data
*sdata,
if (ret)
return;
- ret = rhashtable_walk_start(&iter);
- if (ret && ret != -EAGAIN)
- goto out;
+ rhashtable_walk_start(&iter);
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -627,7 +617,7 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data
*sdata,
if (ether_addr_equal(mpath->mpp, proxy))
__mesh_path_del(tbl, mpath);
}
-out:
+
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
@@ -642,9 +632,7 @@ static void table_flush_by_iface(struct mesh_table *tbl)
if (ret)
return;
- ret = rhashtable_walk_start(&iter);
- if (ret && ret != -EAGAIN)
- goto out;
+ rhashtable_walk_start(&iter);
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -653,7 +641,7 @@ static void table_flush_by_iface(struct mesh_table *tbl)
break;
__mesh_path_del(tbl, mpath);
}
-out:
+
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
@@ -873,9 +861,7 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data
*sdata,
if (ret)
return;
- ret = rhashtable_walk_start(&iter);
- if (ret && ret != -EAGAIN)
- goto out;
+ rhashtable_walk_start(&iter);
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -887,7 +873,7 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data
*sdata,
time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
__mesh_path_del(tbl, mpath);
}
-out:
+
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index f8166c1d5430..3f1624ee056f 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -251,11 +251,7 @@ static void nft_rhash_walk(const struct nft_ctx *ctx,
struct nft_set *set,
if (err)
return;
- err = rhashtable_walk_start(&hti);
- if (err && err != -EAGAIN) {
- iter->err = err;
- goto out;
- }
+ rhashtable_walk_start(&hti);
while ((he = rhashtable_walk_next(&hti))) {
if (IS_ERR(he)) {
@@ -306,9 +302,7 @@ static void nft_rhash_gc(struct work_struct *work)
if (err)
goto schedule;
- err = rhashtable_walk_start(&hti);
- if (err && err != -EAGAIN)
- goto out;
+ rhashtable_walk_start(&hti);
while ((he = rhashtable_walk_next(&hti))) {
if (IS_ERR(he)) {
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index b9e0ee4e22f5..ab325d4d6fef 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2478,8 +2478,9 @@ static int netlink_walk_start(struct nl_seq_iter *iter)
return err;
}
- err = rhashtable_walk_start(&iter->hti);
- return err == -EAGAIN ? 0 : err;
+ rhashtable_walk_start(&iter->hti);
+
+ return 0;
}
static void netlink_walk_stop(struct nl_seq_iter *iter)
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index 8faa20b4d457..7dda33b9b784 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -115,11 +115,7 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct
netlink_callback *cb,
if (!s_num)
rhashtable_walk_enter(&tbl->hash, hti);
- ret = rhashtable_walk_start(hti);
- if (ret == -EAGAIN)
- ret = 0;
- if (ret)
- goto stop;
+ rhashtable_walk_start(hti);
while ((nlsk = rhashtable_walk_next(hti))) {
if (IS_ERR(nlsk)) {
@@ -146,8 +142,8 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct
netlink_callback *cb,
}
}
-stop:
rhashtable_walk_stop(hti);
+
if (ret)
goto done;
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 26b4be6b4172..4545bc2aff84 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -288,12 +288,8 @@ struct sctp_ht_iter {
static void *sctp_transport_seq_start(struct seq_file *seq, loff_t *pos)
{
struct sctp_ht_iter *iter = seq->private;
- int err = sctp_transport_walk_start(&iter->hti);
- if (err) {
- iter->start_fail = 1;
- return ERR_PTR(err);
- }
+ sctp_transport_walk_start(&iter->hti);
iter->start_fail = 0;
return sctp_transport_get_idx(seq_file_net(seq), &iter->hti, *pos);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 014847e25648..1dae4742cac4 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4676,20 +4676,11 @@ int sctp_get_sctp_info(struct sock *sk, struct
sctp_association *asoc,
EXPORT_SYMBOL_GPL(sctp_get_sctp_info);
/* use callback to avoid exporting the core structure */
-int sctp_transport_walk_start(struct rhashtable_iter *iter)
+void sctp_transport_walk_start(struct rhashtable_iter *iter)
{
- int err;
-
rhltable_walk_enter(&sctp_transport_hashtable, iter);
- err = rhashtable_walk_start(iter);
- if (err && err != -EAGAIN) {
- rhashtable_walk_stop(iter);
- rhashtable_walk_exit(iter);
- return err;
- }
-
- return 0;
+ rhashtable_walk_start(iter);
}
void sctp_transport_walk_stop(struct rhashtable_iter *iter)
@@ -4780,12 +4771,10 @@ int sctp_for_each_transport(int (*cb)(struct
sctp_transport *, void *),
struct net *net, int *pos, void *p) {
struct rhashtable_iter hti;
struct sctp_transport *tsp;
- int ret;
+ int ret = 0;
again:
- ret = sctp_transport_walk_start(&hti);
- if (ret)
- return ret;
+ sctp_transport_walk_start(&hti);
tsp = sctp_transport_get_idx(net, &hti, *pos + 1);
for (; !IS_ERR_OR_NULL(tsp); tsp = sctp_transport_get_next(net, &hti)) {
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 5d18c0caa92b..22c4fd8a9dfe 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2640,9 +2640,7 @@ void tipc_sk_reinit(struct net *net)
rhashtable_walk_enter(&tn->sk_rht, &iter);
do {
- tsk = ERR_PTR(rhashtable_walk_start(&iter));
- if (IS_ERR(tsk))
- goto walk_stop;
+ rhashtable_walk_start(&iter);
while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) {
spin_lock_bh(&tsk->sk.sk_lock.slock);
@@ -2651,7 +2649,7 @@ void tipc_sk_reinit(struct net *net)
msg_set_orignode(msg, tn->own_addr);
spin_unlock_bh(&tsk->sk.sk_lock.slock);
}
-walk_stop:
+
rhashtable_walk_stop(&iter);
} while (tsk == ERR_PTR(-EAGAIN));
}
--
2.11.0
