From: cozybit Inc <javier@xxxxxxxxxxx>
It is unnecessary to hold the path table resize lock while allocating a
new table. Allocate first and take lock later. This resolves a
soft-lockup:
[ 293.385799] BUG: soft lockup - CPU#0 stuck for 61s! [kworker/u:3:744]
(...)
[ 293.386049] Call Trace:
[ 293.386049] [<c119fd04>] do_raw_read_lock+0x26/0x29
[ 293.386049] [<c14b2982>] _raw_read_lock+0x8/0xa
[ 293.386049] [<c148c178>] mesh_path_add+0xb7/0x24e
[ 293.386049] [<c148b98d>] ? mesh_path_lookup+0x1b/0xa6
[ 293.386049] [<c148ded5>] hwmp_route_info_get+0x276/0x2fd
[ 293.386049] [<c148dfb6>] mesh_rx_path_sel_frame+0x5a/0x5d9
[ 293.386049] [<c102667d>] ? update_curr+0x1cf/0x1d7
[ 293.386049] [<c148b45a>] ieee80211_mesh_rx_queued_mgmt+0x60/0x67
[ 293.386049] [<c147c374>] ieee80211_iface_work+0x1f0/0x258
(...)
Signed-off-by: Javier Cardona <javier@xxxxxxxxxxx>
---
net/mac80211/mesh_pathtbl.c | 49 ++++++++++++++++++++++---------------------
1 files changed, 25 insertions(+), 24 deletions(-)
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 8d65b47..7776ae5 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -65,42 +65,37 @@ void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
__mesh_table_free(tbl);
}
-static struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
+static int mesh_table_grow(struct mesh_table *oldtbl,
+ struct mesh_table *newtbl)
{
- struct mesh_table *newtbl;
struct hlist_head *oldhash;
struct hlist_node *p, *q;
int i;
- if (atomic_read(&tbl->entries)
- < tbl->mean_chain_len * (tbl->hash_mask + 1))
- goto endgrow;
+ if (atomic_read(&oldtbl->entries)
+ < oldtbl->mean_chain_len * (oldtbl->hash_mask + 1))
+ return -EAGAIN;
- newtbl = mesh_table_alloc(tbl->size_order + 1);
- if (!newtbl)
- goto endgrow;
- newtbl->free_node = tbl->free_node;
- newtbl->mean_chain_len = tbl->mean_chain_len;
- newtbl->copy_node = tbl->copy_node;
- atomic_set(&newtbl->entries, atomic_read(&tbl->entries));
+ newtbl->free_node = oldtbl->free_node;
+ newtbl->mean_chain_len = oldtbl->mean_chain_len;
+ newtbl->copy_node = oldtbl->copy_node;
+ atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
- oldhash = tbl->hash_buckets;
- for (i = 0; i <= tbl->hash_mask; i++)
+ oldhash = oldtbl->hash_buckets;
+ for (i = 0; i <= oldtbl->hash_mask; i++)
hlist_for_each(p, &oldhash[i])
- if (tbl->copy_node(p, newtbl) < 0)
+ if (oldtbl->copy_node(p, newtbl) < 0)
goto errcopy;
- return newtbl;
+ return 0;
errcopy:
for (i = 0; i <= newtbl->hash_mask; i++) {
hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
- tbl->free_node(p, 0);
+ oldtbl->free_node(p, 0);
}
- __mesh_table_free(newtbl);
-endgrow:
- return NULL;
+ return -ENOMEM;
}
@@ -334,10 +329,13 @@ void mesh_mpath_table_grow(void)
{
struct mesh_table *oldtbl, *newtbl;
+ newtbl = mesh_table_alloc(mesh_paths->size_order + 1);
+ if (!newtbl)
+ return;
write_lock(&pathtbl_resize_lock);
oldtbl = mesh_paths;
- newtbl = mesh_table_grow(mesh_paths);
- if (!newtbl) {
+ if (mesh_table_grow(mesh_paths, newtbl) < 0) {
+ __mesh_table_free(newtbl);
write_unlock(&pathtbl_resize_lock);
return;
}
@@ -352,10 +350,13 @@ void mesh_mpp_table_grow(void)
{
struct mesh_table *oldtbl, *newtbl;
+ newtbl = mesh_table_alloc(mpp_paths->size_order + 1);
+ if (!newtbl)
+ return;
write_lock(&pathtbl_resize_lock);
oldtbl = mpp_paths;
- newtbl = mesh_table_grow(mpp_paths);
- if (!newtbl) {
+ if (mesh_table_grow(mpp_paths, newtbl) < 0) {
+ __mesh_table_free(newtbl);
write_unlock(&pathtbl_resize_lock);
return;
}
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
