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authorPatrick McHardy <kaber@trash.net>2011-03-28 04:39:36 -0400
committerDavid S. Miller <davem@davemloft.net>2011-03-30 20:14:33 -0400
commit04f482faf50535229a5a5c8d629cf963899f857c (patch)
tree698d5c8e22e68f9a621c03972556e3a73c525465 /drivers/connector
parente2666f84958adb3a034b98e99699b55705117e01 (diff)
connector: convert to synchronous netlink message processing
Commits 01a16b21 (netlink: kill eff_cap from struct netlink_skb_parms) and c53fa1ed (netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms) removed some members from struct netlink_skb_parms that depend on the current context, all netlink users are now required to do synchronous message processing. connector however queues received messages and processes them in a work queue, which is not valid anymore. This patch converts connector to do synchronous message processing by invoking the registered callback handler directly from the netlink receive function. In order to avoid invoking the callback with connector locks held, a reference count is added to struct cn_callback_entry, the reference is taken when finding a matching callback entry on the device's queue_list and released after the callback handler has been invoked. Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/connector')
-rw-r--r--drivers/connector/cn_queue.c58
-rw-r--r--drivers/connector/connector.c47
2 files changed, 29 insertions, 76 deletions
diff --git a/drivers/connector/cn_queue.c b/drivers/connector/cn_queue.c
index 55653aba6735..c42c9d517790 100644
--- a/drivers/connector/cn_queue.c
+++ b/drivers/connector/cn_queue.c
@@ -31,24 +31,9 @@
31#include <linux/connector.h> 31#include <linux/connector.h>
32#include <linux/delay.h> 32#include <linux/delay.h>
33 33
34void cn_queue_wrapper(struct work_struct *work)
35{
36 struct cn_callback_entry *cbq =
37 container_of(work, struct cn_callback_entry, work);
38 struct cn_callback_data *d = &cbq->data;
39 struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(d->skb));
40 struct netlink_skb_parms *nsp = &NETLINK_CB(d->skb);
41
42 d->callback(msg, nsp);
43
44 kfree_skb(d->skb);
45 d->skb = NULL;
46
47 kfree(d->free);
48}
49
50static struct cn_callback_entry * 34static struct cn_callback_entry *
51cn_queue_alloc_callback_entry(const char *name, struct cb_id *id, 35cn_queue_alloc_callback_entry(struct cn_queue_dev *dev, const char *name,
36 struct cb_id *id,
52 void (*callback)(struct cn_msg *, struct netlink_skb_parms *)) 37 void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
53{ 38{
54 struct cn_callback_entry *cbq; 39 struct cn_callback_entry *cbq;
@@ -59,17 +44,23 @@ cn_queue_alloc_callback_entry(const char *name, struct cb_id *id,
59 return NULL; 44 return NULL;
60 } 45 }
61 46
47 atomic_set(&cbq->refcnt, 1);
48
49 atomic_inc(&dev->refcnt);
50 cbq->pdev = dev;
51
62 snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name); 52 snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
63 memcpy(&cbq->id.id, id, sizeof(struct cb_id)); 53 memcpy(&cbq->id.id, id, sizeof(struct cb_id));
64 cbq->data.callback = callback; 54 cbq->callback = callback;
65
66 INIT_WORK(&cbq->work, &cn_queue_wrapper);
67 return cbq; 55 return cbq;
68} 56}
69 57
70static void cn_queue_free_callback(struct cn_callback_entry *cbq) 58void cn_queue_release_callback(struct cn_callback_entry *cbq)
71{ 59{
72 flush_workqueue(cbq->pdev->cn_queue); 60 if (!atomic_dec_and_test(&cbq->refcnt))
61 return;
62
63 atomic_dec(&cbq->pdev->refcnt);
73 kfree(cbq); 64 kfree(cbq);
74} 65}
75 66
@@ -85,13 +76,10 @@ int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
85 struct cn_callback_entry *cbq, *__cbq; 76 struct cn_callback_entry *cbq, *__cbq;
86 int found = 0; 77 int found = 0;
87 78
88 cbq = cn_queue_alloc_callback_entry(name, id, callback); 79 cbq = cn_queue_alloc_callback_entry(dev, name, id, callback);
89 if (!cbq) 80 if (!cbq)
90 return -ENOMEM; 81 return -ENOMEM;
91 82
92 atomic_inc(&dev->refcnt);
93 cbq->pdev = dev;
94
95 spin_lock_bh(&dev->queue_lock); 83 spin_lock_bh(&dev->queue_lock);
96 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) { 84 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
97 if (cn_cb_equal(&__cbq->id.id, id)) { 85 if (cn_cb_equal(&__cbq->id.id, id)) {
@@ -104,8 +92,7 @@ int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
104 spin_unlock_bh(&dev->queue_lock); 92 spin_unlock_bh(&dev->queue_lock);
105 93
106 if (found) { 94 if (found) {
107 cn_queue_free_callback(cbq); 95 cn_queue_release_callback(cbq);
108 atomic_dec(&dev->refcnt);
109 return -EINVAL; 96 return -EINVAL;
110 } 97 }
111 98
@@ -130,10 +117,8 @@ void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
130 } 117 }
131 spin_unlock_bh(&dev->queue_lock); 118 spin_unlock_bh(&dev->queue_lock);
132 119
133 if (found) { 120 if (found)
134 cn_queue_free_callback(cbq); 121 cn_queue_release_callback(cbq);
135 atomic_dec(&dev->refcnt);
136 }
137} 122}
138 123
139struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls) 124struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls)
@@ -151,12 +136,6 @@ struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls)
151 136
152 dev->nls = nls; 137 dev->nls = nls;
153 138
154 dev->cn_queue = alloc_ordered_workqueue(dev->name, 0);
155 if (!dev->cn_queue) {
156 kfree(dev);
157 return NULL;
158 }
159
160 return dev; 139 return dev;
161} 140}
162 141
@@ -164,9 +143,6 @@ void cn_queue_free_dev(struct cn_queue_dev *dev)
164{ 143{
165 struct cn_callback_entry *cbq, *n; 144 struct cn_callback_entry *cbq, *n;
166 145
167 flush_workqueue(dev->cn_queue);
168 destroy_workqueue(dev->cn_queue);
169
170 spin_lock_bh(&dev->queue_lock); 146 spin_lock_bh(&dev->queue_lock);
171 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) 147 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
172 list_del(&cbq->callback_entry); 148 list_del(&cbq->callback_entry);
diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index f7554de3be5e..d77005849af8 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -122,51 +122,28 @@ EXPORT_SYMBOL_GPL(cn_netlink_send);
122 */ 122 */
123static int cn_call_callback(struct sk_buff *skb) 123static int cn_call_callback(struct sk_buff *skb)
124{ 124{
125 struct cn_callback_entry *__cbq, *__new_cbq; 125 struct cn_callback_entry *i, *cbq = NULL;
126 struct cn_dev *dev = &cdev; 126 struct cn_dev *dev = &cdev;
127 struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb)); 127 struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb));
128 struct netlink_skb_parms *nsp = &NETLINK_CB(skb);
128 int err = -ENODEV; 129 int err = -ENODEV;
129 130
130 spin_lock_bh(&dev->cbdev->queue_lock); 131 spin_lock_bh(&dev->cbdev->queue_lock);
131 list_for_each_entry(__cbq, &dev->cbdev->queue_list, callback_entry) { 132 list_for_each_entry(i, &dev->cbdev->queue_list, callback_entry) {
132 if (cn_cb_equal(&__cbq->id.id, &msg->id)) { 133 if (cn_cb_equal(&i->id.id, &msg->id)) {
133 if (likely(!work_pending(&__cbq->work) && 134 atomic_inc(&i->refcnt);
134 __cbq->data.skb == NULL)) { 135 cbq = i;
135 __cbq->data.skb = skb;
136
137 if (queue_work(dev->cbdev->cn_queue,
138 &__cbq->work))
139 err = 0;
140 else
141 err = -EINVAL;
142 } else {
143 struct cn_callback_data *d;
144
145 err = -ENOMEM;
146 __new_cbq = kzalloc(sizeof(struct cn_callback_entry), GFP_ATOMIC);
147 if (__new_cbq) {
148 d = &__new_cbq->data;
149 d->skb = skb;
150 d->callback = __cbq->data.callback;
151 d->free = __new_cbq;
152
153 INIT_WORK(&__new_cbq->work,
154 &cn_queue_wrapper);
155
156 if (queue_work(dev->cbdev->cn_queue,
157 &__new_cbq->work))
158 err = 0;
159 else {
160 kfree(__new_cbq);
161 err = -EINVAL;
162 }
163 }
164 }
165 break; 136 break;
166 } 137 }
167 } 138 }
168 spin_unlock_bh(&dev->cbdev->queue_lock); 139 spin_unlock_bh(&dev->cbdev->queue_lock);
169 140
141 if (cbq != NULL) {
142 cbq->callback(msg, nsp);
143 kfree_skb(skb);
144 cn_queue_release_callback(cbq);
145 }
146
170 return err; 147 return err;
171} 148}
172 149