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authorDavid Fries <David@Fries.net>2014-01-15 22:29:18 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-07 15:40:17 -0800
commit9fcbbac5ded489c3a4e121343db999dd51cd6c75 (patch)
tree1207602c8d7cc2da54784114a5d32d9ed6924b58 /drivers/w1/w1_netlink.c
parent70b34d2ed807b722413894975a8c60617defb887 (diff)
w1: process w1 netlink commands in w1_process thread
Netlink is a socket interface and is expected to be asynchronous. Clients can now make w1 requests without blocking by making use of the w1_master thread to process netlink commands which was previously only used for doing an automatic bus search. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/w1_netlink.c')
-rw-r--r--drivers/w1/w1_netlink.c166
1 files changed, 129 insertions, 37 deletions
diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c
index 747174be7b50..06d614af1166 100644
--- a/drivers/w1/w1_netlink.c
+++ b/drivers/w1/w1_netlink.c
@@ -119,10 +119,12 @@ static int w1_get_slaves(struct w1_master *dev,
if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
__u64 rn;
+ mutex_lock(&dev->list_mutex);
list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
memcpy(&rn, &sl->reg_num, sizeof(rn));
w1_send_slave(dev, rn);
}
+ mutex_unlock(&dev->list_mutex);
} else {
w1_search_process_cb(dev, cmd->cmd == W1_CMD_ALARM_SEARCH ?
W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave);
@@ -368,29 +370,134 @@ static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rm
return error;
}
+/* Bundle together a reference count, the full message, and broken out
+ * commands to be executed on each w1 master kthread in one memory allocation.
+ */
+struct w1_cb_block {
+ atomic_t refcnt;
+ struct cn_msg msg;
+ /* cn_msg data */
+ /* one or more variable length struct w1_cb_node */
+};
+struct w1_cb_node {
+ struct w1_async_cmd async;
+ /* pointers within w1_cb_block and msg data */
+ struct w1_cb_block *block;
+ struct w1_netlink_msg *m;
+ struct w1_slave *sl;
+ struct w1_master *dev;
+};
+
+static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
+{
+ struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node,
+ async);
+ u16 mlen = node->m->len;
+ u8 *cmd_data = node->m->data;
+ int err = 0;
+ struct w1_slave *sl = node->sl;
+ struct w1_netlink_cmd *cmd = NULL;
+
+ mutex_lock(&dev->mutex);
+ if (sl && w1_reset_select_slave(sl))
+ err = -ENODEV;
+
+ while (mlen && !err) {
+ cmd = (struct w1_netlink_cmd *)cmd_data;
+
+ if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
+ err = -E2BIG;
+ break;
+ }
+
+ if (sl)
+ err = w1_process_command_slave(sl, &node->block->msg,
+ node->m, cmd);
+ else
+ err = w1_process_command_master(dev, &node->block->msg,
+ node->m, cmd);
+
+ w1_netlink_send_error(&node->block->msg, node->m, cmd, err);
+ err = 0;
+
+ cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
+ mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
+ }
+
+ if (!cmd || err)
+ w1_netlink_send_error(&node->block->msg, node->m, cmd, err);
+
+ if (sl)
+ w1_unref_slave(sl);
+ else
+ atomic_dec(&dev->refcnt);
+ mutex_unlock(&dev->mutex);
+
+ mutex_lock(&dev->list_mutex);
+ list_del(&async_cmd->async_entry);
+ mutex_unlock(&dev->list_mutex);
+
+ if (atomic_sub_return(1, &node->block->refcnt) == 0)
+ kfree(node->block);
+}
+
static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
- struct w1_netlink_cmd *cmd;
struct w1_slave *sl;
struct w1_master *dev;
+ u16 msg_len;
int err = 0;
+ struct w1_cb_block *block = NULL;
+ struct w1_cb_node *node = NULL;
+ int node_count = 0;
+
+ /* Count the number of master or slave commands there are to allocate
+ * space for one cb_node each.
+ */
+ msg_len = msg->len;
+ while (msg_len && !err) {
+ if (m->len + sizeof(struct w1_netlink_msg) > msg_len) {
+ err = -E2BIG;
+ break;
+ }
+
+ if (m->type == W1_MASTER_CMD || m->type == W1_SLAVE_CMD)
+ ++node_count;
+
+ msg_len -= sizeof(struct w1_netlink_msg) + m->len;
+ m = (struct w1_netlink_msg *)(((u8 *)m) +
+ sizeof(struct w1_netlink_msg) + m->len);
+ }
+ m = (struct w1_netlink_msg *)(msg + 1);
+ if (node_count) {
+ /* msg->len doesn't include itself */
+ long size = sizeof(struct w1_cb_block) + msg->len +
+ node_count*sizeof(struct w1_cb_node);
+ block = kmalloc(size, GFP_KERNEL);
+ if (!block) {
+ w1_netlink_send_error(msg, m, NULL, -ENOMEM);
+ return;
+ }
+ atomic_set(&block->refcnt, 1);
+ memcpy(&block->msg, msg, sizeof(*msg) + msg->len);
+ node = (struct w1_cb_node *)((u8 *)block->msg.data + msg->len);
+ }
- while (msg->len && !err) {
+ msg_len = msg->len;
+ while (msg_len && !err) {
struct w1_reg_num id;
u16 mlen = m->len;
- u8 *cmd_data = m->data;
dev = NULL;
sl = NULL;
- cmd = NULL;
memcpy(&id, m->id.id, sizeof(id));
#if 0
printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
__func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
#endif
- if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
+ if (m->len + sizeof(struct w1_netlink_msg) > msg_len) {
err = -E2BIG;
break;
}
@@ -415,41 +522,24 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
if (!mlen)
goto out_cont;
- mutex_lock(&dev->mutex);
+ atomic_inc(&block->refcnt);
+ node->async.cb = w1_process_cb;
+ node->block = block;
+ node->m = (struct w1_netlink_msg *)((u8 *)&block->msg +
+ (size_t)((u8 *)m - (u8 *)msg));
+ node->sl = sl;
+ node->dev = dev;
- if (sl && w1_reset_select_slave(sl)) {
- err = -ENODEV;
- goto out_up;
- }
-
- while (mlen) {
- cmd = (struct w1_netlink_cmd *)cmd_data;
-
- if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
- err = -E2BIG;
- break;
- }
-
- if (sl)
- err = w1_process_command_slave(sl, msg, m, cmd);
- else
- err = w1_process_command_master(dev, msg, m, cmd);
+ mutex_lock(&dev->list_mutex);
+ list_add_tail(&node->async.async_entry, &dev->async_list);
+ wake_up_process(dev->thread);
+ mutex_unlock(&dev->list_mutex);
+ ++node;
- w1_netlink_send_error(msg, m, cmd, err);
- err = 0;
-
- cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
- mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
- }
-out_up:
- atomic_dec(&dev->refcnt);
- if (sl)
- atomic_dec(&sl->refcnt);
- mutex_unlock(&dev->mutex);
out_cont:
- if (!cmd || err)
- w1_netlink_send_error(msg, m, cmd, err);
- msg->len -= sizeof(struct w1_netlink_msg) + m->len;
+ if (err)
+ w1_netlink_send_error(msg, m, NULL, err);
+ msg_len -= sizeof(struct w1_netlink_msg) + m->len;
m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
/*
@@ -458,6 +548,8 @@ out_cont:
if (err == -ENODEV)
err = 0;
}
+ if (block && atomic_sub_return(1, &block->refcnt) == 0)
+ kfree(block);
}
int w1_init_netlink(void)

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