dm: eliminate some holes data structures

[safe/jmp/linux-2.6] / drivers / md / dm-log-userspace-transfer.c

diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index 8ce74d9..f1c8cae 100644 (file)
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/drivers/md/dm-log-userspace-transfer.c
@@ -129,11 +129,13 @@ static int fill_pkg(struct cn_msg *msg, struct dm_ulog_request *tfr)
  * This is the connector callback that delivers data
  * that was sent from userspace.
  */
-static void cn_ulog_callback(void *data)
+static void cn_ulog_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 {
-       struct cn_msg *msg = (struct cn_msg *)data;
        struct dm_ulog_request *tfr = (struct dm_ulog_request *)(msg + 1);
 
+       if (!cap_raised(nsp->eff_cap, CAP_SYS_ADMIN))
+               return;
+
        spin_lock(&receiving_list_lock);
        if (msg->len == 0)
                fill_pkg(msg, NULL);
@@ -147,7 +149,8 @@ static void cn_ulog_callback(void *data)
 
 /**
  * dm_consult_userspace
- * @uuid: log's uuid (must be DM_UUID_LEN in size)
+ * @uuid: log's universal unique identifier (must be DM_UUID_LEN in size)
+ * @luid: log's local unique identifier
  * @request_type:  found in include/linux/dm-log-userspace.h
  * @data: data to tx to the server
  * @data_size: size of data in bytes
@@ -163,17 +166,21 @@ static void cn_ulog_callback(void *data)
  *
  * Returns: 0 on success, -EXXX on failure
  **/
-int dm_consult_userspace(const char *uuid, int request_type,
+int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type,
                         char *data, size_t data_size,
                         char *rdata, size_t *rdata_size)
 {
        int r = 0;
        size_t dummy = 0;
-       int overhead_size =
-               sizeof(struct dm_ulog_request *) + sizeof(struct cn_msg);
+       int overhead_size = sizeof(struct dm_ulog_request) + sizeof(struct cn_msg);
        struct dm_ulog_request *tfr = prealloced_ulog_tfr;
        struct receiving_pkg pkg;
 
+       /*
+        * Given the space needed to hold the 'struct cn_msg' and
+        * 'struct dm_ulog_request' - do we have enough payload
+        * space remaining?
+        */
        if (data_size > (DM_ULOG_PREALLOCED_SIZE - overhead_size)) {
                DMINFO("Size of tfr exceeds preallocated size");
                return -EINVAL;
@@ -188,8 +195,9 @@ resend:
         */
        mutex_lock(&dm_ulog_lock);
 
-       memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - overhead_size);
+       memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - sizeof(struct cn_msg));
        memcpy(tfr->uuid, uuid, DM_UUID_LEN);
+       tfr->luid = luid;
        tfr->seq = dm_ulog_seq++;
 
        /*