Fix computation of SKB size for quota messages

Fix computation of size of skb needed for quota message.  We should use
netlink provided functions and not just an ad-hoc number.  Also don't print
the return value from nla_put_foo() as it is always -1.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/fs/dquot.c b/fs/dquot.c
index 686ab63a7c6c..b2592abaa713 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -895,9 +895,6 @@ out_lock:
 
 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
 
-/* Size of quota netlink message - actually an upperbound for buffer size */
-#define QUOTA_NL_MSG_SIZE 32
-
 /* Netlink family structure for quota */
 static struct genl_family quota_genl_family = {
         .id = GENL_ID_GENERATE,
@@ -914,11 +911,13 @@ static void send_warning(const struct dquot *dquot, const char warntype)
         struct sk_buff *skb;
         void *msg_head;
         int ret;
+        int msg_size = 4 * nla_total_size(sizeof(u32)) +
+                       2 * nla_total_size(sizeof(u64));
 
         /* We have to allocate using GFP_NOFS as we are called from a
          * filesystem performing write and thus further recursion into
          * the fs to free some data could cause deadlocks. */
-        skb = genlmsg_new(QUOTA_NL_MSG_SIZE, GFP_NOFS);
+        skb = genlmsg_new(msg_size, GFP_NOFS);
         if (!skb) {
                 printk(KERN_ERR
                   "VFS: Not enough memory to send quota warning.\n");
@@ -959,7 +958,7 @@ static void send_warning(const struct dquot *dquot, const char warntype)
                         "VFS: Failed to send notification message: %d\n", ret);
         return;
 attr_err_out:
-        printk(KERN_ERR "VFS: Failed to compose quota message: %d\n", ret);
+        printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
 err_out:
         kfree_skb(skb);
 }