2 #include <linux/cred.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/kernel.h>
6 #include <linux/quotaops.h>
7 #include <linux/sched.h>
8 #include <net/netlink.h>
9 #include <net/genetlink.h>
11 /* Netlink family structure for quota */
12 static struct genl_family quota_genl_family = {
13 .id = GENL_ID_GENERATE,
17 .maxattr = QUOTA_NL_A_MAX,
21 * quota_send_warning - Send warning to userspace about exceeded quota
22 * @type: The quota type: USRQQUOTA, GRPQUOTA,...
23 * @id: The user or group id of the quota that was exceeded
24 * @dev: The device on which the fs is mounted (sb->s_dev)
25 * @warntype: The type of the warning: QUOTA_NL_...
27 * This can be used by filesystems (including those which don't use
28 * dquot) to send a message to userspace relating to quota limits.
32 void quota_send_warning(short type, unsigned int id, dev_t dev,
39 int msg_size = 4 * nla_total_size(sizeof(u32)) +
40 2 * nla_total_size(sizeof(u64));
42 /* We have to allocate using GFP_NOFS as we are called from a
43 * filesystem performing write and thus further recursion into
44 * the fs to free some data could cause deadlocks. */
45 skb = genlmsg_new(msg_size, GFP_NOFS);
48 "VFS: Not enough memory to send quota warning.\n");
51 msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
52 "a_genl_family, 0, QUOTA_NL_C_WARNING);
55 "VFS: Cannot store netlink header in quota warning.\n");
58 ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
61 ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
64 ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
67 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
70 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
73 ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
76 genlmsg_end(skb, msg_head);
78 genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
81 printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
85 EXPORT_SYMBOL(quota_send_warning);
87 static int __init quota_init(void)
89 if (genl_register_family("a_genl_family) != 0)
91 "VFS: Failed to create quota netlink interface.\n");
95 module_init(quota_init);