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Message-Id: <1254145438.6052.471.camel@localhost.localdomain>
Date: Mon, 28 Sep 2009 14:43:58 +0100
From: Steven Whitehouse <swhiteho@...hat.com>
To: Christoph Hellwig <hch@...radead.org>
Cc: linux-kernel@...r.kernel.org, Al Viro <viro@...IV.linux.org.uk>
Subject: Re: [RFC] VFS: Export dquot_send_warning
Hi,
Here is an updated version (moves the function to quota.c). This has had
some testing with a few different kernel configs and also I've got the
userland quota_nld (in the quota tools) daemon working with it,
Steve.
-----------------------------------------------------------------------
>>From 42a7f843a445c369c189a8929f80692e341f1bce Mon Sep 17 00:00:00 2001
From: Steven Whitehouse <swhiteho@...hat.com>
Date: Mon, 28 Sep 2009 12:35:17 +0100
Subject: [PATCH 11/12] VFS: Export dquot_send_warning
Sending a message to userspace in a generic format to warn
of events (e.g. quota exceeded) in the quota subsystem is
a generically useful feature. This patch makes some minor
changes to the send_message function from dquot.c renaming
it quota_send_message, moving it to quota.c and exporting it
for use by filesystems which do not use the dquot code.
Signed-off-by: Steven Whitehouse <swhiteho@...hat.com>
---
fs/quota/Kconfig | 2 +-
fs/quota/dquot.c | 93 +++++--------------------------------------------
fs/quota/quota.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/quota.h | 11 ++++++
4 files changed, 114 insertions(+), 85 deletions(-)
diff --git a/fs/quota/Kconfig b/fs/quota/Kconfig
index 8047e01..353e78a 100644
--- a/fs/quota/Kconfig
+++ b/fs/quota/Kconfig
@@ -17,7 +17,7 @@ config QUOTA
config QUOTA_NETLINK_INTERFACE
bool "Report quota messages through netlink interface"
- depends on QUOTA && NET
+ depends on QUOTACTL && NET
help
If you say Y here, quota warnings (about exceeding softlimit, reaching
hardlimit, etc.) will be reported through netlink interface. If unsure,
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 39b49c4..9b6ad90 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -77,10 +77,6 @@
#include <linux/capability.h>
#include <linux/quotaops.h>
#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
-#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
-#include <net/netlink.h>
-#include <net/genetlink.h>
-#endif
#include <asm/uaccess.h>
@@ -1071,73 +1067,6 @@ static void print_warning(struct dquot *dquot, const int warntype)
}
#endif
-#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
-
-/* Netlink family structure for quota */
-static struct genl_family quota_genl_family = {
- .id = GENL_ID_GENERATE,
- .hdrsize = 0,
- .name = "VFS_DQUOT",
- .version = 1,
- .maxattr = QUOTA_NL_A_MAX,
-};
-
-/* Send warning to userspace about user which exceeded quota */
-static void send_warning(const struct dquot *dquot, const char warntype)
-{
- static atomic_t seq;
- 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(msg_size, GFP_NOFS);
- if (!skb) {
- printk(KERN_ERR
- "VFS: Not enough memory to send quota warning.\n");
- return;
- }
- msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
- "a_genl_family, 0, QUOTA_NL_C_WARNING);
- if (!msg_head) {
- printk(KERN_ERR
- "VFS: Cannot store netlink header in quota warning.\n");
- goto err_out;
- }
- ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type);
- if (ret)
- goto attr_err_out;
- ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id);
- if (ret)
- goto attr_err_out;
- ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
- if (ret)
- goto attr_err_out;
- ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR,
- MAJOR(dquot->dq_sb->s_dev));
- if (ret)
- goto attr_err_out;
- ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR,
- MINOR(dquot->dq_sb->s_dev));
- if (ret)
- goto attr_err_out;
- ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
- if (ret)
- goto attr_err_out;
- genlmsg_end(skb, msg_head);
-
- genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
- return;
-attr_err_out:
- printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
-err_out:
- kfree_skb(skb);
-}
-#endif
/*
* Write warnings to the console and send warning messages over netlink.
*
@@ -1145,18 +1074,20 @@ err_out:
*/
static void flush_warnings(struct dquot *const *dquots, char *warntype)
{
+ struct dquot *dq;
int i;
- for (i = 0; i < MAXQUOTAS; i++)
- if (dquots[i] && warntype[i] != QUOTA_NL_NOWARN &&
- !warning_issued(dquots[i], warntype[i])) {
+ for (i = 0; i < MAXQUOTAS; i++) {
+ dq = dquots[i];
+ if (dq && warntype[i] != QUOTA_NL_NOWARN &&
+ !warning_issued(dq, warntype[i])) {
#ifdef CONFIG_PRINT_QUOTA_WARNING
- print_warning(dquots[i], warntype[i]);
-#endif
-#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
- send_warning(dquots[i], warntype[i]);
+ print_warning(dq, warntype[i]);
#endif
+ quota_send_warning(dq->dq_type, dq->dq_id,
+ dq->dq_sb->s_dev, warntype[i]);
}
+ }
}
static int ignore_hardlimit(struct dquot *dquot)
@@ -2607,12 +2538,6 @@ static int __init dquot_init(void)
register_shrinker(&dqcache_shrinker);
-#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
- if (genl_register_family("a_genl_family) != 0)
- printk(KERN_ERR
- "VFS: Failed to create quota netlink interface.\n");
-#endif
-
return 0;
}
module_init(dquot_init);
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 95c5b42..ee91e27 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -18,6 +18,8 @@
#include <linux/capability.h>
#include <linux/quotaops.h>
#include <linux/types.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
/* Check validity of generic quotactl commands */
static int generic_quotactl_valid(struct super_block *sb, int type, int cmd,
@@ -525,3 +527,94 @@ asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
return ret;
}
#endif
+
+
+#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
+
+/* Netlink family structure for quota */
+static struct genl_family quota_genl_family = {
+ .id = GENL_ID_GENERATE,
+ .hdrsize = 0,
+ .name = "VFS_DQUOT",
+ .version = 1,
+ .maxattr = QUOTA_NL_A_MAX,
+};
+
+/**
+ * quota_send_warning - Send warning to userspace about exceeded quota
+ * @type: The quota type: USRQQUOTA, GRPQUOTA,...
+ * @id: The user or group id of the quota that was exceeded
+ * @dev: The device on which the fs is mounted (sb->s_dev)
+ * @warntype: The type of the warning: QUOTA_NL_...
+ *
+ * This can be used by filesystems (including those which don't use
+ * dquot) to send a message to userspace relating to quota limits.
+ *
+ */
+
+void quota_send_warning(short type, unsigned int id, dev_t dev,
+ const char warntype)
+{
+ static atomic_t seq;
+ 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(msg_size, GFP_NOFS);
+ if (!skb) {
+ printk(KERN_ERR
+ "VFS: Not enough memory to send quota warning.\n");
+ return;
+ }
+ msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
+ "a_genl_family, 0, QUOTA_NL_C_WARNING);
+ if (!msg_head) {
+ printk(KERN_ERR
+ "VFS: Cannot store netlink header in quota warning.\n");
+ goto err_out;
+ }
+ ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
+ if (ret)
+ goto attr_err_out;
+ ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
+ if (ret)
+ goto attr_err_out;
+ ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
+ if (ret)
+ goto attr_err_out;
+ ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
+ if (ret)
+ goto attr_err_out;
+ ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
+ if (ret)
+ goto attr_err_out;
+ ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
+ if (ret)
+ goto attr_err_out;
+ genlmsg_end(skb, msg_head);
+
+ genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
+ return;
+attr_err_out:
+ printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
+err_out:
+ kfree_skb(skb);
+}
+EXPORT_SYMBOL(quota_send_warning);
+
+static int __init quota_init(void)
+{
+ if (genl_register_family("a_genl_family) != 0)
+ printk(KERN_ERR
+ "VFS: Failed to create quota netlink interface.\n");
+ return 0;
+};
+
+module_init(quota_init);
+#endif
+
diff --git a/include/linux/quota.h b/include/linux/quota.h
index 78c4889..ce9a9b2 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -376,6 +376,17 @@ static inline unsigned int dquot_generic_flag(unsigned int flags, int type)
return flags >> _DQUOT_STATE_FLAGS;
}
+#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
+extern void quota_send_warning(short type, unsigned int id, dev_t dev,
+ const char warntype);
+#else
+static inline void quota_send_warning(short type, unsigned int id, dev_t dev,
+ const char warntype)
+{
+ return;
+}
+#endif /* CONFIG_QUOTA_NETLINK_INTERFACE */
+
struct quota_info {
unsigned int flags; /* Flags for diskquotas on this device */
struct mutex dqio_mutex; /* lock device while I/O in progress */
--
1.6.2.5
--
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