From 86e931a35e93d94e6e91b57cc76456e16d188ea9 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 28 Sep 2009 12:35:17 +0100 Subject: [PATCH] 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 --- 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 8047e01ef46b..353e78a9ebee 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 39b49c42a7ed..9b6ad908dcb2 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -77,10 +77,6 @@ #include #include #include /* for inode_lock, oddly enough.. */ -#ifdef CONFIG_QUOTA_NETLINK_INTERFACE -#include -#include -#endif #include @@ -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 95c5b42384b2..ee91e2756950 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include /* 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 78c48895b12a..ce9a9b2e5cd4 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 */ -- 2.34.1