Implement sending of quota messages via netlink interface. The advantage is that in userspace we can better decide what to do with the message - for example display a dialogue in your X session or just write the message to the console. As a bonus, we can get rid of problems with console locking deep inside filesystem code once we remove the old printing mechanism. Signed-off-by: Jan Kara diff -rupX /home/jack/.kerndiffexclude linux-2.6.23-rc4/fs/dquot.c linux-2.6.23-rc4-1-quota_messages/fs/dquot.c --- linux-2.6.23-rc4/fs/dquot.c 2007-08-28 14:08:51.000000000 +0200 +++ linux-2.6.23-rc4-1-quota_messages/fs/dquot.c 2007-08-28 14:16:26.000000000 +0200 @@ -79,6 +79,10 @@ #include #include #include /* for inode_lock, oddly enough.. */ +#ifdef CONFIG_QUOTA_NETLINK_INTERFACE +#include +#include +#endif #include @@ -823,6 +827,7 @@ static inline void dquot_decr_space(stru clear_bit(DQ_BLKS_B, &dquot->dq_flags); } +#ifdef CONFIG_PRINT_QUOTA_WARNING static int flag_print_warnings = 1; static inline int need_print_warning(struct dquot *dquot) @@ -839,22 +844,15 @@ static inline int need_print_warning(str return 0; } -/* Values of warnings */ -#define NOWARN 0 -#define IHARDWARN 1 -#define ISOFTLONGWARN 2 -#define ISOFTWARN 3 -#define BHARDWARN 4 -#define BSOFTLONGWARN 5 -#define BSOFTWARN 6 - /* Print warning to user which exceeded quota */ static void print_warning(struct dquot *dquot, const char warntype) { char *msg = NULL; struct tty_struct *tty; - int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS_B : - ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0); + int flag = (warntype == QUOTA_NL_BHARDWARN || + warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : + ((warntype == QUOTA_NL_IHARDWARN || + warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags))) return; @@ -864,28 +862,28 @@ static void print_warning(struct dquot * if (!tty) goto out_lock; tty_write_message(tty, dquot->dq_sb->s_id); - if (warntype == ISOFTWARN || warntype == BSOFTWARN) + if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) tty_write_message(tty, ": warning, "); else tty_write_message(tty, ": write failed, "); tty_write_message(tty, quotatypes[dquot->dq_type]); switch (warntype) { - case IHARDWARN: + case QUOTA_NL_IHARDWARN: msg = " file limit reached.\r\n"; break; - case ISOFTLONGWARN: + case QUOTA_NL_ISOFTLONGWARN: msg = " file quota exceeded too long.\r\n"; break; - case ISOFTWARN: + case QUOTA_NL_ISOFTWARN: msg = " file quota exceeded.\r\n"; break; - case BHARDWARN: + case QUOTA_NL_BHARDWARN: msg = " block limit reached.\r\n"; break; - case BSOFTLONGWARN: + case QUOTA_NL_BSOFTLONGWARN: msg = " block quota exceeded too long.\r\n"; break; - case BSOFTWARN: + case QUOTA_NL_BSOFTWARN: msg = " block quota exceeded.\r\n"; break; } @@ -893,14 +891,89 @@ static void print_warning(struct dquot * out_lock: mutex_unlock(&tty_mutex); } +#endif + +#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, + .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 unsigned long seq; + struct sk_buff *skb; + void *msg_head; + int ret; + + skb = genlmsg_new(QUOTA_NL_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, 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->user->uid); + if (ret) + goto attr_err_out; + genlmsg_end(skb, msg_head); + + ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS); + if (ret < 0 && ret != -ESRCH) + printk(KERN_ERR + "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); +err_out: + kfree_skb(skb); +} +#endif static inline void flush_warnings(struct dquot **dquots, char *warntype) { int i; for (i = 0; i < MAXQUOTAS; i++) - if (dquots[i] != NODQUOT && warntype[i] != NOWARN) + if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN) { +#ifdef CONFIG_PRINT_QUOTA_WARNING print_warning(dquots[i], warntype[i]); +#endif +#ifdef CONFIG_QUOTA_NETLINK_INTERFACE + send_warning(dquots[i], warntype[i]); +#endif + } } static inline char ignore_hardlimit(struct dquot *dquot) @@ -914,14 +987,14 @@ static inline char ignore_hardlimit(stru /* needs dq_data_lock */ static int check_idq(struct dquot *dquot, ulong inodes, char *warntype) { - *warntype = NOWARN; + *warntype = QUOTA_NL_NOWARN; if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags)) return QUOTA_OK; if (dquot->dq_dqb.dqb_ihardlimit && (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit && !ignore_hardlimit(dquot)) { - *warntype = IHARDWARN; + *warntype = QUOTA_NL_IHARDWARN; return NO_QUOTA; } @@ -929,14 +1002,14 @@ static int check_idq(struct dquot *dquot (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit && dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime && !ignore_hardlimit(dquot)) { - *warntype = ISOFTLONGWARN; + *warntype = QUOTA_NL_ISOFTLONGWARN; return NO_QUOTA; } if (dquot->dq_dqb.dqb_isoftlimit && (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit && dquot->dq_dqb.dqb_itime == 0) { - *warntype = ISOFTWARN; + *warntype = QUOTA_NL_ISOFTWARN; dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; } @@ -946,7 +1019,7 @@ static int check_idq(struct dquot *dquot /* needs dq_data_lock */ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) { - *warntype = 0; + *warntype = QUOTA_NL_NOWARN; if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags)) return QUOTA_OK; @@ -954,7 +1027,7 @@ static int check_bdq(struct dquot *dquot toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit && !ignore_hardlimit(dquot)) { if (!prealloc) - *warntype = BHARDWARN; + *warntype = QUOTA_NL_BHARDWARN; return NO_QUOTA; } @@ -963,7 +1036,7 @@ static int check_bdq(struct dquot *dquot dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime && !ignore_hardlimit(dquot)) { if (!prealloc) - *warntype = BSOFTLONGWARN; + *warntype = QUOTA_NL_BSOFTLONGWARN; return NO_QUOTA; } @@ -971,7 +1044,7 @@ static int check_bdq(struct dquot *dquot toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit && dquot->dq_dqb.dqb_btime == 0) { if (!prealloc) { - *warntype = BSOFTWARN; + *warntype = QUOTA_NL_BSOFTWARN; dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace; } else @@ -1066,7 +1139,7 @@ out_add: return QUOTA_OK; } for (cnt = 0; cnt < MAXQUOTAS; cnt++) - warntype[cnt] = NOWARN; + warntype[cnt] = QUOTA_NL_NOWARN; down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */ @@ -1112,7 +1185,7 @@ int dquot_alloc_inode(const struct inode if (IS_NOQUOTA(inode)) return QUOTA_OK; for (cnt = 0; cnt < MAXQUOTAS; cnt++) - warntype[cnt] = NOWARN; + warntype[cnt] = QUOTA_NL_NOWARN; down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); if (IS_NOQUOTA(inode)) { up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); @@ -1234,7 +1307,7 @@ int dquot_transfer(struct inode *inode, /* Clear the arrays */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { transfer_to[cnt] = transfer_from[cnt] = NODQUOT; - warntype[cnt] = NOWARN; + warntype[cnt] = QUOTA_NL_NOWARN; } down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); /* Now recheck reliably when holding dqptr_sem */ @@ -1808,6 +1881,7 @@ static ctl_table fs_dqstats_table[] = { .mode = 0444, .proc_handler = &proc_dointvec, }, +#ifdef CONFIG_PRINT_QUOTA_WARNING { .ctl_name = FS_DQ_WARNINGS, .procname = "warnings", @@ -1816,6 +1890,7 @@ static ctl_table fs_dqstats_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, +#endif { .ctl_name = 0 }, }; @@ -1877,6 +1952,11 @@ 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 -rupX /home/jack/.kerndiffexclude linux-2.6.23-rc4/fs/Kconfig linux-2.6.23-rc4-1-quota_messages/fs/Kconfig --- linux-2.6.23-rc4/fs/Kconfig 2007-08-28 14:08:50.000000000 +0200 +++ linux-2.6.23-rc4-1-quota_messages/fs/Kconfig 2007-08-28 14:16:26.000000000 +0200 @@ -537,6 +537,24 @@ config QUOTA with the quota tools. Probably the quota support is only useful for multi user systems. If unsure, say N. +config QUOTA_NETLINK_INTERFACE + bool "Report quota messages through netlink interface" + depends on QUOTA && NET + help + If you say Y here, quota warnings (about exceeding softlimit, reaching + hardlimit, etc.) will be reported through netlink interface. If unsure, + say Y. + +config PRINT_QUOTA_WARNING + bool "Print quota warnings to console (OBSOLETE)" + depends on QUOTA + default y + help + If you say Y here, quota warnings (about exceeding softlimit, reaching + hardlimit, etc.) will be printed to the process' controlling terminal. + Note that this behavior is currently deprecated and may go away in + future. Please use notification via netlink socket instead. + config QFMT_V1 tristate "Old quota format support" depends on QUOTA diff -rupX /home/jack/.kerndiffexclude linux-2.6.23-rc4/include/linux/quota.h linux-2.6.23-rc4-1-quota_messages/include/linux/quota.h --- linux-2.6.23-rc4/include/linux/quota.h 2007-07-16 17:47:29.000000000 +0200 +++ linux-2.6.23-rc4-1-quota_messages/include/linux/quota.h 2007-08-28 14:24:02.000000000 +0200 @@ -128,6 +128,37 @@ struct if_dqinfo { __u32 dqi_valid; }; +/* + * Definitions for quota netlink interface + */ +#define QUOTA_NL_NOWARN 0 +#define QUOTA_NL_IHARDWARN 1 /* Inode hardlimit reached */ +#define QUOTA_NL_ISOFTLONGWARN 2 /* Inode grace time expired */ +#define QUOTA_NL_ISOFTWARN 3 /* Inode softlimit reached */ +#define QUOTA_NL_BHARDWARN 4 /* Block hardlimit reached */ +#define QUOTA_NL_BSOFTLONGWARN 5 /* Block grace time expired */ +#define QUOTA_NL_BSOFTWARN 6 /* Block softlimit reached */ + +enum { + QUOTA_NL_C_UNSPEC, + QUOTA_NL_C_WARNING, + __QUOTA_NL_C_MAX, +}; +#define QUOTA_NL_C_MAX (__QUOTA_NL_C_MAX - 1) + +enum { + QUOTA_NL_A_UNSPEC, + QUOTA_NL_A_QTYPE, + QUOTA_NL_A_EXCESS_ID, + QUOTA_NL_A_WARNING, + QUOTA_NL_A_DEV_MAJOR, + QUOTA_NL_A_DEV_MINOR, + QUOTA_NL_A_CAUSED_ID, + __QUOTA_NL_A_MAX, +}; +#define QUOTA_NL_A_MAX (__QUOTA_NL_A_MAX - 1) + + #ifdef __KERNEL__ #include #include