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quota: send messages via netlink

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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 <jack@suse.cz>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Kara
2007-10-16 23:29:31 -07:00
committed by Linus Torvalds
parent fac8b209b1
commit 8e8934695d
4 changed files with 222 additions and 30 deletions
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144
fs/dquot.c
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@@ -79,6 +79,10 @@
#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>
@@ -823,6 +827,7 @@ static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
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(struct dquot *dquot)
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 *dquot, const char warntype)
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 +891,93 @@ static void print_warning(struct dquot *dquot, const char warntype)
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 atomic_t seq;
struct sk_buff *skb;
void *msg_head;
int ret;
/* 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);
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),
&quota_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 +991,14 @@ static inline char ignore_hardlimit(struct dquot *dquot)
/* 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 +1006,14 @@ static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
(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 +1023,7 @@ static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
/* 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 +1031,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *war
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 +1040,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *war
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 +1048,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *war
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 +1143,7 @@ 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 +1189,7 @@ int dquot_alloc_inode(const struct inode *inode, unsigned long number)
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 +1311,7 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
/* 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 +1885,7 @@ 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 +1894,7 @@ static ctl_table fs_dqstats_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec,
},
#endif
{ .ctl_name = 0 },
};
@@ -1877,6 +1956,11 @@ static int __init dquot_init(void)
register_shrinker(&dqcache_shrinker);
#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
if (genl_register_family(&quota_genl_family) != 0)
printk(KERN_ERR "VFS: Failed to create quota netlink interface.\n");
#endif
return 0;
}
module_init(dquot_init);