quota: special case Q_SYNC without device name

The Q_SYNC command can be called without the path to a device, in which case
it iterates over all superblocks.  Special case this variant directly in
sys_quotactl so that the other code always gets a superblock and doesn't
need to deal with this case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Christoph Hellwig 2010-02-16 03:44:49 -05:00 committed by Jan Kara
parent f450d4fee4
commit 6ae09575b3

View file

@ -124,10 +124,17 @@ void sync_quota_sb(struct super_block *sb, int type)
}
#endif
static void sync_dquots(int type)
static int quota_sync_all(int type)
{
struct super_block *sb;
int cnt;
int ret;
if (type >= MAXQUOTAS)
return -EINVAL;
ret = security_quotactl(Q_SYNC, type, 0, NULL);
if (ret)
return ret;
spin_lock(&sb_lock);
restart:
@ -157,6 +164,8 @@ static void sync_dquots(int type)
goto restart;
}
spin_unlock(&sb_lock);
return 0;
}
static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
@ -322,12 +331,9 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
case Q_SETQUOTA:
return quota_setquota(sb, type, id, addr);
case Q_SYNC:
if (sb) {
if (!sb->s_qcop->quota_sync)
return -ENOSYS;
sync_quota_sb(sb, type);
} else
sync_dquots(type);
if (!sb->s_qcop->quota_sync)
return -ENOSYS;
sync_quota_sb(sb, type);
return 0;
case Q_XQUOTAON:
case Q_XQUOTAOFF:
@ -392,18 +398,26 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
if (cmds != Q_SYNC || special) {
sb = quotactl_block(special);
if (IS_ERR(sb))
return PTR_ERR(sb);
/*
* As a special case Q_SYNC can be called without a specific device.
* It will iterate all superblocks that have quota enabled and call
* the sync action on each of them.
*/
if (!special) {
if (cmds == Q_SYNC)
return quota_sync_all(type);
return -ENODEV;
}
sb = quotactl_block(special);
if (IS_ERR(sb))
return PTR_ERR(sb);
ret = check_quotactl_valid(sb, type, cmds, id);
if (ret >= 0)
ret = do_quotactl(sb, type, cmds, id, addr);
if (sb)
drop_super(sb);
drop_super(sb);
return ret;
}