379 lines
8.9 KiB
C
379 lines
8.9 KiB
C
/*
|
|
* Quota code necessary even when VFS quota support is not compiled
|
|
* into the kernel. The interesting stuff is over in dquot.c, here
|
|
* we have symbols for initial quotactl(2) handling, the sysctl(2)
|
|
* variables, etc - things needed even when quota support disabled.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/slab.h>
|
|
#include <asm/current.h>
|
|
#include <asm/uaccess.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/security.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/quotaops.h>
|
|
|
|
/* Check validity of generic quotactl commands */
|
|
static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
|
|
{
|
|
if (type >= MAXQUOTAS)
|
|
return -EINVAL;
|
|
if (!sb && cmd != Q_SYNC)
|
|
return -ENODEV;
|
|
/* Is operation supported? */
|
|
if (sb && !sb->s_qcop)
|
|
return -ENOSYS;
|
|
|
|
switch (cmd) {
|
|
case Q_GETFMT:
|
|
break;
|
|
case Q_QUOTAON:
|
|
if (!sb->s_qcop->quota_on)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_QUOTAOFF:
|
|
if (!sb->s_qcop->quota_off)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_SETINFO:
|
|
if (!sb->s_qcop->set_info)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_GETINFO:
|
|
if (!sb->s_qcop->get_info)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_SETQUOTA:
|
|
if (!sb->s_qcop->set_dqblk)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_GETQUOTA:
|
|
if (!sb->s_qcop->get_dqblk)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_SYNC:
|
|
if (sb && !sb->s_qcop->quota_sync)
|
|
return -ENOSYS;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Is quota turned on for commands which need it? */
|
|
switch (cmd) {
|
|
case Q_GETFMT:
|
|
case Q_GETINFO:
|
|
case Q_QUOTAOFF:
|
|
case Q_SETINFO:
|
|
case Q_SETQUOTA:
|
|
case Q_GETQUOTA:
|
|
/* This is just informative test so we are satisfied without a lock */
|
|
if (!sb_has_quota_enabled(sb, type))
|
|
return -ESRCH;
|
|
}
|
|
|
|
/* Check privileges */
|
|
if (cmd == Q_GETQUOTA) {
|
|
if (((type == USRQUOTA && current->euid != id) ||
|
|
(type == GRPQUOTA && !in_egroup_p(id))) &&
|
|
!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
}
|
|
else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO)
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Check validity of XFS Quota Manager commands */
|
|
static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
|
|
{
|
|
if (type >= XQM_MAXQUOTAS)
|
|
return -EINVAL;
|
|
if (!sb)
|
|
return -ENODEV;
|
|
if (!sb->s_qcop)
|
|
return -ENOSYS;
|
|
|
|
switch (cmd) {
|
|
case Q_XQUOTAON:
|
|
case Q_XQUOTAOFF:
|
|
case Q_XQUOTARM:
|
|
if (!sb->s_qcop->set_xstate)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_XGETQSTAT:
|
|
if (!sb->s_qcop->get_xstate)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_XSETQLIM:
|
|
if (!sb->s_qcop->set_xquota)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_XGETQUOTA:
|
|
if (!sb->s_qcop->get_xquota)
|
|
return -ENOSYS;
|
|
break;
|
|
case Q_XQUOTASYNC:
|
|
if (!sb->s_qcop->quota_sync)
|
|
return -ENOSYS;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Check privileges */
|
|
if (cmd == Q_XGETQUOTA) {
|
|
if (((type == XQM_USRQUOTA && current->euid != id) ||
|
|
(type == XQM_GRPQUOTA && !in_egroup_p(id))) &&
|
|
!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
} else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) {
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int check_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
|
|
{
|
|
int error;
|
|
|
|
if (XQM_COMMAND(cmd))
|
|
error = xqm_quotactl_valid(sb, type, cmd, id);
|
|
else
|
|
error = generic_quotactl_valid(sb, type, cmd, id);
|
|
if (!error)
|
|
error = security_quotactl(cmd, type, id, sb);
|
|
return error;
|
|
}
|
|
|
|
static void quota_sync_sb(struct super_block *sb, int type)
|
|
{
|
|
int cnt;
|
|
struct inode *discard[MAXQUOTAS];
|
|
|
|
sb->s_qcop->quota_sync(sb, type);
|
|
/* This is not very clever (and fast) but currently I don't know about
|
|
* any other simple way of getting quota data to disk and we must get
|
|
* them there for userspace to be visible... */
|
|
if (sb->s_op->sync_fs)
|
|
sb->s_op->sync_fs(sb, 1);
|
|
sync_blockdev(sb->s_bdev);
|
|
|
|
/* Now when everything is written we can discard the pagecache so
|
|
* that userspace sees the changes. We need i_mutex and so we could
|
|
* not do it inside dqonoff_mutex. Moreover we need to be carefull
|
|
* about races with quotaoff() (that is the reason why we have own
|
|
* reference to inode). */
|
|
mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
|
|
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
|
|
discard[cnt] = NULL;
|
|
if (type != -1 && cnt != type)
|
|
continue;
|
|
if (!sb_has_quota_enabled(sb, cnt))
|
|
continue;
|
|
discard[cnt] = igrab(sb_dqopt(sb)->files[cnt]);
|
|
}
|
|
mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
|
|
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
|
|
if (discard[cnt]) {
|
|
mutex_lock(&discard[cnt]->i_mutex);
|
|
truncate_inode_pages(&discard[cnt]->i_data, 0);
|
|
mutex_unlock(&discard[cnt]->i_mutex);
|
|
iput(discard[cnt]);
|
|
}
|
|
}
|
|
}
|
|
|
|
void sync_dquots(struct super_block *sb, int type)
|
|
{
|
|
int cnt, dirty;
|
|
|
|
if (sb) {
|
|
if (sb->s_qcop->quota_sync)
|
|
quota_sync_sb(sb, type);
|
|
return;
|
|
}
|
|
|
|
spin_lock(&sb_lock);
|
|
restart:
|
|
list_for_each_entry(sb, &super_blocks, s_list) {
|
|
/* This test just improves performance so it needn't be reliable... */
|
|
for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++)
|
|
if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt)
|
|
&& info_any_dirty(&sb_dqopt(sb)->info[cnt]))
|
|
dirty = 1;
|
|
if (!dirty)
|
|
continue;
|
|
sb->s_count++;
|
|
spin_unlock(&sb_lock);
|
|
down_read(&sb->s_umount);
|
|
if (sb->s_root && sb->s_qcop->quota_sync)
|
|
quota_sync_sb(sb, type);
|
|
up_read(&sb->s_umount);
|
|
spin_lock(&sb_lock);
|
|
if (__put_super_and_need_restart(sb))
|
|
goto restart;
|
|
}
|
|
spin_unlock(&sb_lock);
|
|
}
|
|
|
|
/* Copy parameters and call proper function */
|
|
static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, void __user *addr)
|
|
{
|
|
int ret;
|
|
|
|
switch (cmd) {
|
|
case Q_QUOTAON: {
|
|
char *pathname;
|
|
|
|
if (IS_ERR(pathname = getname(addr)))
|
|
return PTR_ERR(pathname);
|
|
ret = sb->s_qcop->quota_on(sb, type, id, pathname);
|
|
putname(pathname);
|
|
return ret;
|
|
}
|
|
case Q_QUOTAOFF:
|
|
return sb->s_qcop->quota_off(sb, type);
|
|
|
|
case Q_GETFMT: {
|
|
__u32 fmt;
|
|
|
|
down_read(&sb_dqopt(sb)->dqptr_sem);
|
|
if (!sb_has_quota_enabled(sb, type)) {
|
|
up_read(&sb_dqopt(sb)->dqptr_sem);
|
|
return -ESRCH;
|
|
}
|
|
fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
|
|
up_read(&sb_dqopt(sb)->dqptr_sem);
|
|
if (copy_to_user(addr, &fmt, sizeof(fmt)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case Q_GETINFO: {
|
|
struct if_dqinfo info;
|
|
|
|
if ((ret = sb->s_qcop->get_info(sb, type, &info)))
|
|
return ret;
|
|
if (copy_to_user(addr, &info, sizeof(info)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case Q_SETINFO: {
|
|
struct if_dqinfo info;
|
|
|
|
if (copy_from_user(&info, addr, sizeof(info)))
|
|
return -EFAULT;
|
|
return sb->s_qcop->set_info(sb, type, &info);
|
|
}
|
|
case Q_GETQUOTA: {
|
|
struct if_dqblk idq;
|
|
|
|
if ((ret = sb->s_qcop->get_dqblk(sb, type, id, &idq)))
|
|
return ret;
|
|
if (copy_to_user(addr, &idq, sizeof(idq)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case Q_SETQUOTA: {
|
|
struct if_dqblk idq;
|
|
|
|
if (copy_from_user(&idq, addr, sizeof(idq)))
|
|
return -EFAULT;
|
|
return sb->s_qcop->set_dqblk(sb, type, id, &idq);
|
|
}
|
|
case Q_SYNC:
|
|
sync_dquots(sb, type);
|
|
return 0;
|
|
|
|
case Q_XQUOTAON:
|
|
case Q_XQUOTAOFF:
|
|
case Q_XQUOTARM: {
|
|
__u32 flags;
|
|
|
|
if (copy_from_user(&flags, addr, sizeof(flags)))
|
|
return -EFAULT;
|
|
return sb->s_qcop->set_xstate(sb, flags, cmd);
|
|
}
|
|
case Q_XGETQSTAT: {
|
|
struct fs_quota_stat fqs;
|
|
|
|
if ((ret = sb->s_qcop->get_xstate(sb, &fqs)))
|
|
return ret;
|
|
if (copy_to_user(addr, &fqs, sizeof(fqs)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case Q_XSETQLIM: {
|
|
struct fs_disk_quota fdq;
|
|
|
|
if (copy_from_user(&fdq, addr, sizeof(fdq)))
|
|
return -EFAULT;
|
|
return sb->s_qcop->set_xquota(sb, type, id, &fdq);
|
|
}
|
|
case Q_XGETQUOTA: {
|
|
struct fs_disk_quota fdq;
|
|
|
|
if ((ret = sb->s_qcop->get_xquota(sb, type, id, &fdq)))
|
|
return ret;
|
|
if (copy_to_user(addr, &fdq, sizeof(fdq)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case Q_XQUOTASYNC:
|
|
return sb->s_qcop->quota_sync(sb, type);
|
|
/* We never reach here unless validity check is broken */
|
|
default:
|
|
BUG();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is the system call interface. This communicates with
|
|
* the user-level programs. Currently this only supports diskquota
|
|
* calls. Maybe we need to add the process quotas etc. in the future,
|
|
* but we probably should use rlimits for that.
|
|
*/
|
|
asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special, qid_t id, void __user *addr)
|
|
{
|
|
uint cmds, type;
|
|
struct super_block *sb = NULL;
|
|
struct block_device *bdev;
|
|
char *tmp;
|
|
int ret;
|
|
|
|
cmds = cmd >> SUBCMDSHIFT;
|
|
type = cmd & SUBCMDMASK;
|
|
|
|
if (cmds != Q_SYNC || special) {
|
|
tmp = getname(special);
|
|
if (IS_ERR(tmp))
|
|
return PTR_ERR(tmp);
|
|
bdev = lookup_bdev(tmp);
|
|
putname(tmp);
|
|
if (IS_ERR(bdev))
|
|
return PTR_ERR(bdev);
|
|
sb = get_super(bdev);
|
|
bdput(bdev);
|
|
if (!sb)
|
|
return -ENODEV;
|
|
}
|
|
|
|
ret = check_quotactl_valid(sb, type, cmds, id);
|
|
if (ret >= 0)
|
|
ret = do_quotactl(sb, type, cmds, id, addr);
|
|
if (sb)
|
|
drop_super(sb);
|
|
|
|
return ret;
|
|
}
|