/*
* 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.
*/
SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
qid_t, id, void __user *, addr)
{
uint cmds, type;
struct super_block *sb = NULL;
struct path path, *pathp = NULL;
int ret;
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
/*
* 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;
}
/*
* Path for quotaon has to be resolved before grabbing superblock
* because that gets s_umount sem which is also possibly needed by path
* resolution (think about autofs) and thus deadlocks could arise.
*/
if (cmds == Q_QUOTAON) {
ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
if (ret)
pathp = ERR_PTR(ret);
else
pathp = &path;
}
sb = quotactl_block(special, cmds);
if (IS_ERR(sb)) {
ret = PTR_ERR(sb);
goto out;
}
ret = do_quotactl(sb, type, cmds, id, addr, pathp);
drop_super(sb);
out:
if (pathp && !IS_ERR(pathp))
path_put(pathp);
return ret;
}
/*
* 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 *special, qid_t id, caddr_t addr)
{
uint cmds, type;
struct super_block *sb = NULL;
int ret = -EINVAL;
lock_kernel();
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
#ifdef CONFIG_QIFACE_COMPAT
if (cmds != Q_V1_GETSTATS && cmds != Q_V2_GETSTATS && IS_ERR(sb = resolve_dev(special))) {
ret = PTR_ERR(sb);
sb = NULL;
goto out;
}
if (!NEW_COMMAND(cmds) && !XQM_COMMAND(cmds)) {
if ((ret = check_compat_quotactl_valid(sb, type, cmds, id)) < 0)
goto out;
ret = do_compat_quotactl(sb, type, cmds, id, addr);
goto out;
}
#else
if (IS_ERR(sb = resolve_dev(special))) {
ret = PTR_ERR(sb);
sb = NULL;
goto out;
}
#endif
if ((ret = check_quotactl_valid(sb, type, cmds, id)) < 0)
goto out;
ret = do_quotactl(sb, type, cmds, id, addr);
out:
if (sb)
drop_super(sb);
unlock_kernel();
return ret;
}
/*
* do_quotas()
* do quotactl commands
*/
static int do_quotas(const dev_info_t *dev, const char *name)
{
int tested = 0, failed = 0, enosys = 0;
#if defined(Q_GETQUOTA)
if (opt_do_run) {
struct dqblk dqblk;
do_quotactl(name, DO_Q_GETQUOTA, "Q_GETQUOTA",
&tested, &failed, &enosys,
QCMD(Q_GETQUOTA, USRQUOTA),
dev->name, 0, (caddr_t)&dqblk);
}
#endif
#if defined(Q_GETFMT)
if (opt_do_run) {
uint32_t format;
do_quotactl(name, DO_Q_GETFMT, "Q_GETFMT",
&tested, &failed, &enosys,
QCMD(Q_GETFMT, USRQUOTA),
dev->name, 0, (caddr_t)&format);
}
#endif
#if defined(Q_GETINFO)
if (opt_do_run) {
struct dqinfo dqinfo;
do_quotactl(name, DO_Q_GETINFO, "Q_GETINFO",
&tested, &failed, &enosys,
QCMD(Q_GETINFO, USRQUOTA),
dev->name, 0, (caddr_t)&dqinfo);
}
#endif
#if defined(Q_GETSTATS)
/* Obsolete in recent kernels */
if (opt_do_run) {
struct dqstats dqstats;
do_quotactl(name, DO_Q_GETSTATS, "Q_GETSTATS",
&tested, &failed, &enosys,
QCMD(Q_GETSTATS, USRQUOTA),
dev->name, 0, (caddr_t)&dqstats);
}
#endif
#if defined(Q_SYNC)
if (opt_do_run) {
do_quotactl(name, DO_Q_SYNC, "Q_SYNC",
&tested, &failed, &enosys,
QCMD(Q_SYNC, USRQUOTA),
dev->name, 0, 0);
}
#endif
if (tested == 0) {
pr_err(stderr, "%s: quotactl() failed, quota commands not available\n", name);
return -1;
}
if (tested == enosys) {
pr_err(stderr, "%s: quotactl() failed, not available on this kernel\n", name);
return -1;
}
if (tested == failed) {
pr_err(stderr, "%s: quotactl() failed, all quota commands failed (maybe privilege issues, use -v to see why)\n", name);
return -1;
}
return 0;
}
