Commit cb0b476a authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

fs/quota: add kernel_quotactl() helper; remove in-kernel call to syscall 

Using the fs-internal kernel_quotactl() helper allows us to get rid of
the fs-internal call to the sys_quotactl() syscall.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net



Acked-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent 183caa3c

fs/quota/compat.c

+4 −4
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, 
	case Q_GETQUOTA:

		dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));

		compat_dqblk = addr;

		ret = sys_quotactl(cmd, special, id, dqblk);

		ret = kernel_quotactl(cmd, special, id, dqblk);

		if (ret)

			break;

		if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
@@ -75,12 +75,12 @@ asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, 
			get_user(data, &compat_dqblk->dqb_valid) ||

			put_user(data, &dqblk->dqb_valid))

			break;

		ret = sys_quotactl(cmd, special, id, dqblk);

		ret = kernel_quotactl(cmd, special, id, dqblk);

		break;

	case Q_XGETQSTAT:

		fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));

		compat_fsqstat = addr;

		ret = sys_quotactl(cmd, special, id, fsqstat);

		ret = kernel_quotactl(cmd, special, id, fsqstat);

		if (ret)

			break;

		ret = -EFAULT;
@@ -113,7 +113,7 @@ asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, 
		ret = 0;

		break;

	default:

		ret = sys_quotactl(cmd, special, id, addr);

		ret = kernel_quotactl(cmd, special, id, addr);

	}

	return ret;

}

fs/quota/quota.c

+8 −2
Original line number Diff line number Diff line
@@ -833,8 +833,8 @@ static struct super_block *quotactl_block(const char __user *special, int cmd) 
 * 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)

int kernel_quotactl(unsigned int cmd, const char __user *special,

		    qid_t id, void __user *addr)

{

	uint cmds, type;

	struct super_block *sb = NULL;
@@ -885,3 +885,9 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, 
		path_put(pathp);

	return ret;

}



SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,

		qid_t, id, void __user *, addr)

{

	return kernel_quotactl(cmd, special, id, addr);

}

include/linux/quotaops.h

+3 −0
Original line number Diff line number Diff line
@@ -27,6 +27,9 @@ static inline bool is_quota_modification(struct inode *inode, struct iattr *ia) 
		(ia->ia_valid & ATTR_GID && !gid_eq(ia->ia_gid, inode->i_gid));

}



int kernel_quotactl(unsigned int cmd, const char __user *special,

		    qid_t id, void __user *addr);



#if defined(CONFIG_QUOTA)



#define quota_error(sb, fmt, args...) \