fs/ext4/ioctl.c - maze/linux - Git at Google

 /*
  * linux/fs/ext4/ioctl.c
  *
  * Copyright (C) 1993, 1994, 1995
  * Remy Card (card@masi.ibp.fr)
  * Laboratoire MASI - Institut Blaise Pascal
  * Universite Pierre et Marie Curie (Paris VI)
  */

 #include <linux/fs.h>
 #include <linux/jbd2.h>
 #include <linux/capability.h>
 #include <linux/time.h>
 #include <linux/compat.h>
 #include <linux/mount.h>
 #include <linux/file.h>
 #include <asm/uaccess.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"

 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = filp->f_dentry->d_inode;
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	unsigned int flags;

 	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);

 	switch (cmd) {
 	case EXT4_IOC_GETFLAGS:
 		ext4_get_inode_flags(ei);
 		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
 		return put_user(flags, (int __user *) arg);
 	case EXT4_IOC_SETFLAGS: {
 		handle_t *handle = NULL;
 		int err, migrate = 0;
 		struct ext4_iloc iloc;
 		unsigned int oldflags;
 		unsigned int jflag;

 		if (!is_owner_or_cap(inode))
 			return -EACCES;

 		if (get_user(flags, (int __user *) arg))
 			return -EFAULT;

 		err = mnt_want_write(filp->f_path.mnt);
 		if (err)
 			return err;

 		flags = ext4_mask_flags(inode->i_mode, flags);

 		err = -EPERM;
 		mutex_lock(&inode->i_mutex);
 		/* Is it quota file? Do not allow user to mess with it */
 		if (IS_NOQUOTA(inode))
 			goto flags_out;

 		oldflags = ei->i_flags;

 		/* The JOURNAL_DATA flag is modifiable only by root */
 		jflag = flags & EXT4_JOURNAL_DATA_FL;

 		/*
 		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 		 * the relevant capability.
 		 *
 		 * This test looks nicer. Thanks to Pauline Middelink
 		 */
 		if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
 			if (!capable(CAP_LINUX_IMMUTABLE))
 				goto flags_out;
 		}

 		/*
 		 * The JOURNAL_DATA flag can only be changed by
 		 * the relevant capability.
 		 */
 		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
 			if (!capable(CAP_SYS_RESOURCE))
 				goto flags_out;
 		}
 		if (oldflags & EXT4_EXTENTS_FL) {
 			/* We don't support clearning extent flags */
 			if (!(flags & EXT4_EXTENTS_FL)) {
 				err = -EOPNOTSUPP;
 				goto flags_out;
 			}
 		} else if (flags & EXT4_EXTENTS_FL) {
 			/* migrate the file */
 			migrate = 1;
 			flags &= ~EXT4_EXTENTS_FL;
 		}

 		handle = ext4_journal_start(inode, 1);
 		if (IS_ERR(handle)) {
 			err = PTR_ERR(handle);
 			goto flags_out;
 		}
 		if (IS_SYNC(inode))
 			ext4_handle_sync(handle);
 		err = ext4_reserve_inode_write(handle, inode, &iloc);
 		if (err)
 			goto flags_err;

 		flags = flags & EXT4_FL_USER_MODIFIABLE;
 		flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 		ei->i_flags = flags;

 		ext4_set_inode_flags(inode);
 		inode->i_ctime = ext4_current_time(inode);

 		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 flags_err:
 		ext4_journal_stop(handle);
 		if (err)
 			goto flags_out;

 		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 			err = ext4_change_inode_journal_flag(inode, jflag);
 		if (err)
 			goto flags_out;
 		if (migrate)
 			err = ext4_ext_migrate(inode);
 flags_out:
 		mutex_unlock(&inode->i_mutex);
 		mnt_drop_write(filp->f_path.mnt);
 		return err;
 	}
 	case EXT4_IOC_GETVERSION:
 	case EXT4_IOC_GETVERSION_OLD:
 		return put_user(inode->i_generation, (int __user *) arg);
 	case EXT4_IOC_SETVERSION:
 	case EXT4_IOC_SETVERSION_OLD: {
 		handle_t *handle;
 		struct ext4_iloc iloc;
 		__u32 generation;
 		int err;

 		if (!is_owner_or_cap(inode))
 			return -EPERM;

 		err = mnt_want_write(filp->f_path.mnt);
 		if (err)
 			return err;
 		if (get_user(generation, (int __user *) arg)) {
 			err = -EFAULT;
 			goto setversion_out;
 		}

 		handle = ext4_journal_start(inode, 1);
 		if (IS_ERR(handle)) {
 			err = PTR_ERR(handle);
 			goto setversion_out;
 		}
 		err = ext4_reserve_inode_write(handle, inode, &iloc);
 		if (err == 0) {
 			inode->i_ctime = ext4_current_time(inode);
 			inode->i_generation = generation;
 			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 		}
 		ext4_journal_stop(handle);
 setversion_out:
 		mnt_drop_write(filp->f_path.mnt);
 		return err;
 	}
 #ifdef CONFIG_JBD2_DEBUG
 	case EXT4_IOC_WAIT_FOR_READONLY:
 		/*
 		 * This is racy - by the time we're woken up and running,
 		 * the superblock could be released.  And the module could
 		 * have been unloaded.  So sue me.
 		 *
 		 * Returns 1 if it slept, else zero.
 		 */
 		{
 			struct super_block *sb = inode->i_sb;
 			DECLARE_WAITQUEUE(wait, current);
 			int ret = 0;

 			set_current_state(TASK_INTERRUPTIBLE);
 			add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 			if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 				schedule();
 				ret = 1;
 			}
 			remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 			return ret;
 		}
 #endif
 	case EXT4_IOC_GROUP_EXTEND: {
 		ext4_fsblk_t n_blocks_count;
 		struct super_block *sb = inode->i_sb;
 		int err, err2;

 		if (!capable(CAP_SYS_RESOURCE))
 			return -EPERM;

 		if (get_user(n_blocks_count, (__u32 __user *)arg))
 			return -EFAULT;

 		err = mnt_want_write(filp->f_path.mnt);
 		if (err)
 			return err;

 		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 		err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 		if (err == 0)
 			err = err2;
 		mnt_drop_write(filp->f_path.mnt);

 		return err;
 	}

 	case EXT4_IOC_MOVE_EXT: {
 		struct move_extent me;
 		struct file *donor_filp;
 		int err;

 		if (copy_from_user(&me,
 			(struct move_extent __user *)arg, sizeof(me)))
 			return -EFAULT;

 		donor_filp = fget(me.donor_fd);
 		if (!donor_filp)
 			return -EBADF;

 		if (!capable(CAP_DAC_OVERRIDE)) {
 			if ((current->real_cred->fsuid != inode->i_uid) ||
 				!(inode->i_mode & S_IRUSR) ||
 				!(donor_filp->f_dentry->d_inode->i_mode &
 				S_IRUSR)) {
 				fput(donor_filp);
 				return -EACCES;
 			}
 		}

 		err = ext4_move_extents(filp, donor_filp, me.orig_start,
 					me.donor_start, me.len, &me.moved_len);
 		fput(donor_filp);

 		if (!err)
 			if (copy_to_user((struct move_extent *)arg,
 				&me, sizeof(me)))
 				return -EFAULT;
 		return err;
 	}

 	case EXT4_IOC_GROUP_ADD: {
 		struct ext4_new_group_data input;
 		struct super_block *sb = inode->i_sb;
 		int err, err2;

 		if (!capable(CAP_SYS_RESOURCE))
 			return -EPERM;

 		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 				sizeof(input)))
 			return -EFAULT;

 		err = mnt_want_write(filp->f_path.mnt);
 		if (err)
 			return err;

 		err = ext4_group_add(sb, &input);
 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 		err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 		if (err == 0)
 			err = err2;
 		mnt_drop_write(filp->f_path.mnt);

 		return err;
 	}

 	case EXT4_IOC_MIGRATE:
 	{
 		int err;
 		if (!is_owner_or_cap(inode))
 			return -EACCES;

 		err = mnt_want_write(filp->f_path.mnt);
 		if (err)
 			return err;
 		/*
 		 * inode_mutex prevent write and truncate on the file.
 		 * Read still goes through. We take i_data_sem in
 		 * ext4_ext_swap_inode_data before we switch the
 		 * inode format to prevent read.
 		 */
 		mutex_lock(&(inode->i_mutex));
 		err = ext4_ext_migrate(inode);
 		mutex_unlock(&(inode->i_mutex));
 		mnt_drop_write(filp->f_path.mnt);
 		return err;
 	}

 	case EXT4_IOC_ALLOC_DA_BLKS:
 	{
 		int err;
 		if (!is_owner_or_cap(inode))
 			return -EACCES;

 		err = mnt_want_write(filp->f_path.mnt);
 		if (err)
 			return err;
 		err = ext4_alloc_da_blocks(inode);
 		mnt_drop_write(filp->f_path.mnt);
 		return err;
 	}

 	default:
 		return -ENOTTY;
 	}
 }

 #ifdef CONFIG_COMPAT
 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	/* These are just misnamed, they actually get/put from/to user an int */
 	switch (cmd) {
 	case EXT4_IOC32_GETFLAGS:
 		cmd = EXT4_IOC_GETFLAGS;
 		break;
 	case EXT4_IOC32_SETFLAGS:
 		cmd = EXT4_IOC_SETFLAGS;
 		break;
 	case EXT4_IOC32_GETVERSION:
 		cmd = EXT4_IOC_GETVERSION;
 		break;
 	case EXT4_IOC32_SETVERSION:
 		cmd = EXT4_IOC_SETVERSION;
 		break;
 	case EXT4_IOC32_GROUP_EXTEND:
 		cmd = EXT4_IOC_GROUP_EXTEND;
 		break;
 	case EXT4_IOC32_GETVERSION_OLD:
 		cmd = EXT4_IOC_GETVERSION_OLD;
 		break;
 	case EXT4_IOC32_SETVERSION_OLD:
 		cmd = EXT4_IOC_SETVERSION_OLD;
 		break;
 #ifdef CONFIG_JBD2_DEBUG
 	case EXT4_IOC32_WAIT_FOR_READONLY:
 		cmd = EXT4_IOC_WAIT_FOR_READONLY;
 		break;
 #endif
 	case EXT4_IOC32_GETRSVSZ:
 		cmd = EXT4_IOC_GETRSVSZ;
 		break;
 	case EXT4_IOC32_SETRSVSZ:
 		cmd = EXT4_IOC_SETRSVSZ;
 		break;
 	case EXT4_IOC_GROUP_ADD:
 		break;
 	default:
 		return -ENOIOCTLCMD;
 	}
 	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif
	/*
	* linux/fs/ext4/ioctl.c
	*
	* Copyright (C) 1993, 1994, 1995
	* Remy Card (card@masi.ibp.fr)
	* Laboratoire MASI - Institut Blaise Pascal
	* Universite Pierre et Marie Curie (Paris VI)
	*/

	#include <linux/fs.h>
	#include <linux/jbd2.h>
	#include <linux/capability.h>
	#include <linux/time.h>
	#include <linux/compat.h>
	#include <linux/mount.h>
	#include <linux/file.h>
	#include <asm/uaccess.h>
	#include "ext4_jbd2.h"
	#include "ext4.h"

	long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = filp->f_dentry->d_inode;
	struct ext4_inode_info *ei = EXT4_I(inode);
	unsigned int flags;

	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);

	switch (cmd) {
	case EXT4_IOC_GETFLAGS:
	ext4_get_inode_flags(ei);
	flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
	return put_user(flags, (int __user *) arg);
	case EXT4_IOC_SETFLAGS: {
	handle_t *handle = NULL;
	int err, migrate = 0;
	struct ext4_iloc iloc;
	unsigned int oldflags;
	unsigned int jflag;

	if (!is_owner_or_cap(inode))
	return -EACCES;

	if (get_user(flags, (int __user *) arg))
	return -EFAULT;

	err = mnt_want_write(filp->f_path.mnt);
	if (err)
	return err;

	flags = ext4_mask_flags(inode->i_mode, flags);

	err = -EPERM;
	mutex_lock(&inode->i_mutex);
	/* Is it quota file? Do not allow user to mess with it */
	if (IS_NOQUOTA(inode))
	goto flags_out;

	oldflags = ei->i_flags;

	/* The JOURNAL_DATA flag is modifiable only by root */
	jflag = flags & EXT4_JOURNAL_DATA_FL;

	/*
	* The IMMUTABLE and APPEND_ONLY flags can only be changed by
	* the relevant capability.
	*
	* This test looks nicer. Thanks to Pauline Middelink
	*/
	if ((flags ^ oldflags) & (EXT4_APPEND_FL \| EXT4_IMMUTABLE_FL)) {
	if (!capable(CAP_LINUX_IMMUTABLE))
	goto flags_out;
	}

	/*
	* The JOURNAL_DATA flag can only be changed by
	* the relevant capability.
	*/
	if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
	if (!capable(CAP_SYS_RESOURCE))
	goto flags_out;
	}
	if (oldflags & EXT4_EXTENTS_FL) {
	/* We don't support clearning extent flags */
	if (!(flags & EXT4_EXTENTS_FL)) {
	err = -EOPNOTSUPP;
	goto flags_out;
	}
	} else if (flags & EXT4_EXTENTS_FL) {
	/* migrate the file */
	migrate = 1;
	flags &= ~EXT4_EXTENTS_FL;
	}

	handle = ext4_journal_start(inode, 1);
	if (IS_ERR(handle)) {
	err = PTR_ERR(handle);
	goto flags_out;
	}
	if (IS_SYNC(inode))
	ext4_handle_sync(handle);
	err = ext4_reserve_inode_write(handle, inode, &iloc);
	if (err)
	goto flags_err;

	flags = flags & EXT4_FL_USER_MODIFIABLE;
	flags \|= oldflags & ~EXT4_FL_USER_MODIFIABLE;
	ei->i_flags = flags;

	ext4_set_inode_flags(inode);
	inode->i_ctime = ext4_current_time(inode);

	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
	flags_err:
	ext4_journal_stop(handle);
	if (err)
	goto flags_out;

	if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
	err = ext4_change_inode_journal_flag(inode, jflag);
	if (err)
	goto flags_out;
	if (migrate)
	err = ext4_ext_migrate(inode);
	flags_out:
	mutex_unlock(&inode->i_mutex);
	mnt_drop_write(filp->f_path.mnt);
	return err;
	}
	case EXT4_IOC_GETVERSION:
	case EXT4_IOC_GETVERSION_OLD:
	return put_user(inode->i_generation, (int __user *) arg);
	case EXT4_IOC_SETVERSION:
	case EXT4_IOC_SETVERSION_OLD: {
	handle_t *handle;
	struct ext4_iloc iloc;
	__u32 generation;
	int err;

	if (!is_owner_or_cap(inode))
	return -EPERM;

	err = mnt_want_write(filp->f_path.mnt);
	if (err)
	return err;
	if (get_user(generation, (int __user *) arg)) {
	err = -EFAULT;
	goto setversion_out;
	}

	handle = ext4_journal_start(inode, 1);
	if (IS_ERR(handle)) {
	err = PTR_ERR(handle);
	goto setversion_out;
	}
	err = ext4_reserve_inode_write(handle, inode, &iloc);
	if (err == 0) {
	inode->i_ctime = ext4_current_time(inode);
	inode->i_generation = generation;
	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
	}
	ext4_journal_stop(handle);
	setversion_out:
	mnt_drop_write(filp->f_path.mnt);
	return err;
	}
	#ifdef CONFIG_JBD2_DEBUG
	case EXT4_IOC_WAIT_FOR_READONLY:
	/*
	* This is racy - by the time we're woken up and running,
	* the superblock could be released. And the module could
	* have been unloaded. So sue me.
	*
	* Returns 1 if it slept, else zero.
	*/
	{
	struct super_block *sb = inode->i_sb;
	DECLARE_WAITQUEUE(wait, current);
	int ret = 0;

	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
	if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
	schedule();
	ret = 1;
	}
	remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
	return ret;
	}
	#endif
	case EXT4_IOC_GROUP_EXTEND: {
	ext4_fsblk_t n_blocks_count;
	struct super_block *sb = inode->i_sb;
	int err, err2;

	if (!capable(CAP_SYS_RESOURCE))
	return -EPERM;

	if (get_user(n_blocks_count, (__u32 __user *)arg))
	return -EFAULT;

	err = mnt_want_write(filp->f_path.mnt);
	if (err)
	return err;

	err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
	jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
	err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
	if (err == 0)
	err = err2;
	mnt_drop_write(filp->f_path.mnt);

	return err;
	}

	case EXT4_IOC_MOVE_EXT: {
	struct move_extent me;
	struct file *donor_filp;
	int err;

	if (copy_from_user(&me,
	(struct move_extent __user *)arg, sizeof(me)))
	return -EFAULT;

	donor_filp = fget(me.donor_fd);
	if (!donor_filp)
	return -EBADF;

	if (!capable(CAP_DAC_OVERRIDE)) {
	if ((current->real_cred->fsuid != inode->i_uid) \|\|
	!(inode->i_mode & S_IRUSR) \|\|
	!(donor_filp->f_dentry->d_inode->i_mode &
	S_IRUSR)) {
	fput(donor_filp);
	return -EACCES;
	}
	}

	err = ext4_move_extents(filp, donor_filp, me.orig_start,
	me.donor_start, me.len, &me.moved_len);
	fput(donor_filp);

	if (!err)
	if (copy_to_user((struct move_extent *)arg,
	&me, sizeof(me)))
	return -EFAULT;
	return err;
	}

	case EXT4_IOC_GROUP_ADD: {
	struct ext4_new_group_data input;
	struct super_block *sb = inode->i_sb;
	int err, err2;

	if (!capable(CAP_SYS_RESOURCE))
	return -EPERM;

	if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
	sizeof(input)))
	return -EFAULT;

	err = mnt_want_write(filp->f_path.mnt);
	if (err)
	return err;

	err = ext4_group_add(sb, &input);
	jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
	err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
	if (err == 0)
	err = err2;
	mnt_drop_write(filp->f_path.mnt);

	return err;
	}

	case EXT4_IOC_MIGRATE:
	{
	int err;
	if (!is_owner_or_cap(inode))
	return -EACCES;

	err = mnt_want_write(filp->f_path.mnt);
	if (err)
	return err;
	/*
	* inode_mutex prevent write and truncate on the file.
	* Read still goes through. We take i_data_sem in
	* ext4_ext_swap_inode_data before we switch the
	* inode format to prevent read.
	*/
	mutex_lock(&(inode->i_mutex));
	err = ext4_ext_migrate(inode);
	mutex_unlock(&(inode->i_mutex));
	mnt_drop_write(filp->f_path.mnt);
	return err;
	}

	case EXT4_IOC_ALLOC_DA_BLKS:
	{
	int err;
	if (!is_owner_or_cap(inode))
	return -EACCES;

	err = mnt_want_write(filp->f_path.mnt);
	if (err)
	return err;
	err = ext4_alloc_da_blocks(inode);
	mnt_drop_write(filp->f_path.mnt);
	return err;
	}

	default:
	return -ENOTTY;
	}
	}

	#ifdef CONFIG_COMPAT
	long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	/* These are just misnamed, they actually get/put from/to user an int */
	switch (cmd) {
	case EXT4_IOC32_GETFLAGS:
	cmd = EXT4_IOC_GETFLAGS;
	break;
	case EXT4_IOC32_SETFLAGS:
	cmd = EXT4_IOC_SETFLAGS;
	break;
	case EXT4_IOC32_GETVERSION:
	cmd = EXT4_IOC_GETVERSION;
	break;
	case EXT4_IOC32_SETVERSION:
	cmd = EXT4_IOC_SETVERSION;
	break;
	case EXT4_IOC32_GROUP_EXTEND:
	cmd = EXT4_IOC_GROUP_EXTEND;
	break;
	case EXT4_IOC32_GETVERSION_OLD:
	cmd = EXT4_IOC_GETVERSION_OLD;
	break;
	case EXT4_IOC32_SETVERSION_OLD:
	cmd = EXT4_IOC_SETVERSION_OLD;
	break;
	#ifdef CONFIG_JBD2_DEBUG
	case EXT4_IOC32_WAIT_FOR_READONLY:
	cmd = EXT4_IOC_WAIT_FOR_READONLY;
	break;
	#endif
	case EXT4_IOC32_GETRSVSZ:
	cmd = EXT4_IOC_GETRSVSZ;
	break;
	case EXT4_IOC32_SETRSVSZ:
	cmd = EXT4_IOC_SETRSVSZ;
	break;
	case EXT4_IOC_GROUP_ADD:
	break;
	default:
	return -ENOIOCTLCMD;
	}
	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
	}
	#endif