fs/ext4/ioctl.c - kernel/msm-5.4 - Gitiles

 /*
  * 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"

 #define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)

 /**
  * Swap memory between @a and @b for @len bytes.
  *
  * @a:          pointer to first memory area
  * @b:          pointer to second memory area
  * @len:        number of bytes to swap
  *
  */
 static void memswap(void *a, void *b, size_t len)
 {
 	unsigned char *ap, *bp;
 	unsigned char tmp;

 	ap = (unsigned char *)a;
 	bp = (unsigned char *)b;
 	while (len-- > 0) {
 		tmp = *ap;
 		*ap = *bp;
 		*bp = tmp;
 		ap++;
 		bp++;
 	}
 }

 /**
  * Swap i_data and associated attributes between @inode1 and @inode2.
  * This function is used for the primary swap between inode1 and inode2
  * and also to revert this primary swap in case of errors.
  *
  * Therefore you have to make sure, that calling this method twice
  * will revert all changes.
  *
  * @inode1:     pointer to first inode
  * @inode2:     pointer to second inode
  */
 static void swap_inode_data(struct inode *inode1, struct inode *inode2)
 {
 	loff_t isize;
 	struct ext4_inode_info *ei1;
 	struct ext4_inode_info *ei2;

 	ei1 = EXT4_I(inode1);
 	ei2 = EXT4_I(inode2);

 	memswap(&inode1->i_flags, &inode2->i_flags, sizeof(inode1->i_flags));
 	memswap(&inode1->i_version, &inode2->i_version,
 		  sizeof(inode1->i_version));
 	memswap(&inode1->i_blocks, &inode2->i_blocks,
 		  sizeof(inode1->i_blocks));
 	memswap(&inode1->i_bytes, &inode2->i_bytes, sizeof(inode1->i_bytes));
 	memswap(&inode1->i_atime, &inode2->i_atime, sizeof(inode1->i_atime));
 	memswap(&inode1->i_mtime, &inode2->i_mtime, sizeof(inode1->i_mtime));

 	memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
 	memswap(&ei1->i_flags, &ei2->i_flags, sizeof(ei1->i_flags));
 	memswap(&ei1->i_disksize, &ei2->i_disksize, sizeof(ei1->i_disksize));
 	ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
 	ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);
 	ext4_es_lru_del(inode1);
 	ext4_es_lru_del(inode2);

 	isize = i_size_read(inode1);
 	i_size_write(inode1, i_size_read(inode2));
 	i_size_write(inode2, isize);
 }

 /**
  * Swap the information from the given @inode and the inode
  * EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
  * important fields of the inodes.
  *
  * @sb:         the super block of the filesystem
  * @inode:      the inode to swap with EXT4_BOOT_LOADER_INO
  *
  */
 static long swap_inode_boot_loader(struct super_block *sb,
 				struct inode *inode)
 {
 	handle_t *handle;
 	int err;
 	struct inode *inode_bl;
 	struct ext4_inode_info *ei_bl;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);

 	if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode)) {
 		err = -EINVAL;
 		goto swap_boot_out;
 	}

 	if (!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN)) {
 		err = -EPERM;
 		goto swap_boot_out;
 	}

 	inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);
 	if (IS_ERR(inode_bl)) {
 		err = PTR_ERR(inode_bl);
 		goto swap_boot_out;
 	}
 	ei_bl = EXT4_I(inode_bl);

 	filemap_flush(inode->i_mapping);
 	filemap_flush(inode_bl->i_mapping);

 	/* Protect orig inodes against a truncate and make sure,
 	 * that only 1 swap_inode_boot_loader is running. */
 	lock_two_nondirectories(inode, inode_bl);

 	truncate_inode_pages(&inode->i_data, 0);
 	truncate_inode_pages(&inode_bl->i_data, 0);

 	/* Wait for all existing dio workers */
 	ext4_inode_block_unlocked_dio(inode);
 	ext4_inode_block_unlocked_dio(inode_bl);
 	inode_dio_wait(inode);
 	inode_dio_wait(inode_bl);

 	handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
 	if (IS_ERR(handle)) {
 		err = -EINVAL;
 		goto swap_boot_out;
 	}

 	/* Protect extent tree against block allocations via delalloc */
 	ext4_double_down_write_data_sem(inode, inode_bl);

 	if (inode_bl->i_nlink == 0) {
 		/* this inode has never been used as a BOOT_LOADER */
 		set_nlink(inode_bl, 1);
 		i_uid_write(inode_bl, 0);
 		i_gid_write(inode_bl, 0);
 		inode_bl->i_flags = 0;
 		ei_bl->i_flags = 0;
 		inode_bl->i_version = 1;
 		i_size_write(inode_bl, 0);
 		inode_bl->i_mode = S_IFREG;
 		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
 					      EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 			ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
 			ext4_ext_tree_init(handle, inode_bl);
 		} else
 			memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
 	}

 	swap_inode_data(inode, inode_bl);

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

 	spin_lock(&sbi->s_next_gen_lock);
 	inode->i_generation = sbi->s_next_generation++;
 	inode_bl->i_generation = sbi->s_next_generation++;
 	spin_unlock(&sbi->s_next_gen_lock);

 	ext4_discard_preallocations(inode);

 	err = ext4_mark_inode_dirty(handle, inode);
 	if (err < 0) {
 		ext4_warning(inode->i_sb,
 			"couldn't mark inode #%lu dirty (err %d)",
 			inode->i_ino, err);
 		/* Revert all changes: */
 		swap_inode_data(inode, inode_bl);
 	} else {
 		err = ext4_mark_inode_dirty(handle, inode_bl);
 		if (err < 0) {
 			ext4_warning(inode_bl->i_sb,
 				"couldn't mark inode #%lu dirty (err %d)",
 				inode_bl->i_ino, err);
 			/* Revert all changes: */
 			swap_inode_data(inode, inode_bl);
 			ext4_mark_inode_dirty(handle, inode);
 		}
 	}

 	ext4_journal_stop(handle);

 	ext4_double_up_write_data_sem(inode, inode_bl);

 	ext4_inode_resume_unlocked_dio(inode);
 	ext4_inode_resume_unlocked_dio(inode_bl);

 	unlock_two_nondirectories(inode, inode_bl);

 	iput(inode_bl);

 swap_boot_out:
 	return err;
 }

 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 	struct super_block *sb = inode->i_sb;
 	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, mask, i;
 		unsigned int jflag;

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

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

 		err = mnt_want_write_file(filp);
 		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 ((flags ^ oldflags) & EXT4_EXTENTS_FL)
 			migrate = 1;

 		if (flags & EXT4_EOFBLOCKS_FL) {
 			/* we don't support adding EOFBLOCKS flag */
 			if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
 				err = -EOPNOTSUPP;
 				goto flags_out;
 			}
 		} else if (oldflags & EXT4_EOFBLOCKS_FL)
 			ext4_truncate(inode);

 		handle = ext4_journal_start(inode, EXT4_HT_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;

 		for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 			if (!(mask & EXT4_FL_USER_MODIFIABLE))
 				continue;
 			if (mask & flags)
 				ext4_set_inode_flag(inode, i);
 			else
 				ext4_clear_inode_flag(inode, i);
 		}

 		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) {
 			if (flags & EXT4_EXTENTS_FL)
 				err = ext4_ext_migrate(inode);
 			else
 				err = ext4_ind_migrate(inode);
 		}

 flags_out:
 		mutex_unlock(&inode->i_mutex);
 		mnt_drop_write_file(filp);
 		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 (!inode_owner_or_capable(inode))
 			return -EPERM;

 		if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 				EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
 			ext4_warning(sb, "Setting inode version is not "
 				     "supported with metadata_csum enabled.");
 			return -ENOTTY;
 		}

 		err = mnt_want_write_file(filp);
 		if (err)
 			return err;
 		if (get_user(generation, (int __user *) arg)) {
 			err = -EFAULT;
 			goto setversion_out;
 		}

 		mutex_lock(&inode->i_mutex);
 		handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 		if (IS_ERR(handle)) {
 			err = PTR_ERR(handle);
 			goto unlock_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);

 unlock_out:
 		mutex_unlock(&inode->i_mutex);
 setversion_out:
 		mnt_drop_write_file(filp);
 		return err;
 	}
 	case EXT4_IOC_GROUP_EXTEND: {
 		ext4_fsblk_t n_blocks_count;
 		int err, err2=0;

 		err = ext4_resize_begin(sb);
 		if (err)
 			return err;

 		if (get_user(n_blocks_count, (__u32 __user *)arg)) {
 			err = -EFAULT;
 			goto group_extend_out;
 		}

 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 			ext4_msg(sb, KERN_ERR,
 				 "Online resizing not supported with bigalloc");
 			err = -EOPNOTSUPP;
 			goto group_extend_out;
 		}

 		err = mnt_want_write_file(filp);
 		if (err)
 			goto group_extend_out;

 		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 		if (EXT4_SB(sb)->s_journal) {
 			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_file(filp);
 group_extend_out:
 		ext4_resize_end(sb);
 		return err;
 	}

 	case EXT4_IOC_MOVE_EXT: {
 		struct move_extent me;
 		struct fd donor;
 		int err;

 		if (!(filp->f_mode & FMODE_READ) ||
 		    !(filp->f_mode & FMODE_WRITE))
 			return -EBADF;

 		if (copy_from_user(&me,
 			(struct move_extent __user *)arg, sizeof(me)))
 			return -EFAULT;
 		me.moved_len = 0;

 		donor = fdget(me.donor_fd);
 		if (!donor.file)
 			return -EBADF;

 		if (!(donor.file->f_mode & FMODE_WRITE)) {
 			err = -EBADF;
 			goto mext_out;
 		}

 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 			ext4_msg(sb, KERN_ERR,
 				 "Online defrag not supported with bigalloc");
 			err = -EOPNOTSUPP;
 			goto mext_out;
 		}

 		err = mnt_want_write_file(filp);
 		if (err)
 			goto mext_out;

 		err = ext4_move_extents(filp, donor.file, me.orig_start,
 					me.donor_start, me.len, &me.moved_len);
 		mnt_drop_write_file(filp);

 		if (copy_to_user((struct move_extent __user *)arg,
 				 &me, sizeof(me)))
 			err = -EFAULT;
 mext_out:
 		fdput(donor);
 		return err;
 	}

 	case EXT4_IOC_GROUP_ADD: {
 		struct ext4_new_group_data input;
 		int err, err2=0;

 		err = ext4_resize_begin(sb);
 		if (err)
 			return err;

 		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 				sizeof(input))) {
 			err = -EFAULT;
 			goto group_add_out;
 		}

 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 			ext4_msg(sb, KERN_ERR,
 				 "Online resizing not supported with bigalloc");
 			err = -EOPNOTSUPP;
 			goto group_add_out;
 		}

 		err = mnt_want_write_file(filp);
 		if (err)
 			goto group_add_out;

 		err = ext4_group_add(sb, &input);
 		if (EXT4_SB(sb)->s_journal) {
 			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_file(filp);
 		if (!err && ext4_has_group_desc_csum(sb) &&
 		    test_opt(sb, INIT_INODE_TABLE))
 			err = ext4_register_li_request(sb, input.group);
 group_add_out:
 		ext4_resize_end(sb);
 		return err;
 	}

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

 		err = mnt_want_write_file(filp);
 		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_file(filp);
 		return err;
 	}

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

 		err = mnt_want_write_file(filp);
 		if (err)
 			return err;
 		err = ext4_alloc_da_blocks(inode);
 		mnt_drop_write_file(filp);
 		return err;
 	}

 	case EXT4_IOC_SWAP_BOOT:
 		if (!(filp->f_mode & FMODE_WRITE))
 			return -EBADF;
 		return swap_inode_boot_loader(sb, inode);

 	case EXT4_IOC_RESIZE_FS: {
 		ext4_fsblk_t n_blocks_count;
 		int err = 0, err2 = 0;
 		ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;

 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 			ext4_msg(sb, KERN_ERR,
 				 "Online resizing not (yet) supported with bigalloc");
 			return -EOPNOTSUPP;
 		}

 		if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
 				   sizeof(__u64))) {
 			return -EFAULT;
 		}

 		err = ext4_resize_begin(sb);
 		if (err)
 			return err;

 		err = mnt_want_write_file(filp);
 		if (err)
 			goto resizefs_out;

 		err = ext4_resize_fs(sb, n_blocks_count);
 		if (EXT4_SB(sb)->s_journal) {
 			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_file(filp);
 		if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
 		    ext4_has_group_desc_csum(sb) &&
 		    test_opt(sb, INIT_INODE_TABLE))
 			err = ext4_register_li_request(sb, o_group);

 resizefs_out:
 		ext4_resize_end(sb);
 		return err;
 	}

 	case FITRIM:
 	{
 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
 		struct fstrim_range range;
 		int ret = 0;

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

 		if (!blk_queue_discard(q))
 			return -EOPNOTSUPP;

 		if (copy_from_user(&range, (struct fstrim_range __user *)arg,
 		    sizeof(range)))
 			return -EFAULT;

 		range.minlen = max((unsigned int)range.minlen,
 				   q->limits.discard_granularity);
 		ret = ext4_trim_fs(sb, &range);
 		if (ret < 0)
 			return ret;

 		if (copy_to_user((struct fstrim_range __user *)arg, &range,
 		    sizeof(range)))
 			return -EFAULT;

 		return 0;
 	}
 	case EXT4_IOC_PRECACHE_EXTENTS:
 		return ext4_ext_precache(inode);

 	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;
 	case EXT4_IOC32_GETRSVSZ:
 		cmd = EXT4_IOC_GETRSVSZ;
 		break;
 	case EXT4_IOC32_SETRSVSZ:
 		cmd = EXT4_IOC_SETRSVSZ;
 		break;
 	case EXT4_IOC32_GROUP_ADD: {
 		struct compat_ext4_new_group_input __user *uinput;
 		struct ext4_new_group_input input;
 		mm_segment_t old_fs;
 		int err;

 		uinput = compat_ptr(arg);
 		err = get_user(input.group, &uinput->group);
 		err |= get_user(input.block_bitmap, &uinput->block_bitmap);
 		err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
 		err |= get_user(input.inode_table, &uinput->inode_table);
 		err |= get_user(input.blocks_count, &uinput->blocks_count);
 		err |= get_user(input.reserved_blocks,
 				&uinput->reserved_blocks);
 		if (err)
 			return -EFAULT;
 		old_fs = get_fs();
 		set_fs(KERNEL_DS);
 		err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
 				 (unsigned long) &input);
 		set_fs(old_fs);
 		return err;
 	}
 	case EXT4_IOC_MOVE_EXT:
 	case FITRIM:
 	case EXT4_IOC_RESIZE_FS:
 	case EXT4_IOC_PRECACHE_EXTENTS:
 		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"

	#define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)

	/**
	* Swap memory between @a and @b for @len bytes.
	*
	* @a: pointer to first memory area
	* @b: pointer to second memory area
	* @len: number of bytes to swap
	*
	*/
	static void memswap(void a, void b, size_t len)
	{
	unsigned char ap, bp;
	unsigned char tmp;

	ap = (unsigned char *)a;
	bp = (unsigned char *)b;
	while (len-- > 0) {
	tmp = *ap;
	ap = bp;
	*bp = tmp;
	ap++;
	bp++;
	}
	}

	/**
	* Swap i_data and associated attributes between @inode1 and @inode2.
	* This function is used for the primary swap between inode1 and inode2
	* and also to revert this primary swap in case of errors.
	*
	* Therefore you have to make sure, that calling this method twice
	* will revert all changes.
	*
	* @inode1: pointer to first inode
	* @inode2: pointer to second inode
	*/
	static void swap_inode_data(struct inode inode1, struct inode inode2)
	{
	loff_t isize;
	struct ext4_inode_info *ei1;
	struct ext4_inode_info *ei2;

	ei1 = EXT4_I(inode1);
	ei2 = EXT4_I(inode2);

	memswap(&inode1->i_flags, &inode2->i_flags, sizeof(inode1->i_flags));
	memswap(&inode1->i_version, &inode2->i_version,
	sizeof(inode1->i_version));
	memswap(&inode1->i_blocks, &inode2->i_blocks,
	sizeof(inode1->i_blocks));
	memswap(&inode1->i_bytes, &inode2->i_bytes, sizeof(inode1->i_bytes));
	memswap(&inode1->i_atime, &inode2->i_atime, sizeof(inode1->i_atime));
	memswap(&inode1->i_mtime, &inode2->i_mtime, sizeof(inode1->i_mtime));

	memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
	memswap(&ei1->i_flags, &ei2->i_flags, sizeof(ei1->i_flags));
	memswap(&ei1->i_disksize, &ei2->i_disksize, sizeof(ei1->i_disksize));
	ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
	ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);
	ext4_es_lru_del(inode1);
	ext4_es_lru_del(inode2);

	isize = i_size_read(inode1);
	i_size_write(inode1, i_size_read(inode2));
	i_size_write(inode2, isize);
	}

	/**
	* Swap the information from the given @inode and the inode
	* EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
	* important fields of the inodes.
	*
	* @sb: the super block of the filesystem
	* @inode: the inode to swap with EXT4_BOOT_LOADER_INO
	*
	*/
	static long swap_inode_boot_loader(struct super_block *sb,
	struct inode *inode)
	{
	handle_t *handle;
	int err;
	struct inode *inode_bl;
	struct ext4_inode_info *ei_bl;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (inode->i_nlink != 1 \|\| !S_ISREG(inode->i_mode)) {
	err = -EINVAL;
	goto swap_boot_out;
	}

	if (!inode_owner_or_capable(inode) \|\| !capable(CAP_SYS_ADMIN)) {
	err = -EPERM;
	goto swap_boot_out;
	}

	inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);
	if (IS_ERR(inode_bl)) {
	err = PTR_ERR(inode_bl);
	goto swap_boot_out;
	}
	ei_bl = EXT4_I(inode_bl);

	filemap_flush(inode->i_mapping);
	filemap_flush(inode_bl->i_mapping);

	/* Protect orig inodes against a truncate and make sure,
	* that only 1 swap_inode_boot_loader is running. */
	lock_two_nondirectories(inode, inode_bl);

	truncate_inode_pages(&inode->i_data, 0);
	truncate_inode_pages(&inode_bl->i_data, 0);

	/* Wait for all existing dio workers */
	ext4_inode_block_unlocked_dio(inode);
	ext4_inode_block_unlocked_dio(inode_bl);
	inode_dio_wait(inode);
	inode_dio_wait(inode_bl);

	handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
	if (IS_ERR(handle)) {
	err = -EINVAL;
	goto swap_boot_out;
	}

	/* Protect extent tree against block allocations via delalloc */
	ext4_double_down_write_data_sem(inode, inode_bl);

	if (inode_bl->i_nlink == 0) {
	/* this inode has never been used as a BOOT_LOADER */
	set_nlink(inode_bl, 1);
	i_uid_write(inode_bl, 0);
	i_gid_write(inode_bl, 0);
	inode_bl->i_flags = 0;
	ei_bl->i_flags = 0;
	inode_bl->i_version = 1;
	i_size_write(inode_bl, 0);
	inode_bl->i_mode = S_IFREG;
	if (EXT4_HAS_INCOMPAT_FEATURE(sb,
	EXT4_FEATURE_INCOMPAT_EXTENTS)) {
	ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
	ext4_ext_tree_init(handle, inode_bl);
	} else
	memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
	}

	swap_inode_data(inode, inode_bl);

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

	spin_lock(&sbi->s_next_gen_lock);
	inode->i_generation = sbi->s_next_generation++;
	inode_bl->i_generation = sbi->s_next_generation++;
	spin_unlock(&sbi->s_next_gen_lock);

	ext4_discard_preallocations(inode);

	err = ext4_mark_inode_dirty(handle, inode);
	if (err < 0) {
	ext4_warning(inode->i_sb,
	"couldn't mark inode #%lu dirty (err %d)",
	inode->i_ino, err);
	/* Revert all changes: */
	swap_inode_data(inode, inode_bl);
	} else {
	err = ext4_mark_inode_dirty(handle, inode_bl);
	if (err < 0) {
	ext4_warning(inode_bl->i_sb,
	"couldn't mark inode #%lu dirty (err %d)",
	inode_bl->i_ino, err);
	/* Revert all changes: */
	swap_inode_data(inode, inode_bl);
	ext4_mark_inode_dirty(handle, inode);
	}
	}

	ext4_journal_stop(handle);

	ext4_double_up_write_data_sem(inode, inode_bl);

	ext4_inode_resume_unlocked_dio(inode);
	ext4_inode_resume_unlocked_dio(inode_bl);

	unlock_two_nondirectories(inode, inode_bl);

	iput(inode_bl);

	swap_boot_out:
	return err;
	}

	long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = file_inode(filp);
	struct super_block *sb = inode->i_sb;
	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, mask, i;
	unsigned int jflag;

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

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

	err = mnt_want_write_file(filp);
	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 ((flags ^ oldflags) & EXT4_EXTENTS_FL)
	migrate = 1;

	if (flags & EXT4_EOFBLOCKS_FL) {
	/* we don't support adding EOFBLOCKS flag */
	if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
	err = -EOPNOTSUPP;
	goto flags_out;
	}
	} else if (oldflags & EXT4_EOFBLOCKS_FL)
	ext4_truncate(inode);

	handle = ext4_journal_start(inode, EXT4_HT_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;

	for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
	if (!(mask & EXT4_FL_USER_MODIFIABLE))
	continue;
	if (mask & flags)
	ext4_set_inode_flag(inode, i);
	else
	ext4_clear_inode_flag(inode, i);
	}

	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) {
	if (flags & EXT4_EXTENTS_FL)
	err = ext4_ext_migrate(inode);
	else
	err = ext4_ind_migrate(inode);
	}

	flags_out:
	mutex_unlock(&inode->i_mutex);
	mnt_drop_write_file(filp);
	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 (!inode_owner_or_capable(inode))
	return -EPERM;

	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
	EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
	ext4_warning(sb, "Setting inode version is not "
	"supported with metadata_csum enabled.");
	return -ENOTTY;
	}

	err = mnt_want_write_file(filp);
	if (err)
	return err;
	if (get_user(generation, (int __user *) arg)) {
	err = -EFAULT;
	goto setversion_out;
	}

	mutex_lock(&inode->i_mutex);
	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
	if (IS_ERR(handle)) {
	err = PTR_ERR(handle);
	goto unlock_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);

	unlock_out:
	mutex_unlock(&inode->i_mutex);
	setversion_out:
	mnt_drop_write_file(filp);
	return err;
	}
	case EXT4_IOC_GROUP_EXTEND: {
	ext4_fsblk_t n_blocks_count;
	int err, err2=0;

	err = ext4_resize_begin(sb);
	if (err)
	return err;

	if (get_user(n_blocks_count, (__u32 __user *)arg)) {
	err = -EFAULT;
	goto group_extend_out;
	}

	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
	EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
	ext4_msg(sb, KERN_ERR,
	"Online resizing not supported with bigalloc");
	err = -EOPNOTSUPP;
	goto group_extend_out;
	}

	err = mnt_want_write_file(filp);
	if (err)
	goto group_extend_out;

	err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
	if (EXT4_SB(sb)->s_journal) {
	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_file(filp);
	group_extend_out:
	ext4_resize_end(sb);
	return err;
	}

	case EXT4_IOC_MOVE_EXT: {
	struct move_extent me;
	struct fd donor;
	int err;

	if (!(filp->f_mode & FMODE_READ) \|\|
	!(filp->f_mode & FMODE_WRITE))
	return -EBADF;

	if (copy_from_user(&me,
	(struct move_extent __user *)arg, sizeof(me)))
	return -EFAULT;
	me.moved_len = 0;

	donor = fdget(me.donor_fd);
	if (!donor.file)
	return -EBADF;

	if (!(donor.file->f_mode & FMODE_WRITE)) {
	err = -EBADF;
	goto mext_out;
	}

	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
	EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
	ext4_msg(sb, KERN_ERR,
	"Online defrag not supported with bigalloc");
	err = -EOPNOTSUPP;
	goto mext_out;
	}

	err = mnt_want_write_file(filp);
	if (err)
	goto mext_out;

	err = ext4_move_extents(filp, donor.file, me.orig_start,
	me.donor_start, me.len, &me.moved_len);
	mnt_drop_write_file(filp);

	if (copy_to_user((struct move_extent __user *)arg,
	&me, sizeof(me)))
	err = -EFAULT;
	mext_out:
	fdput(donor);
	return err;
	}

	case EXT4_IOC_GROUP_ADD: {
	struct ext4_new_group_data input;
	int err, err2=0;

	err = ext4_resize_begin(sb);
	if (err)
	return err;

	if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
	sizeof(input))) {
	err = -EFAULT;
	goto group_add_out;
	}

	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
	EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
	ext4_msg(sb, KERN_ERR,
	"Online resizing not supported with bigalloc");
	err = -EOPNOTSUPP;
	goto group_add_out;
	}

	err = mnt_want_write_file(filp);
	if (err)
	goto group_add_out;

	err = ext4_group_add(sb, &input);
	if (EXT4_SB(sb)->s_journal) {
	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_file(filp);
	if (!err && ext4_has_group_desc_csum(sb) &&
	test_opt(sb, INIT_INODE_TABLE))
	err = ext4_register_li_request(sb, input.group);
	group_add_out:
	ext4_resize_end(sb);
	return err;
	}

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

	err = mnt_want_write_file(filp);
	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_file(filp);
	return err;
	}

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

	err = mnt_want_write_file(filp);
	if (err)
	return err;
	err = ext4_alloc_da_blocks(inode);
	mnt_drop_write_file(filp);
	return err;
	}

	case EXT4_IOC_SWAP_BOOT:
	if (!(filp->f_mode & FMODE_WRITE))
	return -EBADF;
	return swap_inode_boot_loader(sb, inode);

	case EXT4_IOC_RESIZE_FS: {
	ext4_fsblk_t n_blocks_count;
	int err = 0, err2 = 0;
	ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;

	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
	EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
	ext4_msg(sb, KERN_ERR,
	"Online resizing not (yet) supported with bigalloc");
	return -EOPNOTSUPP;
	}

	if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
	sizeof(__u64))) {
	return -EFAULT;
	}

	err = ext4_resize_begin(sb);
	if (err)
	return err;

	err = mnt_want_write_file(filp);
	if (err)
	goto resizefs_out;

	err = ext4_resize_fs(sb, n_blocks_count);
	if (EXT4_SB(sb)->s_journal) {
	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_file(filp);
	if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
	ext4_has_group_desc_csum(sb) &&
	test_opt(sb, INIT_INODE_TABLE))
	err = ext4_register_li_request(sb, o_group);

	resizefs_out:
	ext4_resize_end(sb);
	return err;
	}

	case FITRIM:
	{
	struct request_queue *q = bdev_get_queue(sb->s_bdev);
	struct fstrim_range range;
	int ret = 0;

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

	if (!blk_queue_discard(q))
	return -EOPNOTSUPP;

	if (copy_from_user(&range, (struct fstrim_range __user *)arg,
	sizeof(range)))
	return -EFAULT;

	range.minlen = max((unsigned int)range.minlen,
	q->limits.discard_granularity);
	ret = ext4_trim_fs(sb, &range);
	if (ret < 0)
	return ret;

	if (copy_to_user((struct fstrim_range __user *)arg, &range,
	sizeof(range)))
	return -EFAULT;

	return 0;
	}
	case EXT4_IOC_PRECACHE_EXTENTS:
	return ext4_ext_precache(inode);

	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;
	case EXT4_IOC32_GETRSVSZ:
	cmd = EXT4_IOC_GETRSVSZ;
	break;
	case EXT4_IOC32_SETRSVSZ:
	cmd = EXT4_IOC_SETRSVSZ;
	break;
	case EXT4_IOC32_GROUP_ADD: {
	struct compat_ext4_new_group_input __user *uinput;
	struct ext4_new_group_input input;
	mm_segment_t old_fs;
	int err;

	uinput = compat_ptr(arg);
	err = get_user(input.group, &uinput->group);
	err \|= get_user(input.block_bitmap, &uinput->block_bitmap);
	err \|= get_user(input.inode_bitmap, &uinput->inode_bitmap);
	err \|= get_user(input.inode_table, &uinput->inode_table);
	err \|= get_user(input.blocks_count, &uinput->blocks_count);
	err \|= get_user(input.reserved_blocks,
	&uinput->reserved_blocks);
	if (err)
	return -EFAULT;
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
	(unsigned long) &input);
	set_fs(old_fs);
	return err;
	}
	case EXT4_IOC_MOVE_EXT:
	case FITRIM:
	case EXT4_IOC_RESIZE_FS:
	case EXT4_IOC_PRECACHE_EXTENTS:
	break;
	default:
	return -ENOIOCTLCMD;
	}
	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
	}
	#endif