Commit 783d9485 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: add EXT4_IOC_GOINGDOWN ioctl 



This ioctl is modeled after the xfs's XFS_IOC_GOINGDOWN ioctl.  (In
fact, it uses the same code points.)

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 0db1ff22

fs/ext4/ext4.h

+10 −0
Original line number Diff line number Diff line
@@ -679,6 +679,16 @@ struct fsxattr { 
#define EXT4_IOC_FSGETXATTR		FS_IOC_FSGETXATTR

#define EXT4_IOC_FSSETXATTR		FS_IOC_FSSETXATTR



#define EXT4_IOC_GOINGDOWN _IOR ('X', 125, __u32)



/*

 * Flags for going down operation

 */

#define EXT4_GOING_FLAGS_DEFAULT		0x0	/* going down */

#define EXT4_GOING_FLAGS_LOGFLUSH		0x1	/* flush log but not data */

#define EXT4_GOING_FLAGS_NOLOGFLUSH		0x2	/* don't flush log nor data */





#if defined(__KERNEL__) && defined(CONFIG_COMPAT)

/*

 * ioctl commands in 32 bit emulation

fs/ext4/ioctl.c

+50 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/quotaops.h>

#include <linux/uuid.h>

#include <linux/uaccess.h>

#include <linux/delay.h>

#include "ext4_jbd2.h"

#include "ext4.h"
@@ -442,6 +443,52 @@ static inline unsigned long ext4_xflags_to_iflags(__u32 xflags) 
	return iflags;

}



int ext4_goingdown(struct super_block *sb, unsigned long arg)

{

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	__u32 flags;



	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	if (get_user(flags, (__u32 __user *)arg))

		return -EFAULT;



	if (flags > EXT4_GOING_FLAGS_NOLOGFLUSH)

		return -EINVAL;



	if (ext4_forced_shutdown(sbi))

		return 0;



	ext4_msg(sb, KERN_ALERT, "shut down requested (%d)", flags);



	switch (flags) {

	case EXT4_GOING_FLAGS_DEFAULT:

		freeze_bdev(sb->s_bdev);

		set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);

		thaw_bdev(sb->s_bdev, sb);

		break;

	case EXT4_GOING_FLAGS_LOGFLUSH:

		set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);

		if (sbi->s_journal && !is_journal_aborted(sbi->s_journal)) {

			(void) ext4_force_commit(sb);

			jbd2_journal_abort(sbi->s_journal, 0);

		}

		break;

	case EXT4_GOING_FLAGS_NOLOGFLUSH:

		set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);

		if (sbi->s_journal && !is_journal_aborted(sbi->s_journal)) {

			msleep(100);

			jbd2_journal_abort(sbi->s_journal, 0);

		}

		break;

	default:

		return -EINVAL;

	}

	clear_opt(sb, DISCARD);

	return 0;

}



long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

{

	struct inode *inode = file_inode(filp);
@@ -893,6 +940,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 


		return 0;

	}

	case EXT4_IOC_GOINGDOWN:

		return ext4_goingdown(sb, arg);

	default:

		return -ENOTTY;

	}
@@ -959,6 +1008,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	case EXT4_IOC_SET_ENCRYPTION_POLICY:

	case EXT4_IOC_GET_ENCRYPTION_PWSALT:

	case EXT4_IOC_GET_ENCRYPTION_POLICY:

	case EXT4_IOC_GOINGDOWN:

		break;

	default:

		return -ENOIOCTLCMD;

fs/ext4/super.c

+1 −1
Original line number Diff line number Diff line
@@ -4821,7 +4821,7 @@ static int ext4_freeze(struct super_block *sb) 
 */

static int ext4_unfreeze(struct super_block *sb)

{

	if (sb->s_flags & MS_RDONLY)

	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))

		return 0;



	if (EXT4_SB(sb)->s_journal) {