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Message-Id: <20170205073430.9109-7-tytso@mit.edu>
Date: Sun, 5 Feb 2017 02:34:30 -0500
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: Theodore Ts'o <tytso@....edu>
Subject: [PATCH 7/7] 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: Theodore Ts'o <tytso@....edu>
---
fs/ext4/ext4.h | 10 ++++++++++
fs/ext4/ioctl.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/super.c | 2 +-
3 files changed, 61 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 35d93ab7f3fb..55b7a77a0444 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -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
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index d534399cf607..b383ebf4020c 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -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;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 879e3a6afd9d..de8709269cfb 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4818,7 +4818,7 @@ 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) {
--
2.11.0.rc0.7.gbe5a750
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