From 783d948544993f55bdacc78b127532e8b6e2fc9f Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 5 Feb 2017 19:47:14 -0500 Subject: [PATCH] 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 --- 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 35d93ab..55b7a77a 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 d534399..b383ebf 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -16,6 +16,7 @@ #include #include #include +#include #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 @@ resizefs_out: 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 cfa4ce5..3db5b64 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4821,7 +4821,7 @@ out: */ 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) { -- 2.7.4