Re: [PATCH] f2fs: support .shutdown in f2fs_sops

[Chao Yu]

Ping,

On 2024/2/29 22:38, Chao Yu wrote:
> Support .shutdown callback in f2fs_sops, then, it can be called to
> shut down the file system when underlying block device is marked dead.
>
> Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
> ---
>   fs/f2fs/f2fs.h  |  2 ++
>   fs/f2fs/file.c  | 70 ++++++++++++++++++++++++++++++-------------------
>   fs/f2fs/super.c |  6 +++++
>   3 files changed, 51 insertions(+), 27 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 85eb9a8a5ed3..80789255bf68 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -3506,6 +3506,8 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
>   		 struct iattr *attr);
>   int f2fs_truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
>   void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count);
> +int f2fs_do_shutdown(struct f2fs_sb_info *sbi, unsigned int flag,
> +							bool readonly);
>   int f2fs_precache_extents(struct inode *inode);
>   int f2fs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
>   int f2fs_fileattr_set(struct mnt_idmap *idmap,
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 4ca6c693b33a..d223175b3d5c 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2226,34 +2226,13 @@ static int f2fs_ioc_abort_atomic_write(struct file *filp)
>   	return ret;
>   }
>   
> -static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
> +int f2fs_do_shutdown(struct f2fs_sb_info *sbi, unsigned int flag,
> +							bool readonly)
>   {
> -	struct inode *inode = file_inode(filp);
> -	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>   	struct super_block *sb = sbi->sb;
> -	__u32 in;
>   	int ret = 0;
>   
> -	if (!capable(CAP_SYS_ADMIN))
> -		return -EPERM;
> -
> -	if (get_user(in, (__u32 __user *)arg))
> -		return -EFAULT;
> -
> -	if (in != F2FS_GOING_DOWN_FULLSYNC) {
> -		ret = mnt_want_write_file(filp);
> -		if (ret) {
> -			if (ret == -EROFS) {
> -				ret = 0;
> -				f2fs_stop_checkpoint(sbi, false,
> -						STOP_CP_REASON_SHUTDOWN);
> -				trace_f2fs_shutdown(sbi, in, ret);
> -			}
> -			return ret;
> -		}
> -	}
> -
> -	switch (in) {
> +	switch (flag) {
>   	case F2FS_GOING_DOWN_FULLSYNC:
>   		ret = bdev_freeze(sb->s_bdev);
>   		if (ret)
> @@ -2292,6 +2271,9 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
>   		goto out;
>   	}
>   
> +	if (readonly)
> +		goto out;
> +
>   	f2fs_stop_gc_thread(sbi);
>   	f2fs_stop_discard_thread(sbi);
>   
> @@ -2300,10 +2282,44 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
>   
>   	f2fs_update_time(sbi, REQ_TIME);
>   out:
> -	if (in != F2FS_GOING_DOWN_FULLSYNC)
> -		mnt_drop_write_file(filp);
>   
> -	trace_f2fs_shutdown(sbi, in, ret);
> +	trace_f2fs_shutdown(sbi, flag, ret);
> +
> +	return ret;
> +}
> +
> +static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
> +{
> +	struct inode *inode = file_inode(filp);
> +	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> +	__u32 in;
> +	int ret;
> +	bool need_drop = false, readonly = false;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +
> +	if (get_user(in, (__u32 __user *)arg))
> +		return -EFAULT;
> +
> +	if (in != F2FS_GOING_DOWN_FULLSYNC) {
> +		ret = mnt_want_write_file(filp);
> +		if (ret) {
> +			if (ret != -EROFS)
> +				return ret;
> +
> +			/* fallback to nosync shutdown for readonly fs */
> +			in = F2FS_GOING_DOWN_NOSYNC;
> +			readonly = true;
> +		} else {
> +			need_drop = true;
> +		}
> +	}
> +
> +	ret = f2fs_do_shutdown(sbi, in, readonly);
> +
> +	if (need_drop)
> +		mnt_drop_write_file(filp);
>   
>   	return ret;
>   }
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 78a76583a4aa..0676c2dcbbf7 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2547,6 +2547,11 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
>   	return err;
>   }
>   
> +static void f2fs_shutdown(struct super_block *sb)
> +{
> +	f2fs_do_shutdown(F2FS_SB(sb), F2FS_GOING_DOWN_NOSYNC, false);
> +}
> +
>   #ifdef CONFIG_QUOTA
>   static bool f2fs_need_recovery(struct f2fs_sb_info *sbi)
>   {
> @@ -3146,6 +3151,7 @@ static const struct super_operations f2fs_sops = {
>   	.unfreeze_fs	= f2fs_unfreeze,
>   	.statfs		= f2fs_statfs,
>   	.remount_fs	= f2fs_remount,
> +	.shutdown	= f2fs_shutdown,
>   };
>   
>   #ifdef CONFIG_FS_ENCRYPTION