Re: [f2fs-dev] [PATCH] f2fs: add errors=panic mount option

From: Chao Yu <chao@kernel.org>
To: Sahitya Tummala <stummala@codeaurora.org>,
	Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <yuchao0@huawei.com>,
	linux-f2fs-devel@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Subject: Re: [f2fs-dev] [PATCH] f2fs: add errors=panic mount option
Date: Fri, 24 May 2019 20:13:50 +0800	[thread overview]
Message-ID: <6a4ce8cb-d9ec-1923-8304-6b8956283e85@kernel.org> (raw)
In-Reply-To: <1558694631-12481-1-git-send-email-stummala@codeaurora.org>

On 2019-5-24 18:43, Sahitya Tummala wrote:
> Add errors=panic mount option for debugging purpose. It can be
> set dynamically when the config option CONFIG_F2FS_CHECK_FS
> is not enabled.

Sahitya,

I remember Yunlei has a similar patch for this, could you rebase your code on
that patch, if Yunlei agrees, we can add Signed-off of him.

FYI

https://sourceforge.net/p/linux-f2fs/mailman/linux-f2fs-devel/thread/f6a0b1c3-4057-8b64-a419-4b2914d48394%40kernel.org/#msg36376331

Thanks,

> 
> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
> ---
>  fs/f2fs/f2fs.h  |  9 +++++++--
>  fs/f2fs/super.c | 21 +++++++++++++++++++++
>  2 files changed, 28 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 9b3d997..95adedb 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -32,8 +32,12 @@
>  #define f2fs_bug_on(sbi, condition)					\
>  	do {								\
>  		if (unlikely(condition)) {				\
> -			WARN_ON(1);					\
> -			set_sbi_flag(sbi, SBI_NEED_FSCK);		\
> +			if (test_opt(sbi, ERRORS_PANIC)) {		\
> +				BUG_ON(condition);			\
> +			} else {					\
> +				WARN_ON(1);				\
> +				set_sbi_flag(sbi, SBI_NEED_FSCK);	\
> +			}						\
>  		}							\
>  	} while (0)
>  #endif
> @@ -99,6 +103,7 @@ struct f2fs_fault_info {
>  #define F2FS_MOUNT_INLINE_XATTR_SIZE	0x00800000
>  #define F2FS_MOUNT_RESERVE_ROOT		0x01000000
>  #define F2FS_MOUNT_DISABLE_CHECKPOINT	0x02000000
> +#define F2FS_MOUNT_ERRORS_PANIC		0x04000000
>  
>  #define F2FS_OPTION(sbi)	((sbi)->mount_opt)
>  #define clear_opt(sbi, option)	(F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 912e261..7d6d96a 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -137,6 +137,7 @@ enum {
>  	Opt_fsync,
>  	Opt_test_dummy_encryption,
>  	Opt_checkpoint,
> +	Opt_errors,
>  	Opt_err,
>  };
>  
> @@ -196,6 +197,7 @@ enum {
>  	{Opt_fsync, "fsync_mode=%s"},
>  	{Opt_test_dummy_encryption, "test_dummy_encryption"},
>  	{Opt_checkpoint, "checkpoint=%s"},
> +	{Opt_errors, "errors=%s"},
>  	{Opt_err, NULL},
>  };
>  
> @@ -788,6 +790,23 @@ static int parse_options(struct super_block *sb, char *options)
>  			}
>  			kvfree(name);
>  			break;
> +		case Opt_errors:
> +#ifndef CONFIG_F2FS_CHECK_FS
> +			name = match_strdup(&args[0]);
> +			if (!name)
> +				return -ENOMEM;
> +
> +			if (strlen(name) == 5 && !strncmp(name, "panic", 5)) {
> +				set_opt(sbi, ERRORS_PANIC);
> +			} else {
> +				kvfree(name);
> +				return -EINVAL;
> +			}
> +			kvfree(name);
> +			f2fs_msg(sb, KERN_INFO,
> +				"debug mode errors=panic enabled\n");
> +#endif
> +			break;
>  		default:
>  			f2fs_msg(sb, KERN_ERR,
>  				"Unrecognized mount option \"%s\" or missing value",
> @@ -1417,6 +1436,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
>  		seq_printf(seq, ",fsync_mode=%s", "strict");
>  	else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_NOBARRIER)
>  		seq_printf(seq, ",fsync_mode=%s", "nobarrier");
> +	if (test_opt(sbi, ERRORS_PANIC))
> +		seq_printf(seq, ",errors=%s", "panic");
>  	return 0;
>  }
>  
> 