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Date: Wed, 27 Dec 2023 15:06:21 -0800
From: Jaegeuk Kim <jaegeuk@kernel.org>
To: Chao Yu <chao@kernel.org>
Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 6/6] f2fs: introduce FAULT_INCONSISTENCE
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References: <20231225144335.2548-1-chao@kernel.org>
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On 12/25, Chao Yu wrote:
> We will encounter below inconsistent status when FAULT_BLKADDR type
> fault injection is on.
> 
> Info: checkpoint state = d6 :  nat_bits crc fsck compacted_summary orphan_inodes sudden-power-off
> [ASSERT] (fsck_chk_inode_blk:1254)  --> ino: 0x1c100 has i_blocks: 000000c0, but has 191 blocks
> [FIX] (fsck_chk_inode_blk:1260)  --> [0x1c100] i_blocks=0x000000c0 -> 0xbf
> [FIX] (fsck_chk_inode_blk:1269)  --> [0x1c100] i_compr_blocks=0x00000026 -> 0x27
> [ASSERT] (fsck_chk_inode_blk:1254)  --> ino: 0x1cadb has i_blocks: 0000002f, but has 46 blocks
> [FIX] (fsck_chk_inode_blk:1260)  --> [0x1cadb] i_blocks=0x0000002f -> 0x2e
> [FIX] (fsck_chk_inode_blk:1269)  --> [0x1cadb] i_compr_blocks=0x00000011 -> 0x12
> [ASSERT] (fsck_chk_inode_blk:1254)  --> ino: 0x1c62c has i_blocks: 00000002, but has 1 blocks
> [FIX] (fsck_chk_inode_blk:1260)  --> [0x1c62c] i_blocks=0x00000002 -> 0x1
> 
> After we inject fault into f2fs_is_valid_blkaddr() during truncation,
> a) it missed to increase @nr_free or @valid_blocks
> b) it can cause in blkaddr leak in truncated dnode
> Which may cause inconsistent status.
> 
> This patch separates FAULT_INCONSISTENCE from FAULT_BLKADDR, so that

Could you please rename FAULT_INCONSISTENCE to give exactly what it tries
to break?

> we can:
> a) use FAULT_INCONSISTENCE in f2fs_truncate_data_blocks_range() to
> simulate inconsistent issue independently,
> b) FAULT_BLKADDR fault will not cause any inconsistent status, we can
> just use it to check error path handling in kernel side.
> 
> Signed-off-by: Chao Yu <chao@kernel.org>
> ---
> v2:
> - make __f2fs_is_valid_blkaddr() void.
>  Documentation/ABI/testing/sysfs-fs-f2fs |  1 +
>  Documentation/filesystems/f2fs.rst      |  1 +
>  fs/f2fs/checkpoint.c                    | 19 +++++++++++++++----
>  fs/f2fs/f2fs.h                          |  3 +++
>  fs/f2fs/file.c                          |  8 ++++++--
>  fs/f2fs/super.c                         |  1 +
>  6 files changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> index 4f1d4e636d67..649aabac16c2 100644
> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> @@ -708,6 +708,7 @@ Description:	Support configuring fault injection type, should be
>  		FAULT_DQUOT_INIT         0x000010000
>  		FAULT_LOCK_OP            0x000020000
>  		FAULT_BLKADDR            0x000040000
> +		FAULT_INCONSISTENCE      0x000080000
>  		===================      ===========
>  
>  What:		/sys/fs/f2fs/<disk>/discard_io_aware_gran
> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> index d32c6209685d..5616fb8ae207 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -206,6 +206,7 @@ fault_type=%d		 Support configuring fault injection type, should be
>  			 FAULT_DQUOT_INIT	  0x000010000
>  			 FAULT_LOCK_OP		  0x000020000
>  			 FAULT_BLKADDR		  0x000040000
> +			 FAULT_INCONSISTENCE	  0x000080000
>  			 ===================	  ===========
>  mode=%s			 Control block allocation mode which supports "adaptive"
>  			 and "lfs". In "lfs" mode, there should be no random
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index b0597a539fc5..84546f529cf0 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -170,12 +170,9 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
>  	return exist;
>  }
>  
> -bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
> +static bool __f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
>  					block_t blkaddr, int type)
>  {
> -	if (time_to_inject(sbi, FAULT_BLKADDR))
> -		return false;
> -
>  	switch (type) {
>  	case META_NAT:
>  		break;
> @@ -230,6 +227,20 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
>  	return true;
>  }
>  
> +bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
> +					block_t blkaddr, int type)
> +{
> +	if (time_to_inject(sbi, FAULT_BLKADDR))
> +		return false;
> +	return __f2fs_is_valid_blkaddr(sbi, blkaddr, type);
> +}
> +
> +bool f2fs_is_valid_blkaddr_raw(struct f2fs_sb_info *sbi,
> +					block_t blkaddr, int type)
> +{
> +	return __f2fs_is_valid_blkaddr(sbi, blkaddr, type);
> +}
> +
>  /*
>   * Readahead CP/NAT/SIT/SSA/POR pages
>   */
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 34b20700b5ec..3985296e64cb 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -61,6 +61,7 @@ enum {
>  	FAULT_DQUOT_INIT,
>  	FAULT_LOCK_OP,
>  	FAULT_BLKADDR,
> +	FAULT_INCONSISTENCE,
>  	FAULT_MAX,
>  };
>  
> @@ -3767,6 +3768,8 @@ struct page *f2fs_get_meta_page_retry(struct f2fs_sb_info *sbi, pgoff_t index);
>  struct page *f2fs_get_tmp_page(struct f2fs_sb_info *sbi, pgoff_t index);
>  bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
>  					block_t blkaddr, int type);
> +bool f2fs_is_valid_blkaddr_raw(struct f2fs_sb_info *sbi,
> +					block_t blkaddr, int type);
>  int f2fs_ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages,
>  			int type, bool sync);
>  void f2fs_ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index,
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 9f4e21b5916c..b5149f1f2a20 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -590,9 +590,13 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
>  		f2fs_set_data_blkaddr(dn, NULL_ADDR);
>  
>  		if (__is_valid_data_blkaddr(blkaddr)) {
> -			if (!f2fs_is_valid_blkaddr(sbi, blkaddr,
> -					DATA_GENERIC_ENHANCE))
> +			if (time_to_inject(sbi, FAULT_INCONSISTENCE))
> +				continue;
> +			if (!f2fs_is_valid_blkaddr_raw(sbi, blkaddr,
> +						DATA_GENERIC_ENHANCE)) {
> +				f2fs_handle_error(sbi, ERROR_INVALID_BLKADDR);
>  				continue;
> +			}
>  			if (compressed_cluster)
>  				valid_blocks++;
>  		}
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 206d03c82d96..9a5c5e06f766 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -62,6 +62,7 @@ const char *f2fs_fault_name[FAULT_MAX] = {
>  	[FAULT_DQUOT_INIT]	= "dquot initialize",
>  	[FAULT_LOCK_OP]		= "lock_op",
>  	[FAULT_BLKADDR]		= "invalid blkaddr",
> +	[FAULT_INCONSISTENCE]	= "inconsistence",
>  };
>  
>  void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate,
> -- 
> 2.40.1