[PATCH 6/6] f2fs: introduce FAULT_INCONSISTENCE

[Chao Yu]

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
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@xxxxxxxxxx>
---
 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 5a1686cdd6b4..dfc1e73b17d9 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -209,6 +209,7 @@ 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 f3f3e98fd6b0..b59db6c1932c 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,
+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 9487581db08a..49e4de324841 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,
 };
 
@@ -3787,6 +3788,8 @@ 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 4f3ed627f6a1..6c4c739d73b3 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -593,9 +593,13 @@ 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 29b9e6e3eb5f..5659166b3918 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