[PATCH] f2fs: support fault injection for f2fs_is_valid_blkaddr()

[Chao Yu]

This patch supports to inject fault into f2fs_is_valid_blkaddr() to
simulate accessing inconsistent data/meta block addressses from caller.

Usage:
a) echo 262144 > /sys/fs/f2fs/<dev>/inject_type or
b) mount -o fault_type=262144 <dev> <mountpoint>

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
 Documentation/filesystems/f2fs.rst | 1 +
 fs/f2fs/checkpoint.c               | 5 +++++
 fs/f2fs/f2fs.h                     | 1 +
 fs/f2fs/super.c                    | 1 +
 4 files changed, 8 insertions(+)

diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 6f19e7f9e908..3bca70fff5ea 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -199,6 +199,7 @@ fault_type=%d		 Support configuring fault injection type, should be
 			 FAULT_SLAB_ALLOC	  0x000008000
 			 FAULT_DQUOT_INIT	  0x000010000
 			 FAULT_LOCK_OP		  0x000020000
+			 FAULT_BLKADDR		  0x000040000
 			 ===================	  ===========
 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 109e96c15b84..2a5d9256a6f4 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -168,6 +168,11 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
 bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
 					block_t blkaddr, int type)
 {
+	if (time_to_inject(sbi, FAULT_BLKADDR)) {
+		f2fs_show_injection_info(sbi, FAULT_BLKADDR);
+		return false;
+	}
+
 	switch (type) {
 	case META_NAT:
 		break;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 3a63125ffdfd..fa9ac681f71c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -60,6 +60,7 @@ enum {
 	FAULT_SLAB_ALLOC,
 	FAULT_DQUOT_INIT,
 	FAULT_LOCK_OP,
+	FAULT_BLKADDR,
 	FAULT_MAX,
 };
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 787010893a12..fad333881ea2 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -61,6 +61,7 @@ const char *f2fs_fault_name[FAULT_MAX] = {
 	[FAULT_SLAB_ALLOC]	= "slab alloc",
 	[FAULT_DQUOT_INIT]	= "dquot initialize",
 	[FAULT_LOCK_OP]		= "lock_op",
+	[FAULT_BLKADDR]		= "invalid blkaddr",
 };
 
 void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate,
-- 
2.36.1