[PATCH 2/2] f2fs: fix to update injection attrs according to fault_option

[Chao Yu <chao@kernel.org>]

When we update inject type via sysfs, it shows wrong rate value as
below, there is a same problem when we update inject rate, fix it.

Before:
F2FS-fs (vdd): build fault injection attr: rate: 0, type: 0xffff
F2FS-fs (vdd): build fault injection attr: rate: 1, type: 0x0

After:
F2FS-fs (vdd): build fault injection type: 0x1
F2FS-fs (vdd): build fault injection rate: 1

Meanwhile, let's avoid turning on all fault type when we enable fault
injection via fault_injection mount option, it will lead to shutdown
filesystem or fail the mount() easily.

mount -o fault_injection=4 /dev/vdd /mnt/f2fs
F2FS-fs (vdd): build fault injection attr: rate: 4, type: 0x7fffff
F2FS-fs (vdd): inject kmalloc in f2fs_kmalloc of f2fs_fill_super+0xbdf/0x27c0

Signed-off-by: Chao Yu <chao@kernel.org>
---
 fs/f2fs/checkpoint.c |  2 +-
 fs/f2fs/f2fs.h       | 14 ++++++++++----
 fs/f2fs/super.c      | 26 +++++++++++++-------------
 fs/f2fs/sysfs.c      |  4 ++--
 4 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index cf77987d0698..85b7141f0d89 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -29,7 +29,7 @@ struct kmem_cache *f2fs_inode_entry_slab;
 void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io,
 						unsigned char reason)
 {
-	f2fs_build_fault_attr(sbi, 0, 0);
+	f2fs_build_fault_attr(sbi, 0, 0, FAULT_ALL);
 	if (!end_io)
 		f2fs_flush_merged_writes(sbi);
 	f2fs_handle_critical_error(sbi, reason);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 986ee5b9326d..ca884e39a5ff 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -66,9 +66,14 @@ enum {
 	FAULT_MAX,
 };
 
-#ifdef CONFIG_F2FS_FAULT_INJECTION
-#define F2FS_ALL_FAULT_TYPE		(GENMASK(FAULT_MAX - 1, 0))
+/* indicate which option to update */
+enum fault_option {
+	FAULT_RATE	= 1,	/* only update fault rate */
+	FAULT_TYPE	= 2,	/* only update fault type */
+	FAULT_ALL	= 4,	/* reset all fault injection options/stats */
+};
 
+#ifdef CONFIG_F2FS_FAULT_INJECTION
 struct f2fs_fault_info {
 	atomic_t inject_ops;
 	int inject_rate;
@@ -4765,10 +4770,11 @@ static inline bool f2fs_need_verity(const struct inode *inode, pgoff_t idx)
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 extern int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
-							unsigned long type);
+					unsigned long type, enum fault_option fo);
 #else
 static inline int f2fs_build_fault_attr(struct f2fs_sb_info *sbi,
-					unsigned long rate, unsigned long type)
+					unsigned long rate, unsigned long type,
+					enum fault_option fo)
 {
 	return 0;
 }
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index dfe0604ab558..011925ee54f8 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -68,29 +68,30 @@ const char *f2fs_fault_name[FAULT_MAX] = {
 };
 
 int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
-							unsigned long type)
+				unsigned long type, enum fault_option fo)
 {
 	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
 
-	if (rate) {
+	if (fo & FAULT_ALL) {
+		memset(ffi, 0, sizeof(struct f2fs_fault_info));
+		return 0;
+	}
+
+	if (fo & FAULT_RATE) {
 		if (rate > INT_MAX)
 			return -EINVAL;
 		atomic_set(&ffi->inject_ops, 0);
 		ffi->inject_rate = (int)rate;
+		f2fs_info(sbi, "build fault injection rate: %lu", rate);
 	}
 
-	if (type) {
+	if (fo & FAULT_TYPE) {
 		if (type >= BIT(FAULT_MAX))
 			return -EINVAL;
 		ffi->inject_type = (unsigned int)type;
+		f2fs_info(sbi, "build fault injection type: 0x%lx", type);
 	}
 
-	if (!rate && !type)
-		memset(ffi, 0, sizeof(struct f2fs_fault_info));
-	else
-		f2fs_info(sbi,
-			"build fault injection attr: rate: %lu, type: 0x%lx",
-								rate, type);
 	return 0;
 }
 #endif
@@ -897,8 +898,7 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options, bool is_remoun
 		case Opt_fault_injection:
 			if (args->from && match_int(args, &arg))
 				return -EINVAL;
-			if (f2fs_build_fault_attr(sbi, arg,
-					F2FS_ALL_FAULT_TYPE))
+			if (f2fs_build_fault_attr(sbi, arg, 0, FAULT_RATE))
 				return -EINVAL;
 			set_opt(sbi, FAULT_INJECTION);
 			break;
@@ -906,7 +906,7 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options, bool is_remoun
 		case Opt_fault_type:
 			if (args->from && match_int(args, &arg))
 				return -EINVAL;
-			if (f2fs_build_fault_attr(sbi, 0, arg))
+			if (f2fs_build_fault_attr(sbi, 0, arg, FAULT_TYPE))
 				return -EINVAL;
 			set_opt(sbi, FAULT_INJECTION);
 			break;
@@ -2209,7 +2209,7 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
 	set_opt(sbi, POSIX_ACL);
 #endif
 
-	f2fs_build_fault_attr(sbi, 0, 0);
+	f2fs_build_fault_attr(sbi, 0, 0, FAULT_ALL);
 }
 
 #ifdef CONFIG_QUOTA
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index e87e89d2c023..282e5c14a718 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -494,12 +494,12 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 		return ret;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (a->struct_type == FAULT_INFO_TYPE) {
-		if (f2fs_build_fault_attr(sbi, 0, t))
+		if (f2fs_build_fault_attr(sbi, 0, t, FAULT_TYPE))
 			return -EINVAL;
 		return count;
 	}
 	if (a->struct_type == FAULT_INFO_RATE) {
-		if (f2fs_build_fault_attr(sbi, t, 0))
+		if (f2fs_build_fault_attr(sbi, t, 0, FAULT_RATE))
 			return -EINVAL;
 		return count;
 	}
-- 
2.48.1