f2fs: support fault_type mount option

Previously, once fault injection is on, by default, all kind of faults
will be injected to f2fs, if we want to trigger single or specified
combined type during the test, we need to configure sysfs entry, it will
be a little inconvenient to integrate sysfs configuring into testsuit,
such as xfstest.

So this patch introduces a new mount option 'fault_type' to assist old
option 'fault_injection', with these two mount options, we can specify
any fault rate/type at mount-time.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Documentation/filesystems/f2fs.txt

@@ -157,6 +157,24 @@ data_flush             Enable data flushing before checkpoint in order to
                        persist data of regular and symlink.
 fault_injection=%d     Enable fault injection in all supported types with
                        specified injection rate.
+fault_type=%d          Support configuring fault injection type, should be
+                       enabled with fault_injection option, fault type value
+                       is shown below, it supports single or combined type.
+                       Type_Name		Type_Value
+                       FAULT_KMALLOC		0x000000001
+                       FAULT_KVMALLOC		0x000000002
+                       FAULT_PAGE_ALLOC		0x000000004
+                       FAULT_PAGE_GET		0x000000008
+                       FAULT_ALLOC_BIO		0x000000010
+                       FAULT_ALLOC_NID		0x000000020
+                       FAULT_ORPHAN		0x000000040
+                       FAULT_BLOCK		0x000000080
+                       FAULT_DIR_DEPTH		0x000000100
+                       FAULT_EVICT_INODE	0x000000200
+                       FAULT_TRUNCATE		0x000000400
+                       FAULT_IO			0x000000800
+                       FAULT_CHECKPOINT		0x000001000
+                       FAULT_DISCARD		0x000002000
 mode=%s                Control block allocation mode which supports "adaptive"
                        and "lfs". In "lfs" mode, there should be no random
                        writes towards main area.

fs/f2fs/checkpoint.c

@@ -28,7 +28,7 @@ struct kmem_cache *f2fs_inode_entry_slab;
 
 void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
 {
-	f2fs_build_fault_attr(sbi, 0);
+	f2fs_build_fault_attr(sbi, 0, 0);
 	set_ckpt_flags(sbi, CP_ERROR_FLAG);
 	if (!end_io)
 		f2fs_flush_merged_writes(sbi);

fs/f2fs/f2fs.h

@@ -60,6 +60,8 @@ enum {
 	FAULT_MAX,
 };
 
+#define F2FS_ALL_FAULT_TYPE		((1 << FAULT_MAX) - 1)
+
 struct f2fs_fault_info {
 	atomic_t inject_ops;
 	unsigned int inject_rate;
@@ -3435,9 +3437,10 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, int rw)
 }
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-extern void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate);
+extern void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate,
+							unsigned int type);
 #else
-#define f2fs_build_fault_attr(sbi, rate)		do { } while (0)
+#define f2fs_build_fault_attr(sbi, rate, type)		do { } while (0)
 #endif
 
 #endif

fs/f2fs/super.c

@@ -58,17 +58,21 @@ char *f2fs_fault_name[FAULT_MAX] = {
 	[FAULT_DISCARD]		= "discard error",
 };
 
-void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate)
+void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate,
+							unsigned int type)
 {
 	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
 
 	if (rate) {
 		atomic_set(&ffi->inject_ops, 0);
 		ffi->inject_rate = rate;
-		ffi->inject_type = (1 << FAULT_MAX) - 1;
-	} else {
-		memset(ffi, 0, sizeof(struct f2fs_fault_info));
 	}
+
+	if (type)
+		ffi->inject_type = type;
+
+	if (!rate && !type)
+		memset(ffi, 0, sizeof(struct f2fs_fault_info));
 }
 #endif
 
@@ -113,6 +117,7 @@ enum {
 	Opt_mode,
 	Opt_io_size_bits,
 	Opt_fault_injection,
+	Opt_fault_type,
 	Opt_lazytime,
 	Opt_nolazytime,
 	Opt_quota,
@@ -170,6 +175,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_mode, "mode=%s"},
 	{Opt_io_size_bits, "io_bits=%u"},
 	{Opt_fault_injection, "fault_injection=%u"},
+	{Opt_fault_type, "fault_type=%u"},
 	{Opt_lazytime, "lazytime"},
 	{Opt_nolazytime, "nolazytime"},
 	{Opt_quota, "quota"},
@@ -600,7 +606,18 @@ static int parse_options(struct super_block *sb, char *options)
 			if (args->from && match_int(args, &arg))
 				return -EINVAL;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-			f2fs_build_fault_attr(sbi, arg);
+			f2fs_build_fault_attr(sbi, arg, F2FS_ALL_FAULT_TYPE);
+			set_opt(sbi, FAULT_INJECTION);
+#else
+			f2fs_msg(sb, KERN_INFO,
+				"FAULT_INJECTION was not selected");
+#endif
+			break;
+		case Opt_fault_type:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+			f2fs_build_fault_attr(sbi, 0, arg);
 			set_opt(sbi, FAULT_INJECTION);
 #else
 			f2fs_msg(sb, KERN_INFO,
@@ -1321,9 +1338,12 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 	if (F2FS_IO_SIZE_BITS(sbi))
 		seq_printf(seq, ",io_size=%uKB", F2FS_IO_SIZE_KB(sbi));
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-	if (test_opt(sbi, FAULT_INJECTION))
+	if (test_opt(sbi, FAULT_INJECTION)) {
 		seq_printf(seq, ",fault_injection=%u",
 				F2FS_OPTION(sbi).fault_info.inject_rate);
+		seq_printf(seq, ",fault_type=%u",
+				F2FS_OPTION(sbi).fault_info.inject_type);
+	}
 #endif
 #ifdef CONFIG_QUOTA
 	if (test_opt(sbi, QUOTA))
@@ -1393,7 +1413,7 @@ static void default_options(struct f2fs_sb_info *sbi)
 	set_opt(sbi, POSIX_ACL);
 #endif
 
-	f2fs_build_fault_attr(sbi, 0);
+	f2fs_build_fault_attr(sbi, 0, 0);
 }
 
 #ifdef CONFIG_QUOTA