[PATCH v2 1/2] f2fs: add a proc entry show inject stats

[Chao Yu <chao@kernel.org>]

This patch adds a proc entry named inject_stats to show total injected
count for each fault type.

cat /proc/fs/f2fs/<dev>/inject_stats
fault_type              injected_count
kmalloc                 0
kvmalloc                0
page alloc              0
page get                0
alloc bio(obsolete)     0
alloc nid               0
orphan                  0
no more block           0
too big dir depth       0
evict_inode fail        0
truncate fail           0
read IO error           0
checkpoint error        0
discard error           0
write IO error          0
slab alloc              0
dquot initialize        0
lock_op                 0
invalid blkaddr         0
inconsistent blkaddr    0
no free segment         0
inconsistent footer     0

Signed-off-by: Chao Yu <chao@kernel.org>
---
v2:
- add missing CONFIG_F2FS_FAULT_INJECTION
 fs/f2fs/f2fs.h  |  3 +++
 fs/f2fs/super.c |  1 +
 fs/f2fs/sysfs.c | 22 ++++++++++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f1576dc6ec67..986ee5b9326d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -73,6 +73,8 @@ struct f2fs_fault_info {
 	atomic_t inject_ops;
 	int inject_rate;
 	unsigned int inject_type;
+	/* Used to account total count of injection for each type */
+	unsigned int inject_count[FAULT_MAX];
 };
 
 extern const char *f2fs_fault_name[FAULT_MAX];
@@ -1902,6 +1904,7 @@ static inline bool __time_to_inject(struct f2fs_sb_info *sbi, int type,
 	atomic_inc(&ffi->inject_ops);
 	if (atomic_read(&ffi->inject_ops) >= ffi->inject_rate) {
 		atomic_set(&ffi->inject_ops, 0);
+		ffi->inject_count[type]++;
 		f2fs_info_ratelimited(sbi, "inject %s in %s of %pS",
 				f2fs_fault_name[type], func, parent_func);
 		return true;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f087b2b71c89..dfe0604ab558 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -47,6 +47,7 @@ const char *f2fs_fault_name[FAULT_MAX] = {
 	[FAULT_KVMALLOC]		= "kvmalloc",
 	[FAULT_PAGE_ALLOC]		= "page alloc",
 	[FAULT_PAGE_GET]		= "page get",
+	[FAULT_ALLOC_BIO]		= "alloc bio(obsolete)",
 	[FAULT_ALLOC_NID]		= "alloc nid",
 	[FAULT_ORPHAN]			= "orphan",
 	[FAULT_BLOCK]			= "no more block",
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index c69161366467..46fa94db08a8 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -1679,6 +1679,24 @@ static int __maybe_unused disk_map_seq_show(struct seq_file *seq,
 	return 0;
 }
 
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+static int __maybe_unused inject_stats_seq_show(struct seq_file *seq,
+						void *offset)
+{
+	struct super_block *sb = seq->private;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
+	int i;
+
+	seq_puts(seq, "fault_type		injected_count\n");
+
+	for (i = 0; i < FAULT_MAX; i++)
+		seq_printf(seq, "%-24s%-10u\n", f2fs_fault_name[i],
+						ffi->inject_count[i]);
+	return 0;
+}
+#endif
+
 int __init f2fs_init_sysfs(void)
 {
 	int ret;
@@ -1770,6 +1788,10 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
 				discard_plist_seq_show, sb);
 	proc_create_single_data("disk_map", 0444, sbi->s_proc,
 				disk_map_seq_show, sb);
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	proc_create_single_data("inject_stats", 0444, sbi->s_proc,
+				inject_stats_seq_show, sb);
+#endif
 	return 0;
 put_feature_list_kobj:
 	kobject_put(&sbi->s_feature_list_kobj);
-- 
2.48.1