[PATCH] f2fs: add errors=panic mount option

[Sahitya Tummala <stummala@codeaurora.org>]

Add errors=panic mount option for debugging purpose. It can be
set dynamically when the config option CONFIG_F2FS_CHECK_FS
is not enabled.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
---
 fs/f2fs/f2fs.h  |  9 +++++++--
 fs/f2fs/super.c | 21 +++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9b3d997..95adedb 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -32,8 +32,12 @@
 #define f2fs_bug_on(sbi, condition)					\
 	do {								\
 		if (unlikely(condition)) {				\
-			WARN_ON(1);					\
-			set_sbi_flag(sbi, SBI_NEED_FSCK);		\
+			if (test_opt(sbi, ERRORS_PANIC)) {		\
+				BUG_ON(condition);			\
+			} else {					\
+				WARN_ON(1);				\
+				set_sbi_flag(sbi, SBI_NEED_FSCK);	\
+			}						\
 		}							\
 	} while (0)
 #endif
@@ -99,6 +103,7 @@ struct f2fs_fault_info {
 #define F2FS_MOUNT_INLINE_XATTR_SIZE	0x00800000
 #define F2FS_MOUNT_RESERVE_ROOT		0x01000000
 #define F2FS_MOUNT_DISABLE_CHECKPOINT	0x02000000
+#define F2FS_MOUNT_ERRORS_PANIC		0x04000000
 
 #define F2FS_OPTION(sbi)	((sbi)->mount_opt)
 #define clear_opt(sbi, option)	(F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 912e261..7d6d96a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -137,6 +137,7 @@ enum {
 	Opt_fsync,
 	Opt_test_dummy_encryption,
 	Opt_checkpoint,
+	Opt_errors,
 	Opt_err,
 };
 
@@ -196,6 +197,7 @@ enum {
 	{Opt_fsync, "fsync_mode=%s"},
 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
 	{Opt_checkpoint, "checkpoint=%s"},
+	{Opt_errors, "errors=%s"},
 	{Opt_err, NULL},
 };
 
@@ -788,6 +790,23 @@ static int parse_options(struct super_block *sb, char *options)
 			}
 			kvfree(name);
 			break;
+		case Opt_errors:
+#ifndef CONFIG_F2FS_CHECK_FS
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+
+			if (strlen(name) == 5 && !strncmp(name, "panic", 5)) {
+				set_opt(sbi, ERRORS_PANIC);
+			} else {
+				kvfree(name);
+				return -EINVAL;
+			}
+			kvfree(name);
+			f2fs_msg(sb, KERN_INFO,
+				"debug mode errors=panic enabled\n");
+#endif
+			break;
 		default:
 			f2fs_msg(sb, KERN_ERR,
 				"Unrecognized mount option \"%s\" or missing value",
@@ -1417,6 +1436,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_printf(seq, ",fsync_mode=%s", "strict");
 	else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_NOBARRIER)
 		seq_printf(seq, ",fsync_mode=%s", "nobarrier");
+	if (test_opt(sbi, ERRORS_PANIC))
+		seq_printf(seq, ",errors=%s", "panic");
 	return 0;
 }
 
-- 
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Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.