[PATCH RESEND 6/6] f2fs: introduce sb_status sysfs node

[Chao Yu]

Introduce /sys/fs/f2fs/<devname>/stat/sb_status to show superblock
status in real time as below:

IS_DIRTY:		no
IS_CLOSE:		no
IS_SHUTDOWN:		no
IS_RECOVERED:		no
IS_RESIZEFS:		no
NEED_FSCK:		no
POR_DOING:		no
NEED_SB_WRITE:		no
NEED_CP:		no
CP_DISABLED:		no
CP_DISABLED_QUICK:	no
QUOTA_NEED_FLUSH:	no
QUOTA_SKIP_FLUSH:	no
QUOTA_NEED_REPAIR:	no

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
 Documentation/ABI/testing/sysfs-fs-f2fs |  5 ++++
 fs/f2fs/sysfs.c                         | 36 +++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3dfee94e0618..57ab839dc3a2 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -377,3 +377,8 @@ Description:	This gives a control to limit the bio size in f2fs.
 		Default is zero, which will follow underlying block layer limit,
 		whereas, if it has a certain bytes value, f2fs won't submit a
 		bio larger than that size.
+
+What:		/sys/fs/f2fs/<disk>/stat/sb_status
+Date:		December 2020
+Contact:	"Chao Yu" <yuchao0@xxxxxxxxxx>
+Description:	Show status of f2fs superblock in real time.
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index ebca0b4961e8..1b85e6d16a94 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -101,6 +101,40 @@ static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
 				sbi->sectors_written_start) >> 1)));
 }
 
+#define	SB_STATUS(s)	(s ? "yes" : "no")
+static ssize_t sb_status_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	return sprintf(buf, "IS_DIRTY:		%s\n"
+				"IS_CLOSE:		%s\n"
+				"IS_SHUTDOWN:		%s\n"
+				"IS_RECOVERED:		%s\n"
+				"IS_RESIZEFS:		%s\n"
+				"NEED_FSCK:		%s\n"
+				"POR_DOING:		%s\n"
+				"NEED_SB_WRITE:		%s\n"
+				"NEED_CP:		%s\n"
+				"CP_DISABLED:		%s\n"
+				"CP_DISABLED_QUICK:	%s\n"
+				"QUOTA_NEED_FLUSH:	%s\n"
+				"QUOTA_SKIP_FLUSH:	%s\n"
+				"QUOTA_NEED_REPAIR:	%s\n",
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_IS_DIRTY)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_IS_CLOSE)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_IS_RECOVERED)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_IS_RESIZEFS)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_NEED_FSCK)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_POR_DOING)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_NEED_CP)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_CP_DISABLED)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_CP_DISABLED_QUICK)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_QUOTA_NEED_FLUSH)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH)),
+			SB_STATUS(is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR)));
+}
+
 static ssize_t features_show(struct f2fs_attr *a,
 		struct f2fs_sb_info *sbi, char *buf)
 {
@@ -711,7 +745,9 @@ static struct attribute *f2fs_feat_attrs[] = {
 };
 ATTRIBUTE_GROUPS(f2fs_feat);
 
+F2FS_GENERAL_RO_ATTR(sb_status);
 static struct attribute *f2fs_stat_attrs[] = {
+	ATTR_LIST(sb_status),
 	NULL,
 };
 ATTRIBUTE_GROUPS(f2fs_stat);
-- 
2.29.2