[PATCH v3 5/5] f2fs: introduce sb_status sysfs node

[Chao Yu]

Introduce /sys/fs/f2fs/<devname>/stat/sb_status to show superblock
status in real time as a hexadecimal value.

value           sb status macro                 description

0x1             SBI_IS_DIRTY,                   /* dirty flag for checkpoint */
0x2             SBI_IS_CLOSE,                   /* specify unmounting */
0x4             SBI_NEED_FSCK,                  /* need fsck.f2fs to fix */
0x8             SBI_POR_DOING,                  /* recovery is doing or not */
0x10            SBI_NEED_SB_WRITE,              /* need to recover superblock */
0x20            SBI_NEED_CP,                    /* need to checkpoint */
0x40            SBI_IS_SHUTDOWN,                /* shutdown by ioctl */
0x80            SBI_IS_RECOVERED,               /* recovered orphan/data */
0x100           SBI_CP_DISABLED,                /* CP was disabled last mount */
0x200           SBI_CP_DISABLED_QUICK,          /* CP was disabled quickly */
0x400           SBI_QUOTA_NEED_FLUSH,           /* need to flush quota info in CP */
0x800           SBI_QUOTA_SKIP_FLUSH,           /* skip flushing quota in current CP */
0x1000          SBI_QUOTA_NEED_REPAIR,          /* quota file may be corrupted */
0x2000          SBI_IS_RESIZEFS,                /* resizefs is in process */

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
v3:
- just print one single value as output
 Documentation/ABI/testing/sysfs-fs-f2fs | 21 +++++++++++++++++++++
 fs/f2fs/sysfs.c                         |  8 ++++++++
 2 files changed, 29 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3dfee94e0618..9b2f93eda1f8 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -377,3 +377,24 @@ 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.
+
+		value           sb status macro                 description
+		0x1             SBI_IS_DIRTY,                   /* dirty flag for checkpoint */
+		0x2             SBI_IS_CLOSE,                   /* specify unmounting */
+		0x4             SBI_NEED_FSCK,                  /* need fsck.f2fs to fix */
+		0x8             SBI_POR_DOING,                  /* recovery is doing or not */
+		0x10            SBI_NEED_SB_WRITE,              /* need to recover superblock */
+		0x20            SBI_NEED_CP,                    /* need to checkpoint */
+		0x40            SBI_IS_SHUTDOWN,                /* shutdown by ioctl */
+		0x80            SBI_IS_RECOVERED,               /* recovered orphan/data */
+		0x100           SBI_CP_DISABLED,                /* CP was disabled last mount */
+		0x200           SBI_CP_DISABLED_QUICK,          /* CP was disabled quickly */
+		0x400           SBI_QUOTA_NEED_FLUSH,           /* need to flush quota info in CP */
+		0x800           SBI_QUOTA_SKIP_FLUSH,           /* skip flushing quota in current CP */
+		0x1000          SBI_QUOTA_NEED_REPAIR,          /* quota file may be corrupted */
+		0x2000          SBI_IS_RESIZEFS,                /* resizefs is in process */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index ebca0b4961e8..d5198689ab02 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -101,6 +101,12 @@ static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
 				sbi->sectors_written_start) >> 1)));
 }
 
+static ssize_t sb_status_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	return sprintf(buf, "%lx\n", sbi->s_flag);
+}
+
 static ssize_t features_show(struct f2fs_attr *a,
 		struct f2fs_sb_info *sbi, char *buf)
 {
@@ -711,7 +717,9 @@ 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