[PATCH v3 3/3] f2fs: introduce ipu_mode sysfs node

[Yangtao Li]

Add a ipu_mode sysfs node to show the current ipu policy as a string
for readability, like we do in commit a3951cd199a5 ("f2fs: introduce
gc_mode sysfs node").

Since we use ipu_policy as a bitmap, and the bitmap API parameter is
unsigned long type data, let's change ipu_policy to unsigned long type.

Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
v3:
-drop old_ipu_policy type conversion
 Documentation/ABI/testing/sysfs-fs-f2fs |  6 ++++++
 fs/f2fs/f2fs.h                          |  4 ++--
 fs/f2fs/segment.h                       |  1 +
 fs/f2fs/sysfs.c                         | 28 ++++++++++++++++++++++++-
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 8a71397fa060..10e34753d246 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -724,3 +724,9 @@ Description:	Controls background discard granularity of inner discard thread
 		is smaller than granularity. The unit size is one block(4KB), now only
 		support configuring in range of [0, 512].
 		Default: 512
+
+What:		/sys/fs/f2fs/<disk>/ipu_mode
+Date:		February 2023
+Contact:	"Yangtao Li" <frank.li@xxxxxxxx>
+Description:	Show the current ipu policy as a string.
+		This is a read-only entry.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 08dc64c5050e..066cd497be09 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1070,7 +1070,7 @@ struct f2fs_sm_info {
 
 	struct list_head sit_entry_set;	/* sit entry set list */
 
-	unsigned int ipu_policy;	/* in-place-update policy */
+	unsigned long ipu_policy;	/* in-place-update policy */
 	unsigned int min_ipu_util;	/* in-place-update threshold */
 	unsigned int min_fsync_blocks;	/* threshold for fsync */
 	unsigned int min_seq_blocks;	/* threshold for sequential blocks */
@@ -1322,7 +1322,7 @@ enum {
 	MAX_TIME,
 };
 
-/* Note that you need to keep synchronization with this gc_mode_names array */
+/* Modification on enum should be synchronized with gc_mode_names array */
 enum {
 	GC_NORMAL,
 	GC_IDLE_CB,
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 8ee5e5db9287..92c8be00d396 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -672,6 +672,7 @@ static inline int utilization(struct f2fs_sb_info *sbi)
 
 #define F2FS_IPU_DISABLE	0
 
+/* Modification on enum should be synchronized with ipu_mode_names array */
 enum {
 	F2FS_IPU_FORCE,
 	F2FS_IPU_SSR,
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index e1f1ebfa59d6..2a95545b2938 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -51,6 +51,17 @@ static const char *gc_mode_names[MAX_GC_MODE] = {
 	"GC_URGENT_MID"
 };
 
+static const char *ipu_mode_names[F2FS_IPU_MAX] = {
+	"FORCE",
+	"SSR",
+	"UTIL",
+	"SSR_UTIL",
+	"FSYNC",
+	"ASYNC",
+	"NOCACHE",
+	"HONOR_OPU_WRITE",
+};
+
 struct f2fs_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct f2fs_attr *a, struct f2fs_sb_info *sbi, char *buf);
@@ -149,6 +160,19 @@ static ssize_t gc_mode_show(struct f2fs_attr *a,
 	return sysfs_emit(buf, "%s\n", gc_mode_names[sbi->gc_mode]);
 }
 
+static ssize_t ipu_mode_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	int len = 0, i = 0;
+
+	if (SM_I(sbi)->ipu_policy == F2FS_IPU_DISABLE)
+		return sysfs_emit(buf, "DISABLE\n");
+
+	for_each_set_bit(i, &SM_I(sbi)->ipu_policy, F2FS_IPU_MAX)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n", ipu_mode_names[i]);
+	return len;
+}
+
 static ssize_t features_show(struct f2fs_attr *a,
 		struct f2fs_sb_info *sbi, char *buf)
 {
@@ -702,7 +726,7 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 			return -EINVAL;
 		if (t >= BIT(F2FS_IPU_MAX))
 			return -EINVAL;
-		SM_I(sbi)->ipu_policy = (unsigned int)t;
+		SM_I(sbi)->ipu_policy = t;
 		return count;
 	}
 
@@ -898,6 +922,7 @@ F2FS_GENERAL_RO_ATTR(mounted_time_sec);
 F2FS_GENERAL_RO_ATTR(main_blkaddr);
 F2FS_GENERAL_RO_ATTR(pending_discard);
 F2FS_GENERAL_RO_ATTR(gc_mode);
+F2FS_GENERAL_RO_ATTR(ipu_mode);
 #ifdef CONFIG_F2FS_STAT_FS
 F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, cp_foreground_calls, cp_count);
 F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, cp_background_calls, bg_cp_count);
@@ -987,6 +1012,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(max_ordered_discard),
 	ATTR_LIST(pending_discard),
 	ATTR_LIST(gc_mode),
+	ATTR_LIST(ipu_mode),
 	ATTR_LIST(ipu_policy),
 	ATTR_LIST(min_ipu_util),
 	ATTR_LIST(min_fsync_blocks),
-- 
2.25.1