[PATCH v3 1/3] f2fs: fix to set ipu policy

[Yangtao Li]

For LFS mode, it should update outplace and no need inplace update.
When using LFS mode for small-volume devices, IPU will not be used,
and the OPU writing method is actually used, but F2FS_IPU_FORCE can
be read from the ipu_policy node, which is different from the actual
situation. And remount to lfs mode should be disallowed when
f2fs ipu is enabled, let's fix it.

Fixes: 84b89e5d943d ("f2fs: add auto tuning for small devices")
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
v3:
-add check in __sbi_store()
-introduce IS_F2FS_IPU_DISABLE()
-convert to f2fs_lfs_mode()
 fs/f2fs/segment.h | 10 +++++++++-
 fs/f2fs/super.c   | 13 +++++++++----
 fs/f2fs/sysfs.c   |  9 +++++++++
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 0f3f05cb8c29..8ee5e5db9287 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -670,6 +670,8 @@ static inline int utilization(struct f2fs_sb_info *sbi)
 
 #define SMALL_VOLUME_SEGMENTS	(16 * 512)	/* 16GB */
 
+#define F2FS_IPU_DISABLE	0
+
 enum {
 	F2FS_IPU_FORCE,
 	F2FS_IPU_SSR,
@@ -679,10 +681,16 @@ enum {
 	F2FS_IPU_ASYNC,
 	F2FS_IPU_NOCACHE,
 	F2FS_IPU_HONOR_OPU_WRITE,
+	F2FS_IPU_MAX,
 };
 
+static inline bool IS_F2FS_IPU_DISABLE(struct f2fs_sb_info *sbi)
+{
+	return SM_I(sbi)->ipu_policy == F2FS_IPU_DISABLE;
+}
+
 #define F2FS_IPU_POLICY(name)					\
-static inline int IS_##name(struct f2fs_sb_info *sbi)		\
+static inline bool IS_##name(struct f2fs_sb_info *sbi)		\
 {								\
 	return SM_I(sbi)->ipu_policy & BIT(name);		\
 }
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index fddff5deaed2..f06af2af215f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2302,6 +2302,12 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 		}
 	}
 #endif
+	if (f2fs_lfs_mode(sbi) && !IS_F2FS_IPU_DISABLE(sbi)) {
+		err = -EINVAL;
+		f2fs_warn(sbi, "LFS not compatible with IPU");
+		goto restore_opts;
+	}
+
 	/* disallow enable atgc dynamically */
 	if (no_atgc == !!test_opt(sbi, ATGC)) {
 		err = -EINVAL;
@@ -4081,10 +4087,9 @@ static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
 	/* adjust parameters according to the volume size */
 	if (MAIN_SEGS(sbi) <= SMALL_VOLUME_SEGMENTS) {
 		if (f2fs_block_unit_discard(sbi))
-			SM_I(sbi)->dcc_info->discard_granularity =
-						MIN_DISCARD_GRANULARITY;
-		SM_I(sbi)->ipu_policy = BIT(F2FS_IPU_FORCE) |
-					BIT(F2FS_IPU_HONOR_OPU_WRITE);
+			SM_I(sbi)->dcc_info->discard_granularity = MIN_DISCARD_GRANULARITY;
+		if (!f2fs_lfs_mode(sbi))
+			SM_I(sbi)->ipu_policy = BIT(F2FS_IPU_FORCE) | BIT(F2FS_IPU_HONOR_OPU_WRITE);
 	}
 
 	sbi->readdir_ra = true;
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 3c6425f9ed0a..e1f1ebfa59d6 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -697,6 +697,15 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 		return count;
 	}
 
+	if (!strcmp(a->attr.name, "ipu_policy")) {
+		if (f2fs_lfs_mode(sbi))
+			return -EINVAL;
+		if (t >= BIT(F2FS_IPU_MAX))
+			return -EINVAL;
+		SM_I(sbi)->ipu_policy = (unsigned int)t;
+		return count;
+	}
+
 	*ui = (unsigned int)t;
 
 	return count;
-- 
2.25.1