[PATCH v2 2/5] 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 after remount, ipu should be disabled when convert to
lfs mode, let's fix it.

Fixes: 84b89e5d943d ("f2fs: add auto tuning for small devices")
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
v2:
-restore old_ipu_policy for fail case in remount
 fs/f2fs/segment.h | 2 ++
 fs/f2fs/super.c   | 9 ++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index ad6a9c19f46a..704d27ad682d 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,
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 0cedb693db58..1d2796863f8c 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2156,6 +2156,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
 	struct f2fs_mount_info org_mount_opt;
 	unsigned long old_sb_flags;
+	unsigned int old_ipu_policy;
 	int err;
 	bool need_restart_gc = false, need_stop_gc = false;
 	bool need_restart_ckpt = false, need_stop_ckpt = false;
@@ -2179,6 +2180,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	 */
 	org_mount_opt = sbi->mount_opt;
 	old_sb_flags = sb->s_flags;
+	old_ipu_policy = SM_I(sbi)->ipu_policy;
 
 #ifdef CONFIG_QUOTA
 	org_mount_opt.s_jquota_fmt = F2FS_OPTION(sbi).s_jquota_fmt;
@@ -2212,6 +2214,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	if (err)
 		goto restore_opts;
 
+	if (F2FS_OPTION(sbi).fs_mode == FS_MODE_LFS)
+		SM_I(sbi)->ipu_policy = F2FS_IPU_DISABLE;
+
 	/*
 	 * Previous and new state of filesystem is RO,
 	 * so skip checking GC and FLUSH_MERGE conditions.
@@ -2417,6 +2422,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 		F2FS_OPTION(sbi).s_qf_names[i] = org_mount_opt.s_qf_names[i];
 	}
 #endif
+	SM_I(sbi)->ipu_policy = old_ipu_policy;
 	sbi->mount_opt = org_mount_opt;
 	sb->s_flags = old_sb_flags;
 	return err;
@@ -3944,7 +3950,8 @@ static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
 	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);
+		if (F2FS_OPTION(sbi).fs_mode != FS_MODE_LFS)
+			SM_I(sbi)->ipu_policy = BIT(F2FS_IPU_FORCE) | BIT(F2FS_IPU_HONOR_OPU_WRITE);
 	}
 
 	sbi->readdir_ra = true;
-- 
2.25.1