[PATCH 1/3] f2fs: fix to alloc_mode changed after remount on a small volume device

[Yuwei Guan]

The commit 84b89e5d943d8 ("f2fs: add auto tuning for small devices") add
tuning for small volume device, now support to tune alloce_mode to 'reuse'
if it's small size. But the alloc_mode will change to 'default' when do
remount on this small size dievce.

The commit 4cac90d5491c9 ("f2fs: relocate readdir_ra configure
initialization") relocates readdir_ra variable to tuning process.

This patch fo fix alloc_mode changed when do remount for a small volume
device.

For a small device,
- alloc_mode will keep 'reuse', if no alloc_mode option in remount
  command,
- alloc_mode will be set as remount command, if it has 'alloc_mode='.

Signed-off-by: Yuwei Guan <Yuwei.Guan@xxxxxxxxxxxxx>
---
 fs/f2fs/super.c | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3834ead04620..2f36824ff84b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2190,6 +2190,23 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 	f2fs_flush_ckpt_thread(sbi);
 }
 
+static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi, bool is_remount)
+{
+	struct f2fs_sm_info *sm_i = SM_I(sbi);
+
+	/* adjust parameters according to the volume size */
+	if (sm_i->main_segments <= SMALL_VOLUME_SEGMENTS) {
+		F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
+		if (f2fs_block_unit_discard(sbi))
+			sm_i->dcc_info->discard_granularity = 1;
+		sm_i->ipu_policy = 1 << F2FS_IPU_FORCE |
+					1 << F2FS_IPU_HONOR_OPU_WRITE;
+	}
+
+	if (!is_remount)
+		sbi->readdir_ra = 1;
+}
+
 static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
@@ -2248,6 +2265,8 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 
 	default_options(sbi);
 
+	f2fs_tuning_parameters(sbi, true);
+
 	/* parse mount options */
 	err = parse_options(sb, data, true);
 	if (err)
@@ -4054,22 +4073,6 @@ static int f2fs_setup_casefold(struct f2fs_sb_info *sbi)
 	return 0;
 }
 
-static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
-{
-	struct f2fs_sm_info *sm_i = SM_I(sbi);
-
-	/* adjust parameters according to the volume size */
-	if (sm_i->main_segments <= SMALL_VOLUME_SEGMENTS) {
-		F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
-		if (f2fs_block_unit_discard(sbi))
-			sm_i->dcc_info->discard_granularity = 1;
-		sm_i->ipu_policy = 1 << F2FS_IPU_FORCE |
-					1 << F2FS_IPU_HONOR_OPU_WRITE;
-	}
-
-	sbi->readdir_ra = 1;
-}
-
 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct f2fs_sb_info *sbi;
@@ -4475,7 +4478,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 
 	f2fs_join_shrinker(sbi);
 
-	f2fs_tuning_parameters(sbi);
+	f2fs_tuning_parameters(sbi, false);
 
 	f2fs_notice(sbi, "Mounted with checkpoint version = %llx",
 		    cur_cp_version(F2FS_CKPT(sbi)));
-- 
2.34.1