[PATCH] f2fs: fix to check readonly condition correctly

[Chao Yu]

This patch does below changes:

- If f2fs enables readonly feature or device is readonly, allow to
mount readonly mode only
- Introduce f2fs_dev_is_readonly() to indicate whether image or device
is readonly
- remove unnecessary f2fs_hw_is_readonly() in f2fs_write_checkpoint()
and f2fs_convert_inline_inode()
- enable FLUSH_MERGE only if f2fs is mounted as rw and image/device
is writable

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
 fs/f2fs/checkpoint.c |  2 +-
 fs/f2fs/f2fs.h       | 10 +++++-----
 fs/f2fs/inline.c     |  3 +--
 fs/f2fs/super.c      | 13 +++++++------
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 8e1db5752fff..1eef597ed393 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1604,7 +1604,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	unsigned long long ckpt_ver;
 	int err = 0;
 
-	if (f2fs_readonly(sbi->sb) || f2fs_hw_is_readonly(sbi))
+	if (f2fs_readonly(sbi->sb))
 		return -EROFS;
 
 	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2d4a7ef62537..7de95133478a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4446,6 +4446,11 @@ static inline bool f2fs_hw_is_readonly(struct f2fs_sb_info *sbi)
 	return false;
 }
 
+static inline bool f2fs_dev_is_readonly(struct f2fs_sb_info *sbi)
+{
+	return f2fs_sb_has_readonly(sbi) || f2fs_hw_is_readonly(sbi);
+}
+
 static inline bool f2fs_lfs_mode(struct f2fs_sb_info *sbi)
 {
 	return F2FS_OPTION(sbi).fs_mode == FS_MODE_LFS;
@@ -4546,11 +4551,6 @@ static inline void f2fs_handle_page_eio(struct f2fs_sb_info *sbi, pgoff_t ofs,
 	}
 }
 
-static inline bool f2fs_is_readonly(struct f2fs_sb_info *sbi)
-{
-	return f2fs_sb_has_readonly(sbi) || f2fs_readonly(sbi->sb);
-}
-
 #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
 
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 72269e7efd26..2c36f2dc2317 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -203,8 +203,7 @@ int f2fs_convert_inline_inode(struct inode *inode)
 	struct page *ipage, *page;
 	int err = 0;
 
-	if (!f2fs_has_inline_data(inode) ||
-			f2fs_hw_is_readonly(sbi) || f2fs_readonly(sbi->sb))
+	if (!f2fs_has_inline_data(inode) || f2fs_readonly(sbi->sb))
 		return 0;
 
 	err = f2fs_dquot_initialize(inode);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index d016f398fcad..db7649010c12 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1382,15 +1382,16 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 		return -EINVAL;
 	}
 
-	if (f2fs_is_readonly(sbi) && test_opt(sbi, FLUSH_MERGE)) {
+	if (f2fs_dev_is_readonly(sbi) && !f2fs_readonly(sbi->sb)) {
+		f2fs_err(sbi, "Allow to mount readonly mode only");
+		return -EROFS;
+	}
+
+	if (f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE)) {
 		f2fs_err(sbi, "FLUSH_MERGE not compatible with readonly mode");
 		return -EINVAL;
 	}
 
-	if (f2fs_sb_has_readonly(sbi) && !f2fs_readonly(sbi->sb)) {
-		f2fs_err(sbi, "Allow to mount readonly mode only");
-		return -EROFS;
-	}
 	return 0;
 }
 
@@ -2122,7 +2123,7 @@ static void default_options(struct f2fs_sb_info *sbi)
 	set_opt(sbi, MERGE_CHECKPOINT);
 	F2FS_OPTION(sbi).unusable_cap = 0;
 	sbi->sb->s_flags |= SB_LAZYTIME;
-	if (!f2fs_is_readonly(sbi))
+	if (!f2fs_readonly(sbi->sb) && !f2fs_dev_is_readonly(sbi))
 		set_opt(sbi, FLUSH_MERGE);
 	if (f2fs_hw_support_discard(sbi) || f2fs_hw_should_discard(sbi))
 		set_opt(sbi, DISCARD);
-- 
2.36.1