f2fs: fix to recover quota data correctly

With -O quota mkfs option, xfstests generic/417 fails due to fsck detects
data corruption on quota inodes.

[ASSERT] (fsck_chk_quota_files:2051)  --> Quota file is missing or invalid quota file content found.

The root cause is there is a hole f2fs doesn't hold quota inodes,
so all recovered quota data will be dropped due to SBI_POR_DOING
flag was set.
- f2fs_fill_super
 - f2fs_recover_orphan_inodes
  - f2fs_enable_quota_files
  - f2fs_quota_off_umount
<--- quota inodes were dropped --->
 - f2fs_recover_fsync_data
  - f2fs_enable_quota_files
  - f2fs_quota_off_umount

This patch tries to eliminate the hole by holding quota inodes
during entire recovery flow as below:
- f2fs_fill_super
 - f2fs_recover_quota_begin
 - f2fs_recover_orphan_inodes
 - f2fs_recover_fsync_data
 - f2fs_recover_quota_end

Then, recovered quota data can be persisted after SBI_POR_DOING
is cleared.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8f9086d53d52..4e53b1100b84 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2501,6 +2501,54 @@ restore_opts:
 }
 
 #ifdef CONFIG_QUOTA
+static bool f2fs_need_recovery(struct f2fs_sb_info *sbi)
+{
+	/* need to recovery orphan */
+	if (is_set_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG))
+		return true;
+	/* need to recovery data */
+	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
+		return false;
+	if (test_opt(sbi, NORECOVERY))
+		return false;
+	return !is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG);
+}
+
+static bool f2fs_recover_quota_begin(struct f2fs_sb_info *sbi)
+{
+	bool readonly = f2fs_readonly(sbi->sb);
+
+	if (!f2fs_need_recovery(sbi))
+		return false;
+
+	/* it doesn't need to check f2fs_sb_has_readonly() */
+	if (f2fs_hw_is_readonly(sbi))
+		return false;
+
+	if (readonly) {
+		sbi->sb->s_flags &= ~SB_RDONLY;
+		set_sbi_flag(sbi, SBI_IS_WRITABLE);
+	}
+
+	/*
+	 * Turn on quotas which were not enabled for read-only mounts if
+	 * filesystem has quota feature, so that they are updated correctly.
+	 */
+	return f2fs_enable_quota_files(sbi, readonly);
+}
+
+static void f2fs_recover_quota_end(struct f2fs_sb_info *sbi,
+						bool quota_enabled)
+{
+	if (quota_enabled)
+		f2fs_quota_off_umount(sbi->sb);
+
+	if (is_sbi_flag_set(sbi, SBI_IS_WRITABLE)) {
+		clear_sbi_flag(sbi, SBI_IS_WRITABLE);
+		sbi->sb->s_flags |= SB_RDONLY;
+	}
+}
+
 /* Read data from quotafile */
 static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off)
@@ -4116,6 +4164,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	int recovery, i, valid_super_block;
 	struct curseg_info *seg_i;
 	int retry_cnt = 1;
+#ifdef CONFIG_QUOTA
+	bool quota_enabled = false;
+#endif
 
 try_onemore:
 	err = -EINVAL;
@@ -4409,6 +4460,8 @@ try_onemore:
 		if (err)
 			f2fs_err(sbi, "Cannot turn on quotas: error %d", err);
 	}
+
+	quota_enabled = f2fs_recover_quota_begin(sbi);
 #endif
 	/* if there are any orphan inodes, free them */
 	err = f2fs_recover_orphan_inodes(sbi);
@@ -4466,6 +4519,10 @@ try_onemore:
 		}
 	}
 
+#ifdef CONFIG_QUOTA
+	f2fs_recover_quota_end(sbi, quota_enabled);
+#endif
+
 	/*
 	 * If the f2fs is not readonly and fsync data recovery succeeds,
 	 * check zoned block devices' write pointer consistency.