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>

fs/f2fs/checkpoint.c

@@ -713,11 +713,7 @@ static int recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
 int f2fs_recover_orphan_inodes(struct f2fs_sb_info *sbi)
 {
 	block_t start_blk, orphan_blocks, i, j;
-	unsigned int s_flags = sbi->sb->s_flags;
 	int err = 0;
-#ifdef CONFIG_QUOTA
-	int quota_enabled;
-#endif
 
 	if (!is_set_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG))
 		return 0;
@@ -727,18 +723,8 @@ int f2fs_recover_orphan_inodes(struct f2fs_sb_info *sbi)
 		return 0;
 	}
 
-	if (s_flags & SB_RDONLY) {
+	if (is_sbi_flag_set(sbi, SBI_IS_WRITABLE))
 		f2fs_info(sbi, "orphan cleanup on readonly fs");
-		sbi->sb->s_flags &= ~SB_RDONLY;
-	}
-
-#ifdef CONFIG_QUOTA
-	/*
-	 * Turn on quotas which were not enabled for read-only mounts if
-	 * filesystem has quota feature, so that they are updated correctly.
-	 */
-	quota_enabled = f2fs_enable_quota_files(sbi, s_flags & SB_RDONLY);
-#endif
 
 	start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
 	orphan_blocks = __start_sum_addr(sbi) - 1 - __cp_payload(sbi);
@@ -772,13 +758,6 @@ int f2fs_recover_orphan_inodes(struct f2fs_sb_info *sbi)
 out:
 	set_sbi_flag(sbi, SBI_IS_RECOVERED);
 
-#ifdef CONFIG_QUOTA
-	/* Turn quotas off */
-	if (quota_enabled)
-		f2fs_quota_off_umount(sbi->sb);
-#endif
-	sbi->sb->s_flags = s_flags; /* Restore SB_RDONLY status */
-
 	return err;
 }
 

fs/f2fs/debug.c

@@ -352,6 +352,7 @@ static const char *s_flag[MAX_SBI_FLAG] = {
 	[SBI_QUOTA_NEED_REPAIR]	= "quota_need_repair",
 	[SBI_IS_RESIZEFS]	= "resizefs",
 	[SBI_IS_FREEZING]	= "freezefs",
+	[SBI_IS_WRITABLE]	= "writable",
 };
 
 static const char *ipu_mode_names[F2FS_IPU_MAX] = {

fs/f2fs/f2fs.h

@@ -1294,6 +1294,7 @@ enum {
 	SBI_QUOTA_NEED_REPAIR,			/* quota file may be corrupted */
 	SBI_IS_RESIZEFS,			/* resizefs is in process */
 	SBI_IS_FREEZING,			/* freezefs is in process */
+	SBI_IS_WRITABLE,			/* remove ro mountoption transiently */
 	MAX_SBI_FLAG,
 };
 

fs/f2fs/recovery.c

@@ -825,19 +825,9 @@ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
 	unsigned long s_flags = sbi->sb->s_flags;
 	bool need_writecp = false;
 	bool fix_curseg_write_pointer = false;
-#ifdef CONFIG_QUOTA
-	int quota_enabled;
-#endif
 
-	if (s_flags & SB_RDONLY) {
+	if (is_sbi_flag_set(sbi, SBI_IS_WRITABLE))
 		f2fs_info(sbi, "recover fsync data on readonly fs");
-		sbi->sb->s_flags &= ~SB_RDONLY;
-	}
-
-#ifdef CONFIG_QUOTA
-	/* Turn on quotas so that they are updated correctly */
-	quota_enabled = f2fs_enable_quota_files(sbi, s_flags & SB_RDONLY);
-#endif
 
 	INIT_LIST_HEAD(&inode_list);
 	INIT_LIST_HEAD(&tmp_inode_list);
@@ -909,11 +899,6 @@ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
 		}
 	}
 
-#ifdef CONFIG_QUOTA
-	/* Turn quotas off */
-	if (quota_enabled)
-		f2fs_quota_off_umount(sbi->sb);
-#endif
 	sbi->sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 
 	return ret ? ret : err;

fs/f2fs/super.c

@@ -2501,6 +2501,54 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 }
 
 #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 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 		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 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 		}
 	}
 
+#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.