[PATCH] f2fs: fix to check quota inums

[Yangtao Li]

We should check quota file ino before enable quota, and not only 0.

BTW fix following check error:

WARNING: Do not crash the kernel unless it is absolutely
unavoidable--use WARN_ON_ONCE() plus recovery code (if feasible)
instead of BUG() or variants.

Fixes: ea6767337f86 ("f2fs: support quota sys files")
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
 fs/f2fs/super.c | 54 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 18 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index aa55dc12aff2..c7e0639892e2 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2652,22 +2652,40 @@ int f2fs_enable_quota_files(struct f2fs_sb_info *sbi, bool rdonly)
 	return enabled;
 }
 
+static inline bool f2fs_check_quota_inum(int type, unsigned long qf_inum)
+{
+	switch (type) {
+	case USRQUOTA:
+		return qf_inum == 4;
+	case GRPQUOTA:
+		return qf_inum == 5;
+	case PRJQUOTA:
+		return qf_inum == 6;
+	default:
+		return false;
+	}
+}
+
 static int f2fs_quota_enable(struct super_block *sb, int type, int format_id,
 			     unsigned int flags)
 {
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
 	struct inode *qf_inode;
 	unsigned long qf_inum;
 	int err;
 
-	BUG_ON(!f2fs_sb_has_quota_ino(F2FS_SB(sb)));
+	f2fs_bug_on(sbi, !f2fs_sb_has_quota_ino(sbi));
 
 	qf_inum = f2fs_qf_ino(sb, type);
-	if (!qf_inum)
-		return -EPERM;
+	if (!f2fs_check_quota_inum(type, qf_inum)) {
+		f2fs_err(sbi, "Bad quota inum: %lu, type: %d",
+				qf_inum, type);
+		return -EFSCORRUPTED;
+	}
 
 	qf_inode = f2fs_iget(sb, qf_inum);
 	if (IS_ERR(qf_inode)) {
-		f2fs_err(F2FS_SB(sb), "Bad quota inode %u:%lu", type, qf_inum);
+		f2fs_err(sbi, "Bad quota inode %u:%lu", type, qf_inum);
 		return PTR_ERR(qf_inode);
 	}
 
@@ -2682,7 +2700,7 @@ static int f2fs_enable_quotas(struct super_block *sb)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
 	int type, err = 0;
-	unsigned long qf_inum;
+	char count = MAXQUOTAS;
 	bool quota_mopt[MAXQUOTAS] = {
 		test_opt(sbi, USRQUOTA),
 		test_opt(sbi, GRPQUOTA),
@@ -2696,21 +2714,21 @@ static int f2fs_enable_quotas(struct super_block *sb)
 
 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
 
-	for (type = 0; type < MAXQUOTAS; type++) {
-		qf_inum = f2fs_qf_ino(sb, type);
-		if (qf_inum) {
-			err = f2fs_quota_enable(sb, type, QFMT_VFS_V1,
+	if (!f2fs_sb_has_project_quota(sbi))
+		count--;
+
+	for (type = 0; type < count; type++) {
+		err = f2fs_quota_enable(sb, type, QFMT_VFS_V1,
 				DQUOT_USAGE_ENABLED |
 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
-			if (err) {
-				f2fs_err(sbi, "Failed to enable quota tracking (type=%d, err=%d). Please run fsck to fix.",
-					 type, err);
-				for (type--; type >= 0; type--)
-					dquot_quota_off(sb, type);
-				set_sbi_flag(F2FS_SB(sb),
-						SBI_QUOTA_NEED_REPAIR);
-				return err;
-			}
+		if (err) {
+			f2fs_err(sbi, "Failed to enable quota tracking (type=%d, err=%d). Please run fsck to fix.",
+				 type, err);
+			for (type--; type >= 0; type--)
+				dquot_quota_off(sb, type);
+			set_sbi_flag(F2FS_SB(sb),
+					SBI_QUOTA_NEED_REPAIR);
+			return err;
 		}
 	}
 	return 0;
-- 
2.25.1