Re: [syzbot] Re: kernel BUG in clear_inode()

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Subject: Re: kernel BUG in clear_inode()
Author: dmantipov@xxxxxxxxx

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ff7afaeca1a15fbeaa2c4795ee806c0667bd77b2

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index a360b24ed320..debfc1389cb3 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -3029,14 +3029,23 @@ static void duplicateIXtree(struct super_block *sb, s64 blkno,
  *
  * RETURN VALUES:
  *	0	- success
- *	-ENOMEM	- insufficient memory
+ *	-EINVAL	- unexpected inode type
  */
 static int copy_from_dinode(struct dinode * dip, struct inode *ip)
 {
 	struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 	struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
+	int fileset = le32_to_cpu(dip->di_fileset);
+
+	switch (fileset) {
+	case AGGR_RESERVED_I: case AGGREGATE_I: case BMAP_I:
+	case LOG_I: case BADBLOCK_I: case FILESYSTEM_I:
+		break;
+	default:
+		return -EINVAL;
+	}
 
-	jfs_ip->fileset = le32_to_cpu(dip->di_fileset);
+	jfs_ip->fileset = fileset;
 	jfs_ip->mode2 = le32_to_cpu(dip->di_mode);
 	jfs_set_inode_flags(ip);
 
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index d68a4e6ac345..845abc598334 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1467,8 +1467,14 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, unsig
 		ip = ERR_PTR(rc);
 	} else {
 		ip = jfs_iget(dip->i_sb, inum);
-		if (IS_ERR(ip))
-			jfs_err("jfs_lookup: iget failed on inum %d", (uint)inum);
+		if (IS_ERR(ip)) {
+			long err = PTR_ERR(ip);
+
+			jfs_err("%s: iget failed on inum %d with error"
+				" %ld, consider running 'jfs_fsck -f /dev/%s'",
+				__func__, (uint)inum, err, dip->i_sb->s_id);
+			return ERR_PTR(err);
+		}
 	}
 
 	return d_splice_alias(ip, dentry);
-- 
2.47.0