fscrypt: adjust logging for in-creation inodes

Now that a fscrypt_info may be set up for inodes that are currently
being created and haven't yet had an inode number assigned, avoid
logging confusing messages about "inode 0".

Acked-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20200917041136.178600-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

fs/crypto/crypto.c

@@ -343,9 +343,11 @@ void fscrypt_msg(const struct inode *inode, const char *level,
 	va_start(args, fmt);
 	vaf.fmt = fmt;
 	vaf.va = &args;
-	if (inode)
+	if (inode && inode->i_ino)
 		printk("%sfscrypt (%s, inode %lu): %pV\n",
 		       level, inode->i_sb->s_id, inode->i_ino, &vaf);
+	else if (inode)
+		printk("%sfscrypt (%s): %pV\n", level, inode->i_sb->s_id, &vaf);
 	else
 		printk("%sfscrypt: %pV\n", level, &vaf);
 	va_end(args);

fs/crypto/keyring.c

@@ -817,6 +817,7 @@ static int check_for_busy_inodes(struct super_block *sb,
 	struct list_head *pos;
 	size_t busy_count = 0;
 	unsigned long ino;
+	char ino_str[50] = "";
 
 	spin_lock(&mk->mk_decrypted_inodes_lock);
 
@@ -838,11 +839,15 @@ static int check_for_busy_inodes(struct super_block *sb,
 	}
 	spin_unlock(&mk->mk_decrypted_inodes_lock);
 
+	/* If the inode is currently being created, ino may still be 0. */
+	if (ino)
+		snprintf(ino_str, sizeof(ino_str), ", including ino %lu", ino);
+
 	fscrypt_warn(NULL,
-		     "%s: %zu inode(s) still busy after removing key with %s %*phN, including ino %lu",
+		     "%s: %zu inode(s) still busy after removing key with %s %*phN%s",
 		     sb->s_id, busy_count, master_key_spec_type(&mk->mk_spec),
 		     master_key_spec_len(&mk->mk_spec), (u8 *)&mk->mk_spec.u,
-		     ino);
+		     ino_str);
 	return -EBUSY;
 }