bfs: extra sanity checking and static inode bitmap
Strengthen validation of BFS superblock against corruption. Make
in-core inode bitmap static part of superblock info structure. Print a
warning when mounting a BFS filesystem created with "-N 512" option as
only 510 files can be created in the root directory. Make the kernel
messages more uniform. Update the 'prefix' passed to bfs_dump_imap() to
match the current naming of operations. White space and comments
cleanup.
Link: http://lkml.kernel.org/r/CAK+_RLkFZMduoQF36wZFd3zLi-6ZutWKsydjeHFNdtRvZZEb4w@mail.gmail.com
Signed-off-by: Tigran Aivazian <aivazian.tigran@gmail.com>
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/bfs/bfs.h b/fs/bfs/bfs.h
index 67aef3b..606f937 100644
--- a/fs/bfs/bfs.h
+++ b/fs/bfs/bfs.h
@@ -1,13 +1,20 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* fs/bfs/bfs.h
- * Copyright (C) 1999 Tigran Aivazian <tigran@veritas.com>
+ * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
*/
#ifndef _FS_BFS_BFS_H
#define _FS_BFS_BFS_H
#include <linux/bfs_fs.h>
+/* In theory BFS supports up to 512 inodes, numbered from 2 (for /) up to 513 inclusive.
+ In actual fact, attempting to create the 512th inode (i.e. inode No. 513 or file No. 511)
+ will fail with ENOSPC in bfs_add_entry(): the root directory cannot contain so many entries, counting '..'.
+ So, mkfs.bfs(8) should really limit its -N option to 511 and not 512. For now, we just print a warning
+ if a filesystem is mounted with such "impossible to fill up" number of inodes */
+#define BFS_MAX_LASTI 513
+
/*
* BFS file system in-core superblock info
*/
@@ -17,7 +24,7 @@ struct bfs_sb_info {
unsigned long si_freei;
unsigned long si_lf_eblk;
unsigned long si_lasti;
- unsigned long *si_imap;
+ DECLARE_BITMAP(si_imap, BFS_MAX_LASTI+1);
struct mutex bfs_lock;
};