Commit d1877155 authored by Tigran Aivazian's avatar Tigran Aivazian Committed by Linus Torvalds
Browse files

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: default avatarTigran Aivazian <aivazian.tigran@gmail.com>
Reported-by: default avatarTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 655c16a8

fs/bfs/bfs.h

+9 −2
Original line number Diff line number Diff line 
/* 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;

};

fs/bfs/dir.c

+2 −2
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
/*

 *	fs/bfs/dir.c

 *	BFS directory operations.

 *	Copyright (C) 1999,2000  Tigran Aivazian <tigran@veritas.com>

 *	Copyright (C) 1999-2018  Tigran Aivazian <aivazian.tigran@gmail.com>

 *  Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005

 */

fs/bfs/file.c

+1 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
/*

 *	fs/bfs/file.c

 *	BFS file operations.

 *	Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>

 *	Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>

 *

 *	Make the file block allocation algorithm understand the size

 *	of the underlying block device.

fs/bfs/inode.c

+28 −37
Original line number Diff line number Diff line 
/*

 *	fs/bfs/inode.c

 *	BFS superblock and inode operations.

 *	Copyright (C) 1999-2006 Tigran Aivazian <aivazian.tigran@gmail.com>

 *	Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>

 *	From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.

 *

 *	Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.

 */
@@ -193,7 +192,7 @@ static void bfs_evict_inode(struct inode *inode) 
			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;

		info->si_freei++;

		clear_bit(ino, info->si_imap);

		bfs_dump_imap("delete_inode", s);

		bfs_dump_imap("evict_inode", s);

	}



	/*
@@ -214,7 +213,6 @@ static void bfs_put_super(struct super_block *s) 
		return;



	mutex_destroy(&info->bfs_lock);

	kfree(info->si_imap);

	kfree(info);

	s->s_fs_info = NULL;

}
@@ -311,8 +309,7 @@ void bfs_dump_imap(const char *prefix, struct super_block *s) 
		else

			strcat(tmpbuf, "0");

	}

	printf("BFS-fs: %s: lasti=%08lx <%s>\n",

				prefix, BFS_SB(s)->si_lasti, tmpbuf);

	printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);

	free_page((unsigned long)tmpbuf);

#endif

}
@@ -322,7 +319,7 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) 
	struct buffer_head *bh, *sbh;

	struct bfs_super_block *bfs_sb;

	struct inode *inode;

	unsigned i, imap_len;

	unsigned i;

	struct bfs_sb_info *info;

	int ret = -EINVAL;

	unsigned long i_sblock, i_eblock, i_eoff, s_size;
@@ -341,8 +338,7 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) 
	bfs_sb = (struct bfs_super_block *)sbh->b_data;

	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {

		if (!silent)

			printf("No BFS filesystem on %s (magic=%08x)\n", 

				s->s_id,  le32_to_cpu(bfs_sb->s_magic));

			printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));

		goto out1;

	}

	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
@@ -351,18 +347,16 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) 
	s->s_magic = BFS_MAGIC;



	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||

	    le32_to_cpu(bfs_sb->s_start) < BFS_BSIZE) {

		printf("Superblock is corrupted\n");

	    le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {

		printf("Superblock is corrupted on %s\n", s->s_id);

		goto out1;

	}



	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /

					sizeof(struct bfs_inode)

					+ BFS_ROOT_INO - 1;

	imap_len = (info->si_lasti / 8) + 1;

	info->si_imap = kzalloc(imap_len, GFP_KERNEL | __GFP_NOWARN);

	if (!info->si_imap) {

		printf("Cannot allocate %u bytes\n", imap_len);

	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;

	if (info->si_lasti == BFS_MAX_LASTI)

		printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);

	else if (info->si_lasti > BFS_MAX_LASTI) {

		printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);

		goto out1;

	}

	for (i = 0; i < BFS_ROOT_INO; i++)
@@ -372,26 +366,25 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) 
	inode = bfs_iget(s, BFS_ROOT_INO);

	if (IS_ERR(inode)) {

		ret = PTR_ERR(inode);

		goto out2;

		goto out1;

	}

	s->s_root = d_make_root(inode);

	if (!s->s_root) {

		ret = -ENOMEM;

		goto out2;

		goto out1;

	}



	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;

	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1

			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;

	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;

	info->si_freei = 0;

	info->si_lf_eblk = 0;



	/* can we read the last block? */

	bh = sb_bread(s, info->si_blocks - 1);

	if (!bh) {

		printf("Last block not available: %lu\n", info->si_blocks - 1);

		printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);

		ret = -EIO;

		goto out3;

		goto out2;

	}

	brelse(bh);
@@ -425,11 +418,11 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) 
			(i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||

			i_sblock * BFS_BSIZE > i_eoff) {



			printf("Inode 0x%08x corrupted\n", i);

			printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);



			brelse(bh);

			ret = -EIO;

			goto out3;

			goto out2;

		}



		if (!di->i_ino) {
@@ -445,14 +438,12 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) 
	}

	brelse(bh);

	brelse(sbh);

	bfs_dump_imap("read_super", s);

	bfs_dump_imap("fill_super", s);

	return 0;



out3:

out2:

	dput(s->s_root);

	s->s_root = NULL;

out2:

	kfree(info->si_imap);

out1:

	brelse(sbh);

out:

include/uapi/linux/bfs_fs.h

+1 −1
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */

/*

 *	include/linux/bfs_fs.h - BFS data structures on disk.

 *	Copyright (C) 1999 Tigran Aivazian <tigran@veritas.com>

 *	Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>

 */



#ifndef _LINUX_BFS_FS_H

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