[PATCH 4.19.6] BFS: static inode bitmap and extra sanity checking
From: Tigran Aivazian
Date: Sun Dec 02 2018 - 13:57:41 EST
Hello,
Please find a patch attached which contains the following changes:
1. Simplifies inode bitmap allocation by making it static.
2. Supersedes the changes to BFS that went into 4.19.6 with stronger checking.
3. Other changes are trivial (like whitespace cleanup, warning messages etc).
Fully tested under 4.19.6 kernel.
Kind regards,
Tigran
From: Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
Subject: [PATCH 4.19.6] BFS: static inode bitmap and extra sanity checking
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.
Signed-off-by: Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/bfs/bfs.h | 11 ++++++-
fs/bfs/dir.c | 4 +-
fs/bfs/file.c | 2 -
fs/bfs/inode.c | 65 ++++++++++++++++++--------------------------
include/uapi/linux/bfs_fs.h | 2 -
5 files changed, 41 insertions(+), 43 deletions(-)
--- include/uapi/linux/bfs_fs.h.0 2018-11-13 19:19:55.941267342 +0000
+++ include/uapi/linux/bfs_fs.h 2018-11-13 19:20:24.101182357 +0000
@@ -1,7 +1,7 @@
/* 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@xxxxxxxxxxx>
+ * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
*/
#ifndef _LINUX_BFS_FS_H
--- fs/bfs/bfs.h.0 2018-11-13 19:20:40.151161044 +0000
+++ fs/bfs/bfs.h 2018-11-13 19:21:32.929740656 +0000
@@ -1,13 +1,20 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* fs/bfs/bfs.h
- * Copyright (C) 1999 Tigran Aivazian <tigran@xxxxxxxxxxx>
+ * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
*/
#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 @@
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.0 2018-11-13 19:29:32.361259272 +0000
+++ fs/bfs/dir.c 2018-11-13 19:30:01.380683858 +0000
@@ -2,8 +2,8 @@
/*
* fs/bfs/dir.c
* BFS directory operations.
- * Copyright (C) 1999,2000 Tigran Aivazian <tigran@xxxxxxxxxxx>
- * Made endianness-clean by Andrew Stribblehill <ads@xxxxxxxxxx> 2005
+ * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
+ * Made endianness-clean by Andrew Stribblehill <ads@xxxxxxxxxx> 2005
*/
#include <linux/time.h>
--- fs/bfs/file.c.0 2018-11-13 19:30:11.760489957 +0000
+++ fs/bfs/file.c 2018-11-13 19:30:27.020214845 +0000
@@ -2,7 +2,7 @@
/*
* fs/bfs/file.c
* BFS file operations.
- * Copyright (C) 1999,2000 Tigran Aivazian <tigran@xxxxxxxxxxx>
+ * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
*
* Make the file block allocation algorithm understand the size
* of the underlying block device.
--- fs/bfs/inode.c.0 2018-12-02 18:25:00.452000686 +0000
+++ fs/bfs/inode.c 2018-12-02 18:32:21.751786701 +0000
@@ -1,10 +1,9 @@
/*
* fs/bfs/inode.c
* BFS superblock and inode operations.
- * Copyright (C) 1999-2006 Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
+ * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@xxxxxxxxx>
* From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
- *
- * Made endianness-clean by Andrew Stribblehill <ads@xxxxxxxxxx>, 2005.
+ * Made endianness-clean by Andrew Stribblehill <ads@xxxxxxxxxx>, 2005.
*/
#include <linux/module.h>
@@ -118,12 +117,12 @@
{
struct bfs_sb_info *info = BFS_SB(inode->i_sb);
unsigned int ino = (u16)inode->i_ino;
- unsigned long i_sblock;
+ unsigned long i_sblock;
struct bfs_inode *di;
struct buffer_head *bh;
int err = 0;
- dprintf("ino=%08x\n", ino);
+ dprintf("ino=%08x\n", ino);
di = find_inode(inode->i_sb, ino, &bh);
if (IS_ERR(di))
@@ -144,7 +143,7 @@
di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
- i_sblock = BFS_I(inode)->i_sblock;
+ i_sblock = BFS_I(inode)->i_sblock;
di->i_sblock = cpu_to_le32(i_sblock);
di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
@@ -188,13 +187,13 @@
mark_buffer_dirty(bh);
brelse(bh);
- if (bi->i_dsk_ino) {
+ if (bi->i_dsk_ino) {
if (bi->i_sblock)
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);
+ }
/*
* If this was the last file, make the previous block
@@ -214,7 +213,6 @@
return;
mutex_destroy(&info->bfs_lock);
- kfree(info->si_imap);
kfree(info);
s->s_fs_info = NULL;
}
@@ -311,8 +309,7 @@
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 @@
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 @@
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 @@
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 @@
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 @@
(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 @@
}
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:
@@ -482,7 +473,7 @@
int err = init_inodecache();
if (err)
goto out1;
- err = register_filesystem(&bfs_fs_type);
+ err = register_filesystem(&bfs_fs_type);
if (err)
goto out;
return 0;