linux/fs/bfs/inode.c
Dmitri Vorobiev f433dc5634 Fixes to the BFS filesystem driver
I found a few bugs in the BFS driver.  Detailed description of the bugs as
well as the steps to reproduce the errors are given in the kernel bugzilla.
 Please follow these links for more information:

http://bugzilla.kernel.org/show_bug.cgi?id=9363
http://bugzilla.kernel.org/show_bug.cgi?id=9364
http://bugzilla.kernel.org/show_bug.cgi?id=9365
http://bugzilla.kernel.org/show_bug.cgi?id=9366

This patch fixes the bugs described above.  Besides, the patch introduces
coding style changes to make the BFS driver conform to the requirements
specified for Linux kernel code.  Finally, I made a few cosmetic changes
such as removal of trivial debug output.

Also, the patch removes the fields `si_lf_ioff' and `si_lf_sblk' of the
in-core superblock structure.  These fields are initialized but never
actually used.

If you are wondering why I need BFS, here is the answer: I am using this
driver in the context of Linux kernel classes I am teaching in the Moscow
State University and in the International Institute of Information
Technology in Pune, India.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Cc: Tigran Aivazian <tigran@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:40 -08:00

446 lines
11 KiB
C

/*
* fs/bfs/inode.c
* BFS superblock and inode operations.
* Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
* From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
*
* Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <asm/uaccess.h>
#include "bfs.h"
MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
MODULE_LICENSE("GPL");
#undef DEBUG
#ifdef DEBUG
#define dprintf(x...) printf(x)
#else
#define dprintf(x...)
#endif
void dump_imap(const char *prefix, struct super_block *s);
static void bfs_read_inode(struct inode *inode)
{
unsigned long ino = inode->i_ino;
struct bfs_inode *di;
struct buffer_head *bh;
int block, off;
if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
make_bad_inode(inode);
return;
}
block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
bh = sb_bread(inode->i_sb, block);
if (!bh) {
printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
ino);
make_bad_inode(inode);
return;
}
off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
di = (struct bfs_inode *)bh->b_data + off;
inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
inode->i_mode |= S_IFDIR;
inode->i_op = &bfs_dir_inops;
inode->i_fop = &bfs_dir_operations;
} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
inode->i_mode |= S_IFREG;
inode->i_op = &bfs_file_inops;
inode->i_fop = &bfs_file_operations;
inode->i_mapping->a_ops = &bfs_aops;
}
BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
inode->i_uid = le32_to_cpu(di->i_uid);
inode->i_gid = le32_to_cpu(di->i_gid);
inode->i_nlink = le32_to_cpu(di->i_nlink);
inode->i_size = BFS_FILESIZE(di);
inode->i_blocks = BFS_FILEBLOCKS(di);
inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
inode->i_atime.tv_nsec = 0;
inode->i_mtime.tv_nsec = 0;
inode->i_ctime.tv_nsec = 0;
brelse(bh);
}
static int bfs_write_inode(struct inode *inode, int unused)
{
unsigned int ino = (u16)inode->i_ino;
unsigned long i_sblock;
struct bfs_inode *di;
struct buffer_head *bh;
int block, off;
dprintf("ino=%08x\n", ino);
if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
return -EIO;
}
lock_kernel();
block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
bh = sb_bread(inode->i_sb, block);
if (!bh) {
printf("Unable to read inode %s:%08x\n",
inode->i_sb->s_id, ino);
unlock_kernel();
return -EIO;
}
off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
di = (struct bfs_inode *)bh->b_data + off;
if (ino == BFS_ROOT_INO)
di->i_vtype = cpu_to_le32(BFS_VDIR);
else
di->i_vtype = cpu_to_le32(BFS_VREG);
di->i_ino = cpu_to_le16(ino);
di->i_mode = cpu_to_le32(inode->i_mode);
di->i_uid = cpu_to_le32(inode->i_uid);
di->i_gid = cpu_to_le32(inode->i_gid);
di->i_nlink = cpu_to_le32(inode->i_nlink);
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;
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);
mark_buffer_dirty(bh);
brelse(bh);
unlock_kernel();
return 0;
}
static void bfs_delete_inode(struct inode *inode)
{
unsigned long ino = inode->i_ino;
struct bfs_inode *di;
struct buffer_head *bh;
int block, off;
struct super_block *s = inode->i_sb;
struct bfs_sb_info *info = BFS_SB(s);
struct bfs_inode_info *bi = BFS_I(inode);
dprintf("ino=%08lx\n", ino);
truncate_inode_pages(&inode->i_data, 0);
if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
printf("invalid ino=%08lx\n", ino);
return;
}
inode->i_size = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
lock_kernel();
mark_inode_dirty(inode);
block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
bh = sb_bread(s, block);
if (!bh) {
printf("Unable to read inode %s:%08lx\n",
inode->i_sb->s_id, ino);
unlock_kernel();
return;
}
off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
di = (struct bfs_inode *)bh->b_data + off;
memset((void *)di, 0, sizeof(struct bfs_inode));
mark_buffer_dirty(bh);
brelse(bh);
if (bi->i_dsk_ino) {
info->si_freeb += BFS_FILEBLOCKS(bi);
info->si_freei++;
clear_bit(ino, info->si_imap);
dump_imap("delete_inode", s);
}
/*
* If this was the last file, make the previous block
* "last block of the last file" even if there is no
* real file there, saves us 1 gap.
*/
if (info->si_lf_eblk == bi->i_eblock) {
info->si_lf_eblk = bi->i_sblock - 1;
mark_buffer_dirty(info->si_sbh);
}
unlock_kernel();
clear_inode(inode);
}
static void bfs_put_super(struct super_block *s)
{
struct bfs_sb_info *info = BFS_SB(s);
brelse(info->si_sbh);
kfree(info->si_imap);
kfree(info);
s->s_fs_info = NULL;
}
static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *s = dentry->d_sb;
struct bfs_sb_info *info = BFS_SB(s);
u64 id = huge_encode_dev(s->s_bdev->bd_dev);
buf->f_type = BFS_MAGIC;
buf->f_bsize = s->s_blocksize;
buf->f_blocks = info->si_blocks;
buf->f_bfree = buf->f_bavail = info->si_freeb;
buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
buf->f_ffree = info->si_freei;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen = BFS_NAMELEN;
return 0;
}
static void bfs_write_super(struct super_block *s)
{
lock_kernel();
if (!(s->s_flags & MS_RDONLY))
mark_buffer_dirty(BFS_SB(s)->si_sbh);
s->s_dirt = 0;
unlock_kernel();
}
static struct kmem_cache *bfs_inode_cachep;
static struct inode *bfs_alloc_inode(struct super_block *sb)
{
struct bfs_inode_info *bi;
bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
if (!bi)
return NULL;
return &bi->vfs_inode;
}
static void bfs_destroy_inode(struct inode *inode)
{
kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
}
static void init_once(struct kmem_cache *cachep, void *foo)
{
struct bfs_inode_info *bi = foo;
inode_init_once(&bi->vfs_inode);
}
static int init_inodecache(void)
{
bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
sizeof(struct bfs_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (bfs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
kmem_cache_destroy(bfs_inode_cachep);
}
static const struct super_operations bfs_sops = {
.alloc_inode = bfs_alloc_inode,
.destroy_inode = bfs_destroy_inode,
.read_inode = bfs_read_inode,
.write_inode = bfs_write_inode,
.delete_inode = bfs_delete_inode,
.put_super = bfs_put_super,
.write_super = bfs_write_super,
.statfs = bfs_statfs,
};
void dump_imap(const char *prefix, struct super_block *s)
{
#ifdef DEBUG
int i;
char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
if (!tmpbuf)
return;
for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
if (i > PAGE_SIZE - 100) break;
if (test_bit(i, BFS_SB(s)->si_imap))
strcat(tmpbuf, "1");
else
strcat(tmpbuf, "0");
}
printf("BFS-fs: %s: lasti=%08lx <%s>\n",
prefix, BFS_SB(s)->si_lasti, tmpbuf);
free_page((unsigned long)tmpbuf);
#endif
}
static int bfs_fill_super(struct super_block *s, void *data, int silent)
{
struct buffer_head *bh;
struct bfs_super_block *bfs_sb;
struct inode *inode;
unsigned i, imap_len;
struct bfs_sb_info *info;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
s->s_fs_info = info;
sb_set_blocksize(s, BFS_BSIZE);
bh = sb_bread(s, 0);
if(!bh)
goto out;
bfs_sb = (struct bfs_super_block *)bh->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));
goto out;
}
if (BFS_UNCLEAN(bfs_sb, s) && !silent)
printf("%s is unclean, continuing\n", s->s_id);
s->s_magic = BFS_MAGIC;
info->si_sbh = bh;
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);
if (!info->si_imap)
goto out;
for (i = 0; i < BFS_ROOT_INO; i++)
set_bit(i, info->si_imap);
s->s_op = &bfs_sops;
inode = iget(s, BFS_ROOT_INO);
if (!inode) {
kfree(info->si_imap);
goto out;
}
s->s_root = d_alloc_root(inode);
if (!s->s_root) {
iput(inode);
kfree(info->si_imap);
goto out;
}
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_freei = 0;
info->si_lf_eblk = 0;
bh = NULL;
for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
struct bfs_inode *di;
int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
unsigned long sblock, eblock;
if (!off) {
brelse(bh);
bh = sb_bread(s, block);
}
if (!bh)
continue;
di = (struct bfs_inode *)bh->b_data + off;
if (!di->i_ino) {
info->si_freei++;
continue;
}
set_bit(i, info->si_imap);
info->si_freeb -= BFS_FILEBLOCKS(di);
sblock = le32_to_cpu(di->i_sblock);
eblock = le32_to_cpu(di->i_eblock);
if (eblock > info->si_lf_eblk)
info->si_lf_eblk = eblock;
}
brelse(bh);
if (!(s->s_flags & MS_RDONLY)) {
mark_buffer_dirty(info->si_sbh);
s->s_dirt = 1;
}
dump_imap("read_super", s);
return 0;
out:
brelse(bh);
kfree(info);
s->s_fs_info = NULL;
return -EINVAL;
}
static int bfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
}
static struct file_system_type bfs_fs_type = {
.owner = THIS_MODULE,
.name = "bfs",
.get_sb = bfs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_bfs_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&bfs_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_bfs_fs(void)
{
unregister_filesystem(&bfs_fs_type);
destroy_inodecache();
}
module_init(init_bfs_fs)
module_exit(exit_bfs_fs)