- 根目录:
- fs
- qnx4
- inode.c
/*
* QNX4 file system, Linux implementation.
*
* Version : 0.2.1
*
* Using parts of the xiafs filesystem.
*
* History :
*
* 01-06-1998 by Richard Frowijn : first release.
* 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
* 30-06-1998 by Frank Denis : first step to write inodes.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/highuid.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include "qnx4.h"
#define QNX4_VERSION 4
#define QNX4_BMNAME ".bitmap"
static const struct super_operations qnx4_sops;
static void qnx4_put_super(struct super_block *sb);
static struct inode *qnx4_alloc_inode(struct super_block *sb);
static void qnx4_destroy_inode(struct inode *inode);
static int qnx4_remount(struct super_block *sb, int *flags, char *data);
static int qnx4_statfs(struct dentry *, struct kstatfs *);
static const struct super_operations qnx4_sops =
{
.alloc_inode = qnx4_alloc_inode,
.destroy_inode = qnx4_destroy_inode,
.put_super = qnx4_put_super,
.statfs = qnx4_statfs,
.remount_fs = qnx4_remount,
};
static int qnx4_remount(struct super_block *sb, int *flags, char *data)
{
struct qnx4_sb_info *qs;
sync_filesystem(sb);
qs = qnx4_sb(sb);
qs->Version = QNX4_VERSION;
*flags |= MS_RDONLY;
return 0;
}
static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
{
unsigned long phys;
QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
phys = qnx4_block_map( inode, iblock );
if ( phys ) {
// logical block is before EOF
map_bh(bh, inode->i_sb, phys);
}
return 0;
}
static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset)
{
u32 size = le32_to_cpu(extent->xtnt_size);
if (*offset < size)
return le32_to_cpu(extent->xtnt_blk) + *offset - 1;
*offset -= size;
return 0;
}
unsigned long qnx4_block_map( struct inode *inode, long iblock )
{
int ix;
long i_xblk;
struct buffer_head *bh = NULL;
struct qnx4_xblk *xblk = NULL;
struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
u32 offset = iblock;
u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset);
if (block) {
// iblock is in the first extent. This is easy.
} else {
// iblock is beyond first extent. We have to follow the extent chain.
i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
ix = 0;
while ( --nxtnt > 0 ) {
if ( ix == 0 ) {
// read next xtnt block.
bh = sb_bread(inode->i_sb, i_xblk - 1);
if ( !bh ) {
QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
return -EIO;
}
xblk = (struct qnx4_xblk*)bh->b_data;
if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
return -EIO;
}
}
block = try_extent(&xblk->xblk_xtnts[ix], &offset);
if (block) {
// got it!
break;
}
if ( ++ix >= xblk->xblk_num_xtnts ) {
i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
ix = 0;
brelse( bh );
bh = NULL;
}
}
if ( bh )
brelse( bh );
}
QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
return block;
}
static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = sb->s_magic;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
buf->f_bfree = qnx4_count_free_blocks(sb);
buf->f_bavail = buf->f_bfree;
buf->f_namelen = QNX4_NAME_MAX;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
return 0;
}
/*
* Check the root directory of the filesystem to make sure
* it really _is_ a qnx4 filesystem, and to check the size
* of the directory entry.
*/
static const char *qnx4_checkroot(struct super_block *sb)
{
struct buffer_head *bh;
struct qnx4_inode_entry *rootdir;
int rd, rl;
int i, j;
if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/')
return "no qnx4 filesystem (no root dir).";
QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
for (j = 0; j < rl; j++) {
bh = sb_bread(sb, rd + j); /* root dir, first block */
if (bh == NULL)
return "unable to read root entry.";
rootdir = (struct qnx4_inode_entry *) bh->b_data;
for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {
QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));
if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)
continue;
qnx4_sb(sb)->BitMap = kmemdup(rootdir,
sizeof(struct qnx4_inode_entry),
GFP_KERNEL);
brelse(bh);
if (!qnx4_sb(sb)->BitMap)
return "not enough memory for bitmap inode";
/* keep bitmap inode known */
return NULL;
}
brelse(bh);
}
return "bitmap file not found.";
}
static int qnx4_fill_super(struct super_block *s, void *data, int silent)
{
struct buffer_head *bh;
struct inode *root;
const char *errmsg;
struct qnx4_sb_info *qs;
int ret = -EINVAL;
qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
if (!qs)
return -ENOMEM;
s->s_fs_info = qs;
sb_set_blocksize(s, QNX4_BLOCK_SIZE);
/* Check the superblock signature. Since the qnx4 code is
dangerous, we should leave as quickly as possible
if we don't belong here... */
bh = sb_bread(s, 1);
if (!bh) {
printk(KERN_ERR "qnx4: unable to read the superblock\n");
goto outnobh;
}
if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
if (!silent)
printk(KERN_ERR "qnx4: wrong fsid in superblock.\n");
goto out;
}
s->s_op = &qnx4_sops;
s->s_magic = QNX4_SUPER_MAGIC;
s->s_flags |= MS_RDONLY; /* Yup, read-only yet */
qnx4_sb(s)->sb_buf = bh;
qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
/* check before allocating dentries, inodes, .. */
errmsg = qnx4_checkroot(s);
if (errmsg != NULL) {
if (!silent)
printk(KERN_ERR "qnx4: %s\n", errmsg);
goto out;
}
/* does root not have inode number QNX4_ROOT_INO ?? */
root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
if (IS_ERR(root)) {
printk(KERN_ERR "qnx4: get inode failed\n");
ret = PTR_ERR(root);
goto outb;
}
ret = -ENOMEM;
s->s_root = d_make_root(root);
if (s->s_root == NULL)
goto outb;
brelse(bh);
return 0;
outb:
kfree(qs->BitMap);
out:
brelse(bh);
outnobh:
kfree(qs);
s->s_fs_info = NULL;
return ret;
}
static void qnx4_put_super(struct super_block *sb)
{
struct qnx4_sb_info *qs = qnx4_sb(sb);
kfree( qs->BitMap );
kfree( qs );
sb->s_fs_info = NULL;
return;
}
static int qnx4_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page,qnx4_get_block);
}
static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,qnx4_get_block);
}
static const struct address_space_operations qnx4_aops = {
.readpage = qnx4_readpage,
.bmap = qnx4_bmap
};
struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
{
struct buffer_head *bh;
struct qnx4_inode_entry *raw_inode;
int block;
struct qnx4_inode_entry *qnx4_inode;
struct inode *inode;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
qnx4_inode = qnx4_raw_inode(inode);
inode->i_mode = 0;
QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));
if (!ino) {
printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
"out of range\n",
sb->s_id, ino);
iget_failed(inode);
return ERR_PTR(-EIO);
}
block = ino / QNX4_INODES_PER_BLOCK;
if (!(bh = sb_bread(sb, block))) {
printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "
"%s\n", sb->s_id);
iget_failed(inode);
return ERR_PTR(-EIO);
}
raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
(ino % QNX4_INODES_PER_BLOCK);
inode->i_mode = le16_to_cpu(raw_inode->di_mode);
i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid));
i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid));
set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));
inode->i_size = le32_to_cpu(raw_inode->di_size);
inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime);
inode->i_mtime.tv_nsec = 0;
inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime);
inode->i_atime.tv_nsec = 0;
inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime);
inode->i_ctime.tv_nsec = 0;
inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
if (S_ISREG(inode->i_mode)) {
inode->i_fop = &generic_ro_fops;
inode->i_mapping->a_ops = &qnx4_aops;
qnx4_i(inode)->mmu_private = inode->i_size;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &qnx4_dir_inode_operations;
inode->i_fop = &qnx4_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &qnx4_aops;
qnx4_i(inode)->mmu_private = inode->i_size;
} else {
printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
ino, sb->s_id);
iget_failed(inode);
brelse(bh);
return ERR_PTR(-EIO);
}
brelse(bh);
unlock_new_inode(inode);
return inode;
}
static struct kmem_cache *qnx4_inode_cachep;
static struct inode *qnx4_alloc_inode(struct super_block *sb)
{
struct qnx4_inode_info *ei;
ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
return &ei->vfs_inode;
}
static void qnx4_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
}
static void qnx4_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, qnx4_i_callback);
}
static void init_once(void *foo)
{
struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
inode_init_once(&ei->vfs_inode);
}
static int init_inodecache(void)
{
qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
sizeof(struct qnx4_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (qnx4_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(qnx4_inode_cachep);
}
static struct dentry *qnx4_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
}
static struct file_system_type qnx4_fs_type = {
.owner = THIS_MODULE,
.name = "qnx4",
.mount = qnx4_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("qnx4");
static int __init init_qnx4_fs(void)
{
int err;
err = init_inodecache();
if (err)
return err;
err = register_filesystem(&qnx4_fs_type);
if (err) {
destroy_inodecache();
return err;
}
printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");
return 0;
}
static void __exit exit_qnx4_fs(void)
{
unregister_filesystem(&qnx4_fs_type);
destroy_inodecache();
}
module_init(init_qnx4_fs)
module_exit(exit_qnx4_fs)
MODULE_LICENSE("GPL");