Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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 struct inode *qnx4_alloc_inode(struct super_block *sb);
static void qnx4_free_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,
<------>.free_inode	= qnx4_free_inode,
<------>.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 |= SB_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    = u64_to_fsid(id);
 
<------>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 qnx4_super_block *s)
{
<------>struct buffer_head *bh;
<------>struct qnx4_inode_entry *rootdir;
<------>int rd, rl;
<------>int i, j;
 
<------>if (s->RootDir.di_fname[0] != '/' || s->RootDir.di_fname[1] != '\0')
<------><------>return "no qnx4 filesystem (no root dir).";
<------>QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));
<------>rd = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_blk) - 1;
<------>rl = le32_to_cpu(s->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;
 
<------>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);
 
<------>s->s_op = &qnx4_sops;
<------>s->s_magic = QNX4_SUPER_MAGIC;
<------>s->s_flags |= SB_RDONLY;	/* Yup, read-only yet */
<------>s->s_time_min = 0;
<------>s->s_time_max = U32_MAX;
 
<------>/* 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");
<------><------>return -EINVAL;
<------>}
 
 	/* check before allocating dentries, inodes, .. */
<------>errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data);
<------>brelse(bh);
<------>if (errmsg != NULL) {
 		if (!silent)
<------><------><------>printk(KERN_ERR "qnx4: %s\n", errmsg);
<------><------>return -EINVAL;
<------>}
 
 	/* 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");
<------><------>return PTR_ERR(root);
 	}
 
 	s->s_root = d_make_root(root);
 	if (s->s_root == NULL)
 		return -ENOMEM;
 
<------>return 0;
}
 
static void qnx4_kill_sb(struct super_block *sb)
{
<------>struct qnx4_sb_info *qs = qnx4_sb(sb);
<------>kill_block_super(sb);
<------>if (qs) {
<------><------>kfree(qs->BitMap);
<------><------>kfree(qs);
<------>}
}
 
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_nohighmem(inode);
<------><------>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_free_inode(struct inode *inode)
{
<------>kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
}
 
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|SLAB_ACCOUNT),
<------><------><------><------><------>     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	= qnx4_kill_sb,
<------>.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");
MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);