/* * 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; qs = qnx4_sb(sb); qs->Version = QNX4_VERSION; *flags |= MS_RDONLY; return 0; } static struct buffer_head *qnx4_getblk(struct inode *inode, int nr, int create) { struct buffer_head *result = NULL; if ( nr >= 0 ) nr = qnx4_block_map( inode, nr ); if (nr) { result = sb_getblk(inode->i_sb, nr); return result; } return NULL; } struct buffer_head *qnx4_bread(struct inode *inode, int block, int create) { struct buffer_head *bh; bh = qnx4_getblk(inode, block, create); if (!bh || buffer_uptodate(bh)) { return bh; } ll_rw_block(READ, 1, &bh); wait_on_buffer(bh); if (buffer_uptodate(bh)) { return bh; } brelse(bh); return NULL; } 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; } unsigned long qnx4_block_map( struct inode *inode, long iblock ) { int ix; long offset, i_xblk; unsigned long block = 0; 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); if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) { // iblock is in the first extent. This is easy. block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1; } else { // iblock is beyond first extent. We have to follow the extent chain. i_xblk = le32_to_cpu(qnx4_inode->di_xblk); offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size); 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; } } if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) { // got it! block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1; break; } offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size); 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; int found = 0; if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') { return "no qnx4 filesystem (no root dir)."; } else { 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."; } for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) { rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE); if (rootdir->di_fname != NULL) { QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname)); if (!strcmp(rootdir->di_fname, QNX4_BMNAME)) { found = 1; qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL ); if (!qnx4_sb(sb)->BitMap) { brelse (bh); return "not enough memory for bitmap inode"; } memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) ); /* keep bitmap inode known */ break; } } } brelse(bh); if (found != 0) { break; } } if (found == 0) { return "bitmap file not found."; } } return NULL; } 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 out; } ret = -ENOMEM; s->s_root = d_alloc_root(root); if (s->s_root == NULL) goto outi; brelse(bh); return 0; outi: iput(root); 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_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page,qnx4_get_block, wbc); } static int qnx4_readpage(struct file *file, struct page *page) { return block_read_full_page(page,qnx4_get_block); } static int qnx4_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host); int ret; *pagep = NULL; ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, qnx4_get_block, &qnx4_inode->mmu_private); if (unlikely(ret)) { loff_t isize = mapping->host->i_size; if (pos + len > isize) vmtruncate(mapping->host, isize); } return ret; } 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, .writepage = qnx4_writepage, .sync_page = block_sync_page, .write_begin = qnx4_write_begin, .write_end = generic_write_end, .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); inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid); inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid); inode->i_nlink = 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); INIT_LIST_HEAD(&inode->i_dentry); 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) { 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, }; 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");