diff options
Diffstat (limited to 'fs/qnx4/inode.c')
-rw-r--r-- | fs/qnx4/inode.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c new file mode 100644 index 000000000..c4bcb7788 --- /dev/null +++ b/fs/qnx4/inode.c @@ -0,0 +1,426 @@ +/* + * 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_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, + .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 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 |= MS_RDONLY; /* Yup, read-only yet */ + + /* 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->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 = 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"); + |