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root/fs/qnx4/inode.c

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DEFINITIONS

This source file includes following definitions.
  1. qnx4_sync_inode
  2. qnx4_delete_inode
  3. qnx4_write_super
  4. qnx4_write_inode
  5. qnx4_remount
  6. qnx4_getblk
  7. qnx4_bread
  8. qnx4_get_block
  9. qnx4_block_map
  10. qnx4_statfs
  11. qnx4_checkroot
  12. qnx4_fill_super
  13. qnx4_put_super
  14. qnx4_writepage
  15. qnx4_readpage
  16. qnx4_write_begin
  17. qnx4_bmap
  18. qnx4_iget
  19. qnx4_alloc_inode
  20. qnx4_destroy_inode
  21. init_once
  22. init_inodecache
  23. destroy_inodecache
  24. qnx4_get_sb
  25. init_qnx4_fs
  26. exit_qnx4_fs

/*
 * 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/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/qnx4_fs.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/smp_lock.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <asm/uaccess.h>

#define QNX4_VERSION  4
#define QNX4_BMNAME   ".bitmap"

static const struct super_operations qnx4_sops;

#ifdef CONFIG_QNX4FS_RW

int qnx4_sync_inode(struct inode *inode)
{
        int err = 0;
# if 0
        struct buffer_head *bh;

        bh = qnx4_update_inode(inode);
        if (bh && buffer_dirty(bh))
        {
                sync_dirty_buffer(bh);
                if (buffer_req(bh) && !buffer_uptodate(bh))
                {
                        printk ("IO error syncing qnx4 inode [%s:%08lx]\n",
                                inode->i_sb->s_id, inode->i_ino);
                        err = -1;
                }
                brelse (bh);
        } else if (!bh) {
                err = -1;
        }
# endif

        return err;
}

static void qnx4_delete_inode(struct inode *inode)
{
        QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
        truncate_inode_pages(&inode->i_data, 0);
        inode->i_size = 0;
        qnx4_truncate(inode);
        lock_kernel();
        qnx4_free_inode(inode);
        unlock_kernel();
}

static void qnx4_write_super(struct super_block *sb)
{
        lock_kernel();
        QNX4DEBUG(("qnx4: write_super\n"));
        sb->s_dirt = 0;
        unlock_kernel();
}

static int qnx4_write_inode(struct inode *inode, int unused)
{
        struct qnx4_inode_entry *raw_inode;
        int block, ino;
        struct buffer_head *bh;
        ino = inode->i_ino;

        QNX4DEBUG(("qnx4: write inode 1.\n"));
        if (inode->i_nlink == 0) {
                return 0;
        }
        if (!ino) {
                printk("qnx4: bad inode number on dev %s: %d is out of range\n",
                       inode->i_sb->s_id, ino);
                return -EIO;
        }
        QNX4DEBUG(("qnx4: write inode 2.\n"));
        block = ino / QNX4_INODES_PER_BLOCK;
        lock_kernel();
        if (!(bh = sb_bread(inode->i_sb, block))) {
                printk("qnx4: major problem: unable to read inode from dev "
                       "%s\n", inode->i_sb->s_id);
                unlock_kernel();
                return -EIO;
        }
        raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
            (ino % QNX4_INODES_PER_BLOCK);
        raw_inode->di_mode  = cpu_to_le16(inode->i_mode);
        raw_inode->di_uid   = cpu_to_le16(fs_high2lowuid(inode->i_uid));
        raw_inode->di_gid   = cpu_to_le16(fs_high2lowgid(inode->i_gid));
        raw_inode->di_nlink = cpu_to_le16(inode->i_nlink);
        raw_inode->di_size  = cpu_to_le32(inode->i_size);
        raw_inode->di_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
        raw_inode->di_atime = cpu_to_le32(inode->i_atime.tv_sec);
        raw_inode->di_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
        raw_inode->di_first_xtnt.xtnt_size = cpu_to_le32(inode->i_blocks);
        mark_buffer_dirty(bh);
        brelse(bh);
        unlock_kernel();
        return 0;
}

#endif

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,
#ifdef CONFIG_QNX4FS_RW
        .write_inode    = qnx4_write_inode,
        .delete_inode   = qnx4_delete_inode,
        .write_super    = qnx4_write_super,
#endif
};

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;
#ifndef CONFIG_QNX4FS_RW
        *flags |= MS_RDONLY;
#endif
        if (*flags & MS_RDONLY) {
                return 0;
        }

        mark_buffer_dirty(qs->sb_buf);

        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;
        }
        if (!create) {
                return NULL;
        }
#if 0
        tmp = qnx4_new_block(inode->i_sb);
        if (!tmp) {
                return NULL;
        }
        result = sb_getblk(inode->i_sb, tmp);
        if (tst) {
                qnx4_free_block(inode->i_sb, tmp);
                brelse(result);
                goto repeat;
        }
        tst = tmp;
#endif
        inode->i_ctime = CURRENT_TIME_SEC;
        mark_inode_dirty(inode);
        return result;
}

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(("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);
        } else if ( create ) {
                // to be done.
        }
        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(("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(("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(("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;

        lock_kernel();

        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;

        unlock_kernel();

        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(("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(("Rootdir entry found : [%s]\n", rootdir->di_fname));
                                        if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof 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("qnx4: unable to read the superblock\n");
                goto outnobh;
        }
        if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
                if (!silent)
                        printk("qnx4: wrong fsid in superblock.\n");
                goto out;
        }
        s->s_op = &qnx4_sops;
        s->s_magic = QNX4_SUPER_MAGIC;
#ifndef CONFIG_QNX4FS_RW
        s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
#endif
        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("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("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);
        *pagep = NULL;
        return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
                                qnx4_get_block,
                                &qnx4_inode->mmu_private);
}
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(("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("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_op = &qnx4_file_inode_operations;
                inode->i_fop = &qnx4_file_operations;
                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_destroy_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),
                                             init_once);
        if (qnx4_inode_cachep == NULL)
                return -ENOMEM;
        return 0;
}

static void destroy_inodecache(void)
{
        kmem_cache_destroy(qnx4_inode_cachep);
}

static int qnx4_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, qnx4_fill_super,
                           mnt);
}

static struct file_system_type qnx4_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "qnx4",
        .get_sb         = qnx4_get_sb,
        .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("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");


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