ops_fstype.c

linux 内核源代码

	/* Read in the master statfs inode */
	sdp->sd_statfs_inode = gfs2_lookup_simple(sdp->sd_master_dir, "statfs");
	if (IS_ERR(sdp->sd_statfs_inode)) {
		error = PTR_ERR(sdp->sd_statfs_inode);
		fs_err(sdp, "can't read in statfs inode: %d\n", error);
		goto fail_inum;
	}

	/* Read in the resource index inode */
	sdp->sd_rindex = gfs2_lookup_simple(sdp->sd_master_dir, "rindex");
	if (IS_ERR(sdp->sd_rindex)) {
		error = PTR_ERR(sdp->sd_rindex);
		fs_err(sdp, "can't get resource index inode: %d\n", error);
		goto fail_statfs;
	}
	ip = GFS2_I(sdp->sd_rindex);
	set_bit(GLF_STICKY, &ip->i_gl->gl_flags);
	sdp->sd_rindex_vn = ip->i_gl->gl_vn - 1;

	/* Read in the quota inode */
	sdp->sd_quota_inode = gfs2_lookup_simple(sdp->sd_master_dir, "quota");
	if (IS_ERR(sdp->sd_quota_inode)) {
		error = PTR_ERR(sdp->sd_quota_inode);
		fs_err(sdp, "can't get quota file inode: %d\n", error);
		goto fail_rindex;
	}
	return 0;

fail_qinode:
	iput(sdp->sd_quota_inode);
fail_rindex:
	gfs2_clear_rgrpd(sdp);
	iput(sdp->sd_rindex);
fail_statfs:
	iput(sdp->sd_statfs_inode);
fail_inum:
	iput(sdp->sd_inum_inode);
fail_journal:
	init_journal(sdp, UNDO);
fail_master:
	iput(sdp->sd_master_dir);
fail:
	return error;
}

static int init_per_node(struct gfs2_sbd *sdp, int undo)
{
	struct inode *pn = NULL;
	char buf[30];
	int error = 0;
	struct gfs2_inode *ip;

	if (sdp->sd_args.ar_spectator)
		return 0;

	if (undo)
		goto fail_qc_gh;

	pn = gfs2_lookup_simple(sdp->sd_master_dir, "per_node");
	if (IS_ERR(pn)) {
		error = PTR_ERR(pn);
		fs_err(sdp, "can't find per_node directory: %d\n", error);
		return error;
	}

	sprintf(buf, "inum_range%u", sdp->sd_jdesc->jd_jid);
	sdp->sd_ir_inode = gfs2_lookup_simple(pn, buf);
	if (IS_ERR(sdp->sd_ir_inode)) {
		error = PTR_ERR(sdp->sd_ir_inode);
		fs_err(sdp, "can't find local \"ir\" file: %d\n", error);
		goto fail;
	}

	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
	if (IS_ERR(sdp->sd_sc_inode)) {
		error = PTR_ERR(sdp->sd_sc_inode);
		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
		goto fail_ir_i;
	}

	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
	if (IS_ERR(sdp->sd_qc_inode)) {
		error = PTR_ERR(sdp->sd_qc_inode);
		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
		goto fail_ut_i;
	}

	iput(pn);
	pn = NULL;

	ip = GFS2_I(sdp->sd_ir_inode);
	error = gfs2_glock_nq_init(ip->i_gl,
				   LM_ST_EXCLUSIVE, 0,
				   &sdp->sd_ir_gh);
	if (error) {
		fs_err(sdp, "can't lock local \"ir\" file: %d\n", error);
		goto fail_qc_i;
	}

	ip = GFS2_I(sdp->sd_sc_inode);
	error = gfs2_glock_nq_init(ip->i_gl,
				   LM_ST_EXCLUSIVE, 0,
				   &sdp->sd_sc_gh);
	if (error) {
		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
		goto fail_ir_gh;
	}

	ip = GFS2_I(sdp->sd_qc_inode);
	error = gfs2_glock_nq_init(ip->i_gl,
				   LM_ST_EXCLUSIVE, 0,
				   &sdp->sd_qc_gh);
	if (error) {
		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
		goto fail_ut_gh;
	}

	return 0;

fail_qc_gh:
	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
fail_ut_gh:
	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
fail_ir_gh:
	gfs2_glock_dq_uninit(&sdp->sd_ir_gh);
fail_qc_i:
	iput(sdp->sd_qc_inode);
fail_ut_i:
	iput(sdp->sd_sc_inode);
fail_ir_i:
	iput(sdp->sd_ir_inode);
fail:
	if (pn)
		iput(pn);
	return error;
}

static int init_threads(struct gfs2_sbd *sdp, int undo)
{
	struct task_struct *p;
	int error = 0;

	if (undo)
		goto fail_quotad;

	sdp->sd_log_flush_time = jiffies;
	sdp->sd_jindex_refresh_time = jiffies;

	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
	error = IS_ERR(p);
	if (error) {
		fs_err(sdp, "can't start logd thread: %d\n", error);
		return error;
	}
	sdp->sd_logd_process = p;

	sdp->sd_statfs_sync_time = jiffies;
	sdp->sd_quota_sync_time = jiffies;

	p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
	error = IS_ERR(p);
	if (error) {
		fs_err(sdp, "can't start quotad thread: %d\n", error);
		goto fail;
	}
	sdp->sd_quotad_process = p;

	return 0;


fail_quotad:
	kthread_stop(sdp->sd_quotad_process);
fail:
	kthread_stop(sdp->sd_logd_process);
	return error;
}

/**
 * fill_super - Read in superblock
 * @sb: The VFS superblock
 * @data: Mount options
 * @silent: Don't complain if it's not a GFS2 filesystem
 *
 * Returns: errno
 */

static int fill_super(struct super_block *sb, void *data, int silent)
{
	struct gfs2_sbd *sdp;
	struct gfs2_holder mount_gh;
	int error;

	sdp = init_sbd(sb);
	if (!sdp) {
		printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
		return -ENOMEM;
	}

	error = gfs2_mount_args(sdp, (char *)data, 0);
	if (error) {
		printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
		goto fail;
	}

	init_vfs(sb, SDF_NOATIME);

	/* Set up the buffer cache and fill in some fake block size values
	   to allow us to read-in the on-disk superblock. */
	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
                               GFS2_BASIC_BLOCK_SHIFT;
	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;

	error = init_names(sdp, silent);
	if (error)
		goto fail;

	gfs2_create_debugfs_file(sdp);

	error = gfs2_sys_fs_add(sdp);
	if (error)
		goto fail;

	error = gfs2_lm_mount(sdp, silent);
	if (error)
		goto fail_sys;

	error = init_locking(sdp, &mount_gh, DO);
	if (error)
		goto fail_lm;

	error = init_sb(sdp, silent, DO);
	if (error)
		goto fail_locking;

	error = init_inodes(sdp, DO);
	if (error)
		goto fail_sb;

	error = init_per_node(sdp, DO);
	if (error)
		goto fail_inodes;

	error = gfs2_statfs_init(sdp);
	if (error) {
		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
		goto fail_per_node;
	}

	error = init_threads(sdp, DO);
	if (error)
		goto fail_per_node;

	if (!(sb->s_flags & MS_RDONLY)) {
		error = gfs2_make_fs_rw(sdp);
		if (error) {
			fs_err(sdp, "can't make FS RW: %d\n", error);
			goto fail_threads;
		}
	}

	gfs2_glock_dq_uninit(&mount_gh);

	return 0;

fail_threads:
	init_threads(sdp, UNDO);
fail_per_node:
	init_per_node(sdp, UNDO);
fail_inodes:
	init_inodes(sdp, UNDO);
fail_sb:
	init_sb(sdp, 0, UNDO);
fail_locking:
	init_locking(sdp, &mount_gh, UNDO);
fail_lm:
	gfs2_gl_hash_clear(sdp, WAIT);
	gfs2_lm_unmount(sdp);
	while (invalidate_inodes(sb))
		yield();
fail_sys:
	gfs2_sys_fs_del(sdp);
fail:
	gfs2_delete_debugfs_file(sdp);
	kfree(sdp);
	sb->s_fs_info = NULL;
	return error;
}

static int gfs2_get_sb(struct file_system_type *fs_type, int flags,
		const char *dev_name, void *data, struct vfsmount *mnt)
{
	struct super_block *sb;
	struct gfs2_sbd *sdp;
	int error = get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt);
	if (error)
		goto out;
	sb = mnt->mnt_sb;
	sdp = sb->s_fs_info;
	sdp->sd_gfs2mnt = mnt;
out:
	return error;
}

static int fill_super_meta(struct super_block *sb, struct super_block *new,
			   void *data, int silent)
{
	struct gfs2_sbd *sdp = sb->s_fs_info;
	struct inode *inode;
	int error = 0;

	new->s_fs_info = sdp;
	sdp->sd_vfs_meta = sb;

	init_vfs(new, SDF_NOATIME);

        /* Get the master inode */
	inode = igrab(sdp->sd_master_dir);

	new->s_root = d_alloc_root(inode);
	if (!new->s_root) {
		fs_err(sdp, "can't get root dentry\n");
		error = -ENOMEM;
		iput(inode);
	} else
		new->s_root->d_op = &gfs2_dops;

	return error;
}

static int set_bdev_super(struct super_block *s, void *data)
{
	s->s_bdev = data;
	s->s_dev = s->s_bdev->bd_dev;
	return 0;
}

static int test_bdev_super(struct super_block *s, void *data)
{
	return s->s_bdev == data;
}

static struct super_block* get_gfs2_sb(const char *dev_name)
{
	struct kstat stat;
	struct nameidata nd;
	struct file_system_type *fstype;
	struct super_block *sb = NULL, *s;
	int error;

	error = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
	if (error) {
		printk(KERN_WARNING "GFS2: path_lookup on %s returned error\n",
		       dev_name);
		goto out;
	}
	error = vfs_getattr(nd.mnt, nd.dentry, &stat);

	fstype = get_fs_type("gfs2");
	list_for_each_entry(s, &fstype->fs_supers, s_instances) {
		if ((S_ISBLK(stat.mode) && s->s_dev == stat.rdev) ||
		    (S_ISDIR(stat.mode) && s == nd.dentry->d_inode->i_sb)) {
			sb = s;
			goto free_nd;
		}
	}

	printk(KERN_WARNING "GFS2: Unrecognized block device or "
	       "mount point %s\n", dev_name);

free_nd:
	path_release(&nd);
out:
	return sb;
}

static int gfs2_get_sb_meta(struct file_system_type *fs_type, int flags,
			    const char *dev_name, void *data, struct vfsmount *mnt)
{
	int error = 0;
	struct super_block *sb = NULL, *new;
	struct gfs2_sbd *sdp;

	sb = get_gfs2_sb(dev_name);
	if (!sb) {
		printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
		error = -ENOENT;
		goto error;
	}
	sdp = sb->s_fs_info;
	if (sdp->sd_vfs_meta) {
		printk(KERN_WARNING "GFS2: gfs2meta mount already exists\n");
		error = -EBUSY;
		goto error;
	}
	down(&sb->s_bdev->bd_mount_sem);
	new = sget(fs_type, test_bdev_super, set_bdev_super, sb->s_bdev);
	up(&sb->s_bdev->bd_mount_sem);
	if (IS_ERR(new)) {
		error = PTR_ERR(new);
		goto error;
	}
	module_put(fs_type->owner);
	new->s_flags = flags;
	strlcpy(new->s_id, sb->s_id, sizeof(new->s_id));
	sb_set_blocksize(new, sb->s_blocksize);
	error = fill_super_meta(sb, new, data, flags & MS_SILENT ? 1 : 0);
	if (error) {
		up_write(&new->s_umount);
		deactivate_super(new);
		goto error;
	}

	new->s_flags |= MS_ACTIVE;

	/* Grab a reference to the gfs2 mount point */
	atomic_inc(&sdp->sd_gfs2mnt->mnt_count);
	return simple_set_mnt(mnt, new);
error:
	return error;
}

static void gfs2_kill_sb(struct super_block *sb)
{
	if (sb->s_fs_info) {
		gfs2_delete_debugfs_file(sb->s_fs_info);
		gfs2_meta_syncfs(sb->s_fs_info);
	}
	kill_block_super(sb);
}

static void gfs2_kill_sb_meta(struct super_block *sb)
{
	struct gfs2_sbd *sdp = sb->s_fs_info;
	generic_shutdown_super(sb);
	sdp->sd_vfs_meta = NULL;
	atomic_dec(&sdp->sd_gfs2mnt->mnt_count);
}

struct file_system_type gfs2_fs_type = {
	.name = "gfs2",
	.fs_flags = FS_REQUIRES_DEV,
	.get_sb = gfs2_get_sb,
	.kill_sb = gfs2_kill_sb,
	.owner = THIS_MODULE,
};

struct file_system_type gfs2meta_fs_type = {
	.name = "gfs2meta",
	.fs_flags = FS_REQUIRES_DEV,
	.get_sb = gfs2_get_sb_meta,
	.kill_sb = gfs2_kill_sb_meta,
	.owner = THIS_MODULE,
};