inode.c

linux 内核源代码

static int
spufs_create_context(struct inode *inode, struct dentry *dentry,
			struct vfsmount *mnt, int flags, int mode,
			struct file *aff_filp)
{
	int ret;
	int affinity;
	struct spu_gang *gang;
	struct spu_context *neighbor;

	ret = -EPERM;
	if ((flags & SPU_CREATE_NOSCHED) &&
	    !capable(CAP_SYS_NICE))
		goto out_unlock;

	ret = -EINVAL;
	if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
	    == SPU_CREATE_ISOLATE)
		goto out_unlock;

	ret = -ENODEV;
	if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader)
		goto out_unlock;

	gang = NULL;
	neighbor = NULL;
	affinity = flags & (SPU_CREATE_AFFINITY_MEM | SPU_CREATE_AFFINITY_SPU);
	if (affinity) {
		gang = SPUFS_I(inode)->i_gang;
		ret = -EINVAL;
		if (!gang)
			goto out_unlock;
		mutex_lock(&gang->aff_mutex);
		neighbor = spufs_assert_affinity(flags, gang, aff_filp);
		if (IS_ERR(neighbor)) {
			ret = PTR_ERR(neighbor);
			goto out_aff_unlock;
		}
	}

	ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
	if (ret)
		goto out_aff_unlock;

	if (affinity)
		spufs_set_affinity(flags, SPUFS_I(dentry->d_inode)->i_ctx,
								neighbor);

	/*
	 * get references for dget and mntget, will be released
	 * in error path of *_open().
	 */
	ret = spufs_context_open(dget(dentry), mntget(mnt));
	if (ret < 0) {
		WARN_ON(spufs_rmdir(inode, dentry));
		mutex_unlock(&inode->i_mutex);
		spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
		goto out;
	}

out_aff_unlock:
	if (affinity)
		mutex_unlock(&gang->aff_mutex);
out_unlock:
	mutex_unlock(&inode->i_mutex);
out:
	dput(dentry);
	return ret;
}

static int
spufs_mkgang(struct inode *dir, struct dentry *dentry, int mode)
{
	int ret;
	struct inode *inode;
	struct spu_gang *gang;

	ret = -ENOSPC;
	inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
	if (!inode)
		goto out;

	ret = 0;
	if (dir->i_mode & S_ISGID) {
		inode->i_gid = dir->i_gid;
		inode->i_mode &= S_ISGID;
	}
	gang = alloc_spu_gang();
	SPUFS_I(inode)->i_ctx = NULL;
	SPUFS_I(inode)->i_gang = gang;
	if (!gang)
		goto out_iput;

	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;

	d_instantiate(dentry, inode);
	dir->i_nlink++;
	dentry->d_inode->i_nlink++;
	return ret;

out_iput:
	iput(inode);
out:
	return ret;
}

static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt)
{
	int ret;
	struct file *filp;

	ret = get_unused_fd();
	if (ret < 0) {
		dput(dentry);
		mntput(mnt);
		goto out;
	}

	filp = dentry_open(dentry, mnt, O_RDONLY);
	if (IS_ERR(filp)) {
		put_unused_fd(ret);
		ret = PTR_ERR(filp);
		goto out;
	}

	filp->f_op = &simple_dir_operations;
	fd_install(ret, filp);
out:
	return ret;
}

static int spufs_create_gang(struct inode *inode,
			struct dentry *dentry,
			struct vfsmount *mnt, int mode)
{
	int ret;

	ret = spufs_mkgang(inode, dentry, mode & S_IRWXUGO);
	if (ret)
		goto out;

	/*
	 * get references for dget and mntget, will be released
	 * in error path of *_open().
	 */
	ret = spufs_gang_open(dget(dentry), mntget(mnt));
	if (ret < 0) {
		int err = simple_rmdir(inode, dentry);
		WARN_ON(err);
	}

out:
	mutex_unlock(&inode->i_mutex);
	dput(dentry);
	return ret;
}


static struct file_system_type spufs_type;

long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode,
							struct file *filp)
{
	struct dentry *dentry;
	int ret;

	ret = -EINVAL;
	/* check if we are on spufs */
	if (nd->dentry->d_sb->s_type != &spufs_type)
		goto out;

	/* don't accept undefined flags */
	if (flags & (~SPU_CREATE_FLAG_ALL))
		goto out;

	/* only threads can be underneath a gang */
	if (nd->dentry != nd->dentry->d_sb->s_root) {
		if ((flags & SPU_CREATE_GANG) ||
		    !SPUFS_I(nd->dentry->d_inode)->i_gang)
			goto out;
	}

	dentry = lookup_create(nd, 1);
	ret = PTR_ERR(dentry);
	if (IS_ERR(dentry))
		goto out_dir;

	ret = -EEXIST;
	if (dentry->d_inode)
		goto out_dput;

	mode &= ~current->fs->umask;

	if (flags & SPU_CREATE_GANG)
		return spufs_create_gang(nd->dentry->d_inode,
					dentry, nd->mnt, mode);
	else
		return spufs_create_context(nd->dentry->d_inode,
					dentry, nd->mnt, flags, mode, filp);

out_dput:
	dput(dentry);
out_dir:
	mutex_unlock(&nd->dentry->d_inode->i_mutex);
out:
	return ret;
}

/* File system initialization */
enum {
	Opt_uid, Opt_gid, Opt_mode, Opt_err,
};

static match_table_t spufs_tokens = {
	{ Opt_uid,  "uid=%d" },
	{ Opt_gid,  "gid=%d" },
	{ Opt_mode, "mode=%o" },
	{ Opt_err,   NULL  },
};

static int
spufs_parse_options(char *options, struct inode *root)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];

	while ((p = strsep(&options, ",")) != NULL) {
		int token, option;

		if (!*p)
			continue;

		token = match_token(p, spufs_tokens, args);
		switch (token) {
		case Opt_uid:
			if (match_int(&args[0], &option))
				return 0;
			root->i_uid = option;
			break;
		case Opt_gid:
			if (match_int(&args[0], &option))
				return 0;
			root->i_gid = option;
			break;
		case Opt_mode:
			if (match_octal(&args[0], &option))
				return 0;
			root->i_mode = option | S_IFDIR;
			break;
		default:
			return 0;
		}
	}
	return 1;
}

static void spufs_exit_isolated_loader(void)
{
	free_pages((unsigned long) isolated_loader,
			get_order(isolated_loader_size));
}

static void
spufs_init_isolated_loader(void)
{
	struct device_node *dn;
	const char *loader;
	int size;

	dn = of_find_node_by_path("/spu-isolation");
	if (!dn)
		return;

	loader = of_get_property(dn, "loader", &size);
	if (!loader)
		return;

	/* the loader must be align on a 16 byte boundary */
	isolated_loader = (char *)__get_free_pages(GFP_KERNEL, get_order(size));
	if (!isolated_loader)
		return;

	isolated_loader_size = size;
	memcpy(isolated_loader, loader, size);
	printk(KERN_INFO "spufs: SPU isolation mode enabled\n");
}

static int
spufs_create_root(struct super_block *sb, void *data)
{
	struct inode *inode;
	int ret;

	ret = -ENODEV;
	if (!spu_management_ops)
		goto out;

	ret = -ENOMEM;
	inode = spufs_new_inode(sb, S_IFDIR | 0775);
	if (!inode)
		goto out;

	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	SPUFS_I(inode)->i_ctx = NULL;

	ret = -EINVAL;
	if (!spufs_parse_options(data, inode))
		goto out_iput;

	ret = -ENOMEM;
	sb->s_root = d_alloc_root(inode);
	if (!sb->s_root)
		goto out_iput;

	return 0;
out_iput:
	iput(inode);
out:
	return ret;
}

static int
spufs_fill_super(struct super_block *sb, void *data, int silent)
{
	static struct super_operations s_ops = {
		.alloc_inode = spufs_alloc_inode,
		.destroy_inode = spufs_destroy_inode,
		.statfs = simple_statfs,
		.delete_inode = spufs_delete_inode,
		.drop_inode = generic_delete_inode,
	};

	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = SPUFS_MAGIC;
	sb->s_op = &s_ops;

	return spufs_create_root(sb, data);
}

static int
spufs_get_sb(struct file_system_type *fstype, int flags,
		const char *name, void *data, struct vfsmount *mnt)
{
	return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
}

static struct file_system_type spufs_type = {
	.owner = THIS_MODULE,
	.name = "spufs",
	.get_sb = spufs_get_sb,
	.kill_sb = kill_litter_super,
};

static int __init spufs_init(void)
{
	int ret;

	ret = -ENODEV;
	if (!spu_management_ops)
		goto out;

	ret = -ENOMEM;
	spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
			sizeof(struct spufs_inode_info), 0,
			SLAB_HWCACHE_ALIGN, spufs_init_once);

	if (!spufs_inode_cache)
		goto out;
	ret = spu_sched_init();
	if (ret)
		goto out_cache;
	ret = register_filesystem(&spufs_type);
	if (ret)
		goto out_sched;
	ret = register_spu_syscalls(&spufs_calls);
	if (ret)
		goto out_fs;

	spufs_init_isolated_loader();

	return 0;

out_fs:
	unregister_filesystem(&spufs_type);
out_sched:
	spu_sched_exit();
out_cache:
	kmem_cache_destroy(spufs_inode_cache);
out:
	return ret;
}
module_init(spufs_init);

static void __exit spufs_exit(void)
{
	spu_sched_exit();
	spufs_exit_isolated_loader();
	unregister_spu_syscalls(&spufs_calls);
	unregister_filesystem(&spufs_type);
	kmem_cache_destroy(spufs_inode_cache);
}
module_exit(spufs_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arnd Bergmann <[e-mail]>");