C++ OCFS2_SB函数代码示例

/*
 * Initialize the ACLs of a new inode. If parent directory has default ACL,
 * then clone to new inode. Called from ocfs2_mknod.
 */
int ocfs2_init_acl(handle_t *handle,
		   struct inode *inode,
		   struct inode *dir,
		   struct buffer_head *di_bh,
		   struct buffer_head *dir_bh,
		   struct ocfs2_alloc_context *meta_ac,
		   struct ocfs2_alloc_context *data_ac)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct posix_acl *acl = NULL;
	int ret = 0;
	mode_t mode;

	if (!S_ISLNK(inode->i_mode)) {
		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
						   dir_bh);
			if (IS_ERR(acl))
				return PTR_ERR(acl);
		}
		if (!acl) {
			mode = inode->i_mode & ~current_umask();
			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
			if (ret) {
				mlog_errno(ret);
				goto cleanup;
			}
		}
	}
	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
		struct posix_acl *clone;

		if (S_ISDIR(inode->i_mode)) {
			ret = ocfs2_set_acl(handle, inode, di_bh,
					    ACL_TYPE_DEFAULT, acl,
					    meta_ac, data_ac);
			if (ret)
				goto cleanup;
		}
		clone = posix_acl_clone(acl, GFP_NOFS);
		ret = -ENOMEM;
		if (!clone)
			goto cleanup;

		mode = inode->i_mode;
		ret = posix_acl_create_masq(clone, &mode);
		if (ret >= 0) {
			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
			if (ret > 0) {
				ret = ocfs2_set_acl(handle, inode,
						    di_bh, ACL_TYPE_ACCESS,
						    clone, meta_ac, data_ac);
			}
		}
		posix_acl_release(clone);
	}
cleanup:
	posix_acl_release(acl);
	return ret;
}

static int ocfs2_block_group_search(struct inode *inode,
				    struct buffer_head *group_bh,
				    u32 bits_wanted, u32 min_bits,
				    u64 max_block,
				    u16 *bit_off, u16 *bits_found)
{
	int ret = -ENOSPC;
	u64 blkoff;
	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;

	BUG_ON(min_bits != 1);
	BUG_ON(ocfs2_is_cluster_bitmap(inode));

	if (bg->bg_free_bits_count) {
		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
							group_bh, bits_wanted,
							le16_to_cpu(bg->bg_bits),
							bit_off, bits_found);
		if (!ret && max_block) {
			blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
				*bits_found;
			mlog(0, "Checking %llu against %llu\n",
			     (unsigned long long)blkoff,
			     (unsigned long long)max_block);
			if (blkoff > max_block)
				ret = -ENOSPC;
		}
	}

	return ret;
}

int ocfs2_info_handle_fs_features(struct inode *inode,
				  struct ocfs2_info_request __user *req)
{
	int status = -EFAULT;
	struct ocfs2_info_fs_features oif;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oif, req))
		goto bail;

	oif.if_compat_features = osb->s_feature_compat;
	oif.if_incompat_features = osb->s_feature_incompat;
	oif.if_ro_compat_features = osb->s_feature_ro_compat;

	o2info_set_request_filled(&oif.if_req);

	if (o2info_to_user(oif, req))
		goto bail;

	status = 0;
bail:
	if (status)
		o2info_set_request_error(&oif.if_req, req);

	return status;
}

void ocfs2_compute_meta_ecc_bhs(struct super_block *sb,
				struct buffer_head **bhs, int nr,
				struct ocfs2_block_check *bc)
{
	if (ocfs2_meta_ecc(OCFS2_SB(sb)))
		ocfs2_block_check_compute_bhs(bhs, nr, bc);
}

static struct dentry *ocfs2_get_dentry(struct super_block *sb,
        struct ocfs2_inode_handle *handle)
{
    struct inode *inode;
    struct dentry *result;

    mlog_entry("(0x%p, 0x%p)\n", sb, handle);

    if (handle->ih_blkno == 0) {
        mlog_errno(-ESTALE);
        return ERR_PTR(-ESTALE);
    }

    inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno, 0, 0);

    if (IS_ERR(inode))
        return (void *)inode;

    if (handle->ih_generation != inode->i_generation) {
        iput(inode);
        return ERR_PTR(-ESTALE);
    }

    result = d_alloc_anon(inode);

    if (!result) {
        iput(inode);
        mlog_errno(-ENOMEM);
        return ERR_PTR(-ENOMEM);
    }
    result->d_op = &ocfs2_dentry_ops;

    mlog_exit_ptr(result);
    return result;
}

handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
							 struct page *page,
							 unsigned from,
							 unsigned to)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	handle_t *handle;
	int ret = 0;

	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	if (ocfs2_should_order_data(inode)) {
		ret = walk_page_buffers(handle,
					page_buffers(page),
					from, to, NULL,
					ocfs2_journal_dirty_data);
		if (ret < 0) 
			mlog_errno(ret);
	}
out:
	if (ret) {
		if (!IS_ERR(handle))
			ocfs2_commit_trans(osb, handle);
		handle = ERR_PTR(ret);
	}
	return handle;
}

int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
	int ret = 0, lock_level = 0;
	struct ocfs2_super *osb = OCFS2_SB(file->f_dentry->d_inode->i_sb);

	/*
	 * Only support shared writeable mmap for local mounts which
	 * don't know about holes.
	 */
	if ((!ocfs2_mount_local(osb) || ocfs2_sparse_alloc(osb)) &&
	    ((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE)) &&
	    ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
		mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags);
		/* This is -EINVAL because generic_file_readonly_mmap
		 * returns it in a similar situation. */
		return -EINVAL;
	}

	ret = ocfs2_meta_lock_atime(file->f_dentry->d_inode,
				    file->f_vfsmnt, &lock_level);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}
	ocfs2_meta_unlock(file->f_dentry->d_inode, lock_level);
out:
	vma->vm_ops = &ocfs2_file_vm_ops;
	vma->vm_flags |= VM_CAN_NONLINEAR;
	return 0;
}

static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
		const void *value, size_t size, int flags, int type)
{
	struct inode *inode = dentry->d_inode;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct posix_acl *acl;
	int ret = 0;

	if (strcmp(name, "") != 0)
		return -EINVAL;
	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
		return -EOPNOTSUPP;

	if (!is_owner_or_cap(inode))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		else if (acl) {
			ret = posix_acl_valid(acl);
			if (ret)
				goto cleanup;
		}
	} else
		acl = NULL;

	ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);

cleanup:
	posix_acl_release(acl);
	return ret;
}

static char *ocfs2_fast_symlink_getlink(struct inode *inode,
					struct buffer_head **bh)
{
	int status;
	char *link = NULL;
	struct ocfs2_dinode *fe;

	mlog_entry_void();

	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				  OCFS2_I(inode)->ip_blkno,
				  bh,
				  OCFS2_BH_CACHED,
				  inode);
	if (status < 0) {
		mlog_errno(status);
		link = ERR_PTR(status);
		goto bail;
	}

	fe = (struct ocfs2_dinode *) (*bh)->b_data;
	link = (char *) fe->id2.i_symlink;
bail:
	mlog_exit(status);

	return link;
}

int ocfs2_check_acl(struct inode *inode, int mask)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct buffer_head *di_bh = NULL;
	struct posix_acl *acl;
	int ret = -EAGAIN;

	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
		return ret;

	ret = ocfs2_read_inode_block(inode, &di_bh);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}

	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);

	brelse(di_bh);

	if (IS_ERR(acl)) {
		mlog_errno(PTR_ERR(acl));
		return PTR_ERR(acl);
	}
	if (acl) {
		ret = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return ret;
	}

	return -EAGAIN;
}

static struct dentry *ocfs2_get_parent(struct dentry *child)
{
	int status;
	u64 blkno;
	struct dentry *parent;
	struct inode *dir = child->d_inode;

	trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
			       (unsigned long long)OCFS2_I(dir)->ip_blkno);

	status = ocfs2_inode_lock(dir, NULL, 0);
	if (status < 0) {
		if (status != -ENOENT)
			mlog_errno(status);
		parent = ERR_PTR(status);
		goto bail;
	}

	status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
	if (status < 0) {
		parent = ERR_PTR(-ENOENT);
		goto bail_unlock;
	}

	parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));

bail_unlock:
	ocfs2_inode_unlock(dir, 0);

bail:
	trace_ocfs2_get_parent_end(parent);

	return parent;
}

/*
 * Get posix acl.
 */
static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct buffer_head *di_bh = NULL;
	struct posix_acl *acl;
	int ret;

	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
		return NULL;

	ret = ocfs2_inode_lock(inode, &di_bh, 0);
	if (ret < 0) {
		mlog_errno(ret);
		acl = ERR_PTR(ret);
		return acl;
	}

	acl = ocfs2_get_acl_nolock(inode, type, di_bh);

	ocfs2_inode_unlock(inode, 0);

	brelse(di_bh);

	return acl;
}

int ocfs2_acl_chmod(struct inode *inode)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct posix_acl *acl, *clone;
	int ret;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
		return 0;

	acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);
	clone = posix_acl_clone(acl, GFP_KERNEL);
	posix_acl_release(acl);
	if (!clone)
		return -ENOMEM;
	ret = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!ret)
		ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
				    clone, NULL, NULL);
	posix_acl_release(clone);
	return ret;
}

static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
				  handle_t *handle,
				  u32 bits_wanted,
				  u32 min_bits,
				  u16 *bit_off,
				  unsigned int *num_bits,
				  u64 gd_blkno,
				  u16 *bits_left)
{
	int ret;
	u16 found;
	struct buffer_head *group_bh = NULL;
	struct ocfs2_group_desc *gd;
	struct inode *alloc_inode = ac->ac_inode;

	ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
			       &group_bh, OCFS2_BH_CACHED, alloc_inode);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}

	gd = (struct ocfs2_group_desc *) group_bh->b_data;
	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
		OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
		ret = -EIO;
		goto out;
	}

	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
				  bit_off, &found);
	if (ret < 0) {
		if (ret != -ENOSPC)
			mlog_errno(ret);
		goto out;
	}

	*num_bits = found;

	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
					       *num_bits,
					       le16_to_cpu(gd->bg_chain));
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
					 *bit_off, *num_bits);
	if (ret < 0)
		mlog_errno(ret);

	*bits_left = le16_to_cpu(gd->bg_free_bits_count);

out:
	brelse(group_bh);

	return ret;
}

static struct dentry *ocfs2_get_parent(struct dentry *child)
{
	int status;
	u64 blkno;
	struct dentry *parent;
	struct inode *inode;
	struct inode *dir = child->d_inode;
	struct buffer_head *dirent_bh = NULL;
	struct ocfs2_dir_entry *dirent;

	mlog_entry("(0x%p, '%.*s')\n", child,
		   child->d_name.len, child->d_name.name);

	mlog(0, "find parent of directory %llu\n",
	     (unsigned long long)OCFS2_I(dir)->ip_blkno);

	status = ocfs2_meta_lock(dir, NULL, 0);
	if (status < 0) {
		if (status != -ENOENT)
			mlog_errno(status);
		parent = ERR_PTR(status);
		goto bail;
	}

	status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh,
					  &dirent);
	if (status < 0) {
		parent = ERR_PTR(-ENOENT);
		goto bail_unlock;
	}

	inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0);
	if (IS_ERR(inode)) {
		mlog(ML_ERROR, "Unable to create inode %llu\n",
		     (unsigned long long)blkno);
		parent = ERR_PTR(-EACCES);
		goto bail_unlock;
	}

	parent = d_alloc_anon(inode);
	if (!parent) {
		iput(inode);
		parent = ERR_PTR(-ENOMEM);
	}

	parent->d_op = &ocfs2_dentry_ops;

bail_unlock:
	ocfs2_meta_unlock(dir, 0);

	if (dirent_bh)
		brelse(dirent_bh);

bail:
	mlog_exit_ptr(parent);

	return parent;
}