From: Al Viro <viro@zeniv.linux.org.uk>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, seanjc@google.com
Subject: Re: [PATCH gmem FIXUP] kvm: guestmem: do not use a file system
Date: Mon, 9 Oct 2023 03:16:44 +0100 [thread overview]
Message-ID: <20231009021644.GC800259@ZenIV> (raw)
In-Reply-To: <20230928180651.1525674-1-pbonzini@redhat.com>
On Thu, Sep 28, 2023 at 02:06:51PM -0400, Paolo Bonzini wrote:
> Use a run-of-the-mill anonymous inode, there is nothing useful
> being provided by kvm_gmem_fs.
> - inode = alloc_anon_inode(mnt->mnt_sb);
> - if (IS_ERR(inode))
> - return PTR_ERR(inode);
> + fd = get_unused_fd_flags(0);
> + if (fd < 0)
> + return fd;
>
> - err = security_inode_init_security_anon(inode, &qname, NULL);
> - if (err)
> - goto err_inode;
> + gmem = kzalloc(sizeof(*gmem), GFP_KERNEL);
> + if (!gmem) {
> + err = -ENOMEM;
> + goto err_fd;
> + }
> +
> + file = anon_inode_getfile(anon_name, &kvm_gmem_fops, gmem,
> + O_RDWR);
> + inode = file->f_inode;
> + WARN_ON(file->f_mapping != inode->i_mapping);
>
> inode->i_private = (void *)(unsigned long)flags;
> inode->i_op = &kvm_gmem_iops;
That's very badly broken. The whole point of anon_inode_getfile() is
that *ALL* resulting files share the same inode. You are not allowed
to modify the damn thing.
prev parent reply other threads:[~2023-10-09 2:16 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-28 18:06 [PATCH gmem FIXUP] kvm: guestmem: do not use a file system Paolo Bonzini
2023-09-29 2:22 ` Sean Christopherson
2023-10-09 2:22 ` Al Viro
2023-10-09 2:35 ` Al Viro
2023-10-09 14:32 ` Sean Christopherson
2023-10-09 20:06 ` Al Viro
2023-10-09 20:20 ` Sean Christopherson
2023-10-09 20:40 ` Al Viro
2023-10-09 21:26 ` Sean Christopherson
2023-10-10 0:09 ` Al Viro
2023-10-10 0:27 ` Sean Christopherson
2023-10-10 0:37 ` Al Viro
2023-10-10 23:30 ` Sean Christopherson
2023-10-11 15:06 ` Xu Yilun
2023-10-11 17:57 ` Paolo Bonzini
2023-10-13 16:55 ` Sean Christopherson
2023-10-16 15:19 ` Paolo Bonzini
2023-10-09 2:16 ` Al Viro [this message]
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