From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 22/26] sys_mknodat(): elevate write count for vfs_mknod/create()
Date: Sat, 23 Jun 2007 08:51:03 +0100
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References: <20070622200303.82D9CC3A@kernel> <20070622200332.DCCD1884@kernel>
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	viro@ftp.linux.org.uk
To: Dave Hansen <haveblue@us.ibm.com>
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On Fri, Jun 22, 2007 at 01:03:32PM -0700, Dave Hansen wrote:
> 
> 
> This takes care of all of the direct callers of vfs_mknod().
> Since a few of these cases also handle normal file creation
> as well, this also covers some calls to vfs_create().

Ok.

> diff -puN fs/namei.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create fs/namei.c
> --- lxc/fs/namei.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create	2007-06-21 23:23:25.000000000 -0700
> +++ lxc-dave/fs/namei.c	2007-06-21 23:23:25.000000000 -0700
> @@ -1897,14 +1897,26 @@ asmlinkage long sys_mknodat(int dfd, con
>  	if (!IS_ERR(dentry)) {
>  		switch (mode & S_IFMT) {
>  		case 0: case S_IFREG:
> +			error = mnt_want_write(nd.mnt);
> +			if (error)
> +				break;
>  			error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd);
> +			mnt_drop_write(nd.mnt);
>  			break;
>  		case S_IFCHR: case S_IFBLK:
> +			error = mnt_want_write(nd.mnt);
> +			if (error)
> +				break;
>  			error = vfs_mknod(nd.dentry->d_inode,dentry,mode,
>  					new_decode_dev(dev));
> +			mnt_drop_write(nd.mnt);
>  			break;
>  		case S_IFIFO: case S_IFSOCK:
> +			error = mnt_want_write(nd.mnt);
> +			if (error)
> +				break;
>  			error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0);
> +			mnt_drop_write(nd.mnt);
>  			break;
>  		case S_IFDIR:
>  			error = -EPERM;

Should we just take the calls outside the switch statement?