linux-kernel - Re: [PATCH 19/27] ocfs2: Convert to new freezing mechanism

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Message-ID: <20120417021921.GC31464@dhcp-172-17-9-228.mtv.corp.google.com>
Date:	Mon, 16 Apr 2012 19:19:21 -0700
From:	Joel Becker <jlbec@...lplan.org>
To:	Jan Kara <jack@...e.cz>
Cc:	Al Viro <viro@...IV.linux.org.uk>, dchinner@...hat.com,
	LKML <linux-kernel@...r.kernel.org>,
	linux-fsdevel@...r.kernel.org, Mark Fasheh <mfasheh@...e.com>,
	ocfs2-devel@....oracle.com
Subject: Re: [PATCH 19/27] ocfs2: Convert to new freezing mechanism

On Mon, Apr 16, 2012 at 06:13:57PM +0200, Jan Kara wrote:
> Protect ocfs2_page_mkwrite() and ocfs2_file_aio_write() using the new
> freeze protection. We also protect several ioctl entry points which
> were missing the protection.
> 
> CC: Mark Fasheh <mfasheh@...e.com>
> CC: Joel Becker <jlbec@...lplan.org>
> CC: ocfs2-devel@....oracle.com
> Signed-off-by: Jan Kara <jack@...e.cz>

Acked-by: Joel Becker <jlbec@...lplan.org>

> ---
>  fs/ocfs2/file.c  |   11 +++++++++--
>  fs/ocfs2/ioctl.c |   14 ++++++++++++--
>  fs/ocfs2/mmap.c  |    2 ++
>  3 files changed, 23 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 061591a..9b1e3d4 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1971,6 +1971,7 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd,
>  {
>  	struct inode *inode = file->f_path.dentry->d_inode;
>  	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
> +	int ret;
>  
>  	if ((cmd == OCFS2_IOC_RESVSP || cmd == OCFS2_IOC_RESVSP64) &&
>  	    !ocfs2_writes_unwritten_extents(osb))
> @@ -1985,7 +1986,12 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd,
>  	if (!(file->f_mode & FMODE_WRITE))
>  		return -EBADF;
>  
> -	return __ocfs2_change_file_space(file, inode, file->f_pos, cmd, sr, 0);
> +	ret = mnt_want_write_file(file);
> +	if (ret)
> +		return ret;
> +	ret = __ocfs2_change_file_space(file, inode, file->f_pos, cmd, sr, 0);
> +	mnt_drop_write_file(file);
> +	return ret;
>  }
>  
>  static long ocfs2_fallocate(struct file *file, int mode, loff_t offset,
> @@ -2261,7 +2267,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
>  	if (iocb->ki_left == 0)
>  		return 0;
>  
> -	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
> +	sb_start_write(inode->i_sb);
>  
>  	appending = file->f_flags & O_APPEND ? 1 : 0;
>  	direct_io = file->f_flags & O_DIRECT ? 1 : 0;
> @@ -2434,6 +2440,7 @@ out_sems:
>  		ocfs2_iocb_clear_sem_locked(iocb);
>  
>  	mutex_unlock(&inode->i_mutex);
> +	sb_end_write(inode->i_sb);
>  
>  	if (written)
>  		ret = written;
> diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
> index a1a1bfd..d9c352b 100644
> --- a/fs/ocfs2/ioctl.c
> +++ b/fs/ocfs2/ioctl.c
> @@ -926,7 +926,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  		if (get_user(new_clusters, (int __user *)arg))
>  			return -EFAULT;
>  
> -		return ocfs2_group_extend(inode, new_clusters);
> +		status = mnt_want_write_file(filp);
> +		if (status)
> +			return status;
> +		status = ocfs2_group_extend(inode, new_clusters);
> +		mnt_drop_write_file(filp);
> +		return status;
>  	case OCFS2_IOC_GROUP_ADD:
>  	case OCFS2_IOC_GROUP_ADD64:
>  		if (!capable(CAP_SYS_RESOURCE))
> @@ -935,7 +940,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  		if (copy_from_user(&input, (int __user *) arg, sizeof(input)))
>  			return -EFAULT;
>  
> -		return ocfs2_group_add(inode, &input);
> +		status = mnt_want_write_file(filp);
> +		if (status)
> +			return status;
> +		status = ocfs2_group_add(inode, &input);
> +		mnt_drop_write_file(filp);
> +		return status;
>  	case OCFS2_IOC_REFLINK:
>  		if (copy_from_user(&args, (struct reflink_arguments *)arg,
>  				   sizeof(args)))
> diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
> index 9cd4108..d150372 100644
> --- a/fs/ocfs2/mmap.c
> +++ b/fs/ocfs2/mmap.c
> @@ -136,6 +136,7 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
>  	sigset_t oldset;
>  	int ret;
>  
> +	sb_start_pagefault(inode->i_sb);
>  	ocfs2_block_signals(&oldset);
>  
>  	/*
> @@ -165,6 +166,7 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
>  
>  out:
>  	ocfs2_unblock_signals(&oldset);
> +	sb_end_pagefault(inode->i_sb);
>  	return ret;
>  }
>  
> -- 
> 1.7.1
> 

-- 

Life's Little Instruction Book #197

	"Don't forget, a person's greatest emotional need is to 
	 feel appreciated."

			http://www.jlbec.org/
			jlbec@...lplan.org
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