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Date: Sun, 27 Apr 2008 19:26:17 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [patch 3/5] fuse: fix race in llseek
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On Fri, 25 Apr 2008 19:55:23 +0200 Miklos Szeredi <miklos@szeredi.hu> wrote:

> +static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
> +{
> +	long long retval;

I switched this to have a type of loff_t.

> +	struct inode *inode = file->f_path.dentry->d_inode;
> +
> +	mutex_lock(&inode->i_mutex);
> +	switch (origin) {
> +	case SEEK_END:
> +		offset += i_size_read(inode);

As we hold i_mutex we could directly read inode->i_size here, save a few
cycles.

> +		break;
> +	case SEEK_CUR:
> +		offset += file->f_pos;
> +	}
> +	retval = -EINVAL;
> +	if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
> +		if (offset != file->f_pos) {
> +			file->f_pos = offset;
> +			file->f_version = 0;
> +		}
> +		retval = offset;
> +	}
> +	mutex_unlock(&inode->i_mutex);
> +	return retval;
> +}