Re: [patch 3/5] fuse: fix race in llseek

Andrew Morton
2008-04-28T02:26:54Z

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;
> +}