linux-ext4 - Re: [PATCH v3] ext4: Rewrite ext4_page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110623103937.GB5171@infradead.org>
Date:	Thu, 23 Jun 2011 06:39:37 -0400
From:	Christoph Hellwig <hch@...radead.org>
To:	Jan Kara <jack@...e.cz>
Cc:	Ted Tso <tytso@....edu>, Christoph Hellwig <hch@...radead.org>,
	linux-ext4@...r.kernel.org
Subject: Re: [PATCH v3] ext4: Rewrite ext4_page_mkwrite() to use generic
 helpers

>  	loff_t size;
>  	unsigned long len;
> +	int ret;
>  	struct file *file = vma->vm_file;
>  	struct inode *inode = file->f_path.dentry->d_inode;
>  	struct address_space *mapping = inode->i_mapping;
> +	handle_t *handle;
> +	get_block_t *get_block;
> +	int retries = 0;
>  
>  	/*
> +	 * This check is racy but catches the common case. We rely on
> +	 * __block_page_mkwrite() to do a reliable check.
>  	 */
> +	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
> +	/* Delalloc case is easy... */
> +	if (test_opt(inode->i_sb, DELALLOC) &&
> +	    !ext4_should_journal_data(inode) &&
> +	    !ext4_nonda_switch(inode->i_sb)) {
> +		do {
> +			ret = __block_page_mkwrite(vma, vmf,
> +						   ext4_da_get_block_prep);
> +		} while (ret == -ENOSPC &&
> +		       ext4_should_retry_alloc(inode->i_sb, &retries));
> +		goto out_ret;

Is there any way to simply provide a different vm_operations_struct
and thus ->fault implementation for the delalloc vs non-delalloc case?

I think splitting those two cases completely would make the code a lot
more readable, even if there is a tiny amount of code duplication.

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html