linux-kernel - Re: [PATCH v3 4/4] fs/sysv: Replace kmap() with kmap_local

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Message-ID: <Y8nmLh0cyloTzfAN@ZenIV>
Date:   Fri, 20 Jan 2023 00:54:06 +0000
From:   Al Viro <viro@...iv.linux.org.uk>
To:     "Fabio M. De Francesco" <fmdefrancesco@...il.com>
Cc:     Christoph Hellwig <hch@...radead.org>,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        Ira Weiny <ira.weiny@...el.com>
Subject: Re: [PATCH v3 4/4] fs/sysv: Replace kmap() with kmap_local_page()

On Thu, Jan 19, 2023 at 04:32:32PM +0100, Fabio M. De Francesco wrote:
> @@ -228,6 +239,12 @@ int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
>  {
>  	struct inode *inode = page->mapping->host;
>  	loff_t pos = page_offset(page) + offset_in_page(de);
> +	/*
> +	 * The "de" dentry points somewhere in the same page whose we need the
> +	 * address of; therefore, we can simply get the base address "kaddr" by
> +	 * masking the previous with PAGE_MASK.
> +	 */
> +	char *kaddr = (char *)((unsigned long)de & PAGE_MASK);

er...  ITYM "therefore we can pass de to dir_put_page() and get rid of that kaddr
thing"...

Anyway, with that change the series rebased and applied on top of Christoph's sysv
patch.