From: Theodore Ts'o <tytso@mit.edu>
To: Nikolay Borisov <kernel@kyup.com>
Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] ext4: make use of sb_getblk_gfp
Date: Thu, 2 Jul 2015 10:17:54 -0400 [thread overview]
Message-ID: <20150702141754.GA9456@thunk.org> (raw)
In-Reply-To: <5594D742.6040202@kyup.com>
On Thu, Jul 02, 2015 at 09:16:34AM +0300, Nikolay Borisov wrote:
>
> Just a question that popped to my mind after discussing with a colleague
> - Is GFP_NOFS enough here or should it be GFP_NOIO? Presumably the
> latter is a stronger guarantee that we are not going to hit any
> fs/writeback related code?
GFP_NOFS is fine here; file system code calls the I/O codepaths, but
device driver code doesn't call fs code. Put another way, if there
are pages that are backed by a block device, which can be cleaned
without going through the FS code paths, it's fine to let that happen
while we are inside file system code.
- Ted
next prev parent reply other threads:[~2015-07-02 14:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-30 6:26 [PATCH 1/2] bufferhead: Add _gfp version for sb_getblk() Nikolay Borisov
2015-06-30 6:26 ` [PATCH 2/2] ext4: make use of sb_getblk_gfp Nikolay Borisov
2015-07-02 6:14 ` Theodore Ts'o
2015-07-02 6:16 ` Nikolay Borisov
2015-07-02 14:17 ` Theodore Ts'o [this message]
2015-07-02 6:14 ` [PATCH 1/2] bufferhead: Add _gfp version for sb_getblk() Theodore Ts'o
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150702141754.GA9456@thunk.org \
--to=tytso@mit.edu \
--cc=adilger.kernel@dilger.ca \
--cc=kernel@kyup.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).