From: David Sterba <dsterba@suse.cz>
To: Qu Wenruo <quwenruo@cn.fujitsu.com>
Cc: linux-btrfs@vger.kernel.org, kilobyte@angband.pl
Subject: Re: [PATCH] btrfs: Remove false alert when fiemap range is smaller than on-disk extent
Date: Tue, 27 Jun 2017 15:14:40 +0200 [thread overview]
Message-ID: <20170627131440.GW2866@suse.cz> (raw)
In-Reply-To: <20170622020121.8381-1-quwenruo@cn.fujitsu.com>
On Thu, Jun 22, 2017 at 10:01:21AM +0800, Qu Wenruo wrote:
> Commit 4751832da990 ("btrfs: fiemap: Cache and merge fiemap extent before
> submit it to user") introduced a warning to catch unemitted cached
> fiemap extent.
>
> However such warning doesn't take the following case into consideration:
>
> 0 4K 8K
> |<---- fiemap range --->|
> |<----------- On-disk extent ------------------>|
>
> In this case, the whole 0~8K is cached, and since it's larger than
> fiemap range, it break the fiemap extent emit loop.
> This leaves the fiemap extent cached but not emitted, and caught by the
> final fiemap extent sanity check, causing kernel warning.
>
> This patch removes the kernel warning and renames the sanity check to
> emit_last_fiemap_cache() since it's possible and valid to have cached
> fiemap extent.
>
> Reported-by: David Sterba <dsterba@suse.cz>
> Reported-by: Adam Borowski <kilobyte@angband.pl>
> Fixes: 4751832da990 ("btrfs: fiemap: Cache and merge fiemap extent ...")
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Thanks, added to 4.13 queue.
prev parent reply other threads:[~2017-06-27 13:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-22 2:01 [PATCH] btrfs: Remove false alert when fiemap range is smaller than on-disk extent Qu Wenruo
2017-06-22 2:39 ` Adam Borowski
2017-06-27 13:14 ` David Sterba [this message]
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=20170627131440.GW2866@suse.cz \
--to=dsterba@suse.cz \
--cc=kilobyte@angband.pl \
--cc=linux-btrfs@vger.kernel.org \
--cc=quwenruo@cn.fujitsu.com \
/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).