From: "Austin S. Hemmelgarn" <ahferroin7@gmail.com>
To: linux-btrfs@vger.kernel.org
Subject: Re: commands like "du", "df", and "btrfs fs sync" hang
Date: Mon, 2 May 2016 09:19:13 -0400 [thread overview]
Message-ID: <e3286f17-fc34-9b48-0256-cbc7dafe576a@gmail.com> (raw)
In-Reply-To: <pan$cd18$90efec60$149cab40$cd3d9864@cox.net>
On 2016-05-01 19:49, Duncan wrote:
> Kai Krakow posted on Sun, 01 May 2016 18:54:18 +0200 as excerpted:
>
>> It affects all file systems. The "btrfs fi sync" is used to finish my
>> rsync backup and ensure everything is written before I'm trying to
>> unmount it or the system goes back to sleep.
>>
>> "df" and friends also freeze on tmp (ramdisk) fs and vfat fs (my EFI
>> boot partition).
>
> That's just weird, there. df on tmpfs triggers a stall as well? Weird
> to the point I wonder if you're seeing a general block layer bug... only
> involving btrfs if btrfs is somehow fowling up the block layer for
> everyone else as well. Whatever it is, it's obviously far different than
> my first guess, which now looks ridiculously wrong. Oh, well...
The question is: is it actually on a ramdisk (with a separate filesystem
on top of that), or is it on tmpfs? The ramdisk method is used by some
people because it lets you do some more interesting things, but tmpfs is
much more efficient (in terms of both processing time, and RAM usage).
If it's on a ramdisk, then it may be a block layer bug, but if it's on
tmpfs, then it's a VFS layer bug instead.
That said, if something i8n BTRFS is causing stalls in the block layer,
that would definately explain what is going on, as that can cause all
I/O to stall across the whole system.
next prev parent reply other threads:[~2016-05-02 13:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-01 7:00 commands like "du", "df", and "btrfs fs sync" hang Kai Krakow
2016-05-01 12:47 ` Duncan
2016-05-01 13:54 ` Mike Fleetwood
2016-05-01 23:16 ` Duncan
2016-05-01 16:54 ` Kai Krakow
2016-05-01 23:22 ` Duncan
2016-05-01 23:49 ` Duncan
2016-05-02 13:19 ` Austin S. Hemmelgarn [this message]
2016-05-03 6:44 ` Kai Krakow
2016-05-02 0:23 ` Duncan
2016-05-02 13:13 ` Austin S. Hemmelgarn
2016-05-03 15:09 ` Duncan
2016-05-02 0:39 ` Nicholas D Steeves
2016-05-03 6:48 ` Kai Krakow
2016-05-05 6:35 ` Kai Krakow
2016-05-07 11:40 ` Kai Krakow
2016-05-09 17:13 ` Nicholas D Steeves
2016-05-09 18:20 ` Kai Krakow
-- strict thread matches above, loose matches on Subject: below --
2016-05-01 10:22 Kai Krakow
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=e3286f17-fc34-9b48-0256-cbc7dafe576a@gmail.com \
--to=ahferroin7@gmail.com \
--cc=linux-btrfs@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).