From: "Theodore Ts'o" <tytso@mit.edu>
To: Pavel Machek <pavel@ucw.cz>
Cc: Reindl Harald <h.reindl@thelounge.net>,
linux-ext4@vger.kernel.org,
kernel list <linux-kernel@vger.kernel.org>,
kent.overstreet@gmail.com, linux-bcache@vger.kernel.org
Subject: Re: bcache with existing ext4 filesystem
Date: Tue, 25 Jul 2017 14:02:25 -0400 [thread overview]
Message-ID: <20170725180225.2k3o6xtdnhygrhia@thunk.org> (raw)
In-Reply-To: <20170725134604.GA26445@amd>
On Tue, Jul 25, 2017 at 03:46:04PM +0200, Pavel Machek wrote:
>
> Is there some field in ext2 superblock that changes every time
> filesystem is changed? Is mtime changed by fsck/badblocks/...?
No, there isn't. If we were writing the superblock every time the
file system is changed it would be ***extremely*** flash unfriendly.
It would also be a scalability bottleneck, it would cause us to pay an
extra HDD seek, etc. So it's a really bad Bad BAD idea, and so we
don't do it.
Cheers,
- Ted
next prev parent reply other threads:[~2017-07-25 18:02 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-24 18:57 Pavel Machek
2017-07-24 19:08 ` Reindl Harald
2017-07-24 19:15 ` Pavel Machek
2017-07-24 19:27 ` Theodore Ts'o
2017-07-24 20:04 ` Pavel Machek
2017-07-25 4:51 ` Theodore Ts'o
2017-07-25 6:43 ` Pavel Machek
2017-07-25 10:32 ` Vojtech Pavlik
2017-07-25 11:12 ` Pavel Machek
2017-07-25 16:10 ` Theodore Ts'o
2017-07-25 18:13 ` Eric Wheeler
2017-07-25 22:02 ` Pavel Machek
2017-07-26 17:41 ` Eric Wheeler
2017-07-26 18:59 ` Austin S. Hemmelgarn
2017-07-26 19:16 ` Eric Wheeler
2017-07-26 20:01 ` Pavel Machek
2017-07-25 13:46 ` Pavel Machek
2017-07-25 18:02 ` Theodore Ts'o [this message]
2017-07-25 20:55 ` Pavel Machek
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