From: Pavel Machek <pavel@ucw.cz>
To: Metztli Information Technology <jose.r.r@metztli.com>
Cc: edward.shishkin@gmail.com, reiserfs-devel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [ANNOUNCE] Reiser5: Selective File Migration - User Interface
Date: Sun, 4 Oct 2020 11:59:23 +0200 [thread overview]
Message-ID: <20201004095922.GC1104@bug> (raw)
In-Reply-To: <20200826205216.07BC868EF679@huitzilopochtli.metztli-it.com>
Hi!
> > In particular, using this functionality, user is able to push out
> > "hot" files on any high-performance device (e.g. proxy device) and pin
> > them there.
What permissions are normally required for file migration?
> > COMMENT. After ioctl successful completion the file is not necessarily
> > written to the target device! To make sure of it, call fsync(2) after
> > successful ioctl completion, or open the file with O_SYNC flag before
> > migration.
Ok.
> > COMMENT. File migration is a volume operation (like adding, removing a device to/from
> > a logical volumes), and all volume operations are serialized. So, any attempt to
> > migrate a file, while performing other operation on that volume will fail. If some
> > file migration procedure fails (with EBUSY, or other errors), or was interrupted by
> > user, then it should be repeated in the current mount session. File migration
> > procedures interrupted by system crash, hared reset, etc) should be repeated in the
> > next mount sessions.
Dunno. Returning -EBUSY is kind of "interesting" there. I'd expect kernel to queue
the callers, because userland can't really do that easily.
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2020-10-04 9:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-26 20:52 [ANNOUNCE] Reiser5: Selective File Migration - User Interface Metztli Information Technology
2020-08-26 21:13 ` Edward Shishkin
2020-10-04 9:59 ` Pavel Machek [this message]
2020-10-17 15:53 ` Edward Shishkin
-- strict thread matches above, loose matches on Subject: below --
2020-08-30 7:04 Metztli Information Technology
2020-08-27 21:53 Metztli Information Technology
2020-08-27 23:50 ` Edward Shishkin
2020-08-29 9:54 ` Edward Shishkin
2020-07-05 11:12 Edward Shishkin
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