Linux Btrfs filesystem development
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From: calin <calin@splitreflection.com>
To: Stephan von Krawczynski <skraw@ithnet.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Some very basic questions
Date: Tue, 21 Oct 2008 10:37:14 -0700	[thread overview]
Message-ID: <20081021173714.29505.qmail@splitreflection.com> (raw)

> question is: if you had such an implementation, are there
> drawbacks expectable for the single-mount case? If not I'd vote for it
> because there are not really many alternatives "on the market".

As I understand it, the largest issue is in locking and boundaries.  Two different systems could mount a filesystem, and try to use some sort of on-disk markers to keep from writing to the same area at the same time... but there is often some bit of time between when a system sends data to the disk and when it would become available to read from the disk, and little or no guarantee about the order in which the data is written.  All the work that goes into making transactions atomic depends on there only being a single path to the disk - through the code that handles transactions.  If data can arrive on the disk without being managed by that code, all bets are off.

             reply	other threads:[~2008-10-21 17:37 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-21 17:37 calin [this message]
2008-10-21 20:08 ` Some very basic questions jim owens
2008-10-22  7:15   ` Avi Kivity
2008-10-22 14:13     ` jim owens
2008-10-22 14:25       ` Avi Kivity
  -- strict thread matches above, loose matches on Subject: below --
2008-10-22 14:35 dbz
2008-10-27 15:43 ` Stephan von Krawczynski
2008-10-21 11:23 Stephan von Krawczynski
2008-10-21 12:13 ` Andi Kleen
2008-10-21 14:22   ` Stephan von Krawczynski
2008-10-21 15:34     ` jim owens
2008-10-22 11:36       ` Stephan von Krawczynski
2008-10-22 12:15         ` Avi Kivity
2008-10-22 13:03           ` Ric Wheeler
2008-10-22 13:13             ` Chris Mason
2008-10-22 13:16             ` Avi Kivity
2008-10-21 13:20 ` jim owens
2008-10-21 17:01   ` Stephan von Krawczynski
2008-10-21 17:15     ` Christoph Hellwig
2008-10-21 17:31       ` Ric Wheeler
2008-10-22 12:27         ` Stephan von Krawczynski
2008-10-22 13:15           ` Chris Mason
2008-10-22 13:27             ` Ric Wheeler
2008-10-22 14:32               ` Avi Kivity
2008-10-22 14:36                 ` Chris Mason
2008-10-22 14:40                   ` Avi Kivity
2008-10-22 14:46                 ` Ric Wheeler
2008-10-22 14:54                   ` Avi Kivity
2008-10-22 15:02                     ` Ric Wheeler
2008-10-22 15:13                       ` Avi Kivity
2008-10-22 15:25                         ` Ric Wheeler
2008-10-22 15:33                           ` Chris Mason
2008-10-22 15:43                             ` Avi Kivity
2008-10-22 15:54                               ` Ric Wheeler
2008-10-22 18:28                                 ` Avi Kivity
2008-10-22 15:39                           ` Avi Kivity
2008-10-22 13:52             ` Stephan von Krawczynski
2008-10-22 15:56               ` Michel Salim
2008-10-22 16:56                 ` jim owens
2008-10-23  9:47                 ` Stephan von Krawczynski
2008-10-22 11:40       ` Stephan von Krawczynski
2008-10-21 13:59 ` Chris Mason
2008-10-21 16:09   ` Andi Kleen
2008-10-22 11:43     ` Stephan von Krawczynski
2008-10-21 16:27   ` Stephan von Krawczynski
2008-10-21 16:59     ` Andi Kleen
2008-10-22 11:46       ` Stephan von Krawczynski
2008-10-21 17:49     ` Chris Mason
2008-10-22 12:19       ` Stephan von Krawczynski
2008-10-22 12:48         ` Jeff Schroeder
2008-10-22 14:02           ` Stephan von Krawczynski
2008-10-22 13:50         ` Chris Mason
2008-10-22 14:04           ` Matthias Wächter
2008-10-22 14:32             ` Ric Wheeler
2008-10-22 14:44               ` jim owens
2008-10-24  8:42           ` Chris Samuel
2008-10-24  8:39         ` Chris Samuel
2008-10-21 20:54   ` Eric Anopolsky
2008-10-21 22:18     ` Ric Wheeler
2008-10-22  2:29       ` Eric Anopolsky
2008-10-22 10:42         ` Ric Wheeler
2008-10-22 10:53           ` Tejun Heo
2008-10-22 12:57             ` Ric Wheeler
2008-10-22 12:57             ` Ric Wheeler
2008-10-22 13:15               ` Tejun Heo
2008-10-22 13:19                 ` Chris Mason
2008-10-22 13:38                   ` Ric Wheeler
2008-10-22 13:59                     ` Chris Mason
2008-10-22 14:23                       ` Ric Wheeler
2008-10-22 13:23                 ` Ric Wheeler
2008-10-22 16:14                   ` Tejun Heo
2008-10-22 16:34                     ` Ric Wheeler
2008-10-23  3:59                       ` Tejun Heo
2008-10-22 18:32                     ` Avi Kivity
2008-10-22 19:13                       ` jim owens
2008-10-22 19:22                         ` Avi Kivity
2008-10-22 19:59                       ` Ric Wheeler
2008-10-22 21:31                     ` Eric Anopolsky
2008-10-22 21:56                       ` Ric Wheeler

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