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From: Richard Weinberger <richard@nod.at>
To: Tim Bird <tim.bird@am.sony.com>
Cc: "artem.bityutskiy@linux.intel.com"
	<artem.bityutskiy@linux.intel.com>,
	"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"adrian.hunter@intel.com" <adrian.hunter@intel.com>,
	"Heinz.Egger@linutronix.de" <Heinz.Egger@linutronix.de>,
	"thomas.wucher@linutronix.de" <thomas.wucher@linutronix.de>,
	"shmulik.ladkani@gmail.com" <shmulik.ladkani@gmail.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"Marius.Mazarel@ugal.ro" <Marius.Mazarel@ugal.ro>,
	"nyoushchenko@mvista.com" <nyoushchenko@mvista.com>
Subject: Re: UBI fastmap updates
Date: Thu, 2 Aug 2012 19:06:17 +0200	[thread overview]
Message-ID: <20120802190617.7182924f@spider.haslach.nod.at> (raw)
In-Reply-To: <501AB2C8.9010805@am.sony.com>

Am Thu, 2 Aug 2012 10:03:04 -0700
schrieb Tim Bird <tim.bird@am.sony.com>:
> >> If everything goes wrong, fastmap makes sure that no fastmap is on
> >> flash.
> >> In case of a powercut we fall back to scanning mode.
> >> R/O mode is overkill IMHO.
> > 
> > So can I interpret this the following way. Not only fastmap give no
> > guarantees that it exists after an unclean reboot, it does not even
> > give guarantees that it exists after a clean reboot.
> > 
> > Unless I am confused, the fastmap design is over-simplified.
> 
> Fastmap is an optimization.  Maybe I'm missing something, but
> I'm not sure why, if the optimization stopped working, you
> would want to reduce the functionality of the file system.

That's *exactly* my point.
If fastmap is available - fine, we have fast boot - yay!
But if something really nasty happens we can safely fall back
to scanning mode.
And fastmap is designed to allow this.

Thanks,
//richard

  reply	other threads:[~2012-08-02 17:06 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-09 12:18 UBI fastmap updates Richard Weinberger
2012-07-09 12:18 ` [PATCH 1/7] UBI: Fastmap: Fix lock imbalance in case of an error Richard Weinberger
2012-07-09 12:18 ` [PATCH 2/7] UBI: Fastmap: Get rid of find_fastmap switch Richard Weinberger
2012-07-09 12:18 ` [PATCH 3/7] UBI: Fastmap: Fix memory leak in error path Richard Weinberger
2012-07-09 12:18 ` [PATCH 4/7] UBI: Fastmap: Fix double free " Richard Weinberger
2012-07-09 12:18 ` [PATCH 5/7] UBI: Fastmap: Kerneldoc fixes Richard Weinberger
2012-07-09 12:18 ` [PATCH 6/7] UBI: Fastmap: Make sure that find_wl_entry() never returns NULL Richard Weinberger
2012-07-09 12:18 ` [PATCH 7/7] UBI: Fastmap: Make checkpatch.pl happy Richard Weinberger
2012-08-02 14:12 ` UBI fastmap updates Artem Bityutskiy
2012-08-02 14:15   ` Richard Weinberger
2012-08-02 14:29     ` Artem Bityutskiy
2012-08-02 14:51       ` Richard Weinberger
2012-08-02 16:17         ` Artem Bityutskiy
2012-08-02 16:32           ` Richard Weinberger
2012-08-02 16:45             ` Artem Bityutskiy
2012-08-02 16:54               ` Richard Weinberger
2012-08-02 17:03               ` Tim Bird
2012-08-02 17:06                 ` Richard Weinberger [this message]
2012-08-02 17:40                 ` Artem Bityutskiy
2012-08-02 17:45                   ` Richard Weinberger
2012-08-02 17:59                     ` Artem Bityutskiy
2012-08-02 18:03                       ` Richard Weinberger
2012-08-02 18:15                         ` Artem Bityutskiy
2012-08-05  8:23                     ` Shmulik Ladkani
2012-08-05 14:25                       ` Richard Weinberger
2012-08-02 17:50                 ` Artem Bityutskiy
2012-08-02 14:58 ` Artem Bityutskiy
2012-08-02 14:59   ` Richard Weinberger
2012-08-02 15:18     ` Artem Bityutskiy
2012-08-02 15:19       ` Richard Weinberger
2012-08-06 17:36   ` Richard Weinberger
2012-08-07  4:21     ` Artem Bityutskiy
2012-08-07  7:29       ` Richard Weinberger
2012-08-07 18:53         ` Artem Bityutskiy
2012-08-02 18:50 ` Artem Bityutskiy
2012-08-02 18:56   ` Artem Bityutskiy
2012-08-03  8:47 ` Artem Bityutskiy
2012-08-03  8:56   ` Richard Weinberger
2012-08-17 13:11 ` Artem Bityutskiy
2012-08-17 13:33   ` Richard Weinberger
2012-08-17 13:41     ` Artem Bityutskiy
2012-08-17 13:43       ` Richard Weinberger
2012-08-17 14:06         ` Artem Bityutskiy
  -- strict thread matches above, loose matches on Subject: below --
2013-09-28 13:55 Richard Weinberger
2013-10-03 16:44 ` Artem Bityutskiy
2012-07-02 16:23 Richard Weinberger
2012-06-29 15:14 Richard Weinberger
2012-06-30 10:43 ` Artem Bityutskiy
2012-06-30 10:53   ` Richard Weinberger
2012-06-30 11:24     ` Artem Bityutskiy
2012-06-30 14:24     ` Artem Bityutskiy
2012-07-08 11:47 ` Shmulik Ladkani
2012-07-08 12:07   ` Richard Weinberger
2012-07-08 15:11     ` Richard Weinberger
2012-07-09  7:37     ` Shmulik Ladkani
2012-07-09  8:19       ` Richard Weinberger
2012-06-27 15:57 Richard Weinberger
2012-06-23 13:03 Richard Weinberger
2012-06-27  4:20 ` Namjae Jeon
2012-06-27  6:48   ` Nikita V. Youshchenko
2012-06-27  7:17     ` Richard Weinberger
2012-06-18 16:18 UBI Fastmap updates Richard Weinberger

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