From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
To: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
adrian.hunter@intel.com, Heinz.Egger@linutronix.de,
thomas.wucher@linutronix.de, shmulik.ladkani@gmail.com,
tglx@linutronix.de, tim.bird@am.sony.com, Marius.Mazarel@ugal.ro,
nyoushchenko@mvista.com
Subject: Re: UBI fastmap updates
Date: Thu, 02 Aug 2012 19:45:30 +0300 [thread overview]
Message-ID: <1343925930.25013.163.camel@sauron.fi.intel.com> (raw)
In-Reply-To: <20120802183210.7076aa48@spider.haslach.nod.at>
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Richard,
On Thu, 2012-08-02 at 18:32 +0200, Richard Weinberger wrote:
> > This should not happen. Fastmap should _reserve_ enough of PEBs for it
> > to operate. It should always find the PEB to write.
>
> What is the benefit?
> IOW what is wrong with the current approach?
Several reasons. The main is: fastmap will start consuming PEBs reserved
for volumes when the amount of available PEBs is just enough to map all
LEBs. This will break UBI liability.
> Why?
> 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.
--
Best Regards,
Artem Bityutskiy
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next prev parent reply other threads:[~2012-08-02 16:41 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 [this message]
2012-08-02 16:54 ` Richard Weinberger
2012-08-02 17:03 ` Tim Bird
2012-08-02 17:06 ` Richard Weinberger
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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