From: Andi Kleen <andi@firstfloor.org>
To: Jan Schmidt <list.btrfs@jan-o-sch.net>
Cc: Andi Kleen <andi@firstfloor.org>,
chris.mason@oracle.com, linux-btrfs@vger.kernel.org
Subject: Re: [RFC PATCH 4/4] btrfs: Moved repair code from inode.c to extent_io.c
Date: Mon, 25 Jul 2011 01:01:43 +0200 [thread overview]
Message-ID: <20110724230143.GY8006@one.firstfloor.org> (raw)
In-Reply-To: <4E2C5628.1020406@jan-o-sch.net>
> I wasn't clear enough on that: We only track read errors, here. Ans
> error correction can only happen on the read path. So if the write
> attempt fails, we can't go into a loop.
Not in a loop, but you trigger more IO errors, which can be nasty
if the IO error logging triggers more IO (pretty common because
syslogd calls fsync). And then your code does even more IO, floods
more etc.etc. And the user will be unhappy if their
console gets flooded.
We've have a similar problems in the past with readahead causing
error flooding.
Any time where an error can cause more IO you have to be extremly
careful.
Right now this seems rather risky to me.
-Andi
next prev parent reply other threads:[~2011-07-24 23:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-22 14:58 [RFC PATCH 0/4] btrfs: Suggestion for raid auto-repair Jan Schmidt
2011-07-22 14:58 ` [RFC PATCH 1/4] btrfs: btrfs_multi_bio replaced with btrfs_bio Jan Schmidt
2011-07-22 14:58 ` [RFC PATCH 2/4] btrfs: Do not use bio->bi_bdev after submission Jan Schmidt
2011-07-22 14:58 ` [RFC PATCH 3/4] btrfs: Put mirror_num in bi_bdev Jan Schmidt
2011-07-22 14:58 ` [RFC PATCH 4/4] btrfs: Moved repair code from inode.c to extent_io.c Jan Schmidt
2011-07-24 16:24 ` Andi Kleen
2011-07-24 17:28 ` Jan Schmidt
2011-07-24 23:01 ` Andi Kleen [this message]
2011-07-25 8:52 ` Jan Schmidt
2011-07-25 3:58 ` Ian Kent
2011-07-25 8:59 ` Jan Schmidt
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