From: Qu Wenruo <quwenruo@cn.fujitsu.com>
To: dsterba@suse.cz, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH v2 07/11] btrfs: Add noinode_cache mount option.
Date: Mon, 06 Jan 2014 08:54:53 +0800 [thread overview]
Message-ID: <52C9FEDD.9010301@cn.fujitsu.com> (raw)
In-Reply-To: <20140103175244.GR6498@twin.jikos.cz>
On fri, 3 Jan 2014 18:52:44 +0100, David Sterba wrote:
> On Fri, Jan 03, 2014 at 02:10:30PM +0800, Qu Wenruo wrote:
>> Add noinode_cache mount option to disable inode map cache with
>> remount option.
> This looks almost safe, there's a sync_filesystem called before the
> filesystem's remount handler, the transaction gets committed and flushes
> all tha data related to inode_cache.
>
> The caching thread keeps running, which is not a serious problem as
> it'll finish at umount time, only consuming resources.
>
> There's a window between sync_filesystem and successful remount when the
> INODE_MAP_CACHE bit is set and the cache could be used to get a free ino,
> then the INODE_MAP_CACHE is cleared but the ino cache remains is not
> synced back to disk, normally called from transaction commit via
> btrfs_unpin_free_ino. I haven't looked if something else blocks that to
> happen.
>
> I'd leave this patch out for now, it probably needs more code updates
> than just unsetting the bit.
>
> david
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>
Thanks for pointing out the hidden problem.
I'll check the related source again to keep this behavior safe or
add new codes.
So in next patchset, the inode map cache option will not be included
and will be seperated to a new patch.
Qu
next prev parent reply other threads:[~2014-01-06 0:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-03 6:10 [PATCH v2 00/11] btrfs: Add missing pairing mount options Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 01/11] btrfs: Add "barrier" option to support "-o remount,barrier" Qu Wenruo
2014-01-03 8:44 ` Mike Fleetwood
2014-01-03 9:20 ` Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 02/11] btrfs: Add noautodefrag mount option Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 03/11] btrfs: Add nocheck_int " Qu Wenruo
2014-01-03 17:13 ` David Sterba
2014-01-06 0:51 ` Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 04/11] btrfs: Add nodiscard " Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 05/11] btrfs: Add noenospc_debug " Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 06/11] btrfs: Add noflushoncommit " Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 07/11] btrfs: Add noinode_cache " Qu Wenruo
2014-01-03 17:52 ` David Sterba
2014-01-06 0:54 ` Qu Wenruo [this message]
2014-01-03 6:10 ` [PATCH v2 08/11] btrfs: Add acl " Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 09/11] btrfs: Add datacow " Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 10/11] btrfs: Add datasum " Qu Wenruo
2014-01-03 6:10 ` [PATCH v2 11/11] btrfs: Add treelog " Qu Wenruo
2014-01-03 17:52 ` [PATCH v2 00/11] btrfs: Add missing pairing mount options Eric Sandeen
2014-01-06 0:58 ` Qu Wenruo
2014-01-03 17:58 ` David Sterba
2014-01-06 1:01 ` Qu Wenruo
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