From: Zhang Yi <yi.zhang@huaweicloud.com>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org, tytso@mit.edu,
adilger.kernel@dilger.ca, jack@suse.cz, ritesh.list@gmail.com,
hch@infradead.org, djwong@kernel.org, willy@infradead.org,
zokeefe@google.com, yi.zhang@huawei.com, chengzhihao1@huawei.com,
yukuai3@huawei.com, wangkefeng.wang@huawei.com
Subject: Re: [RFC PATCH v4 29/34] ext4: fall back to buffer_head path for defrag
Date: Mon, 6 May 2024 21:05:22 +0800 [thread overview]
Message-ID: <5dbb3021-b92e-2e53-7eee-5a6595a5ad03@huaweicloud.com> (raw)
In-Reply-To: <ZjIMQTAtxZ0NhCD2@dread.disaster.area>
On 2024/5/1 17:32, Dave Chinner wrote:
> On Wed, Apr 10, 2024 at 11:03:08PM +0800, Zhang Yi wrote:
>> From: Zhang Yi <yi.zhang@huawei.com>
>>
>> Online defrag doesn't support iomap path yet, we have to fall back to
>> buffer_head path for the inode which has been using iomap. Changing
>> active inode is dangerous, before we start, we must hold the inode lock
>> and the mapping->invalidate_lock, and writeback all dirty folios and
>> drop the inode's pagecache.
>
> Even then, I don't think this is obviously safe. We went through
> this with DAX and we couldn't make it work safely.
>
> Just return EOPNOTSUPP to the online defrag ioctl if iomap is in use
> - that avoids all the excitement involved in doing dangerous things
> like swapping aops structures on actively referenced inodes...
>
Okay, this is just a temporary solution to support defrag. I've been
looking at how to support defrag for iomap recently, I hope it could
be supported in the near future, so let's drop this dangerous
operation.
Thanks,
Yi.
next prev parent reply other threads:[~2024-05-06 13:05 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-10 14:29 [RESEND RFC PATCH v4 00/34] ext4: use iomap for regular file's buffered IO path and enable large folio Zhang Yi
2024-04-10 14:29 ` [PATCH v4 01/34] ext4: factor out a common helper to query extent map Zhang Yi
2024-04-26 11:55 ` Ritesh Harjani
2024-04-10 14:29 ` [PATCH v4 02/34] ext4: check the extent status again before inserting delalloc block Zhang Yi
2024-04-26 12:31 ` Ritesh Harjani
2024-04-26 12:57 ` Ritesh Harjani
2024-04-26 13:19 ` Zhang Yi
2024-04-26 16:39 ` Ritesh Harjani
2024-04-28 3:00 ` Zhang Yi
2024-04-29 14:59 ` Ritesh Harjani
2024-05-07 3:15 ` Zhang Yi
2024-05-01 7:47 ` Dave Chinner
2024-05-01 6:51 ` Dave Chinner
2024-05-01 12:19 ` Ritesh Harjani
2024-05-01 22:49 ` Dave Chinner
2024-05-02 4:11 ` Ritesh Harjani
2024-05-06 3:49 ` Zhang Yi
2024-04-10 14:29 ` [PATCH v4 03/34] ext4: trim delalloc extent Zhang Yi
2024-05-01 14:31 ` Ritesh Harjani
2024-05-06 6:15 ` Zhang Yi
2024-04-10 14:29 ` [PATCH v4 04/34] ext4: drop iblock parameter Zhang Yi
2024-05-01 14:41 ` Ritesh Harjani
2024-04-10 14:29 ` [PATCH v4 05/34] ext4: make ext4_es_insert_delayed_block() insert multi-blocks Zhang Yi
2024-04-10 14:29 ` [PATCH v4 06/34] ext4: make ext4_da_reserve_space() reserve multi-clusters Zhang Yi
2024-04-10 14:29 ` [PATCH v4 07/34] ext4: factor out check for whether a cluster is allocated Zhang Yi
2024-04-10 14:29 ` [PATCH v4 08/34] ext4: make ext4_insert_delayed_block() insert multi-blocks Zhang Yi
2024-04-10 14:29 ` [PATCH v4 09/34] ext4: make ext4_da_map_blocks() buffer_head unaware Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 10/34] ext4: factor out ext4_map_create_blocks() to allocate new blocks Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 11/34] ext4: optimize the EXT4_GET_BLOCKS_DELALLOC_RESERVE flag set Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 12/34] ext4: don't set EXTENT_STATUS_DELAYED on allocated blocks Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 13/34] ext4: let __revise_pending() return newly inserted pendings Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 14/34] ext4: count removed reserved blocks for delalloc only extent entry Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 15/34] ext4: update delalloc data reserve spcae in ext4_es_insert_extent() Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 16/34] ext4: drop ext4_es_delayed_clu() Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 17/34] ext4: use ext4_map_query_blocks() in ext4_map_blocks() Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 18/34] ext4: drop ext4_es_is_delonly() Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 19/34] ext4: drop all delonly descriptions Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 20/34] ext4: use reserved metadata blocks when splitting extent on endio Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 21/34] ext4: introduce seq counter for the extent status entry Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 22/34] ext4: add a new iomap aops for regular file's buffered IO path Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 23/34] ext4: implement buffered read iomap path Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 24/34] ext4: implement buffered write " Zhang Yi
2024-05-01 8:11 ` Dave Chinner
2024-05-01 8:33 ` Dave Chinner
2024-05-06 11:44 ` Zhang Yi
2024-05-06 23:19 ` Dave Chinner
2024-05-07 5:10 ` Zhang Yi
2024-05-06 11:21 ` Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 25/34] ext4: implement writeback " Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 26/34] ext4: implement mmap " Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 27/34] ext4: implement zero_range " Zhang Yi
2024-05-01 9:40 ` Dave Chinner
2024-05-06 12:33 ` Zhang Yi
2024-04-10 14:29 ` [RFC PATCH v4 28/34] ext4: writeback partial blocks before zeroing out range Zhang Yi
2024-04-10 15:03 ` [RFC PATCH v4 29/34] ext4: fall back to buffer_head path for defrag Zhang Yi
2024-05-01 9:32 ` Dave Chinner
2024-05-06 13:05 ` Zhang Yi [this message]
2024-04-10 15:03 ` [RFC PATCH v4 30/34] ext4: partial enable iomap for regular file's buffered IO path Zhang Yi
2024-04-10 15:03 ` [RFC PATCH v4 31/34] filemap: support disable large folios on active inode Zhang Yi
2024-04-10 15:03 ` [RFC PATCH v4 32/34] ext4: enable large folio for regular file with iomap buffered IO path Zhang Yi
2024-04-10 15:03 ` [RFC PATCH v4 33/34] ext4: don't mark IOMAP_F_DIRTY for buffer write Zhang Yi
2024-05-01 9:27 ` Dave Chinner
2024-05-06 14:02 ` Zhang Yi
2024-04-10 15:03 ` [RFC PATCH v4 34/34] ext4: add mount option for buffered IO iomap path Zhang Yi
2024-04-11 1:12 ` [RESEND RFC PATCH v4 00/34] ext4: use iomap for regular file's buffered IO path and enable large folio Zhang Yi
2024-04-24 8:12 ` Zhang Yi
-- strict thread matches above, loose matches on Subject: below --
2024-04-10 13:27 [RFC " Zhang Yi
2024-04-10 13:28 ` [RFC PATCH v4 29/34] ext4: fall back to buffer_head path for defrag Zhang Yi
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