From: Matthew Wilcox <willy@infradead.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: jfs-discussion@lists.sourceforge.net,
linux-fsdevel@vger.kernel.org,
"Darrick J . Wong" <djwong@kernel.org>
Subject: Re: [RFC PATCH 2/9] jfs: Add jfs_iomap_begin()
Date: Fri, 27 May 2022 14:45:12 +0100 [thread overview]
Message-ID: <YpDV6NPBefdYRywi@casper.infradead.org> (raw)
In-Reply-To: <YpBkiy4zvIcEXihd@infradead.org>
On Thu, May 26, 2022 at 10:41:31PM -0700, Christoph Hellwig wrote:
> I suspect this might be where your problems lies:
>
> blockdev_direct_IO calls __blockdev_direct_IO with DIO_SKIP_HOLES set.
> DIO_SKIP_HOLES causes get_more_blocks to never set the create bit
> to get_block except for writes beyond i_size. If we want to replicate
> that behavior with iomap, ->iomap_begin needs to return -ENOTBLK
> when it encounters a hole for writing. To properly supporting writing
> to holes we'd need unwritten extents, which jfs does not support.
> gfs2 might be a place to look for how to implement this.
I think JFS does support unwritten extents,
fs/jfs/jfs_xtree.h:#define XAD_NOTRECORDED 0x08 /* allocated but not recorded */
However, we always pass 'false' to extAlloc() today, so I think it
hasn't been tested in a while? I'm not sure I want to be the one to
start using new features on JFS for something that's supposed to be
a relatively quick cleanup.
next prev parent reply other threads:[~2022-05-27 13:45 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-26 19:29 [RFC PATCH 0/9] Convert JFS to use iomap Matthew Wilcox (Oracle)
2022-05-26 19:29 ` [RFC PATCH 1/9] IOMAP_DIO_NOSYNC Matthew Wilcox (Oracle)
2022-05-27 5:35 ` Christoph Hellwig
2022-05-27 13:20 ` Matthew Wilcox
2022-05-26 19:29 ` [RFC PATCH 2/9] jfs: Add jfs_iomap_begin() Matthew Wilcox (Oracle)
2022-05-27 5:41 ` Christoph Hellwig
2022-05-27 13:45 ` Matthew Wilcox [this message]
2022-05-27 14:58 ` [Jfs-discussion] " Dave Kleikamp
2022-05-26 19:29 ` [RFC PATCH 3/9] jfs: Convert direct_IO read support to use iomap Matthew Wilcox (Oracle)
2022-05-26 19:29 ` [RFC PATCH 4/9] jfs: Convert direct_IO write " Matthew Wilcox (Oracle)
2022-05-26 19:29 ` [RFC PATCH 5/9] jfs: Remove old direct_IO support Matthew Wilcox (Oracle)
2022-05-26 19:29 ` [RFC PATCH 6/9] jfs: Handle bmap with iomap Matthew Wilcox (Oracle)
2022-05-26 19:29 ` [RFC PATCH 7/9] jfs: Read quota through the page cache Matthew Wilcox (Oracle)
2022-05-27 5:43 ` Christoph Hellwig
2022-05-27 13:56 ` Matthew Wilcox
2022-06-03 14:40 ` generic_quota_read Matthew Wilcox
2022-06-06 7:37 ` generic_quota_read Jan Kara
2022-05-26 19:29 ` [RFC PATCH 8/9] jfs: Write quota through the page cache Matthew Wilcox (Oracle)
2022-05-27 5:46 ` Christoph Hellwig
2022-05-26 19:29 ` [RFC PATCH 9/9] jfs: Convert buffered IO paths to iomap Matthew Wilcox (Oracle)
2022-05-28 0:02 ` [RFC PATCH 0/9] Convert JFS to use iomap Dave Chinner
2022-05-28 2:15 ` Matthew Wilcox
2022-05-28 5:36 ` Dave Chinner
2022-05-28 18:59 ` Theodore Ts'o
2022-05-29 23:51 ` Dave Chinner
2022-05-31 13:51 ` [Jfs-discussion] " Dave Kleikamp
2022-05-31 15:31 ` Matthew Wilcox
2022-05-31 15:56 ` Dave Kleikamp
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