From: Christoph Hellwig <hch@lst.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 14/17] xfs: use bios directly to read and write the log recovery buffers
Date: Tue, 21 May 2019 07:09:43 +0200 [thread overview]
Message-ID: <20190521050943.GA29120@lst.de> (raw)
In-Reply-To: <20190520233233.GF29573@dread.disaster.area>
On Tue, May 21, 2019 at 09:32:33AM +1000, Dave Chinner wrote:
> So while it's easy to drop the uncached buffer API from the kernel
> side, it leaves me with the question of what API do we use in
> userspace to provide this same functionality? I suspect that we
> probably need to separate all this log-to-bio code out into a
> separate file (e.g. xfs_log_io.[ch]) to leave a set of API stubs
> that we can reimplement in userspace to pread/pwrite directly to
> the log buftarg device fd as I've done already for the buffer
> code...
For one we still keep the uncached buffers in xfs_buf.c as we have users
of that outside of the log code, but I guess that is not what you mean.
I can split the log recovery code into a separate file, as you said
it should just be malloc + pread/pwrite in userspace, so implementing
it should be trivial. The xlog_sync case is pretty different in the
kernel as it isn't synchonous, and it also doesn't currently exist in
userspace. I'd rather keep that as-is unless you have plans to port
the logging code to userspace? Even in that case we'll probably want
a different abstraction that maps to aio.
next prev parent reply other threads:[~2019-05-21 5:10 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-20 16:13 use bios directly in the log code Christoph Hellwig
2019-05-20 16:13 ` [PATCH 01/17] xfs: remove the no-op spinlock_destroy stub Christoph Hellwig
2019-05-20 16:13 ` [PATCH 02/17] xfs: remove the never used _XBF_COMPOUND flag Christoph Hellwig
2019-05-20 16:13 ` [PATCH 03/17] xfs: renumber XBF_WRITE_FAIL Christoph Hellwig
2019-05-20 16:13 ` [PATCH 04/17] xfs: reformat xlog_get_lowest_lsn Christoph Hellwig
2019-05-20 16:13 ` [PATCH 05/17] xfs: don't use REQ_PREFLUSH for split log writes Christoph Hellwig
2019-05-20 16:13 ` [PATCH 06/17] xfs: factor out log buffer writing Christoph Hellwig
2019-05-20 16:13 ` [PATCH 07/17] xfs: factor out splitting of an iclog from xlog_sync Christoph Hellwig
2019-05-20 16:13 ` [PATCH 08/17] xfs: split iclog size calculation out of xlog_sync Christoph Hellwig
2019-05-20 16:13 ` [PATCH 09/17] xfs: update both state counters together in xlog_sync Christoph Hellwig
2019-05-20 16:13 ` [PATCH 10/17] xfs: remove the syncing argument from xlog_verify_iclog Christoph Hellwig
2019-05-20 16:13 ` [PATCH 11/17] xfs: make use of the l_targ field in struct xlog Christoph Hellwig
2019-05-20 16:13 ` [PATCH 12/17] xfs: use bios directly to write log buffers Christoph Hellwig
2019-05-20 16:13 ` [PATCH 13/17] xfs: return an offset instead of a pointer from xlog_align Christoph Hellwig
2019-05-20 16:13 ` [PATCH 14/17] xfs: use bios directly to read and write the log recovery buffers Christoph Hellwig
2019-05-20 23:32 ` Dave Chinner
2019-05-21 5:09 ` Christoph Hellwig [this message]
2019-05-21 22:24 ` Dave Chinner
2019-05-22 5:12 ` Christoph Hellwig
2019-05-22 6:19 ` Dave Chinner
2019-05-22 17:31 ` Christoph Hellwig
2019-05-22 23:28 ` Dave Chinner
2019-05-23 6:22 ` Christoph Hellwig
2019-05-20 16:13 ` [PATCH 15/17] xfs: remove unused buffer cache APIs Christoph Hellwig
2019-05-20 16:13 ` [PATCH 16/17] xfs: properly type the b_log_item field in struct xfs_buf Christoph Hellwig
2019-05-20 16:13 ` [PATCH 17/17] xfs: remove the b_io_length " Christoph Hellwig
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