From: Mike Snitzer <snitzer@redhat.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>, Ira Weiny <ira.weiny@intel.com>,
device-mapper development <dm-devel@redhat.com>,
linux-xfs <linux-xfs@vger.kernel.org>,
Linux NVDIMM <nvdimm@lists.linux.dev>,
linux-s390 <linux-s390@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-erofs@lists.ozlabs.org,
linux-ext4 <linux-ext4@vger.kernel.org>,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH 07/11] dax: remove dax_capable
Date: Mon, 1 Nov 2021 12:17:43 -0400 [thread overview]
Message-ID: <YYATJ+oDT15TD9Np@redhat.com> (raw)
In-Reply-To: <CAPcyv4gE8UXjQAe_6=BKFRCyLWNP_9CNxKFH---RpPnYfmBQLg@mail.gmail.com>
On Wed, Oct 27 2021 at 8:16P -0400,
Dan Williams <dan.j.williams@intel.com> wrote:
> I am going to change the subject of this patch to:
>
> dax: remove ->dax_supported()
>
> On Sun, Oct 17, 2021 at 9:41 PM Christoph Hellwig <hch@lst.de> wrote:
> >
>
> I'll add a bit more background to help others review this.
>
> The ->dax_supported() operation arranges for a stack of devices to
> each answer the question "is dax operational". That request routes to
> generic_fsdax_supported() at last level device and that attempted an
> actual dax_direct_access() call and did some sanity checks. However,
> those sanity checks can be validated in other ways and with those
> removed the only question to answer is "has each block device driver
> in the stack performed dax_add_host()". That can be validated without
> a dax_operation. So, just open code the block size and dax_dev == NULL
> checks in the callers, and delete ->dax_supported().
>
> Mike, let me know if you have any concerns.
Thanks for your additional background, it helped.
>
> > Just open code the block size and dax_dev == NULL checks in the callers.
> >
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> > drivers/dax/super.c | 36 ------------------------------------
> > drivers/md/dm-table.c | 22 +++++++++++-----------
> > drivers/md/dm.c | 21 ---------------------
> > drivers/md/dm.h | 4 ----
> > drivers/nvdimm/pmem.c | 1 -
> > drivers/s390/block/dcssblk.c | 1 -
> > fs/erofs/super.c | 11 +++++++----
> > fs/ext2/super.c | 6 ++++--
> > fs/ext4/super.c | 9 ++++++---
> > fs/xfs/xfs_super.c | 21 ++++++++-------------
> > include/linux/dax.h | 14 --------------
> > 11 files changed, 36 insertions(+), 110 deletions(-)
> >
> > diff --git a/drivers/dax/super.c b/drivers/dax/super.c
> > index 482fe775324a4..803942586d1b6 100644
> > --- a/drivers/dax/super.c
> > +++ b/drivers/dax/super.c
> > @@ -108,42 +108,6 @@ struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
> > return dax_dev;
> > }
> > EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
> > -
> > -bool generic_fsdax_supported(struct dax_device *dax_dev,
> > - struct block_device *bdev, int blocksize, sector_t start,
> > - sector_t sectors)
> > -{
> > - if (blocksize != PAGE_SIZE) {
> > - pr_info("%pg: error: unsupported blocksize for dax\n", bdev);
> > - return false;
> > - }
> > -
> > - if (!dax_dev) {
> > - pr_debug("%pg: error: dax unsupported by block device\n", bdev);
> > - return false;
> > - }
> > -
> > - return true;
> > -}
> > -EXPORT_SYMBOL_GPL(generic_fsdax_supported);
> > -
> > -bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
> > - int blocksize, sector_t start, sector_t len)
> > -{
> > - bool ret = false;
> > - int id;
> > -
> > - if (!dax_dev)
> > - return false;
> > -
> > - id = dax_read_lock();
> > - if (dax_alive(dax_dev) && dax_dev->ops->dax_supported)
> > - ret = dax_dev->ops->dax_supported(dax_dev, bdev, blocksize,
> > - start, len);
> > - dax_read_unlock(id);
> > - return ret;
> > -}
> > -EXPORT_SYMBOL_GPL(dax_supported);
> > #endif /* CONFIG_BLOCK && CONFIG_FS_DAX */
> >
> > enum dax_device_flags {
> > diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> > index 1fa4d5582dca5..4ae671c2168ea 100644
> > --- a/drivers/md/dm-table.c
> > +++ b/drivers/md/dm-table.c
> > @@ -807,12 +807,14 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
> > EXPORT_SYMBOL_GPL(dm_table_set_type);
> >
> > /* validate the dax capability of the target device span */
> > -int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
> > +static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
> > sector_t start, sector_t len, void *data)
> > {
> > - int blocksize = *(int *) data;
> > + if (dev->dax_dev)
> > + return false;
> >
> > - return !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
> > + pr_debug("%pg: error: dax unsupported by block device\n", dev->bdev);
Would prefer the use of DMDEBUG() here (which doesn't need trailing \n)
But otherwise:
Acked-by: Mike Snitzer <snitzer@redhat.com>
next prev parent reply other threads:[~2021-11-01 16:17 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-18 4:40 futher decouple DAX from block devices Christoph Hellwig
2021-10-18 4:40 ` [PATCH 01/11] dm: make the DAX support dependend on CONFIG_FS_DAX Christoph Hellwig
2021-10-27 20:53 ` Dan Williams
2021-11-01 16:12 ` Mike Snitzer
2021-10-18 4:40 ` [PATCH 02/11] dax: remove CONFIG_DAX_DRIVER Christoph Hellwig
2021-10-27 20:54 ` Dan Williams
2021-10-18 4:40 ` [PATCH 03/11] dax: simplify the dax_device <-> gendisk association Christoph Hellwig
2021-10-27 22:03 ` Dan Williams
2021-10-29 4:57 ` Ira Weiny
2021-11-01 16:28 ` Mike Snitzer
2021-10-18 4:40 ` [PATCH 04/11] dax: remove the pgmap sanity checks in generic_fsdax_supported Christoph Hellwig
2021-10-27 23:02 ` Dan Williams
2021-10-18 4:40 ` [PATCH 05/11] dax: move the partition alignment check into fs_dax_get_by_bdev Christoph Hellwig
2021-10-27 23:07 ` Dan Williams
2021-10-18 4:40 ` [PATCH 06/11] xfs: factor out a xfs_setup_dax helper Christoph Hellwig
2021-10-18 16:43 ` Darrick J. Wong
2021-10-19 7:23 ` Christoph Hellwig
2021-10-27 23:37 ` Dan Williams
2021-10-18 4:40 ` [PATCH 07/11] dax: remove dax_capable Christoph Hellwig
2021-10-18 12:25 ` Gao Xiang
2021-10-19 15:44 ` [dm-devel] " Darrick J. Wong
2021-10-28 0:20 ` Dan Williams
2021-10-28 0:16 ` Dan Williams
2021-11-01 16:17 ` Mike Snitzer [this message]
2021-10-18 4:40 ` [PATCH 08/11] dm-linear: add a linear_dax_pgoff helper Christoph Hellwig
2021-10-28 1:32 ` Dan Williams
2021-11-01 16:18 ` Mike Snitzer
2021-10-18 4:40 ` [PATCH 09/11] dm-log-writes: add a log_writes_dax_pgoff helper Christoph Hellwig
2021-10-28 1:36 ` Dan Williams
2021-11-01 16:19 ` Mike Snitzer
2021-10-18 4:40 ` [PATCH 10/11] dm-stripe: add a stripe_dax_pgoff helper Christoph Hellwig
2021-10-28 1:41 ` Dan Williams
2021-11-01 16:21 ` Mike Snitzer
2021-10-18 4:40 ` [PATCH 11/11] dax: move bdev_dax_pgoff to fs/dax.c Christoph Hellwig
2021-10-28 1:44 ` Dan Williams
2021-10-27 20:46 ` futher decouple DAX from block devices Dan Williams
2021-10-28 23:51 ` Stephen Rothwell
2021-10-29 15:42 ` Dan Williams
2021-10-29 15:55 ` Darrick J. Wong
2021-10-29 16:16 ` Dan Williams
2021-11-03 17:59 ` Eric Sandeen
2021-11-04 8:17 ` Christoph Hellwig
2021-11-04 17:34 ` Darrick J. Wong
2021-11-04 17:35 ` Christoph Hellwig
2021-11-04 18:10 ` Dan Williams
2021-11-04 19:04 ` Darrick J. Wong
2021-11-05 3:09 ` Theodore Ts'o
2021-11-05 3:30 ` Matthew Wilcox
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