From: John Groves <John@groves.net>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: John Groves <jgroves@micron.com>,
Jonathan Corbet <corbet@lwn.net>,
Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Matthew Wilcox <willy@infradead.org>,
linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
nvdimm@lists.linux.dev, john@jagalactic.com,
Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@infradead.org>,
dave.hansen@linux.intel.com, gregory.price@memverge.com
Subject: Re: [RFC PATCH 10/20] famfs: famfs_open_device() & dax_holder_operations
Date: Mon, 26 Feb 2024 16:22:11 -0600 [thread overview]
Message-ID: <xslmwjulygnvrqvzevrzj5clalxwhqnmv5p2k2yvrp56bkqdn6@bbdmfeb24axf> (raw)
In-Reply-To: <20240226125642.000076d2@Huawei.com>
On 24/02/26 12:56PM, Jonathan Cameron wrote:
> On Fri, 23 Feb 2024 11:41:54 -0600
> John Groves <John@Groves.net> wrote:
>
> > Famfs works on both /dev/pmem and /dev/dax devices. This commit introduces
> > the function that opens a block (pmem) device and the struct
> > dax_holder_operations that are needed for that ABI.
> >
> > In this commit, support for opening character /dev/dax is stubbed. A
> > later commit introduces this capability.
> >
> > Signed-off-by: John Groves <john@groves.net>
>
> Formatting comments mostly same as previous patches, so I'll stop repeating them.
I tried to bulk apply those recommendations.
>
> > ---
> > fs/famfs/famfs_inode.c | 83 ++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 83 insertions(+)
> >
> > diff --git a/fs/famfs/famfs_inode.c b/fs/famfs/famfs_inode.c
> > index 3329aff000d1..82c861998093 100644
> > --- a/fs/famfs/famfs_inode.c
> > +++ b/fs/famfs/famfs_inode.c
> > @@ -68,5 +68,88 @@ static const struct super_operations famfs_ops = {
> > .show_options = famfs_show_options,
> > };
> >
> > +/***************************************************************************************
> > + * dax_holder_operations for block dax
> > + */
> > +
> > +static int
> > +famfs_blk_dax_notify_failure(
> > + struct dax_device *dax_devp,
> > + u64 offset,
> > + u64 len,
> > + int mf_flags)
> > +{
> > +
> > + pr_err("%s: dax_devp %llx offset %llx len %lld mf_flags %x\n",
> > + __func__, (u64)dax_devp, (u64)offset, (u64)len, mf_flags);
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +const struct dax_holder_operations famfs_blk_dax_holder_ops = {
> > + .notify_failure = famfs_blk_dax_notify_failure,
> > +};
> > +
> > +static int
> > +famfs_open_char_device(
> > + struct super_block *sb,
> > + struct fs_context *fc)
> > +{
> > + pr_err("%s: Root device is %s, but your kernel does not support famfs on /dev/dax\n",
> > + __func__, fc->source);
> > + return -ENODEV;
> > +}
> > +
> > +/**
> > + * famfs_open_device()
> > + *
> > + * Open the memory device. If it looks like /dev/dax, call famfs_open_char_device().
> > + * Otherwise try to open it as a block/pmem device.
> > + */
> > +static int
> > +famfs_open_device(
> > + struct super_block *sb,
> > + struct fs_context *fc)
> > +{
> > + struct famfs_fs_info *fsi = sb->s_fs_info;
> > + struct dax_device *dax_devp;
> > + u64 start_off = 0;
> > + struct bdev_handle *handlep;
> Definitely don't force alignment in local parameter definitions.
> Always goes wrong and makes for unreadable mess in patches!
Okay, undone. Everywhere.
>
> > +
> > + if (fsi->dax_devp) {
> > + pr_err("%s: already mounted\n", __func__);
> Fine to fail but worth a error message? Not sure on convention on this but seems noisy
> and maybe in userspace control which isn't good.
Changing to pr_debug. Would be good to have access to it in that way
> > + return -EALREADY;
> > + }
> > +
> > + if (strstr(fc->source, "/dev/dax")) /* There is probably a better way to check this */
> > + return famfs_open_char_device(sb, fc);
> > +
> > + if (!strstr(fc->source, "/dev/pmem")) { /* There is probably a better way to check this */
> > + pr_err("%s: primary backing dev (%s) is not pmem\n",
> > + __func__, fc->source);
> > + return -EINVAL;
> > + }
> > +
> > + handlep = bdev_open_by_path(fc->source, FAMFS_BLKDEV_MODE, fsi, &fs_holder_ops);
> > + if (IS_ERR(handlep->bdev)) {
> > + pr_err("%s: failed blkdev_get_by_path(%s)\n", __func__, fc->source);
> > + return PTR_ERR(handlep->bdev);
> > + }
> > +
> > + dax_devp = fs_dax_get_by_bdev(handlep->bdev, &start_off,
> > + fsi /* holder */,
> > + &famfs_blk_dax_holder_ops);
> > + if (IS_ERR(dax_devp)) {
> > + pr_err("%s: unable to get daxdev from handlep->bdev\n", __func__);
> > + bdev_release(handlep);
> > + return -ENODEV;
> > + }
> > + fsi->bdev_handle = handlep;
> > + fsi->dax_devp = dax_devp;
> > +
> > + pr_notice("%s: root device is block dax (%s)\n", __func__, fc->source);
>
> pr_debug() Kernel log is too noisy anyway! + I'd assume we can tell this succeeded
> in lots of other ways.
Done
>
>
> > + return 0;
> > +}
> > +
> > +
> >
> > MODULE_LICENSE("GPL");
Thanks,
John
>
next prev parent reply other threads:[~2024-02-26 22:22 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-23 17:41 [RFC PATCH 00/20] Introduce the famfs shared-memory file system John Groves
2024-02-23 17:41 ` [RFC PATCH 01/20] famfs: Documentation John Groves
2024-02-23 17:41 ` [RFC PATCH 02/20] dev_dax_iomap: Add fs_dax_get() func to prepare dax for fs-dax usage John Groves
2024-02-26 12:05 ` Jonathan Cameron
2024-02-26 15:00 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 03/20] dev_dax_iomap: Move dax_pgoff_to_phys from device.c to bus.c since both need it now John Groves
2024-02-26 12:10 ` Jonathan Cameron
2024-02-26 15:13 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 04/20] dev_dax_iomap: Save the kva from memremap John Groves
2024-02-26 12:21 ` Jonathan Cameron
2024-02-26 15:48 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 05/20] dev_dax_iomap: Add dax_operations for use by fs-dax on devdax John Groves
2024-02-26 12:32 ` Jonathan Cameron
2024-02-26 16:09 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 06/20] dev_dax_iomap: Add CONFIG_DEV_DAX_IOMAP kernel build parameter John Groves
2024-02-26 12:34 ` Jonathan Cameron
2024-02-26 16:12 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 07/20] famfs: Add include/linux/famfs_ioctl.h John Groves
2024-02-24 1:39 ` Randy Dunlap
2024-02-24 2:23 ` John Groves
2024-02-24 3:27 ` Randy Dunlap
2024-02-24 23:32 ` John Groves
2024-02-24 23:40 ` Randy Dunlap
2024-02-26 12:39 ` Jonathan Cameron
2024-02-26 16:44 ` John Groves
2024-02-26 16:56 ` Jonathan Cameron
2024-02-26 18:04 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 08/20] famfs: Add famfs_internal.h John Groves
2024-02-26 12:48 ` Jonathan Cameron
2024-02-26 17:35 ` John Groves
2024-02-27 10:28 ` Jonathan Cameron
2024-02-28 1:06 ` John Groves
2024-02-27 13:38 ` Christian Brauner
2024-02-27 14:12 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 09/20] famfs: Add super_operations John Groves
2024-02-26 12:51 ` Jonathan Cameron
2024-02-26 21:47 ` John Groves
2024-02-27 10:34 ` Jonathan Cameron
2024-02-27 17:48 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 10/20] famfs: famfs_open_device() & dax_holder_operations John Groves
2024-02-26 12:56 ` Jonathan Cameron
2024-02-26 22:22 ` John Groves [this message]
2024-02-27 13:39 ` Christian Brauner
2024-02-27 18:38 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 11/20] famfs: Add fs_context_operations John Groves
2024-02-26 13:20 ` Jonathan Cameron
2024-02-26 22:43 ` John Groves
2024-02-27 13:41 ` Christian Brauner
2024-02-28 0:59 ` John Groves
2024-02-28 1:49 ` Randy Dunlap
2024-02-28 8:17 ` Christian Brauner
2024-02-28 10:07 ` Christian Brauner
2024-02-28 12:01 ` Christian Brauner
2024-02-23 17:41 ` [RFC PATCH 12/20] famfs: Add inode_operations and file_system_type John Groves
2024-02-26 13:25 ` Jonathan Cameron
2024-02-26 22:53 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 13/20] famfs: Add iomap_ops John Groves
2024-02-26 13:30 ` Jonathan Cameron
2024-02-26 23:00 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 14/20] famfs: Add struct file_operations John Groves
2024-02-26 13:32 ` Jonathan Cameron
2024-02-26 23:09 ` John Groves
2024-02-23 17:41 ` [RFC PATCH 15/20] famfs: Add ioctl to file_operations John Groves
2024-02-26 13:44 ` Jonathan Cameron
2024-02-23 17:42 ` [RFC PATCH 16/20] famfs: Add fault counters John Groves
2024-02-23 18:23 ` Dave Hansen
2024-02-23 19:56 ` John Groves
2024-02-23 20:04 ` Dan Williams
2024-02-23 20:39 ` John Groves
2024-02-23 21:19 ` Dave Hansen
2024-02-23 23:50 ` Dan Williams
2024-02-24 3:59 ` Matthew Wilcox
2024-02-24 4:30 ` Dan Williams
2024-02-23 17:42 ` [RFC PATCH 17/20] famfs: Add module stuff John Groves
2024-02-26 13:47 ` Jonathan Cameron
2024-02-27 22:15 ` John Groves
2024-02-23 17:42 ` [RFC PATCH 18/20] famfs: Support character dax via the dev_dax_iomap patch John Groves
2024-02-26 13:52 ` Jonathan Cameron
2024-02-27 22:27 ` John Groves
2024-02-23 17:42 ` [RFC PATCH 19/20] famfs: Update MAINTAINERS file John Groves
2024-02-23 17:42 ` [RFC PATCH 20/20] famfs: Add Kconfig and Makefile plumbing John Groves
2024-02-24 1:50 ` Randy Dunlap
2024-02-24 2:24 ` John Groves
2024-02-24 0:07 ` [RFC PATCH 00/20] Introduce the famfs shared-memory file system Luis Chamberlain
2024-02-26 13:27 ` John Groves
2024-02-26 15:53 ` Luis Chamberlain
2024-02-26 21:16 ` John Groves
2024-02-27 0:58 ` Luis Chamberlain
2024-02-27 2:05 ` John Groves
2024-02-29 2:15 ` Dave Chinner
2024-02-29 14:52 ` John Groves
2024-03-11 1:29 ` Dave Chinner
2024-02-29 6:52 ` Amir Goldstein
2024-02-29 22:16 ` John Groves
2024-05-17 9:55 ` Miklos Szeredi
2024-05-19 5:59 ` Amir Goldstein
2024-05-22 2:05 ` John Groves
2024-05-22 8:58 ` Miklos Szeredi
2024-05-22 10:16 ` Amir Goldstein
2024-05-22 11:28 ` Miklos Szeredi
2024-05-22 13:41 ` Amir Goldstein
2024-05-23 2:49 ` John Groves
2024-05-23 13:57 ` Miklos Szeredi
2024-05-24 0:47 ` John Groves
2024-05-24 7:55 ` Miklos Szeredi
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