From: Kent Overstreet <kent.overstreet@linux.dev>
To: "Ricardo B. Marliere" <ricardo@marliere.net>
Cc: Brian Foster <bfoster@redhat.com>,
linux-bcachefs@vger.kernel.org, linux-kernel@vger.kernel.org,
Hongbo Li <lihongbo22@huawei.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v2] bcachefs: chardev: make bch_chardev_class constant
Date: Thu, 11 Apr 2024 22:44:39 -0400 [thread overview]
Message-ID: <vl32k2zzdeohe6ek5cmfibme7ka2e76x57xbxcm26olxlog6ef@lkxtlw63csnv> (raw)
In-Reply-To: <20240308-bcachefs-v2-1-3e84c845055e@marliere.net>
On Fri, Mar 08, 2024 at 09:12:47AM -0300, Ricardo B. Marliere wrote:
> Since commit 43a7206b0963 ("driver core: class: make class_register() take
> a const *"), the driver core allows for struct class to be in read-only
> memory, so move the bch_chardev_class structure to be declared at build
> time placing it into read-only memory, instead of having to be dynamically
> allocated at boot time. Also, correctly clean up after failing paths in
> bch2_chardev_init().
>
> Cc: Hongbo Li <lihongbo22@huawei.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Thanks, applied
> ---
> Changes in v2:
> - Used "free the last thing" pattern in bch2_chardev_init().
> - Link to v1: https://lore.kernel.org/r/20240305-bcachefs-v1-1-436196e25729@marliere.net
> ---
> fs/bcachefs/chardev.c | 35 ++++++++++++++++++++++-------------
> 1 file changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/fs/bcachefs/chardev.c b/fs/bcachefs/chardev.c
> index 226b39c17667..dc09f547dae6 100644
> --- a/fs/bcachefs/chardev.c
> +++ b/fs/bcachefs/chardev.c
> @@ -940,7 +940,9 @@ static const struct file_operations bch_chardev_fops = {
> };
>
> static int bch_chardev_major;
> -static struct class *bch_chardev_class;
> +static const struct class bch_chardev_class = {
> + .name = "bcachefs",
> +};
> static struct device *bch_chardev;
>
> void bch2_fs_chardev_exit(struct bch_fs *c)
> @@ -957,7 +959,7 @@ int bch2_fs_chardev_init(struct bch_fs *c)
> if (c->minor < 0)
> return c->minor;
>
> - c->chardev = device_create(bch_chardev_class, NULL,
> + c->chardev = device_create(&bch_chardev_class, NULL,
> MKDEV(bch_chardev_major, c->minor), c,
> "bcachefs%u-ctl", c->minor);
> if (IS_ERR(c->chardev))
> @@ -968,32 +970,39 @@ int bch2_fs_chardev_init(struct bch_fs *c)
>
> void bch2_chardev_exit(void)
> {
> - if (!IS_ERR_OR_NULL(bch_chardev_class))
> - device_destroy(bch_chardev_class,
> - MKDEV(bch_chardev_major, U8_MAX));
> - if (!IS_ERR_OR_NULL(bch_chardev_class))
> - class_destroy(bch_chardev_class);
> + device_destroy(&bch_chardev_class, MKDEV(bch_chardev_major, U8_MAX));
> + class_unregister(&bch_chardev_class);
> if (bch_chardev_major > 0)
> unregister_chrdev(bch_chardev_major, "bcachefs");
> }
>
> int __init bch2_chardev_init(void)
> {
> + int ret;
> +
> bch_chardev_major = register_chrdev(0, "bcachefs-ctl", &bch_chardev_fops);
> if (bch_chardev_major < 0)
> return bch_chardev_major;
>
> - bch_chardev_class = class_create("bcachefs");
> - if (IS_ERR(bch_chardev_class))
> - return PTR_ERR(bch_chardev_class);
> + ret = class_register(&bch_chardev_class);
> + if (ret)
> + goto major_out;
>
> - bch_chardev = device_create(bch_chardev_class, NULL,
> + bch_chardev = device_create(&bch_chardev_class, NULL,
> MKDEV(bch_chardev_major, U8_MAX),
> NULL, "bcachefs-ctl");
> - if (IS_ERR(bch_chardev))
> - return PTR_ERR(bch_chardev);
> + if (IS_ERR(bch_chardev)) {
> + ret = PTR_ERR(bch_chardev);
> + goto class_out;
> + }
>
> return 0;
> +
> +class_out:
> + class_unregister(&bch_chardev_class);
> +major_out:
> + unregister_chrdev(bch_chardev_major, "bcachefs-ctl");
> + return ret;
> }
>
> #endif /* NO_BCACHEFS_CHARDEV */
>
> ---
> base-commit: 90d35da658da8cff0d4ecbb5113f5fac9d00eb72
> change-id: 20240305-bcachefs-27a4bb8b9f4f
>
> Best regards,
> --
> Ricardo B. Marliere <ricardo@marliere.net>
>
prev parent reply other threads:[~2024-04-12 2:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-08 12:12 [PATCH v2] bcachefs: chardev: make bch_chardev_class constant Ricardo B. Marliere
2024-03-11 1:41 ` Hongbo Li
2024-04-12 2:31 ` Hongbo Li
2024-04-12 2:44 ` Kent Overstreet [this message]
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