* [PATCH v2] bcachefs: chardev: make bch_chardev_class constant
@ 2024-03-08 12:12 Ricardo B. Marliere
2024-03-11 1:41 ` Hongbo Li
2024-04-12 2:44 ` Kent Overstreet
0 siblings, 2 replies; 4+ messages in thread
From: Ricardo B. Marliere @ 2024-03-08 12:12 UTC (permalink / raw)
To: Kent Overstreet, Brian Foster
Cc: linux-bcachefs, linux-kernel, Hongbo Li, Greg Kroah-Hartman,
Ricardo B. Marliere
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>
---
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>
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2] bcachefs: chardev: make bch_chardev_class constant
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
1 sibling, 1 reply; 4+ messages in thread
From: Hongbo Li @ 2024-03-11 1:41 UTC (permalink / raw)
To: Ricardo B. Marliere, Kent Overstreet, Brian Foster
Cc: linux-bcachefs, linux-kernel, Greg Kroah-Hartman
It's fine for me.
On 2024/3/8 20:12, 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>
> ---
> 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,
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] bcachefs: chardev: make bch_chardev_class constant
2024-03-11 1:41 ` Hongbo Li
@ 2024-04-12 2:31 ` Hongbo Li
0 siblings, 0 replies; 4+ messages in thread
From: Hongbo Li @ 2024-04-12 2:31 UTC (permalink / raw)
To: Ricardo B. Marliere, Kent Overstreet, Brian Foster
Cc: linux-bcachefs, linux-kernel, Greg Kroah-Hartman
On 2024/3/11 9:41, Hongbo Li wrote:
> It's fine for me.
>
> On 2024/3/8 20:12, 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>
>> ---
>> 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,
>
This is a useful patch, and also works on latest code. Maybe we almost
forgot it.
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] bcachefs: chardev: make bch_chardev_class constant
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 2:44 ` Kent Overstreet
1 sibling, 0 replies; 4+ messages in thread
From: Kent Overstreet @ 2024-04-12 2:44 UTC (permalink / raw)
To: Ricardo B. Marliere
Cc: Brian Foster, linux-bcachefs, linux-kernel, Hongbo Li,
Greg Kroah-Hartman
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>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-03-08 12:12 [PATCH v2] bcachefs: chardev: make bch_chardev_class constant Ricardo B. Marliere
2024-03-11 1:41 ` Hongbo Li
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