The ubiblock_init called by ubi_init will register device number, but
device number is not released in error handling path of ubi_init when
ubi is loaded by inserting module (eg. attaching failure), which leads
to subsequent ubi_init calls failed by running out of device number
(dmesg shows that "__register_blkdev: failed to get major for ubiblock").
Since ubiblock_init() registers notifier and invokes notification
functions, so we can move it after ubi_init_attach() to fix the problem.
Fixes: 927c145208b0 ("mtd: ubi: attach from device tree")
Signed-off-by: Zhihao Cheng <[email protected]>
---
drivers/mtd/ubi/build.c | 51 +++++++++++++++++++++--------------------
1 file changed, 26 insertions(+), 25 deletions(-)
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 7f95fd7968a8..bc63fbf5e947 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1263,9 +1263,21 @@ static struct mtd_notifier ubi_mtd_notifier = {
.remove = ubi_notify_remove,
};
+static void detach_mtd_devs(int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++)
+ if (ubi_devices[i]) {
+ mutex_lock(&ubi_devices_mutex);
+ ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
+ mutex_unlock(&ubi_devices_mutex);
+ }
+}
+
static int __init ubi_init_attach(void)
{
- int err, i, k;
+ int err, i;
/* Attach MTD devices */
for (i = 0; i < mtd_devs; i++) {
@@ -1317,12 +1329,7 @@ static int __init ubi_init_attach(void)
return 0;
out_detach:
- for (k = 0; k < i; k++)
- if (ubi_devices[k]) {
- mutex_lock(&ubi_devices_mutex);
- ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
- mutex_unlock(&ubi_devices_mutex);
- }
+ detach_mtd_devs(i);
return err;
}
#ifndef CONFIG_MTD_UBI_MODULE
@@ -1366,15 +1373,6 @@ static int __init ubi_init(void)
if (err)
goto out_slab;
- err = ubiblock_init();
- if (err) {
- pr_err("UBI error: block: cannot initialize, error %d\n", err);
-
- /* See comment above re-ubi_is_module(). */
- if (ubi_is_module())
- goto out_debugfs;
- }
-
register_mtd_user(&ubi_mtd_notifier);
if (ubi_is_module()) {
@@ -1383,11 +1381,21 @@ static int __init ubi_init(void)
goto out_mtd_notifier;
}
+ err = ubiblock_init();
+ if (err) {
+ pr_err("UBI error: block: cannot initialize, error %d\n", err);
+
+ /* See comment above re-ubi_is_module(). */
+ if (ubi_is_module())
+ goto out_detach;
+ }
+
return 0;
+out_detach:
+ detach_mtd_devs(mtd_devs);
out_mtd_notifier:
unregister_mtd_user(&ubi_mtd_notifier);
-out_debugfs:
ubi_debugfs_exit();
out_slab:
kmem_cache_destroy(ubi_wl_entry_slab);
@@ -1403,17 +1411,10 @@ device_initcall(ubi_init);
static void __exit ubi_exit(void)
{
- int i;
-
ubiblock_exit();
unregister_mtd_user(&ubi_mtd_notifier);
- for (i = 0; i < UBI_MAX_DEVICES; i++)
- if (ubi_devices[i]) {
- mutex_lock(&ubi_devices_mutex);
- ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
- mutex_unlock(&ubi_devices_mutex);
- }
+ detach_mtd_devs(UBI_MAX_DEVICES);
ubi_debugfs_exit();
kmem_cache_destroy(ubi_wl_entry_slab);
misc_deregister(&ubi_ctrl_cdev);
--
2.39.2
On Thu, Apr 11, 2024 at 11:19:01AM +0800, Zhihao Cheng wrote:
> The ubiblock_init called by ubi_init will register device number, but
> device number is not released in error handling path of ubi_init when
> ubi is loaded by inserting module (eg. attaching failure), which leads
> to subsequent ubi_init calls failed by running out of device number
> (dmesg shows that "__register_blkdev: failed to get major for ubiblock").
> Since ubiblock_init() registers notifier and invokes notification
> functions, so we can move it after ubi_init_attach() to fix the problem.
>
> Fixes: 927c145208b0 ("mtd: ubi: attach from device tree")
> Signed-off-by: Zhihao Cheng <[email protected]>
> ---
> drivers/mtd/ubi/build.c | 51 +++++++++++++++++++++--------------------
> 1 file changed, 26 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
> index 7f95fd7968a8..bc63fbf5e947 100644
> --- a/drivers/mtd/ubi/build.c
> +++ b/drivers/mtd/ubi/build.c
> @@ -1263,9 +1263,21 @@ static struct mtd_notifier ubi_mtd_notifier = {
> .remove = ubi_notify_remove,
> };
>
> +static void detach_mtd_devs(int count)
Missing __init to avoid section missmatch.
See also: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> +{
> + int i;
> +
> + for (i = 0; i < count; i++)
> + if (ubi_devices[i]) {
> + mutex_lock(&ubi_devices_mutex);
> + ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
> + mutex_unlock(&ubi_devices_mutex);
> + }
> +}
> +
> static int __init ubi_init_attach(void)
> {
> - int err, i, k;
> + int err, i;
>
> /* Attach MTD devices */
> for (i = 0; i < mtd_devs; i++) {
> @@ -1317,12 +1329,7 @@ static int __init ubi_init_attach(void)
> return 0;
>
> out_detach:
> - for (k = 0; k < i; k++)
> - if (ubi_devices[k]) {
> - mutex_lock(&ubi_devices_mutex);
> - ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
> - mutex_unlock(&ubi_devices_mutex);
> - }
> + detach_mtd_devs(i);
> return err;
> }
> #ifndef CONFIG_MTD_UBI_MODULE
> @@ -1366,15 +1373,6 @@ static int __init ubi_init(void)
> if (err)
> goto out_slab;
>
> - err = ubiblock_init();
> - if (err) {
> - pr_err("UBI error: block: cannot initialize, error %d\n", err);
> -
> - /* See comment above re-ubi_is_module(). */
> - if (ubi_is_module())
> - goto out_debugfs;
> - }
> -
> register_mtd_user(&ubi_mtd_notifier);
>
> if (ubi_is_module()) {
> @@ -1383,11 +1381,21 @@ static int __init ubi_init(void)
> goto out_mtd_notifier;
> }
>
> + err = ubiblock_init();
> + if (err) {
> + pr_err("UBI error: block: cannot initialize, error %d\n", err);
> +
> + /* See comment above re-ubi_is_module(). */
> + if (ubi_is_module())
> + goto out_detach;
> + }
> +
> return 0;
>
> +out_detach:
> + detach_mtd_devs(mtd_devs);
> out_mtd_notifier:
> unregister_mtd_user(&ubi_mtd_notifier);
> -out_debugfs:
> ubi_debugfs_exit();
> out_slab:
> kmem_cache_destroy(ubi_wl_entry_slab);
> @@ -1403,17 +1411,10 @@ device_initcall(ubi_init);
>
> static void __exit ubi_exit(void)
> {
> - int i;
> -
> ubiblock_exit();
> unregister_mtd_user(&ubi_mtd_notifier);
>
> - for (i = 0; i < UBI_MAX_DEVICES; i++)
> - if (ubi_devices[i]) {
> - mutex_lock(&ubi_devices_mutex);
> - ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
> - mutex_unlock(&ubi_devices_mutex);
> - }
> + detach_mtd_devs(UBI_MAX_DEVICES);
> ubi_debugfs_exit();
> kmem_cache_destroy(ubi_wl_entry_slab);
> misc_deregister(&ubi_ctrl_cdev);
> --
> 2.39.2
>
…
> Since ubiblock_init() registers notifier and invokes notification
> functions, so we can move it after ubi_init_attach() to fix the problem.
I find this change description improvable.
Would an imperative wording be also more desirable here?
Regards,
Markus
?? 2024/4/11 23:48, Daniel Golle д??:
> On Thu, Apr 11, 2024 at 11:19:01AM +0800, Zhihao Cheng wrote:
>> The ubiblock_init called by ubi_init will register device number, but
>> device number is not released in error handling path of ubi_init when
>> ubi is loaded by inserting module (eg. attaching failure), which leads
>> to subsequent ubi_init calls failed by running out of device number
>> (dmesg shows that "__register_blkdev: failed to get major for ubiblock").
>> Since ubiblock_init() registers notifier and invokes notification
>> functions, so we can move it after ubi_init_attach() to fix the problem.
>>
>> Fixes: 927c145208b0 ("mtd: ubi: attach from device tree")
>> Signed-off-by: Zhihao Cheng <[email protected]>
>> ---
>> drivers/mtd/ubi/build.c | 51 +++++++++++++++++++++--------------------
>> 1 file changed, 26 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
>> index 7f95fd7968a8..bc63fbf5e947 100644
>> --- a/drivers/mtd/ubi/build.c
>> +++ b/drivers/mtd/ubi/build.c
>> @@ -1263,9 +1263,21 @@ static struct mtd_notifier ubi_mtd_notifier = {
>> .remove = ubi_notify_remove,
>> };
>>
>> +static void detach_mtd_devs(int count)
>
> Missing __init to avoid section missmatch.
>
> See also: https://lore.kernel.org/oe-kbuild-all/[email protected]/
I think function without '__init' attributes can be called in ubi_init,
for example misc_register, kmem_cache_create, and I verify it by make
W=1 in local machine. And above warning(in your link) is only detected
in my v1 series.
After investigating the '__init' and '__exit', I understand that there
are two independent text section for these functions, for example,
__init text section will be removed from memory after it is finished, so
we cannot call __exit function in __init function.
>
>> +{
>> + int i;
>> +
>> + for (i = 0; i < count; i++)
>> + if (ubi_devices[i]) {
>> + mutex_lock(&ubi_devices_mutex);
>> + ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
>> + mutex_unlock(&ubi_devices_mutex);
>> + }
>> +}