diff mbox series

pstore/blk: Export a method to implemente panic_write()

Message ID 20230203113515.93540-1-victor@allwinnertech.com (mailing list archive)
State Superseded
Headers show
Series pstore/blk: Export a method to implemente panic_write() | expand

Commit Message

Victor Hassan Feb. 3, 2023, 11:35 a.m. UTC 
The panic_write() is necessary to write the pstore frontend message
to blk devices when panic. Here is a way to register panic_write when
we use "best_effort" way to register the pstore blk-backend.

Usage:

    xx_register_pstore_panic_write(pstore_blk_notifier_type type,
	    struct pstore_device_info *pdi)
    {
	switch (type) {
	case PSTORE_BLK_BACKEND_REGISTER:
	case PSTORE_BLK_BACKEND_PANIC_DRV_REGISTER:
	    ...

	    pid->zone.panic_write = xxx;

	    ...
	    break;
	case PSTORE_BLK_BACKEND_UNREGISTER:
	case PSTORE_BLK_BACKEND_PANIC_DRV_UNREGISTER:
	    ...

	    pdi->zone.panic_write = NULL;

	    ...
	    break;
	default:
	    break;
	}

    }

    static struct pstore_blk_notifier pbn = {
	.notitifer_call = xx_register_pstore_panic_write;
    }

    use {un,}register_pstore_blk_panic_notifier() to register/unregister
    pstore_blk_notifier

Signed-off-by: Victor Hassan <victor@allwinnertech.com>
---
 fs/pstore/blk.c            | 101 +++++++++++++++++++++++++++++++++++--
 include/linux/pstore_blk.h |  19 +++++++
 2 files changed, 116 insertions(+), 4 deletions(-)

Comments

kernel test robot Feb. 3, 2023, 7:57 p.m. UTC | #1 
Hi Victor,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kees/for-next/pstore]
[also build test ERROR on kees/for-next/kspp linus/master v6.2-rc6 next-20230203]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Victor-Hassan/pstore-blk-Export-a-method-to-implemente-panic_write/20230203-193548
base:   https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/pstore
patch link:    https://lore.kernel.org/r/20230203113515.93540-1-victor%40allwinnertech.com
patch subject: [PATCH] pstore/blk: Export a method to implemente panic_write()
config: x86_64-randconfig-a012 (https://download.01.org/0day-ci/archive/20230204/202302040337.IyKFZgIk-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/368e42ba015da6c7bdd201b8fdb669e936307cbb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Victor-Hassan/pstore-blk-Export-a-method-to-implemente-panic_write/20230203-193548
        git checkout 368e42ba015da6c7bdd201b8fdb669e936307cbb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/pstore/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from fs/pstore/blk.c:16:
>> include/linux/pstore_blk.h:32:41: error: must use 'enum' tag to refer to type 'pstore_blk_notifier_type'
   typedef int (*pstore_blk_notifier_fn_t)(pstore_blk_notifier_type type,
                                           ^
                                           enum 
   1 error generated.


vim +32 include/linux/pstore_blk.h

    31	
  > 32	typedef	int (*pstore_blk_notifier_fn_t)(pstore_blk_notifier_type type,
    33			struct pstore_device_info *dev);
    34
kernel test robot Feb. 3, 2023, 9:19 p.m. UTC | #2 
Hi Victor,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kees/for-next/pstore]
[also build test ERROR on kees/for-next/kspp linus/master v6.2-rc6 next-20230203]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Victor-Hassan/pstore-blk-Export-a-method-to-implemente-panic_write/20230203-193548
base:   https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/pstore
patch link:    https://lore.kernel.org/r/20230203113515.93540-1-victor%40allwinnertech.com
patch subject: [PATCH] pstore/blk: Export a method to implemente panic_write()
config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20230204/202302040515.tdCoWcUS-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/368e42ba015da6c7bdd201b8fdb669e936307cbb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Victor-Hassan/pstore-blk-Export-a-method-to-implemente-panic_write/20230203-193548
        git checkout 368e42ba015da6c7bdd201b8fdb669e936307cbb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/ fs/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from drivers/mtd/mtdpstore.c:7:
>> include/linux/pstore_blk.h:32:41: error: unknown type name 'pstore_blk_notifier_type'
      32 | typedef int (*pstore_blk_notifier_fn_t)(pstore_blk_notifier_type type,
         |                                         ^~~~~~~~~~~~~~~~~~~~~~~~
>> include/linux/pstore_blk.h:37:9: error: unknown type name 'pstore_blk_notifier_fn_t'
      37 |         pstore_blk_notifier_fn_t notifier_call;
         |         ^~~~~~~~~~~~~~~~~~~~~~~~
--
   In file included from fs/pstore/blk.c:16:
>> include/linux/pstore_blk.h:32:41: error: unknown type name 'pstore_blk_notifier_type'
      32 | typedef int (*pstore_blk_notifier_fn_t)(pstore_blk_notifier_type type,
         |                                         ^~~~~~~~~~~~~~~~~~~~~~~~
>> include/linux/pstore_blk.h:37:9: error: unknown type name 'pstore_blk_notifier_fn_t'
      37 |         pstore_blk_notifier_fn_t notifier_call;
         |         ^~~~~~~~~~~~~~~~~~~~~~~~
   fs/pstore/blk.c: In function 'pstore_blk_panic_notifier_call':
>> fs/pstore/blk.c:114:23: error: called object is not a function or function pointer
     114 |                 ret = pbn->notifier_call(action, data);
         |                       ^~~


vim +/pstore_blk_notifier_type +32 include/linux/pstore_blk.h

    31	
  > 32	typedef	int (*pstore_blk_notifier_fn_t)(pstore_blk_notifier_type type,
    33			struct pstore_device_info *dev);
    34	
    35	struct pstore_blk_notifier {
    36		struct notifier_block nb;
  > 37		pstore_blk_notifier_fn_t notifier_call;
    38	};
    39
diff mbox series

Patch

diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c
index 4ae0cfcd15f2..2c70a3bff1ae 100644
--- a/fs/pstore/blk.c
+++ b/fs/pstore/blk.c
@@ -18,6 +18,7 @@ 
 #include <linux/file.h>
 #include <linux/init_syscalls.h>
 #include <linux/mount.h>
+#include <linux/notifier.h>
 
 static long kmsg_size = CONFIG_PSTORE_BLK_KMSG_SIZE;
 module_param(kmsg_size, long, 0400);
@@ -72,6 +73,14 @@  static DEFINE_MUTEX(pstore_blk_lock);
 static struct file *psblk_file;
 static struct pstore_device_info *pstore_device_info;
 
+static struct {
+	struct raw_notifier_head chain;
+	struct pstore_blk_notifier *pbn;
+	bool notifier;
+} pstore_blk_panic_notifier = {
+	.chain = RAW_NOTIFIER_INIT(pstore_blk_panic_notifier.chain),
+};
+
 #define check_size(name, alignsize) ({				\
 	long _##name_ = (name);					\
 	_##name_ = _##name_ <= 0 ? 0 : (_##name_ * 1024);	\
@@ -94,6 +103,82 @@  static struct pstore_device_info *pstore_device_info;
 	dev->zone.name = _##name_;				\
 }
 
+static int pstore_blk_panic_notifier_call(struct notifier_block *nb,
+			     unsigned long action, void *data)
+{
+	int ret = 0;
+	struct pstore_blk_notifier *pbn =
+				container_of(nb, struct pstore_blk_notifier, nb);
+
+	if (pbn)
+		ret = pbn->notifier_call(action, data);
+
+	return ret;
+}
+
+int register_pstore_blk_panic_notifier(struct pstore_blk_notifier *pbn)
+{
+	int err = 0;
+	struct notifier_block *nb;
+
+	mutex_lock(&pstore_blk_lock);
+
+	if (pstore_blk_panic_notifier.notifier) {
+		pr_info("had register panic\n");
+		goto unlock;
+	}
+
+	nb = &pbn->nb;
+	nb->notifier_call = pstore_blk_panic_notifier_call;
+
+	err = raw_notifier_chain_register(&pstore_blk_panic_notifier.chain, nb);
+	if (err)
+		goto unlock;
+
+	if (pstore_device_info)
+		err = nb->notifier_call(nb, PSTORE_BLK_BACKEND_PANIC_DRV_REGISTER,
+				pstore_device_info);
+
+	if (!err)
+		pstore_blk_panic_notifier.notifier = true;
+
+unlock:
+	mutex_unlock(&pstore_blk_lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(register_pstore_blk_panic_notifier);
+
+void unregister_pstore_blk_panic_notifier(struct pstore_blk_notifier *pbn)
+{
+	struct notifier_block *nb = &pbn->nb;
+
+	mutex_lock(&pstore_blk_lock);
+
+	raw_notifier_chain_unregister(&pstore_blk_panic_notifier.chain, nb);
+
+	if (pstore_device_info)
+		nb->notifier_call(nb, PSTORE_BLK_BACKEND_PANIC_DRV_UNREGISTER,
+				pstore_device_info);
+
+	pstore_blk_panic_notifier.notifier = false;
+
+	mutex_unlock(&pstore_blk_lock);
+}
+EXPORT_SYMBOL_GPL(unregister_pstore_blk_panic_notifier);
+
+static int pstore_blk_panic_notifier_init_call(struct pstore_device_info *pdi)
+{
+	return raw_notifier_call_chain(&pstore_blk_panic_notifier.chain,
+			PSTORE_BLK_BACKEND_REGISTER, pdi);
+}
+
+static int pstore_blk_panic_notifier_exit_call(struct pstore_device_info *pdi)
+{
+	return raw_notifier_call_chain(&pstore_blk_panic_notifier.chain,
+			PSTORE_BLK_BACKEND_UNREGISTER, pdi);
+}
+
 static int __register_pstore_device(struct pstore_device_info *dev)
 {
 	int ret;
@@ -301,16 +386,22 @@  static int __init __best_effort_init(void)
 	if (!best_effort_dev)
 		return -ENOMEM;
 
+	strcpy(best_effort_dev->path, blkdev);
 	best_effort_dev->zone.read = psblk_generic_blk_read;
 	best_effort_dev->zone.write = psblk_generic_blk_write;
 
 	ret = __register_pstore_blk(best_effort_dev,
 				    early_boot_devpath(blkdev));
-	if (ret)
+	if (ret) {
 		kfree(best_effort_dev);
-	else
-		pr_info("attached %s (%lu) (no dedicated panic_write!)\n",
-			blkdev, best_effort_dev->zone.total_size);
+	} else {
+		if (pstore_blk_panic_notifier_init_call(best_effort_dev) == NOTIFY_OK)
+			pr_info("attached %s (%lu) (dedicated panic_write!)\n",
+				    blkdev, best_effort_dev->zone.total_size);
+		else
+			pr_info("attached %s (%lu) (no dedicated panic_write!)\n",
+				    blkdev, best_effort_dev->zone.total_size);
+	}
 
 	return ret;
 }
@@ -326,6 +417,8 @@  static void __exit __best_effort_exit(void)
 	if (psblk_file) {
 		struct pstore_device_info *dev = pstore_device_info;
 
+		pstore_blk_panic_notifier_exit_call(dev);
+
 		__unregister_pstore_device(dev);
 		kfree(dev);
 		fput(psblk_file);
diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h
index 924ca07aafbd..4c1fc8debdc7 100644
--- a/include/linux/pstore_blk.h
+++ b/include/linux/pstore_blk.h
@@ -17,13 +17,32 @@ 
  *
  */
 struct pstore_device_info {
+	char path[80];
 	unsigned int flags;
 	struct pstore_zone_info zone;
 };
 
+enum pstore_blk_notifier_type {
+	PSTORE_BLK_BACKEND_REGISTER = 1,
+	PSTORE_BLK_BACKEND_PANIC_DRV_REGISTER,
+	PSTORE_BLK_BACKEND_UNREGISTER,
+	PSTORE_BLK_BACKEND_PANIC_DRV_UNREGISTER,
+};
+
+typedef	int (*pstore_blk_notifier_fn_t)(pstore_blk_notifier_type type,
+		struct pstore_device_info *dev);
+
+struct pstore_blk_notifier {
+	struct notifier_block nb;
+	pstore_blk_notifier_fn_t notifier_call;
+};
+
 int  register_pstore_device(struct pstore_device_info *dev);
 void unregister_pstore_device(struct pstore_device_info *dev);
 
+int register_pstore_blk_panic_notifier(struct pstore_blk_notifier *pbn);
+void unregister_pstore_blk_panic_notifier(struct pstore_blk_notifier *nb);
+
 /**
  * struct pstore_blk_config - the pstore_blk backend configuration
  *