Re: [PATCH] pstore: pass reason to backend write callback

[Chen Gong <gong.chen@linux.intel.com>]

于 2011/11/15 7:29, Kees Cook 写道:
> This allows a backend to filter on the dmesg reason as well as the pstore
> reason. When ramoops is switched to pstore, this is needed since it has
> no interest in storing non-crash dmesg details.
>
> Signed-off-by: Kees Cook<keescook@chromium.org>
> ---
>   drivers/acpi/apei/erst.c   |    6 ++++--
>   drivers/firmware/efivars.c |    8 +++++---
>   fs/pstore/platform.c       |    9 +++++----
>   include/linux/pstore.h     |   12 +++++++++---
>   4 files changed, 23 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
> index b8b97d6..76d0f84 100644
> --- a/drivers/acpi/apei/erst.c
> +++ b/drivers/acpi/apei/erst.c
> @@ -934,7 +934,8 @@ static int erst_close_pstore(struct pstore_info *psi);
>   static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
>   			   struct timespec *time, char **buf,
>   			   struct pstore_info *psi);
> -static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part,
> +static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
> +		       u64 *id, unsigned int part,
>   		       size_t size, struct pstore_info *psi);
>   static int erst_clearer(enum pstore_type_id type, u64 id,
>   			struct pstore_info *psi);
> @@ -1051,7 +1052,8 @@ out:
>   	return (rc<  0) ? rc : (len - sizeof(*rcd));
>   }
>
> -static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part,
> +static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
> +		       u64 *id, unsigned int part,
>   		       size_t size, struct pstore_info *psi)
>   {
>   	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
> diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
> index a54a6b9..0a53a05 100644
> --- a/drivers/firmware/efivars.c
> +++ b/drivers/firmware/efivars.c
> @@ -495,7 +495,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
>   	return 0;
>   }
>
> -static int efi_pstore_write(enum pstore_type_id type, u64 *id,
> +static int efi_pstore_write(enum pstore_type_id type,
> +		enum kmsg_dump_reason reason, u64 *id,
>   		unsigned int part, size_t size, struct pstore_info *psi)
>   {
>   	char name[DUMP_NAME_LEN];
> @@ -565,7 +566,7 @@ static int efi_pstore_write(enum pstore_type_id type, u64 *id,
>   static int efi_pstore_erase(enum pstore_type_id type, u64 id,
>   			    struct pstore_info *psi)
>   {
> -	efi_pstore_write(type,&id, (unsigned int)id, 0, psi);
> +	efi_pstore_write(type, 0,&id, (unsigned int)id, 0, psi);
>
>   	return 0;
>   }
> @@ -586,7 +587,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
>   	return -1;
>   }
>
> -static int efi_pstore_write(enum pstore_type_id type, u64 *id,
> +static int efi_pstore_write(enum pstore_type_id type,
> +		enum kmsg_dump_reason reason, u64 *id,
>   		unsigned int part, size_t size, struct pstore_info *psi)
>   {
>   	return 0;
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index c09cbb4..2454dbe 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -122,7 +122,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
>   		memcpy(dst, s1 + s1_start, l1_cpy);
>   		memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
>
> -		ret = psinfo->write(PSTORE_TYPE_DMESG,&id, part,
> +		ret = psinfo->write(PSTORE_TYPE_DMESG, reason,&id, part,
>   				   hsize + l1_cpy + l2_cpy, psinfo);
>   		if (ret == 0&&  reason == KMSG_DUMP_OOPS&&  pstore_is_mounted())
>   			pstore_new_entry = 1;
> @@ -244,7 +244,8 @@ static void pstore_timefunc(unsigned long dummy)
>    * Call platform driver to write a record to the
>    * persistent store.
>    */
> -int pstore_write(enum pstore_type_id type, char *buf, size_t size)
> +int pstore_write(enum pstore_type_id type, enum kmsg_dump_reason reason,
> +		 char *buf, size_t size)
>   {
>   	u64		id;
>   	int		ret;
> @@ -258,10 +259,10 @@ int pstore_write(enum pstore_type_id type, char *buf, size_t size)
>
>   	spin_lock_irqsave(&psinfo->buf_lock, flags);
>   	memcpy(psinfo->buf, buf, size);
> -	ret = psinfo->write(type,&id, 0, size, psinfo);
> +	ret = psinfo->write(type, reason,&id, 0, size, psinfo);
>   	spin_unlock_irqrestore(&psinfo->buf_lock, flags);
>   	if (ret == 0&&  pstore_is_mounted())
> -		pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id, buf,
> +		pstore_mkfile(type, psinfo->name, id, buf,
>   			      size, CURRENT_TIME, psinfo);
>
>   	return 0;
> diff --git a/include/linux/pstore.h b/include/linux/pstore.h
> index 781cf43..dabf5eb 100644
> --- a/include/linux/pstore.h
> +++ b/include/linux/pstore.h
> @@ -22,6 +22,9 @@
>   #ifndef _LINUX_PSTORE_H
>   #define _LINUX_PSTORE_H
>
> +#include<linux/time.h>
> +#include<linux/kmsg_dump.h>
> +
>   /* types */
>   enum pstore_type_id {
>   	PSTORE_TYPE_DMESG	= 0,
> @@ -40,7 +43,8 @@ struct pstore_info {
>   	ssize_t		(*read)(u64 *id, enum pstore_type_id *type,
>   			struct timespec *time, char **buf,
>   			struct pstore_info *psi);
> -	int		(*write)(enum pstore_type_id type, u64 *id,
> +	int		(*write)(enum pstore_type_id type,
> +			enum kmsg_dump_reason reason, u64 *id,
>   			unsigned int part, size_t size, struct pstore_info *psi);
>   	int		(*erase)(enum pstore_type_id type, u64 id,
>   			struct pstore_info *psi);
> @@ -49,7 +53,8 @@ struct pstore_info {
>
>   #ifdef CONFIG_PSTORE
>   extern int pstore_register(struct pstore_info *);
> -extern int pstore_write(enum pstore_type_id type, char *buf, size_t size);
> +extern int pstore_write(enum pstore_type_id type, enum kmsg_dump_reason reason,
> +			char *buf, size_t size);
>   #else
>   static inline int
>   pstore_register(struct pstore_info *psi)
> @@ -57,7 +62,8 @@ pstore_register(struct pstore_info *psi)
>   	return -ENODEV;
>   }
>   static inline int
> -pstore_write(enum pstore_type_id type, char *buf, size_t size)
> +pstore_write(enum pstore_type_id type, enum kmsg_dump_reason reason,
> +	     char *buf, size_t size)
>   {
>   	return -ENODEV;
>   }

We ever talked about it here: https://lkml.org/lkml/2011/9/20/468.
Matthew's patch is good enough if pstore_write can be cleaned.