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Commit 0edae0b3 authored by Kees Cook's avatar Kees Cook
Browse files

pstore: Add kernel-doc for struct pstore_info 



This adds documentation for struct pstore_info, which also includes
the basic API the backends need to implement.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 0d7cd09a

include/linux/pstore.h

+128 −5
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ 
#include <linux/time.h>

#include <linux/types.h>



/* types */

/* pstore record types (see fs/pstore/inode.c for filename templates) */

enum pstore_type_id {

	PSTORE_TYPE_DMESG	= 0,

	PSTORE_TYPE_MCE		= 1,
@@ -47,14 +47,138 @@ enum pstore_type_id { 


struct module;



/**

 * struct pstore_info - backend pstore driver structure

 *

 * @owner:	module which is repsonsible for this backend driver

 * @name:	name of the backend driver

 *

 * @buf_lock:	spinlock to serialize access to @buf

 * @buf:	preallocated crash dump buffer

 * @bufsize:	size of @buf available for crash dump writes

 *

 * @read_mutex:	serializes @open, @read, @close, and @erase callbacks

 * @flags:	bitfield of frontends the backend can accept writes for

 * @data:	backend-private pointer passed back during callbacks

 *

 * Callbacks:

 *

 * @open:

 *	Notify backend that pstore is starting a full read of backend

 *	records. Followed by one or more @read calls, and a final @close.

 *

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns 0 on success, and non-zero on error.

 *

 * @close:

 *	Notify backend that pstore has finished a full read of backend

 *	records. Always preceded by an @open call and one or more @read

 *	calls.

 *

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns 0 on success, and non-zero on error. (Though pstore will

 *	ignore the error.)

 *

 * @read:

 *	Read next available backend record. Called after a successful

 *	@open.

 *

 *	@id:	out: unique identifier for the record

 *	@type:	out: pstore record type

 *	@count: out: for PSTORE_TYPE_DMESG, the Oops count.

 *	@time:	out: timestamp for the record

 *	@buf:	out: kmalloc copy of record contents, to be freed by pstore

 *	@compressed:

 *		out: if the record contents are compressed

 *	@ecc_notice_size:

 *		out: ECC information

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns record size on success, zero when no more records are

 *	available, or negative on error.

 *

 * @write:

 *	Perform a frontend notification of a write to a backend record. The

 *	data to be stored has already been written to the registered @buf

 *	of the @psi structure.

 *

 *	@type:	in: pstore record type to write

 *	@reason:

 *		in: pstore write reason

 *	@id:	out: unique identifier for the record

 *	@part:	in: position in a multipart write

 *	@count:	in: increasing from 0 since boot, the number of this Oops

 *	@compressed:

 *		in: if the record is compressed

 *	@size:	in: size of the write

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns 0 on success, and non-zero on error.

 *

 * @write_buf:

 *	Perform a frontend write to a backend record, using a specified

 *	buffer. Unlike @write, this does not use the @psi @buf.

 *

 *	@type:	in: pstore record type to write

 *	@reason:

 *		in: pstore write reason

 *	@id:	out: unique identifier for the record

 *	@part:	in: position in a multipart write

 *	@buf:	in: pointer to contents to write to backend record

 *	@compressed:

 *		in: if the record is compressed

 *	@size:	in: size of the write

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns 0 on success, and non-zero on error.

 *

 * @write_buf_user:

 *	Perform a frontend write to a backend record, using a specified

 *	buffer that is coming directly from userspace.

 *

 *	@type:	in: pstore record type to write

 *	@reason:

 *		in: pstore write reason

 *	@id:	out: unique identifier for the record

 *	@part:	in: position in a multipart write

 *	@buf:	in: pointer to userspace contents to write to backend record

 *	@compressed:

 *		in: if the record is compressed

 *	@size:	in: size of the write

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns 0 on success, and non-zero on error.

 *

 * @erase:

 *	Delete a record from backend storage.  Different backends

 *	identify records differently, so all possible methods of

 *	identification are included to help the backend locate the

 *	record to remove.

 *

 *	@type:	in: pstore record type to write

 *	@id:	in: per-type unique identifier for the record

 *	@count:	in: Oops count

 *	@time:	in: timestamp for the record

 *	@psi:	in: pointer to the struct pstore_info for the backend

 *

 *	Returns 0 on success, and non-zero on error.

 *

 */

struct pstore_info {

	struct module	*owner;

	char		*name;

	spinlock_t	buf_lock;	/* serialize access to 'buf' */



	spinlock_t	buf_lock;

	char		*buf;

	size_t		bufsize;

	struct mutex	read_mutex;	/* serialize open/read/close */



	struct mutex	read_mutex;



	int		flags;

	void		*data;



	int		(*open)(struct pstore_info *psi);

	int		(*close)(struct pstore_info *psi);

	ssize_t		(*read)(u64 *id, enum pstore_type_id *type,
@@ -76,11 +200,10 @@ struct pstore_info { 
	int		(*erase)(enum pstore_type_id type, u64 id,

			int count, struct timespec time,

			struct pstore_info *psi);

	void		*data;

};



/* Supported frontends */

#define PSTORE_FLAGS_DMESG	(1 << 0)

#define PSTORE_FLAGS_FRAGILE	PSTORE_FLAGS_DMESG

#define PSTORE_FLAGS_CONSOLE	(1 << 1)

#define PSTORE_FLAGS_FTRACE	(1 << 2)

#define PSTORE_FLAGS_PMSG	(1 << 3)