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Commit 755d4fe4 authored by Seiji Aguchi's avatar Seiji Aguchi Committed by Tony Luck
Browse files

efi_pstore: Add a sequence counter to a variable name 



[Issue]

Currently, a variable name, which identifies each entry, consists of type, id and ctime.
But if multiple events happens in a short time, a second/third event may fail to log because
efi_pstore can't distinguish each event with current variable name.

[Solution]

A reasonable way to identify all events precisely is introducing a sequence counter to
the variable name.

The sequence counter has already supported in a pstore layer with "oopscount".
So, this patch adds it to a variable name.
Also, it is passed to read/erase callbacks of platform drivers in accordance with
the modification of the variable name.

  <before applying this patch>
 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

 If multiple events happen in a short time, efi_pstore can't distinguish them because
 variable names are same among them.

  <after applying this patch>

 it can be distinguishable by adding a sequence counter as follows.

 a variable name of first event: dump-type0-1-1-12345678
 a variable name of Second event: dump-type0-1-2-12345678

  type:0
  id:1
  sequence counter: 1(first event), 2(second event)
  ctime:12345678

In case of a write callback executed in pstore_console_write(), "0" is added to
an argument of the write callback because it just logs all kernel messages and
doesn't need to care about multiple events.

Signed-off-by: default avatarSeiji Aguchi <seiji.aguchi@hds.com>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarMike Waychison <mikew@google.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent a9efd39c

drivers/acpi/apei/erst.c

+6 −6
Original line number Diff line number Diff line
@@ -931,13 +931,13 @@ static int erst_check_table(struct acpi_table_erst *erst_tab) 


static int erst_open_pstore(struct pstore_info *psi);

static int erst_close_pstore(struct pstore_info *psi);

static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,

static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,

			   struct timespec *time, char **buf,

			   struct pstore_info *psi);

static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,

		       u64 *id, unsigned int part,

		       u64 *id, unsigned int part, int count,

		       size_t size, struct pstore_info *psi);

static int erst_clearer(enum pstore_type_id type, u64 id,

static int erst_clearer(enum pstore_type_id type, u64 id, int count,

			struct timespec time, struct pstore_info *psi);



static struct pstore_info erst_info = {
@@ -987,7 +987,7 @@ static int erst_close_pstore(struct pstore_info *psi) 
	return 0;

}



static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,

static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,

			   struct timespec *time, char **buf,

			   struct pstore_info *psi)

{
@@ -1055,7 +1055,7 @@ out: 
}



static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,

		       u64 *id, unsigned int part,

		       u64 *id, unsigned int part, int count,

		       size_t size, struct pstore_info *psi)

{

	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
@@ -1101,7 +1101,7 @@ static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason, 
	return ret;

}



static int erst_clearer(enum pstore_type_id type, u64 id,

static int erst_clearer(enum pstore_type_id type, u64 id, int count,

			struct timespec time, struct pstore_info *psi)

{

	return erst_clear(id);

drivers/firmware/efivars.c

+14 −9
Original line number Diff line number Diff line
@@ -658,13 +658,14 @@ static int efi_pstore_close(struct pstore_info *psi) 
}



static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,

			       struct timespec *timespec,

			       int *count, struct timespec *timespec,

			       char **buf, struct pstore_info *psi)

{

	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;

	struct efivars *efivars = psi->data;

	char name[DUMP_NAME_LEN];

	int i;

	int cnt;

	unsigned int part, size;

	unsigned long time;
@@ -674,8 +675,10 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, 
			for (i = 0; i < DUMP_NAME_LEN; i++) {

				name[i] = efivars->walk_entry->var.VariableName[i];

			}

			if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {

			if (sscanf(name, "dump-type%u-%u-%d-%lu",

				   type, &part, &cnt, &time) == 4) {

				*id = part;

				*count = cnt;

				timespec->tv_sec = time;

				timespec->tv_nsec = 0;

				get_var_data_locked(efivars, &efivars->walk_entry->var);
@@ -698,7 +701,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, 


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)

		unsigned int part, int count, size_t size,

		struct pstore_info *psi)

{

	char name[DUMP_NAME_LEN];

	efi_char16_t efi_name[DUMP_NAME_LEN];
@@ -725,7 +729,7 @@ static int efi_pstore_write(enum pstore_type_id type, 
		return -ENOSPC;

	}



	sprintf(name, "dump-type%u-%u-%lu", type, part,

	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,

		get_seconds());



	for (i = 0; i < DUMP_NAME_LEN; i++)
@@ -746,7 +750,7 @@ static int efi_pstore_write(enum pstore_type_id type, 
	return ret;

};



static int efi_pstore_erase(enum pstore_type_id type, u64 id,

static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,

			    struct timespec time, struct pstore_info *psi)

{

	char name[DUMP_NAME_LEN];
@@ -756,7 +760,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, 
	struct efivar_entry *entry, *found = NULL;

	int i;



	sprintf(name, "dump-type%u-%u-%lu", type, (unsigned int)id,

	sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,

		time.tv_sec);



	spin_lock(&efivars->lock);
@@ -807,7 +811,7 @@ static int efi_pstore_close(struct pstore_info *psi) 
	return 0;

}



static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,

static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count,

			       struct timespec *timespec,

			       char **buf, struct pstore_info *psi)

{
@@ -816,12 +820,13 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, 


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)

		unsigned int part, int count, size_t size,

		struct pstore_info *psi)

{

	return 0;

}



static int efi_pstore_erase(enum pstore_type_id type, u64 id,

static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,

			    struct timespec time, struct pstore_info *psi)

{

	return 0;

fs/pstore/inode.c

+5 −3
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ struct pstore_private { 
	struct pstore_info *psi;

	enum pstore_type_id type;

	u64	id;

	int	count;

	ssize_t	size;

	char	data[];

};
@@ -175,8 +176,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry) 
	struct pstore_private *p = dentry->d_inode->i_private;



	if (p->psi->erase)

		p->psi->erase(p->type, p->id, dentry->d_inode->i_ctime,

			      p->psi);

		p->psi->erase(p->type, p->id, p->count,

			      dentry->d_inode->i_ctime, p->psi);



	return simple_unlink(dir, dentry);

}
@@ -271,7 +272,7 @@ int pstore_is_mounted(void) 
 * Load it up with "size" bytes of data from "buf".

 * Set the mtime & ctime to the date that this record was originally stored.

 */

int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,

int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,

		  char *data, size_t size, struct timespec time,

		  struct pstore_info *psi)

{
@@ -307,6 +308,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, 
		goto fail_alloc;

	private->type = type;

	private->id = id;

	private->count = count;

	private->psi = psi;



	switch (type) {

fs/pstore/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ extern struct pstore_info *psinfo; 
extern void	pstore_set_kmsg_bytes(int);

extern void	pstore_get_records(int);

extern int	pstore_mkfile(enum pstore_type_id, char *psname, u64 id,

			      char *data, size_t size,

			      int count, char *data, size_t size,

			      struct timespec time, struct pstore_info *psi);

extern int	pstore_is_mounted(void);

fs/pstore/platform.c

+7 −6
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ static void pstore_dump(struct kmsg_dumper *dumper, 
			break;



		ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,

				    hsize + len, psinfo);

				    oopscount, hsize + len, psinfo);

		if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())

			pstore_new_entry = 1;
@@ -173,7 +173,7 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) 
			spin_lock_irqsave(&psinfo->buf_lock, flags);

		}

		memcpy(psinfo->buf, s, c);

		psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, c, psinfo);

		psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, c, psinfo);

		spin_unlock_irqrestore(&psinfo->buf_lock, flags);

		s += c;

		c = e - s;
@@ -197,7 +197,7 @@ static void pstore_register_console(void) {} 


static int pstore_write_compat(enum pstore_type_id type,

			       enum kmsg_dump_reason reason,

			       u64 *id, unsigned int part,

			       u64 *id, unsigned int part, int count,

			       size_t size, struct pstore_info *psi)

{

	return psi->write_buf(type, reason, id, part, psinfo->buf, size, psi);
@@ -267,6 +267,7 @@ void pstore_get_records(int quiet) 
	char			*buf = NULL;

	ssize_t			size;

	u64			id;

	int			count;

	enum pstore_type_id	type;

	struct timespec		time;

	int			failed = 0, rc;
@@ -278,9 +279,9 @@ void pstore_get_records(int quiet) 
	if (psi->open && psi->open(psi))

		goto out;



	while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) {

		rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size,

				  time, psi);

	while ((size = psi->read(&id, &type, &count, &time, &buf, psi)) > 0) {

		rc = pstore_mkfile(type, psi->name, id, count, buf,

				  (size_t)size, time, psi);

		kfree(buf);

		buf = NULL;

		if (rc && (rc != -EEXIST || !quiet))