Commit 06cf91b4 authored by Chen Gong's avatar Chen Gong Committed by Tony Luck
Browse files

pstore: fix pstore filesystem mount/remount issue 



Currently after mount/remount operation on pstore filesystem,
the content on pstore will be lost. It is because current ERST
implementation doesn't support multi-user usage, which moves
internal pointer to the end after accessing it. Adding
multi-user support for pstore usage.

Signed-off-by: default avatarChen Gong <gong.chen@linux.intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 8d38d74b

drivers/acpi/apei/erst.c

+35 −13
Original line number Diff line number Diff line
@@ -929,6 +929,8 @@ static int erst_check_table(struct acpi_table_erst *erst_tab) 
	return 0;

}



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,

		       struct timespec *time);

static u64 erst_writer(enum pstore_type_id type, size_t size);
@@ -936,6 +938,8 @@ static u64 erst_writer(enum pstore_type_id type, size_t size); 
static struct pstore_info erst_info = {

	.owner		= THIS_MODULE,

	.name		= "erst",

	.open		= erst_open_pstore,

	.close		= erst_close_pstore,

	.read		= erst_reader,

	.write		= erst_writer,

	.erase		= erst_clear
@@ -957,12 +961,32 @@ struct cper_pstore_record { 
	char data[];

} __packed;



static int reader_pos;



static int erst_open_pstore(struct pstore_info *psi)

{

	int rc;



	if (erst_disable)

		return -ENODEV;



	rc = erst_get_record_id_begin(&reader_pos);



	return rc;

}



static int erst_close_pstore(struct pstore_info *psi)

{

	erst_get_record_id_end();



	return 0;

}



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

		       struct timespec *time)

{

	int rc;

	ssize_t len;

	unsigned long flags;

	ssize_t len = 0;

	u64 record_id;

	struct cper_pstore_record *rcd = (struct cper_pstore_record *)

					(erst_info.buf - sizeof(*rcd));
@@ -970,24 +994,21 @@ static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, 
	if (erst_disable)

		return -ENODEV;



	raw_spin_lock_irqsave(&erst_lock, flags);

skip:

	rc = __erst_get_next_record_id(&record_id);

	if (rc) {

		raw_spin_unlock_irqrestore(&erst_lock, flags);

		return rc;

	}

	rc = erst_get_record_id_next(&reader_pos, &record_id);

	if (rc)

		goto out;



	/* no more record */

	if (record_id == APEI_ERST_INVALID_RECORD_ID) {

		raw_spin_unlock_irqrestore(&erst_lock, flags);

		return 0;

		rc = -1;

		goto out;

	}



	len = __erst_read(record_id, &rcd->hdr, sizeof(*rcd) +

	len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +

			  erst_erange.size);

	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)

		goto skip;

	raw_spin_unlock_irqrestore(&erst_lock, flags);



	*id = record_id;

	if (uuid_le_cmp(rcd->sec_hdr.section_type,
@@ -1005,7 +1026,8 @@ skip: 
		time->tv_sec = 0;

	time->tv_nsec = 0;



	return len - sizeof(*rcd);

out:

	return (rc < 0) ? rc : (len - sizeof(*rcd));

}



static u64 erst_writer(enum pstore_type_id type, size_t size)

fs/pstore/platform.c

+7 −1
Original line number Diff line number Diff line
@@ -156,17 +156,23 @@ void pstore_get_records(void) 
	u64			id;

	enum pstore_type_id	type;

	struct timespec		time;

	int			failed = 0;

	int			failed = 0, rc;



	if (!psi)

		return;



	mutex_lock(&psinfo->buf_mutex);

	rc = psi->open(psi);

	if (rc)

		goto out;



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

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

				  time, psi->erase))

			failed++;

	}

	psi->close(psi);

out:

	mutex_unlock(&psinfo->buf_mutex);



	if (failed)

include/linux/pstore.h

+2 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ struct pstore_info { 
	struct mutex	buf_mutex;	/* serialize access to 'buf' */

	char		*buf;

	size_t		bufsize;

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

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

	ssize_t		(*read)(u64 *id, enum pstore_type_id *type,

			struct timespec *time);

	u64		(*write)(enum pstore_type_id type, size_t size);

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