pstore: Introduce new argument 'compressed' in the read callback

Backends will set the flag 'compressed' after reading the log from
persistent store to indicate the data being returned to pstore is
compressed or not.
Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/powerpc/platforms/pseries/nvram.c

@@ -598,7 +598,7 @@ static int nvram_pstore_write(enum pstore_type_id type,
  */
 static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
 				int *count, struct timespec *time, char **buf,
-				struct pstore_info *psi)
+				bool *compressed, struct pstore_info *psi)
 {
 	struct oops_log_info *oops_hdr;
 	unsigned int err_type, id_no, size = 0;

drivers/acpi/apei/erst.c

@@ -935,7 +935,7 @@ 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, int *count,
 			   struct timespec *time, char **buf,
-			   struct pstore_info *psi);
+			   bool *compressed, struct pstore_info *psi);
 static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
 		       u64 *id, unsigned int part, int count, bool compressed,
 		       size_t size, struct pstore_info *psi);
@@ -991,7 +991,7 @@ static int erst_close_pstore(struct pstore_info *psi)
 
 static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
 			   struct timespec *time, char **buf,
-			   struct pstore_info *psi)
+			   bool *compressed, struct pstore_info *psi)
 {
 	int rc;
 	ssize_t len = 0;

drivers/firmware/efi/efi-pstore.c

@@ -87,7 +87,8 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 
 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 			       int *count, struct timespec *timespec,
-			       char **buf, struct pstore_info *psi)
+			       char **buf, bool *compressed,
+			       struct pstore_info *psi)
 {
 	struct pstore_read_data data;
 

fs/pstore/platform.c

@@ -428,6 +428,7 @@ void pstore_get_records(int quiet)
 	enum pstore_type_id	type;
 	struct timespec		time;
 	int			failed = 0, rc;
+	bool			compressed;
 
 	if (!psi)
 		return;
@@ -436,7 +437,8 @@ void pstore_get_records(int quiet)
 	if (psi->open && psi->open(psi))
 		goto out;
 
-	while ((size = psi->read(&id, &type, &count, &time, &buf, psi)) > 0) {
+	while ((size = psi->read(&id, &type, &count, &time, &buf, &compressed,
+				psi)) > 0) {
 		rc = pstore_mkfile(type, psi->name, id, count, buf,
 				  (size_t)size, time, psi);
 		kfree(buf);

fs/pstore/ram.c

@@ -133,7 +133,8 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 
 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 				   int *count, struct timespec *time,
-				   char **buf, struct pstore_info *psi)
+				   char **buf, bool *compressed,
+				   struct pstore_info *psi)
 {
 	ssize_t size;
 	ssize_t ecc_notice_size;

include/linux/pstore.h

@@ -55,7 +55,7 @@ struct pstore_info {
 	int		(*close)(struct pstore_info *psi);
 	ssize_t		(*read)(u64 *id, enum pstore_type_id *type,
 			int *count, struct timespec *time, char **buf,
-			struct pstore_info *psi);
+			bool *compressed, struct pstore_info *psi);
 	int		(*write)(enum pstore_type_id type,
 			enum kmsg_dump_reason reason, u64 *id,
 			unsigned int part, int count, bool compressed,