pstore: Don't allow high traffic options on fragile devices
Some pstore backing devices use on board flash as persistent
storage. These have limited numbers of write cycles so it
is a poor idea to use them from high frequency operations.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 26311f2..cb1d557 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -942,6 +942,7 @@
static struct pstore_info erst_info = {
.owner = THIS_MODULE,
.name = "erst",
+ .flags = PSTORE_FLAGS_FRAGILE,
.open = erst_open_pstore,
.close = erst_close_pstore,
.read = erst_reader,
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 743fd42..4b9dc83 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -356,6 +356,7 @@
static struct pstore_info efi_pstore_info = {
.owner = THIS_MODULE,
.name = "efi",
+ .flags = PSTORE_FLAGS_FRAGILE,
.open = efi_pstore_open,
.close = efi_pstore_close,
.read = efi_pstore_read,
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index b8e93a4..78c3c20 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -443,8 +443,11 @@
pstore_get_records(0);
kmsg_dump_register(&pstore_dumper);
- pstore_register_console();
- pstore_register_ftrace();
+
+ if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
+ pstore_register_console();
+ pstore_register_ftrace();
+ }
if (pstore_update_ms >= 0) {
pstore_timer.expires = jiffies +
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index abd437d..ece0c6b 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -51,6 +51,7 @@
char *buf;
size_t bufsize;
struct mutex read_mutex; /* serialize open/read/close */
+ int flags;
int (*open)(struct pstore_info *psi);
int (*close)(struct pstore_info *psi);
ssize_t (*read)(u64 *id, enum pstore_type_id *type,
@@ -70,6 +71,8 @@
void *data;
};
+#define PSTORE_FLAGS_FRAGILE 1
+
#ifdef CONFIG_PSTORE
extern int pstore_register(struct pstore_info *);
extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
