For function tracing we need to stop using pstore.buf directly, since in a tracing callback we can't use spinlocks, and thus we can't safely use the global buffer.
With write_buf callback, backends no longer need to access pstore.buf directly, and thus we can pass any buffers (e.g. allocated on stack).
Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org --- fs/pstore/platform.c | 10 ++++++++++ include/linux/pstore.h | 4 ++++ 2 files changed, 14 insertions(+)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 6b3ff04..ef5ca8a 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -188,6 +188,14 @@ static void pstore_register_console(void) static void pstore_register_console(void) {} #endif
+static int pstore_write_compat(enum pstore_type_id type, + enum kmsg_dump_reason reason, + u64 *id, unsigned int part, + size_t size, struct pstore_info *psi) +{ + return psi->write_buf(type, reason, id, part, psinfo->buf, size, psi); +} + /* * platform specific persistent storage driver registers with * us here. If pstore is already mounted, call the platform @@ -212,6 +220,8 @@ int pstore_register(struct pstore_info *psi) return -EINVAL; }
+ if (!psi->write) + psi->write = pstore_write_compat; psinfo = psi; mutex_init(&psinfo->read_mutex); spin_unlock(&pstore_lock); diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 1bd014b..b107484 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -48,6 +48,10 @@ struct pstore_info { int (*write)(enum pstore_type_id type, enum kmsg_dump_reason reason, u64 *id, unsigned int part, size_t size, struct pstore_info *psi); + int (*write_buf)(enum pstore_type_id type, + enum kmsg_dump_reason reason, u64 *id, + unsigned int part, const char *buf, size_t size, + struct pstore_info *psi); int (*erase)(enum pstore_type_id type, u64 id, struct pstore_info *psi); void *data;