pstore: Introduce write_buf backend callback
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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) {}
#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 @@
return -EINVAL;
}
+ if (!psi->write)
+ psi->write = pstore_write_compat;
psinfo = psi;
mutex_init(&psinfo->read_mutex);
spin_unlock(&pstore_lock);