On 6/23/21 5:16 PM, Hannes Reinecke wrote:

On 6/23/21 7:26 AM, Coly Li wrote:

quoted

On 6/22/21 6:39 PM, Hannes Reinecke wrote:

quoted

On 6/15/21 7:49 AM, Coly Li wrote:

quoted

From: Jianpeng Ma <redacted>

This patch define the prototype data structures in memory and
initializes the nvm pages allocator.

The nvm address space which is managed by this allocator can
consist of
many nvm namespaces, and some namespaces can compose into one nvm set,
like cache set. For this initial implementation, only one set can be
supported.

The users of this nvm pages allocator need to call
register_namespace()
to register the nvdimm device (like /dev/pmemX) into this allocator as
the instance of struct nvm_namespace.

Reported-by: Randy Dunlap <redacted>
Signed-off-by: Jianpeng Ma <redacted>
Co-developed-by: Qiaowei Ren <redacted>
Signed-off-by: Qiaowei Ren <redacted>
Signed-off-by: Coly Li <redacted>
---
  drivers/md/bcache/Kconfig     |  10 ++
  drivers/md/bcache/Makefile    |   1 +
  drivers/md/bcache/nvm-pages.c | 295
++++++++++++++++++++++++++++++++++
  drivers/md/bcache/nvm-pages.h |  74 +++++++++
  drivers/md/bcache/super.c     |   3 +
  5 files changed, 383 insertions(+)
  create mode 100644 drivers/md/bcache/nvm-pages.c
  create mode 100644 drivers/md/bcache/nvm-pages.h

diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
index d1ca4d059c20..a69f6c0e0507 100644
--- a/drivers/md/bcache/Kconfig
+++ b/drivers/md/bcache/Kconfig

@@ -35,3 +35,13 @@ config BCACHE_ASYNC_REGISTRATION

      device path into this file will returns immediately and the real
      registration work is handled in kernel work queue in
asynchronous
      way.
+
+config BCACHE_NVM_PAGES
+    bool "NVDIMM support for bcache (EXPERIMENTAL)"
+    depends on BCACHE
+    depends on 64BIT
+    depends on LIBNVDIMM
+    depends on DAX
+    help
+      Allocate/release NV-memory pages for bcache and provide
allocated pages
+      for each requestor after system reboot.

diff --git a/drivers/md/bcache/Makefile b/drivers/md/bcache/Makefile
index 5b87e59676b8..2397bb7c7ffd 100644
--- a/drivers/md/bcache/Makefile
+++ b/drivers/md/bcache/Makefile

@@ -5,3 +5,4 @@ obj-$(CONFIG_BCACHE)    += bcache.o

  bcache-y        := alloc.o bset.o btree.o closure.o debug.o
extents.o\
      io.o journal.o movinggc.o request.o stats.o super.o sysfs.o
trace.o\
      util.o writeback.o features.o
+bcache-$(CONFIG_BCACHE_NVM_PAGES) += nvm-pages.o

diff --git a/drivers/md/bcache/nvm-pages.c

b/drivers/md/bcache/nvm-pages.c
new file mode 100644
index 000000000000..18fdadbc502f

--- /dev/null
+++ b/drivers/md/bcache/nvm-pages.c

@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Nvdimm page-buddy allocator
+ *
+ * Copyright (c) 2021, Intel Corporation.
+ * Copyright (c) 2021, Qiaowei Ren <qiaowei.ren@intel.com>.
+ * Copyright (c) 2021, Jianpeng Ma <jianpeng.ma@intel.com>.
+ */
+
+#if defined(CONFIG_BCACHE_NVM_PAGES)
+

No need for this 'if' statement as it'll be excluded by the Makefile
anyway if the config option isn't set.

Such if is necessary because stub routines are defined when
CONFIG_BCACHE_NVM_PAGES is not defined, e.g.

426 +#else
427 +
428 +static inline struct bch_nvm_namespace
*bch_register_namespace(const char *dev_path)
429 +{
430 +       return NULL;
431 +}
432 +static inline int bch_nvm_init(void)
433 +{
434 +       return 0;
435 +}
436 +static inline void bch_nvm_exit(void) { }
437 +
438 +#endif /* CONFIG_BCACHE_NVM_PAGES */

But then these stubs should be defined in the header file, not here.

[ .. ]

Copied, it will be improved in next post. Thanks for your review and
comment.

Coly Li