[SRU][Bionic][PATCH 0/1] Fix for Bionic build error (LP: #1838533)

[Kleber Sacilotto de Souza]

[Impact]

When compiling bionic linux 4.15.0-56.62 with CONFIG_NVM disabled, it fails with:

make[5]: *** [drivers/nvme/host/core.o] Error 1
make[5]: *** Waiting for unfinished jobs....
In file included from /tmp/kernel-kleber-57dc2e6-NQe1/build/drivers/nvme/host/multipath.c:15:0:
/tmp/kernel-kleber-57dc2e6-NQe1/build/drivers/nvme/host/nvme.h: In function
'nvme_nvm_register_sysfs':
/tmp/kernel-kleber-57dc2e6-NQe1/build/drivers/nvme/host/nvme.h:502:6: error:
'ctrl' undeclared (first use in this function)
  if (ctrl->subsys->cmic & (1 << 3))
      ^
/tmp/kernel-kleber-57dc2e6-NQe1/build/drivers/nvme/host/nvme.h:502:6: note:
each undeclared identifier is reported only once for each function it appears in

[Fix]
The culprit is this patch:

commit 993f70b886c0062fb5ec7c3c556d074bb3380b9d
Author: Christoph Hellwig <hch at lst.de>
Date: Tue Nov 20 16:57:54 2018 +0100

    nvme: warn when finding multi-port subsystems without multipathing enabled

    BugLink: https://bugs.launchpad.net/bugs/1837161

    [ Upstream commit 14a1336e6fff47dd1028b484d6c802105c58e2ee ]
[...]
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -499,6 +499,9 @@ static inline int nvme_nvm_register(struct nvme_ns *ns, char *disk_name,
 static inline void nvme_nvm_unregister(struct nvme_ns *ns) {};
 static inline int nvme_nvm_register_sysfs(struct nvme_ns *ns)
 {
+ if (ctrl->subsys->cmic & (1 << 3))
+ dev_warn(ctrl->device,
+"Please enable CONFIG_NVME_MULTIPATH for full support of multi-port devices.\n");
        return 0;
 }

which is adding the new lines to a different function than the original upstream
commit:

--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -531,6 +531,9 @@ static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
 static inline int nvme_mpath_init(struct nvme_ctrl *ctrl,
                struct nvme_id_ctrl *id)
 {
+ if (ctrl->subsys->cmic & (1 << 3))
+ dev_warn(ctrl->device,
+"Please enable CONFIG_NVME_MULTIPATH for full support of multi-port devices.\n");
        return 0;
 }

This patch was probably wrongly backported for bug #1837161 from linux-4.19.y
stable and not needed since bionic/linux lacks commit 0d0b660f214d (nvme: add
ANA support) which introduced nvme_mpath_init(). The fix is to revert this patch.

[Test Case]

Disabled kernel config CONFIG_NVM and compile the kernel.

[Regression Potential]

Low. The patch was wrongly backported and can be safely reverted.

Kleber Sacilotto de Souza (1):
  Revert "nvme: warn when finding multi-port subsystems without
    multipathing enabled"

 drivers/nvme/host/nvme.h | 3 ---
 1 file changed, 3 deletions(-)

-- 
2.17.1