+ mm-memory_hotplug-fix-unpaired-mem_hotplug_begin-done.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm/memory_hotplug: fix unpaired mem_hotplug_begin/done
has been added to the -mm tree.  Its filename is
     mm-memory_hotplug-fix-unpaired-mem_hotplug_begin-done.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-fix-unpaired-mem_hotplug_begin-done.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-fix-unpaired-mem_hotplug_begin-done.patch

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------------------------------------------------------
From: Jia He <justin.he@arm.com>
Subject: mm/memory_hotplug: fix unpaired mem_hotplug_begin/done

When check_memblock_offlined_cb() returns failed rc(e.g. the memblock is
online at that time), mem_hotplug_begin/done is unpaired in such case.

Therefore a warning:
 Call Trace:
  percpu_up_write+0x33/0x40
  try_remove_memory+0x66/0x120
  ? _cond_resched+0x19/0x30
  remove_memory+0x2b/0x40
  dev_dax_kmem_remove+0x36/0x72 [kmem]
  device_release_driver_internal+0xf0/0x1c0
  device_release_driver+0x12/0x20
  bus_remove_device+0xe1/0x150
  device_del+0x17b/0x3e0
  unregister_dev_dax+0x29/0x60
  devm_action_release+0x15/0x20
  release_nodes+0x19a/0x1e0
  devres_release_all+0x3f/0x50
  device_release_driver_internal+0x100/0x1c0
  driver_detach+0x4c/0x8f
  bus_remove_driver+0x5c/0xd0
  driver_unregister+0x31/0x50
  dax_pmem_exit+0x10/0xfe0 [dax_pmem]

Link: http://lkml.kernel.org/r/20200710031619.18762-3-justin.he@arm.com
Fixes: f1037ec0cc8a ("mm/memory_hotplug: fix remove_memory() lockdep splat")
Signed-off-by: Jia He <justin.he@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>	[5.6+]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chuhong Yuan <hslester96@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Cc: Kaly Xin <Kaly.Xin@arm.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory_hotplug.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/mm/memory_hotplug.c~mm-memory_hotplug-fix-unpaired-mem_hotplug_begin-done
+++ a/mm/memory_hotplug.c
@@ -1756,7 +1756,7 @@ static int __ref try_remove_memory(int n
 	 */
 	rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb);
 	if (rc)
-		goto done;
+		return rc;
 
 	/* remove memmap entry */
 	firmware_map_remove(start, start + size, "System RAM");
@@ -1780,9 +1780,8 @@ static int __ref try_remove_memory(int n
 
 	try_offline_node(nid);
 
-done:
 	mem_hotplug_done();
-	return rc;
+	return 0;
 }
 
 /**
_

Patches currently in -mm which might be from justin.he@arm.com are

mm-memory_hotplug-introduce-default-dummy-memory_add_physaddr_to_nid.patch
mm-memory_hotplug-fix-unpaired-mem_hotplug_begin-done.patch