From: David Hildenbrand <da...@redhat.com> [ Upstream commit 5666848774ef43d3db5151ec518f1deb63515c20 ]
Let's perform all checking + offlining + removing under device_hotplug_lock, so nobody can mess with these devices via sysfs concurrently. [da...@redhat.com: take device_hotplug_lock outside of loop] Link: http://lkml.kernel.org/r/20180927092554.13567-6-da...@redhat.com Link: http://lkml.kernel.org/r/20180925091457.28651-6-da...@redhat.com Signed-off-by: David Hildenbrand <da...@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatas...@microsoft.com> Reviewed-by: Rashmica Gupta <rashmic...@gmail.com> Acked-by: Balbir Singh <bsinghar...@gmail.com> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Rashmica Gupta <rashmic...@gmail.com> Cc: Michael Neuling <mi...@neuling.org> Cc: Boris Ostrovsky <boris.ostrov...@oracle.com> Cc: Dan Williams <dan.j.willi...@intel.com> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Haiyang Zhang <haiya...@microsoft.com> Cc: Heiko Carstens <heiko.carst...@de.ibm.com> Cc: John Allen <jal...@linux.vnet.ibm.com> Cc: Jonathan Corbet <cor...@lwn.net> Cc: Joonsoo Kim <iamjoonsoo....@lge.com> Cc: Juergen Gross <jgr...@suse.com> Cc: Kate Stewart <kstew...@linuxfoundation.org> Cc: "K. Y. Srinivasan" <k...@microsoft.com> Cc: Len Brown <l...@kernel.org> Cc: Martin Schwidefsky <schwidef...@de.ibm.com> Cc: Mathieu Malaterre <ma...@debian.org> Cc: Michal Hocko <mho...@suse.com> Cc: Nathan Fontenot <nf...@linux.vnet.ibm.com> Cc: Oscar Salvador <osalva...@suse.de> Cc: Philippe Ombredanne <pombreda...@nexb.com> Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net> Cc: Stephen Hemminger <sthem...@microsoft.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Vlastimil Babka <vba...@suse.cz> Cc: YASUAKI ISHIMATSU <yasu.isim...@gmail.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- arch/powerpc/platforms/powernv/memtrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index a29fdf8a2e56e..232bf5987f91d 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -70,6 +70,7 @@ static int change_memblock_state(struct memory_block *mem, void *arg) return 0; } +/* called with device_hotplug_lock held */ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) { u64 end_pfn = start_pfn + nr_pages - 1; @@ -110,6 +111,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) /* Trace memory needs to be aligned to the size */ end_pfn = round_down(end_pfn - nr_pages, nr_pages); + lock_device_hotplug(); for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) { /* @@ -118,7 +120,6 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) * we never try to remove memory that spans two iomem * resources. */ - lock_device_hotplug(); end_pfn = base_pfn + nr_pages; for (pfn = base_pfn; pfn < end_pfn; pfn += bytes>> PAGE_SHIFT) { remove_memory(nid, pfn << PAGE_SHIFT, bytes); @@ -127,6 +128,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) return base_pfn << PAGE_SHIFT; } } + unlock_device_hotplug(); return 0; } -- 2.20.1
