The madvise_inject_error() routine uses get_user_pages() to lookup the pfn and other information for injected error, but it fails to release that pin.
The dax-dma-vs-truncate warning catches this failure with the following signature:
Injecting memory failure for pfn 0x208900 at process virtual address 0x7f3908d00000 Memory failure: 0x208900: reserved kernel page still referenced by 1 users Memory failure: 0x208900: recovery action for reserved kernel page: Failed WARNING: CPU: 37 PID: 9566 at fs/dax.c:348 dax_disassociate_entry+0x4e/0x90 CPU: 37 PID: 9566 Comm: umount Tainted: G W OE 4.17.0-rc6+ #1900 [..] RIP: 0010:dax_disassociate_entry+0x4e/0x90 RSP: 0018:ffffc9000a9b3b30 EFLAGS: 00010002 RAX: ffffea0008224000 RBX: 0000000000208a00 RCX: 0000000000208900 RDX: 0000000000000001 RSI: ffff8804058c6160 RDI: 0000000000000008 RBP: 000000000822000a R08: 0000000000000002 R09: 0000000000208800 R10: 0000000000000000 R11: 0000000000208801 R12: ffff8804058c6168 R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000001 FS: 00007f4548027fc0(0000) GS:ffff880431d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056316d5f8988 CR3: 00000004298cc000 CR4: 00000000000406e0 Call Trace: __dax_invalidate_mapping_entry+0xab/0xe0 dax_delete_mapping_entry+0xf/0x20 truncate_exceptional_pvec_entries.part.14+0x1d4/0x210 truncate_inode_pages_range+0x291/0x920 ? kmem_cache_free+0x1f8/0x300 ? lock_acquire+0x9f/0x200 ? truncate_inode_pages_final+0x31/0x50 ext4_evict_inode+0x69/0x740
Cc: stable@vger.kernel.org Fixes: bd1ce5f91f54 ("HWPOISON: avoid grabbing the page count...") Cc: Michal Hocko mhocko@suse.com Cc: Andi Kleen ak@linux.intel.com Cc: Wu Fengguang fengguang.wu@intel.com Signed-off-by: Dan Williams dan.j.williams@intel.com --- mm/madvise.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/mm/madvise.c b/mm/madvise.c index 4d3c922ea1a1..246fa4d4eee2 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -631,11 +631,13 @@ static int madvise_inject_error(int behavior,
for (; start < end; start += PAGE_SIZE << order) { + unsigned long pfn; int ret;
ret = get_user_pages_fast(start, 1, 0, &page); if (ret != 1) return ret; + pfn = page_to_pfn(page);
/* * When soft offlining hugepages, after migrating the page @@ -651,17 +653,20 @@ static int madvise_inject_error(int behavior,
if (behavior == MADV_SOFT_OFFLINE) { pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", - page_to_pfn(page), start); + pfn, start);
ret = soft_offline_page(page, MF_COUNT_INCREASED); + put_page(page); if (ret) return ret; continue; } + put_page(page); + pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", - page_to_pfn(page), start); + pfn, start);
- ret = memory_failure(page_to_pfn(page), MF_COUNT_INCREASED); + ret = memory_failure(pfn, MF_COUNT_INCREASED); if (ret) return ret; }