@@ -81,6 +81,7 @@ static int virtio_pmem_probe(struct virtio_device *vdev)
ndr_desc.res = &res;
ndr_desc.numa_node = nid;
ndr_desc.flush = async_pmem_flush;
+ ndr_desc.provider_data = vdev;
set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
@@ -89,7 +90,6 @@ static int virtio_pmem_probe(struct virtio_device *vdev)
err = -ENXIO;
goto out_nd;
}
- nd_region->provider_data = dev_to_virtio(nd_region->dev.parent->parent);
return 0;
out_nd:
nvdimm_bus_unregister(vpmem->nvdimm_bus);
We used to initialize the provider_data manually after nvdimm_pemm_region_create(). This seems to be racy if the flush is issued before the initialization of provider_data[1]. Fixing this by initializing the provider_data through nd_region_desc to make sure the provider_data is ready after the pmem is created. [1]: [ 80.152281] nd_pmem namespace0.0: unable to guarantee persistence of writes [ 92.393956] BUG: kernel NULL pointer dereference, address: 0000000000000318 [ 92.394551] #PF: supervisor read access in kernel mode [ 92.394955] #PF: error_code(0x0000) - not-present page [ 92.395365] PGD 0 P4D 0 [ 92.395566] Oops: 0000 [#1] PREEMPT SMP PTI [ 92.395867] CPU: 2 PID: 506 Comm: mkfs.ext4 Not tainted 5.19.0-rc1+ #453 [ 92.396365] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 92.397178] RIP: 0010:virtio_pmem_flush+0x2f/0x1f0 [ 92.397521] Code: 55 41 54 55 53 48 81 ec a0 00 00 00 65 48 8b 04 25 28 00 00 00 48 89 84 24 98 00 00 00 31 c0 48 8b 87 78 03 00 00 48 89 04 24 <48> 8b 98 18 03 00 00 e8 85 bf 6b 00 ba 58 00 00 00 be c0 0c 00 00 [ 92.398982] RSP: 0018:ffff9a7380aefc88 EFLAGS: 00010246 [ 92.399349] RAX: 0000000000000000 RBX: ffff8e77c3f86f00 RCX: 0000000000000000 [ 92.399833] RDX: ffffffffad4ea720 RSI: ffff8e77c41e39c0 RDI: ffff8e77c41c5c00 [ 92.400388] RBP: ffff8e77c41e39c0 R08: ffff8e77c19f0600 R09: 0000000000000000 [ 92.400874] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8e77c0814e28 [ 92.401364] R13: 0000000000000000 R14: 0000000000000000 R15: ffff8e77c41e39c0 [ 92.401849] FS: 00007f3cd75b2780(0000) GS:ffff8e7937d00000(0000) knlGS:0000000000000000 [ 92.402423] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 92.402821] CR2: 0000000000000318 CR3: 0000000103c80002 CR4: 0000000000370ee0 [ 92.403307] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 92.403793] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 92.404278] Call Trace: [ 92.404481] <TASK> [ 92.404654] ? mempool_alloc+0x5d/0x160 [ 92.404939] ? terminate_walk+0x5f/0xf0 [ 92.405226] ? bio_alloc_bioset+0xbb/0x3f0 [ 92.405525] async_pmem_flush+0x17/0x80 [ 92.405806] nvdimm_flush+0x11/0x30 [ 92.406067] pmem_submit_bio+0x1e9/0x200 [ 92.406354] __submit_bio+0x80/0x120 [ 92.406621] submit_bio_noacct_nocheck+0xdc/0x2a0 [ 92.406958] submit_bio_wait+0x4e/0x80 [ 92.407234] blkdev_issue_flush+0x31/0x50 [ 92.407526] ? punt_bios_to_rescuer+0x230/0x230 [ 92.407852] blkdev_fsync+0x1e/0x30 [ 92.408112] do_fsync+0x33/0x70 [ 92.408354] __x64_sys_fsync+0xb/0x10 [ 92.408625] do_syscall_64+0x43/0x90 [ 92.408895] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 92.409257] RIP: 0033:0x7f3cd76c6c44 Fixes 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver") Acked-by: Pankaj Gupta <pankaj.gupta@amd.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- Changes since V1: - Add calltrace to explain the issue in detail --- drivers/nvdimm/virtio_pmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)