This continues the 4.11 status quo of disabling of error clearing from
the BTT I/O path. Toshi found that even though we have eliminated all
the libnvdimm sources of sleeping-while-atomic triggers, we still have
sleeping operations that will occur in the path to send the ACPI DSM to
the DIMM to clear the error:
BUG: sleeping function called from invalid context at mm/slab.h:432
in_atomic(): 1, irqs_disabled(): 0, pid: 13353, name: dd
Call Trace:
dump_stack+0x86/0xc3
___might_sleep+0x17d/0x250
__might_sleep+0x4a/0x80
__kmalloc+0x1c0/0x2e0
acpi_os_allocate_zeroed+0x2d/0x2f
acpi_evaluate_object+0x59/0x3b1
acpi_evaluate_dsm+0xbd/0x10c
acpi_nfit_ctl+0x1ef/0x7c0 [nfit]
? nsio_rw_bytes+0x152/0x280
nvdimm_clear_poison+0x77/0x140
nsio_rw_bytes+0x18f/0x280
btt_write_pg+0x1d4/0x3d0 [nd_btt]
btt_make_request+0x119/0x2d0 [nd_btt]
A solution for tracking and handling media errors natively in the BTT is
needed.
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Reported-by: Toshi Kani <toshi.kani@xxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/nvdimm/claim.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 35b210dc1e56..6945e35058bf 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -250,7 +250,16 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
- if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)) {
+ /*
+ * FIXME: nsio_rw_bytes() may be called from atomic
+ * context in the btt case and the ACPI DSM path for
+ * clearing the error takes sleeping locks and allocates
+ * memory. An explicit error clearing path, and support
+ * for tracking badblocks in BTT metadata is needed to
+ * work around this collision.
+ */
+ if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
+ && (!ndns->claim || !is_nd_btt(ndns->claim))) {
long cleared;
cleared = nvdimm_clear_poison(&ndns->dev,
--
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