From b3b454f694db663773bc22002e10909afe9c1739 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 13 Apr 2017 14:25:17 -0700 Subject: libnvdimm: fix clear poison locking with spinlock and GFP_NOWAIT allocation The following warning results from holding a lane spinlock, preempt_disable(), or the btt map spinlock and then trying to take the reconfig_mutex to walk the poison list and potentially add new entries. BUG: sleeping function called from invalid context at kernel/locking/mutex. c:747 in_atomic(): 1, irqs_disabled(): 0, pid: 17159, name: dd [..] Call Trace: dump_stack+0x85/0xc8 ___might_sleep+0x184/0x250 __might_sleep+0x4a/0x90 __mutex_lock+0x58/0x9b0 ? nvdimm_bus_lock+0x21/0x30 [libnvdimm] ? __nvdimm_bus_badblocks_clear+0x2f/0x60 [libnvdimm] ? acpi_nfit_forget_poison+0x79/0x80 [nfit] ? _raw_spin_unlock+0x27/0x40 mutex_lock_nested+0x1b/0x20 nvdimm_bus_lock+0x21/0x30 [libnvdimm] nvdimm_forget_poison+0x25/0x50 [libnvdimm] nvdimm_clear_poison+0x106/0x140 [libnvdimm] nsio_rw_bytes+0x164/0x270 [libnvdimm] btt_write_pg+0x1de/0x3e0 [nd_btt] ? blk_queue_enter+0x30/0x290 btt_make_request+0x11a/0x310 [nd_btt] ? blk_queue_enter+0xb7/0x290 ? blk_queue_enter+0x30/0x290 generic_make_request+0x118/0x3b0 A spinlock is introduced to protect the poison list. This allows us to not having to acquire the reconfig_mutex for touching the poison list. The add_poison() function has been broken out into two helper functions. One to allocate the poison entry and the other to apppend the entry. This allows us to unlock the poison_lock in non-I/O path and continue to be able to allocate the poison entry with GFP_KERNEL. We will use GFP_NOWAIT in the I/O path in order to satisfy being in atomic context. Reviewed-by: Vishal Verma Signed-off-by: Dave Jiang Signed-off-by: Dan Williams --- include/linux/libnvdimm.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/libnvdimm.h') diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h index 1c609e89048a..98b207611b06 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -122,8 +122,6 @@ static inline struct nd_blk_region_desc *to_blk_region_desc( int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length); void nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, phys_addr_t start, unsigned int len); -void __nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, - phys_addr_t start, unsigned int len); struct nvdimm_bus *nvdimm_bus_register(struct device *parent, struct nvdimm_bus_descriptor *nfit_desc); void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus); -- cgit v1.2.3-59-g8ed1b