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 --- drivers/nvdimm/bus.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/nvdimm/bus.c') diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 5ad2e5909e1a..d214ac44d111 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -296,6 +296,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent, init_waitqueue_head(&nvdimm_bus->probe_wait); nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL); mutex_init(&nvdimm_bus->reconfig_mutex); + spin_lock_init(&nvdimm_bus->poison_lock); if (nvdimm_bus->id < 0) { kfree(nvdimm_bus); return NULL; @@ -364,9 +365,9 @@ static int nd_bus_remove(struct device *dev) nd_synchronize(); device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister); - nvdimm_bus_lock(&nvdimm_bus->dev); + spin_lock(&nvdimm_bus->poison_lock); free_poison_list(&nvdimm_bus->poison_list); - nvdimm_bus_unlock(&nvdimm_bus->dev); + spin_unlock(&nvdimm_bus->poison_lock); nvdimm_bus_destroy_ndctl(nvdimm_bus); @@ -990,7 +991,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm, if (clear_err->cleared) { /* clearing the poison list we keep track of */ - __nvdimm_forget_poison(nvdimm_bus, clear_err->address, + nvdimm_forget_poison(nvdimm_bus, clear_err->address, clear_err->cleared); /* now sync the badblocks lists */ -- cgit v1.2.3-59-g8ed1b