diff options
author | Dave Jiang <dave.jiang@intel.com> | 2017-04-13 14:25:17 -0700 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2017-04-13 14:23:51 -0700 |
commit | b3b454f694db663773bc22002e10909afe9c1739 (patch) | |
tree | cca98ec1b74eb5b95569476bec8782d79aa04829 /drivers/nvdimm/core.c | |
parent | efebc711180f7fed701f6e23f23814fcfda7fbfc (diff) | |
download | linux-b3b454f694db663773bc22002e10909afe9c1739.tar.bz2 |
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 <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/core.c')
-rw-r--r-- | drivers/nvdimm/core.c | 56 |
1 files changed, 33 insertions, 23 deletions
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c index 40a3da088fd2..2dee908e4bae 100644 --- a/drivers/nvdimm/core.c +++ b/drivers/nvdimm/core.c @@ -518,6 +518,15 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region, } EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate); +static void append_poison_entry(struct nvdimm_bus *nvdimm_bus, + struct nd_poison *pl, u64 addr, u64 length) +{ + lockdep_assert_held(&nvdimm_bus->poison_lock); + pl->start = addr; + pl->length = length; + list_add_tail(&pl->list, &nvdimm_bus->poison_list); +} + static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length, gfp_t flags) { @@ -527,19 +536,24 @@ static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length, if (!pl) return -ENOMEM; - pl->start = addr; - pl->length = length; - list_add_tail(&pl->list, &nvdimm_bus->poison_list); - + append_poison_entry(nvdimm_bus, pl, addr, length); return 0; } static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) { - struct nd_poison *pl; + struct nd_poison *pl, *pl_new; - if (list_empty(&nvdimm_bus->poison_list)) - return add_poison(nvdimm_bus, addr, length, GFP_KERNEL); + spin_unlock(&nvdimm_bus->poison_lock); + pl_new = kzalloc(sizeof(*pl_new), GFP_KERNEL); + spin_lock(&nvdimm_bus->poison_lock); + + if (list_empty(&nvdimm_bus->poison_list)) { + if (!pl_new) + return -ENOMEM; + append_poison_entry(nvdimm_bus, pl_new, addr, length); + return 0; + } /* * There is a chance this is a duplicate, check for those first. @@ -551,6 +565,7 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) /* If length has changed, update this list entry */ if (pl->length != length) pl->length = length; + kfree(pl_new); return 0; } @@ -559,30 +574,33 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) * as any overlapping ranges will get resolved when the list is consumed * and converted to badblocks */ - return add_poison(nvdimm_bus, addr, length, GFP_KERNEL); + if (!pl_new) + return -ENOMEM; + append_poison_entry(nvdimm_bus, pl_new, addr, length); + + return 0; } int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length) { int rc; - nvdimm_bus_lock(&nvdimm_bus->dev); + spin_lock(&nvdimm_bus->poison_lock); rc = bus_add_poison(nvdimm_bus, addr, length); - nvdimm_bus_unlock(&nvdimm_bus->dev); + spin_unlock(&nvdimm_bus->poison_lock); return rc; } EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison); -void __nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, phys_addr_t start, +void nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, phys_addr_t start, unsigned int len) { struct list_head *poison_list = &nvdimm_bus->poison_list; u64 clr_end = start + len - 1; struct nd_poison *pl, *next; - lockdep_assert_held(&nvdimm_bus->reconfig_mutex); - + spin_lock(&nvdimm_bus->poison_lock); WARN_ON_ONCE(list_empty(poison_list)); /* @@ -629,21 +647,13 @@ void __nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, phys_addr_t start, u64 new_len = pl_end - new_start + 1; /* Add new entry covering the right half */ - add_poison(nvdimm_bus, new_start, new_len, GFP_NOIO); + add_poison(nvdimm_bus, new_start, new_len, GFP_NOWAIT); /* Adjust this entry to cover the left half */ pl->length = start - pl->start; continue; } } -} -EXPORT_SYMBOL_GPL(__nvdimm_forget_poison); - -void nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, - phys_addr_t start, unsigned int len) -{ - nvdimm_bus_lock(&nvdimm_bus->dev); - __nvdimm_forget_poison(nvdimm_bus, start, len); - nvdimm_bus_unlock(&nvdimm_bus->dev); + spin_unlock(&nvdimm_bus->poison_lock); } EXPORT_SYMBOL_GPL(nvdimm_forget_poison); |