@@ -24,6 +24,7 @@
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/mm.h>
+#include <linux/mempool.h>
#include <linux/nd.h>
#include "nd-core.h"
#include "nd.h"
@@ -33,6 +34,7 @@ int nvdimm_major;
static int nvdimm_bus_major;
static struct class *nd_class;
static DEFINE_IDA(nd_ida);
+extern mempool_t *poison_mempool;
static int to_nd_device_type(struct device *dev)
{
@@ -296,6 +298,7 @@ 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;
@@ -342,13 +345,14 @@ static int child_unregister(struct device *dev, void *data)
return 0;
}
-static void free_poison_list(struct list_head *poison_list)
+static void free_poison_list(struct nvdimm_bus *nvdimm_bus)
{
+ struct list_head *poison_list = &nvdimm_bus->poison_list;
struct nd_poison *pl, *next;
list_for_each_entry_safe(pl, next, poison_list, list) {
list_del(&pl->list);
- kfree(pl);
+ mempool_free(pl, poison_mempool);
}
list_del_init(poison_list);
}
@@ -364,9 +368,9 @@ 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);
- free_poison_list(&nvdimm_bus->poison_list);
- nvdimm_bus_unlock(&nvdimm_bus->dev);
+ spin_lock(&nvdimm_bus->poison_lock);
+ free_poison_list(nvdimm_bus);
+ spin_unlock(&nvdimm_bus->poison_lock);
nvdimm_bus_destroy_ndctl(nvdimm_bus);
@@ -990,7 +994,7 @@ 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 */
@@ -21,11 +21,15 @@
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/io.h>
+#include <linux/mempool.h>
#include "nd-core.h"
#include "nd.h"
LIST_HEAD(nvdimm_bus_list);
DEFINE_MUTEX(nvdimm_bus_list_mutex);
+struct kmem_cache *poison_cache;
+mempool_t *poison_mempool;
+
void nvdimm_bus_lock(struct device *dev)
{
@@ -518,12 +522,11 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region,
}
EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);
-static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length,
- gfp_t flags)
+static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
{
struct nd_poison *pl;
- pl = kzalloc(sizeof(*pl), flags);
+ pl = mempool_alloc(poison_mempool, GFP_NOWAIT);
if (!pl)
return -ENOMEM;
@@ -539,7 +542,7 @@ static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
struct nd_poison *pl;
if (list_empty(&nvdimm_bus->poison_list))
- return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);
+ return add_poison(nvdimm_bus, addr, length);
/*
* There is a chance this is a duplicate, check for those first.
@@ -559,30 +562,29 @@ 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);
+ return add_poison(nvdimm_bus, addr, length);
}
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));
/*
@@ -604,7 +606,7 @@ void __nvdimm_forget_poison(struct nvdimm_bus *nvdimm_bus, phys_addr_t start,
/* Delete completely overlapped poison entries */
if ((pl->start >= start) && (pl_end <= clr_end)) {
list_del(&pl->list);
- kfree(pl);
+ mempool_free(pl, poison_mempool);
continue;
}
/* Adjust start point of partially cleared entries */
@@ -629,21 +631,13 @@ 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);
/* 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);
@@ -680,9 +674,21 @@ static __init int libnvdimm_init(void)
{
int rc;
+ poison_cache = kmem_cache_create("nvdimm_bus_poison",
+ sizeof(struct nd_poison), 0,
+ SLAB_HWCACHE_ALIGN, NULL);
+ if (!poison_cache)
+ return -ENOMEM;
+
+ poison_mempool = mempool_create_slab_pool(SZ_4K, poison_cache);
+ if (!poison_mempool) {
+ rc = -ENOMEM;
+ goto err_mempool;
+ }
+
rc = nvdimm_bus_init();
if (rc)
- return rc;
+ goto err_bus;
rc = nvdimm_init();
if (rc)
goto err_dimm;
@@ -694,6 +700,10 @@ static __init int libnvdimm_init(void)
nvdimm_exit();
err_dimm:
nvdimm_bus_exit();
+ err_bus:
+ mempool_destroy(poison_mempool);
+ err_mempool:
+ kmem_cache_destroy(poison_cache);
return rc;
}
@@ -705,6 +715,8 @@ static __exit void libnvdimm_exit(void)
nvdimm_bus_exit();
nd_region_devs_exit();
nvdimm_devs_exit();
+ mempool_destroy(poison_mempool);
+ kmem_cache_destroy(poison_cache);
}
MODULE_LICENSE("GPL v2");
@@ -32,6 +32,7 @@ struct nvdimm_bus {
struct list_head poison_list;
struct list_head mapping_list;
struct mutex reconfig_mutex;
+ spinlock_t poison_lock;
};
struct nvdimm {
@@ -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);
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 Two things are done to address this issue. First, we introduce a spinlock to protect the poison list. This allows us to not having to acquire the reconfig_mutex for touching the poison list. Second, we introduce a mempool for the poison list entry allocation. This provides a pool of entries we can allocate from. Once we run out, we will acquire entries via GFP_NOWAIT to avoid the sleep with GFP_KERNEL allocation. Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- drivers/nvdimm/bus.c | 16 ++++++++----- drivers/nvdimm/core.c | 56 +++++++++++++++++++++++++++------------------ drivers/nvdimm/nd-core.h | 1 + include/linux/libnvdimm.h | 2 -- 4 files changed, 45 insertions(+), 30 deletions(-)