Merge 4.5-rc4 into usb-next

We want the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-14 14:38:30 -08:00
parent a44007a42d 18558cae02
commit 172ad9af55
735 changed files with 6611 additions and 56920 deletions
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -682,9 +682,12 @@ static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
 /*
 * q->prep_rq_fn return values
 */
-#define BLKPREP_OK		0	/* serve it */
-#define BLKPREP_KILL		1	/* fatal error, kill */
-#define BLKPREP_DEFER		2	/* leave on queue */
+enum {
+	BLKPREP_OK,		/* serve it */
+	BLKPREP_KILL,		/* fatal error, kill, return -EIO */
+	BLKPREP_DEFER,		/* leave on queue */
+	BLKPREP_INVALID,	/* invalid command, kill, return -EREMOTEIO */
+};

 extern unsigned long blk_max_low_pfn, blk_max_pfn;

--- a/include/linux/ceph/ceph_features.h
+++ b/include/linux/ceph/ceph_features.h
@@ -63,6 +63,18 @@
 #define CEPH_FEATURE_OSD_MIN_SIZE_RECOVERY (1ULL<<49)
 // duplicated since it was introduced at the same time as MIN_SIZE_RECOVERY
 #define CEPH_FEATURE_OSD_PROXY_FEATURES (1ULL<<49)  /* overlap w/ above */
+#define CEPH_FEATURE_MON_METADATA (1ULL<<50)
+#define CEPH_FEATURE_OSD_BITWISE_HOBJ_SORT (1ULL<<51) /* can sort objs bitwise */
+#define CEPH_FEATURE_OSD_PROXY_WRITE_FEATURES (1ULL<<52)
+#define CEPH_FEATURE_ERASURE_CODE_PLUGINS_V3 (1ULL<<53)
+#define CEPH_FEATURE_OSD_HITSET_GMT (1ULL<<54)
+#define CEPH_FEATURE_HAMMER_0_94_4 (1ULL<<55)
+#define CEPH_FEATURE_NEW_OSDOP_ENCODING   (1ULL<<56) /* New, v7 encoding */
+#define CEPH_FEATURE_MON_STATEFUL_SUB (1ULL<<57) /* stateful mon subscription */
+#define CEPH_FEATURE_MON_ROUTE_OSDMAP (1ULL<<57) /* peon sends osdmaps */
+#define CEPH_FEATURE_CRUSH_TUNABLES5	(1ULL<<58) /* chooseleaf stable mode */
+// duplicated since it was introduced at the same time as CEPH_FEATURE_CRUSH_TUNABLES5
+#define CEPH_FEATURE_NEW_OSDOPREPLY_ENCODING   (1ULL<<58) /* New, v7 encoding */

 /*
 * The introduction of CEPH_FEATURE_OSD_SNAPMAPPER caused the feature
@@ -108,7 +120,9 @@ static inline u64 ceph_sanitize_features(u64 features)
 	 CEPH_FEATURE_CRUSH_TUNABLES3 |		\
 	 CEPH_FEATURE_OSD_PRIMARY_AFFINITY |	\
 	 CEPH_FEATURE_MSGR_KEEPALIVE2 |		\
-	 CEPH_FEATURE_CRUSH_V4)
+	 CEPH_FEATURE_CRUSH_V4 |		\
+	 CEPH_FEATURE_CRUSH_TUNABLES5 |		\
+	 CEPH_FEATURE_NEW_OSDOPREPLY_ENCODING)

 #define CEPH_FEATURES_REQUIRED_DEFAULT   \
 	(CEPH_FEATURE_NOSRCADDR |	 \
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -127,6 +127,12 @@ struct cgroup_subsys_state {
 	 */
 	u64 serial_nr;

+	/*
+	 * Incremented by online self and children.  Used to guarantee that
+	 * parents are not offlined before their children.
+	 */
+	atomic_t online_cnt;
+
 	/* percpu_ref killing and RCU release */
 	struct rcu_head rcu_head;
 	struct work_struct destroy_work;
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -137,6 +137,8 @@ static inline void set_mems_allowed(nodemask_t nodemask)
 	task_unlock(current);
 }

+extern void cpuset_post_attach_flush(void);
+
 #else /* !CONFIG_CPUSETS */

 static inline bool cpusets_enabled(void) { return false; }
@@ -243,6 +245,10 @@ static inline bool read_mems_allowed_retry(unsigned int seq)
 	return false;
 }

+static inline void cpuset_post_attach_flush(void)
+{
+}
+
 #endif /* !CONFIG_CPUSETS */

 #endif /* _LINUX_CPUSET_H */
--- a/include/linux/crush/crush.h
+++ b/include/linux/crush/crush.h
@@ -59,7 +59,8 @@ enum {
 	CRUSH_RULE_SET_CHOOSELEAF_TRIES = 9, /* override chooseleaf_descend_once */
 	CRUSH_RULE_SET_CHOOSE_LOCAL_TRIES = 10,
 	CRUSH_RULE_SET_CHOOSE_LOCAL_FALLBACK_TRIES = 11,
-	CRUSH_RULE_SET_CHOOSELEAF_VARY_R = 12
+	CRUSH_RULE_SET_CHOOSELEAF_VARY_R = 12,
+	CRUSH_RULE_SET_CHOOSELEAF_STABLE = 13
 };

 /*
@@ -205,6 +206,11 @@ struct crush_map {
 	 * mappings line up a bit better with previous mappings. */
 	__u8 chooseleaf_vary_r;

+	/* if true, it makes chooseleaf firstn to return stable results (if
+	 * no local retry) so that data migrations would be optimal when some
+	 * device fails. */
+	__u8 chooseleaf_stable;
+
 #ifndef __KERNEL__
 	/*
 	 * version 0 (original) of straw_calc has various flaws.  version 1
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -14,6 +14,17 @@ int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t,
 		dax_iodone_t);
 int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t,
 		dax_iodone_t);
+
+#ifdef CONFIG_FS_DAX
+struct page *read_dax_sector(struct block_device *bdev, sector_t n);
+#else
+static inline struct page *read_dax_sector(struct block_device *bdev,
+		sector_t n)
+{
+	return ERR_PTR(-ENXIO);
+}
+#endif
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
 				unsigned int flags, get_block_t, dax_iodone_t);
--- a/include/linux/devpts_fs.h
+++ b/include/linux/devpts_fs.h
@@ -19,6 +19,8 @@

 int devpts_new_index(struct inode *ptmx_inode);
 void devpts_kill_index(struct inode *ptmx_inode, int idx);
+void devpts_add_ref(struct inode *ptmx_inode);
+void devpts_del_ref(struct inode *ptmx_inode);
 /* mknod in devpts */
 struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
 		void *priv);
@@ -32,6 +34,8 @@ void devpts_pty_kill(struct inode *inode);
 /* Dummy stubs in the no-pty case */
 static inline int devpts_new_index(struct inode *ptmx_inode) { return -EINVAL; }
 static inline void devpts_kill_index(struct inode *ptmx_inode, int idx) { }
+static inline void devpts_add_ref(struct inode *ptmx_inode) { }
+static inline void devpts_del_ref(struct inode *ptmx_inode) { }
 static inline struct inode *devpts_pty_new(struct inode *ptmx_inode,
 		dev_t device, int index, void *priv)
 {
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -484,9 +484,6 @@ struct block_device {
 	int			bd_fsfreeze_count;
 	/* Mutex for freeze */
 	struct mutex		bd_fsfreeze_mutex;
-#ifdef CONFIG_FS_DAX
-	int			bd_map_count;
-#endif
 };

 /*
@@ -2907,7 +2904,7 @@ extern void replace_mount_options(struct super_block *sb, char *options);

 static inline bool io_is_direct(struct file *filp)
 {
-	return (filp->f_flags & O_DIRECT) || IS_DAX(file_inode(filp));
+	return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
 }

 static inline int iocb_flags(struct file *file)
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -547,16 +547,16 @@ static inline bool pm_suspended_storage(void)
 }
 #endif /* CONFIG_PM_SLEEP */

-#ifdef CONFIG_CMA
-
+#if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
 /* The below functions must be run on a range from a single zone. */
 extern int alloc_contig_range(unsigned long start, unsigned long end,
 			      unsigned migratetype);
 extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
+#endif

+#ifdef CONFIG_CMA
 /* CMA stuff */
 extern void init_cma_reserved_pageblock(struct page *page);
-
 #endif

 #endif /* __LINUX_GFP_H */
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -526,6 +526,7 @@ enum ata_lpm_policy {
 enum ata_lpm_hints {
 	ATA_LPM_EMPTY		= (1 << 0), /* port empty/probing */
 	ATA_LPM_HIPM		= (1 << 1), /* may use HIPM */
+	ATA_LPM_WAKE_ONLY	= (1 << 2), /* only wake up link */
 };

 /* forward declarations */
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -66,7 +66,7 @@ struct lock_class {
 	/*
 	 * class-hash:
 	 */
-	struct list_head		hash_entry;
+	struct hlist_node		hash_entry;

 	/*
 	 * global list of all lock-classes:
@@ -199,7 +199,7 @@ struct lock_chain {
 	u8				irq_context;
 	u8				depth;
 	u16				base;
-	struct list_head		entry;
+	struct hlist_node		entry;
 	u64				chain_key;
 };

--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -51,7 +51,7 @@ enum mem_cgroup_stat_index {
 	MEM_CGROUP_STAT_SWAP,		/* # of pages, swapped out */
 	MEM_CGROUP_STAT_NSTATS,
 	/* default hierarchy stats */
-	MEMCG_SOCK,
+	MEMCG_SOCK = MEM_CGROUP_STAT_NSTATS,
 	MEMCG_NR_STAT,
 };

--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -201,11 +201,13 @@ extern unsigned int kobjsize(const void *objp);
 #endif

 #ifdef CONFIG_STACK_GROWSUP
-#define VM_STACK_FLAGS	(VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
+#define VM_STACK	VM_GROWSUP
 #else
-#define VM_STACK_FLAGS	(VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
+#define VM_STACK	VM_GROWSDOWN
 #endif

+#define VM_STACK_FLAGS	(VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
+
 /*
 * Special vmas that are non-mergable, non-mlock()able.
 * Note: mm/huge_memory.c VM_NO_THP depends on this definition.
@@ -1341,8 +1343,7 @@ static inline int stack_guard_page_end(struct vm_area_struct *vma,
 		!vma_growsup(vma->vm_next, addr);
 }

-extern struct task_struct *task_of_stack(struct task_struct *task,
-				struct vm_area_struct *vma, bool in_group);
+int vma_is_stack_for_task(struct vm_area_struct *vma, struct task_struct *t);

 extern unsigned long move_page_tables(struct vm_area_struct *vma,
 		unsigned long old_addr, struct vm_area_struct *new_vma,
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -424,9 +424,9 @@ struct mm_struct {
 	unsigned long total_vm;		/* Total pages mapped */
 	unsigned long locked_vm;	/* Pages that have PG_mlocked set */
 	unsigned long pinned_vm;	/* Refcount permanently increased */
-	unsigned long data_vm;		/* VM_WRITE & ~VM_SHARED/GROWSDOWN */
-	unsigned long exec_vm;		/* VM_EXEC & ~VM_WRITE */
-	unsigned long stack_vm;		/* VM_GROWSUP/DOWN */
+	unsigned long data_vm;		/* VM_WRITE & ~VM_SHARED & ~VM_STACK */
+	unsigned long exec_vm;		/* VM_EXEC & ~VM_WRITE & ~VM_STACK */
+	unsigned long stack_vm;		/* VM_STACK */
 	unsigned long def_flags;
 	unsigned long start_code, end_code, start_data, end_data;
 	unsigned long start_brk, brk, start_stack;
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -682,6 +682,12 @@ typedef struct pglist_data {
 	 */
 	unsigned long first_deferred_pfn;
 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	spinlock_t split_queue_lock;
+	struct list_head split_queue;
+	unsigned long split_queue_len;
+#endif
 } pg_data_t;

 #define node_present_pages(nid)	(NODE_DATA(nid)->node_present_pages)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -324,6 +324,12 @@ struct module_layout {
 #define __module_layout_align
 #endif

+struct mod_kallsyms {
+	Elf_Sym *symtab;
+	unsigned int num_symtab;
+	char *strtab;
+};
+
 struct module {
 	enum module_state state;

@@ -405,15 +411,10 @@ struct module {
 #endif

 #ifdef CONFIG_KALLSYMS
-	/*
-	 * We keep the symbol and string tables for kallsyms.
-	 * The core_* fields below are temporary, loader-only (they
-	 * could really be discarded after module init).
-	 */
-	Elf_Sym *symtab, *core_symtab;
-	unsigned int num_symtab, core_num_syms;
-	char *strtab, *core_strtab;
-
+	/* Protected by RCU and/or module_mutex: use rcu_dereference() */
+	struct mod_kallsyms *kallsyms;
+	struct mod_kallsyms core_kallsyms;
+	
 	/* Section attributes */
 	struct module_sect_attrs *sect_attrs;

--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -512,7 +512,6 @@ static inline void napi_enable(struct napi_struct *n)
 	clear_bit(NAPI_STATE_NPSVC, &n->state);
 }

-#ifdef CONFIG_SMP
 /**
 *	napi_synchronize - wait until NAPI is not running
 *	@n: napi context
@@ -523,12 +522,12 @@ static inline void napi_enable(struct napi_struct *n)
 */
 static inline void napi_synchronize(const struct napi_struct *n)
 {
-	while (test_bit(NAPI_STATE_SCHED, &n->state))
-		msleep(1);
+	if (IS_ENABLED(CONFIG_SMP))
+		while (test_bit(NAPI_STATE_SCHED, &n->state))
+			msleep(1);
+	else
+		barrier();
 }
-#else
-# define napi_synchronize(n)	barrier()
-#endif

 enum netdev_queue_state_t {
 	__QUEUE_STATE_DRV_XOFF,
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -929,7 +929,7 @@ static inline int of_get_available_child_count(const struct device_node *np)
 	return num;
 }

-#ifdef CONFIG_OF
+#if defined(CONFIG_OF) && !defined(MODULE)
 #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
 	static const struct of_device_id __of_table_##name		\
 		__used __section(__##table##_of_table)			\
--- a/include/linux/pfn.h
+++ b/include/linux/pfn.h
@@ -10,7 +10,7 @@
 * backing is indicated by flags in the high bits of the value.
 */
 typedef struct {
-	unsigned long val;
+	u64 val;
 } pfn_t;
 #endif

--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -9,14 +9,13 @@
 * PFN_DEV - pfn is not covered by system memmap by default
 * PFN_MAP - pfn has a dynamic page mapping established by a device driver
 */
-#define PFN_FLAGS_MASK (((unsigned long) ~PAGE_MASK) \
-		<< (BITS_PER_LONG - PAGE_SHIFT))
-#define PFN_SG_CHAIN (1UL << (BITS_PER_LONG - 1))
-#define PFN_SG_LAST (1UL << (BITS_PER_LONG - 2))
-#define PFN_DEV (1UL << (BITS_PER_LONG - 3))
-#define PFN_MAP (1UL << (BITS_PER_LONG - 4))
+#define PFN_FLAGS_MASK (((u64) ~PAGE_MASK) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
+#define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
+#define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2))
+#define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3))
+#define PFN_MAP (1ULL << (BITS_PER_LONG_LONG - 4))

-static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, unsigned long flags)
+static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, u64 flags)
 {
 	pfn_t pfn_t = { .val = pfn | (flags & PFN_FLAGS_MASK), };

@@ -29,7 +28,7 @@ static inline pfn_t pfn_to_pfn_t(unsigned long pfn)
 	return __pfn_to_pfn_t(pfn, 0);
 }

-extern pfn_t phys_to_pfn_t(dma_addr_t addr, unsigned long flags);
+extern pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags);

 static inline bool pfn_t_has_page(pfn_t pfn)
 {
@@ -48,7 +47,7 @@ static inline struct page *pfn_t_to_page(pfn_t pfn)
 	return NULL;
 }

-static inline dma_addr_t pfn_t_to_phys(pfn_t pfn)
+static inline phys_addr_t pfn_t_to_phys(pfn_t pfn)
 {
 	return PFN_PHYS(pfn_t_to_pfn(pfn));
 }
@@ -87,7 +86,7 @@ static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot)
 #ifdef __HAVE_ARCH_PTE_DEVMAP
 static inline bool pfn_t_devmap(pfn_t pfn)
 {
-	const unsigned long flags = PFN_DEV|PFN_MAP;
+	const u64 flags = PFN_DEV|PFN_MAP;

 	return (pfn.val & flags) == flags;
 }
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -378,13 +378,29 @@ radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
 void **radix_tree_next_chunk(struct radix_tree_root *root,
 			     struct radix_tree_iter *iter, unsigned flags);

+/**
+ * radix_tree_iter_retry - retry this chunk of the iteration
+ * @iter:	iterator state
+ *
+ * If we iterate over a tree protected only by the RCU lock, a race
+ * against deletion or creation may result in seeing a slot for which
+ * radix_tree_deref_retry() returns true.  If so, call this function
+ * and continue the iteration.
+ */
+static inline __must_check
+void **radix_tree_iter_retry(struct radix_tree_iter *iter)
+{
+	iter->next_index = iter->index;
+	return NULL;
+}
+
 /**
 * radix_tree_chunk_size - get current chunk size
 *
 * @iter:	pointer to radix tree iterator
 * Returns:	current chunk size
 */
-static __always_inline unsigned
+static __always_inline long
 radix_tree_chunk_size(struct radix_tree_iter *iter)
 {
 	return iter->next_index - iter->index;
@@ -418,9 +434,9 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
 			return slot + offset + 1;
 		}
 	} else {
-		unsigned size = radix_tree_chunk_size(iter) - 1;
+		long size = radix_tree_chunk_size(iter);

-		while (size--) {
+		while (--size > 0) {
 			slot++;
 			iter->index++;
 			if (likely(*slot))
--- a/include/linux/raid/pq.h
+++ b/include/linux/raid/pq.h
@@ -152,6 +152,8 @@ void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,

 # define jiffies	raid6_jiffies()
 # define printk 	printf
+# define pr_err(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
+# define pr_info(format, ...) fprintf(stdout, format, ## __VA_ARGS__)
 # define GFP_KERNEL	0
 # define __get_free_pages(x, y)	((unsigned long)mmap(NULL, PAGE_SIZE << (y), \
 						     PROT_READ|PROT_WRITE,   \
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -109,20 +109,6 @@ static inline void put_anon_vma(struct anon_vma *anon_vma)
 		__put_anon_vma(anon_vma);
 }

-static inline void vma_lock_anon_vma(struct vm_area_struct *vma)
-{
-	struct anon_vma *anon_vma = vma->anon_vma;
-	if (anon_vma)
-		down_write(&anon_vma->root->rwsem);
-}
-
-static inline void vma_unlock_anon_vma(struct vm_area_struct *vma)
-{
-	struct anon_vma *anon_vma = vma->anon_vma;
-	if (anon_vma)
-		up_write(&anon_vma->root->rwsem);
-}
-
 static inline void anon_vma_lock_write(struct anon_vma *anon_vma)
 {
 	down_write(&anon_vma->root->rwsem);
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -299,6 +299,7 @@ struct sk_buff;
 #else
 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
 #endif
+extern int sysctl_max_skb_frags;

 typedef struct skb_frag_struct skb_frag_t;

--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -311,6 +311,7 @@ enum {

 	__WQ_DRAINING		= 1 << 16, /* internal: workqueue is draining */
 	__WQ_ORDERED		= 1 << 17, /* internal: workqueue is ordered */
+	__WQ_LEGACY		= 1 << 18, /* internal: create*_workqueue() */

 	WQ_MAX_ACTIVE		= 512,	  /* I like 512, better ideas? */
 	WQ_MAX_UNBOUND_PER_CPU	= 4,	  /* 4 * #cpus for unbound wq */
@@ -411,12 +412,12 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
 	alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)

 #define create_workqueue(name)						\
-	alloc_workqueue("%s", WQ_MEM_RECLAIM, 1, (name))
+	alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
 #define create_freezable_workqueue(name)				\
-	alloc_workqueue("%s", WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, \
-			1, (name))
+	alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND |	\
+			WQ_MEM_RECLAIM, 1, (name))
 #define create_singlethread_workqueue(name)				\
-	alloc_ordered_workqueue("%s", WQ_MEM_RECLAIM, name)
+	alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)

 extern void destroy_workqueue(struct workqueue_struct *wq);