- Add some spinlocks to cover all the private data in the mutex. I don't

think this should fix anything but it's a good idea regardless.

- Drop the lock before calling the construct/destructor for the slab
otherwise we can't sleep in a constructor/destructor and for long running
functions we may NMI.

- Do something braindead, but safe for the console debug logs for now.


git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@73 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c

3 files changed, 76 insertions, 31 deletions

diff --git a/include/sys/mutex.h b/include/sys/mutex.h
index 068fde1ab..ae8b81a7f 100644
--- a/include/sys/mutex.h
+++ b/include/sys/mutex.h
@@ -29,16 +29,19 @@ typedef struct {
 	char *km_name;
 	struct task_struct *km_owner;
 	struct semaphore km_sem;
+	spinlock_t km_lock;
 } kmutex_t;
 
 #undef mutex_init
 static __inline__ void
 mutex_init(kmutex_t *mp, char *name, int type, void *ibc)
 {
+	BUG_ON(mp == NULL);
 	BUG_ON(ibc != NULL);		/* XXX - Spin mutexes not needed? */
 	BUG_ON(type != MUTEX_DEFAULT);	/* XXX - Only default type supported? */
 
 	mp->km_magic = KM_MAGIC;
+	spin_lock_init(&mp->km_lock);
 	sema_init(&mp->km_sem, 1);
 	mp->km_owner = NULL;
 	mp->km_name = NULL;
@@ -54,49 +57,65 @@ mutex_init(kmutex_t *mp, char *name, int type, void *ibc)
 static __inline__ void
 mutex_destroy(kmutex_t *mp)
 {
+	BUG_ON(mp == NULL);
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_magic != KM_MAGIC);
 
 	if (mp->km_name)
 		kfree(mp->km_name);
 
 	memset(mp, KM_POISON, sizeof(*mp));
+	spin_unlock(&mp->km_lock);
 }
 
 static __inline__ void
 mutex_enter(kmutex_t *mp)
 {
+	BUG_ON(mp == NULL);
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_magic != KM_MAGIC);
 
 	if (unlikely(in_atomic() && !current->exit_state)) {
 		printk("May schedule while atomic: %s/0x%08x/%d\n",
 		       current->comm, preempt_count(), current->pid);
+		spin_unlock(&mp->km_lock);
 		BUG();
 	}
 
-	down(&mp->km_sem);  /* Will check in_atomic() for us */
+	spin_unlock(&mp->km_lock);
+
+	down(&mp->km_sem);
+
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_owner != NULL);
 	mp->km_owner = current;
+	spin_unlock(&mp->km_lock);
 }
 
-/* Return 1 if we acquired the mutex, else zero.
- */
+/* Return 1 if we acquired the mutex, else zero.  */
 static __inline__ int
 mutex_tryenter(kmutex_t *mp)
 {
-	int result;
+	int rc;
 
+	BUG_ON(mp == NULL);
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_magic != KM_MAGIC);
 
 	if (unlikely(in_atomic() && !current->exit_state)) {
 		printk("May schedule while atomic: %s/0x%08x/%d\n",
 		       current->comm, preempt_count(), current->pid);
+		spin_unlock(&mp->km_lock);
 		BUG();
 	}
 
-	result = down_trylock(&mp->km_sem); /* returns 0 if acquired */
-	if (result == 0) {
+	spin_unlock(&mp->km_lock);
+	rc = down_trylock(&mp->km_sem); /* returns 0 if acquired */
+	if (rc == 0) {
+		spin_lock(&mp->km_lock);
 		BUG_ON(mp->km_owner != NULL);
 		mp->km_owner = current;
+		spin_unlock(&mp->km_lock);
 		return 1;
 	}
 	return 0;
@@ -105,28 +124,43 @@ mutex_tryenter(kmutex_t *mp)
 static __inline__ void
 mutex_exit(kmutex_t *mp)
 {
+	BUG_ON(mp == NULL);
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_magic != KM_MAGIC);
 	BUG_ON(mp->km_owner != current);
 	mp->km_owner = NULL;
+	spin_unlock(&mp->km_lock);
 	up(&mp->km_sem);
 }
 
-/* Return 1 if mutex is held by current process, else zero.
- */
+/* Return 1 if mutex is held by current process, else zero.  */
 static __inline__ int
 mutex_owned(kmutex_t *mp)
 {
+	int rc;
+
+	BUG_ON(mp == NULL);
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_magic != KM_MAGIC);
-	return (mp->km_owner == current);
+	rc = (mp->km_owner == current);
+	spin_unlock(&mp->km_lock);
+
+	return rc;
 }
 
-/* Return owner if mutex is owned, else NULL.
- */
+/* Return owner if mutex is owned, else NULL.  */
 static __inline__ kthread_t *
 mutex_owner(kmutex_t *mp)
 {
+	kthread_t *thr;
+
+	BUG_ON(mp == NULL);
+	spin_lock(&mp->km_lock);
 	BUG_ON(mp->km_magic != KM_MAGIC);
-	return mp->km_owner;
+	thr = mp->km_owner;
+	spin_unlock(&mp->km_lock);
+
+	return thr;
 }
 
 #ifdef	__cplusplus
diff --git a/modules/spl/spl-generic.c b/modules/spl/spl-generic.c
index 3faa4b6b3..8cd217cf1 100644
--- a/modules/spl/spl-generic.c
+++ b/modules/spl/spl-generic.c
@@ -10,7 +10,8 @@
 /*
  * Generic support
  */
-static char spl_debug_buffer[MAXMSGLEN];
+static char spl_debug_buffer1[1024];
+static char spl_debug_buffer2[1024];
 static spinlock_t spl_debug_lock = SPIN_LOCK_UNLOCKED;
 
 unsigned long spl_debug_mask = 0;
@@ -83,12 +84,11 @@ EXPORT_SYMBOL(ddi_strtoul);
 void
 __dprintf(const char *file, const char *func, int line, const char *fmt, ...)
 {
-        char *sfp, *start, *ptr;
+        char *sfp;
         struct timeval tv;
 	unsigned long flags;
         va_list ap;
 
-	start = ptr = spl_debug_buffer;
         sfp = strrchr(file, '/');
         do_gettimeofday(&tv);
 
@@ -98,18 +98,21 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...)
 	 * reason why we really, really, need an internal debug log.
 	 */
 	spin_lock_irqsave(&spl_debug_lock, flags);
-        ptr += snprintf(ptr, MAXMSGLEN - 1,
-                        "spl: %lu.%06lu:%d:%u:%s:%d:%s(): ",
-                        tv.tv_sec, tv.tv_usec, current->pid,
-                        smp_processor_id(),
-                        sfp == NULL ? file : sfp + 1,
-                        line, func);
+	memset(spl_debug_buffer1, 0, 1024);
+	memset(spl_debug_buffer2, 0, 1024);
+
+        snprintf(spl_debug_buffer1, 1023,
+                 "spl: %lu.%06lu:%d:%u:%s:%d:%s(): ",
+                 tv.tv_sec, tv.tv_usec, current->pid,
+                 smp_processor_id(),
+                 sfp == NULL ? file : sfp + 1,
+                 line, func);
 
         va_start(ap, fmt);
-        ptr += vsnprintf(ptr, MAXMSGLEN - (ptr - start) - 1, fmt, ap);
+        vsnprintf(spl_debug_buffer2, 1023, fmt, ap);
         va_end(ap);
 
-        printk("%s", start);
+        printk("%s%s", spl_debug_buffer1, spl_debug_buffer2);
 	spin_unlock_irqrestore(&spl_debug_lock, flags);
 }
 EXPORT_SYMBOL(__dprintf);
diff --git a/modules/spl/spl-kmem.c b/modules/spl/spl-kmem.c
index 1b9eaafe6..7c88eda5f 100644
--- a/modules/spl/spl-kmem.c
+++ b/modules/spl/spl-kmem.c
@@ -50,7 +50,6 @@ typedef struct kmem_cache_cb {
 
 
 static spinlock_t kmem_cache_cb_lock = SPIN_LOCK_UNLOCKED;
-//static spinlock_t kmem_cache_cb_lock = (spinlock_t) { 1 SPINLOCK_MAGIC_INIT };
 static LIST_HEAD(kmem_cache_cb_list);
 static struct shrinker *kmem_cache_shrinker;
 
@@ -110,17 +109,22 @@ static void
 kmem_cache_generic_constructor(void *ptr, kmem_cache_t *cache, unsigned long flags)
 {
         kmem_cache_cb_t *kcc;
+	kmem_constructor_t constructor;
+	void *private;
 
 	spin_lock(&kmem_cache_cb_lock);
 
         /* Callback list must be in sync with linux slab caches */
         kcc = kmem_cache_find_cache_cb(cache);
         BUG_ON(!kcc);
-
-	if (kcc->kcc_constructor)
-		kcc->kcc_constructor(ptr, kcc->kcc_private, (int)flags);
+	constructor = kcc->kcc_constructor;
+	private = kcc->kcc_private;
 
 	spin_unlock(&kmem_cache_cb_lock);
+
+	if (constructor)
+		constructor(ptr, private, (int)flags);
+
 	/* Linux constructor has no return code, silently eat it */
 }
 
@@ -128,18 +132,22 @@ static void
 kmem_cache_generic_destructor(void *ptr, kmem_cache_t *cache, unsigned long flags)
 {
         kmem_cache_cb_t *kcc;
+        kmem_destructor_t destructor;
+	void *private;
 
 	spin_lock(&kmem_cache_cb_lock);
 
         /* Callback list must be in sync with linux slab caches */
         kcc = kmem_cache_find_cache_cb(cache);
         BUG_ON(!kcc);
-
-	/* Solaris destructor takes no flags, silently eat them */
-	if (kcc->kcc_destructor)
-		kcc->kcc_destructor(ptr, kcc->kcc_private);
+	destructor = kcc->kcc_destructor;
+	private = kcc->kcc_private;
 
 	spin_unlock(&kmem_cache_cb_lock);
+
+	/* Solaris destructor takes no flags, silently eat them */
+	if (destructor)
+		destructor(ptr, private);
 }
 
 /* XXX - Arguments are ignored */