1 files changed, 309 insertions, 273 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 06b0c3568f0b..accb40cdb12a 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -41,6 +41,8 @@
 #include <linux/utsname.h>
 #include <linux/hash.h>
 #include <linux/ftrace.h>
+#include <linux/stringify.h>
+#include <trace/lockdep.h>
 
 #include <asm/sections.h>
 
@@ -310,12 +312,14 @@ EXPORT_SYMBOL(lockdep_on);
 #if VERBOSE
 # define HARDIRQ_VERBOSE        1
 # define SOFTIRQ_VERBOSE        1
+# define RECLAIM_VERBOSE        1
 #else
 # define HARDIRQ_VERBOSE        0
 # define SOFTIRQ_VERBOSE        0
+# define RECLAIM_VERBOSE        0
 #endif
 
-#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE
+#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE || RECLAIM_VERBOSE
 /*
  * Quick filtering for interesting events:
  */
@@ -430,30 +434,24 @@ atomic_t nr_find_usage_forwards_checks;
 atomic_t nr_find_usage_forwards_recursions;
 atomic_t nr_find_usage_backwards_checks;
 atomic_t nr_find_usage_backwards_recursions;
-# define debug_atomic_inc(ptr)          atomic_inc(ptr)
-# define debug_atomic_dec(ptr)          atomic_dec(ptr)
-# define debug_atomic_read(ptr)         atomic_read(ptr)
-#else
-# define debug_atomic_inc(ptr)          do { } while (0)
-# define debug_atomic_dec(ptr)          do { } while (0)
-# define debug_atomic_read(ptr)         0
 #endif
 
 /*
  * Locking printouts:
  */
 
+#define __USAGE(__STATE)                                                \
+        [LOCK_USED_IN_##__STATE] = "IN-"__stringify(__STATE)"-W",       \
+        [LOCK_ENABLED_##__STATE] = __stringify(__STATE)"-ON-W",         \
+        [LOCK_USED_IN_##__STATE##_READ] = "IN-"__stringify(__STATE)"-R",\
+        [LOCK_ENABLED_##__STATE##_READ] = __stringify(__STATE)"-ON-R",
+
 static const char *usage_str[] =
 {
-        [LOCK_USED] =                   "initial-use ",
-        [LOCK_USED_IN_HARDIRQ] =        "in-hardirq-W",
-        [LOCK_USED_IN_SOFTIRQ] =        "in-softirq-W",
-        [LOCK_ENABLED_SOFTIRQS] =       "softirq-on-W",
-        [LOCK_ENABLED_HARDIRQS] =       "hardirq-on-W",
-        [LOCK_USED_IN_HARDIRQ_READ] =   "in-hardirq-R",
-        [LOCK_USED_IN_SOFTIRQ_READ] =   "in-softirq-R",
-        [LOCK_ENABLED_SOFTIRQS_READ] =  "softirq-on-R",
-        [LOCK_ENABLED_HARDIRQS_READ] =  "hardirq-on-R",
+#define LOCKDEP_STATE(__STATE) __USAGE(__STATE)
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+        [LOCK_USED] = "INITIAL USE",
 };
 
 const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
@@ -461,46 +459,45 @@ const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
         return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
 }
 
-void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4)
+static inline unsigned long lock_flag(enum lock_usage_bit bit)
 {
-        *c1 = '.', *c2 = '.', *c3 = '.', *c4 = '.';
-
-        if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
-                *c1 = '+';
-        else
-                if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
-                        *c1 = '-';
+        return 1UL << bit;
+}
 
-        if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
-                *c2 = '+';
-        else
-                if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
-                        *c2 = '-';
+static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit)
+{
+        char c = '.';
 
-        if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
-                *c3 = '-';
-        if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) {
-                *c3 = '+';
-                if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
-                        *c3 = '?';
+        if (class->usage_mask & lock_flag(bit + 2))
+                c = '+';
+        if (class->usage_mask & lock_flag(bit)) {
+                c = '-';
+                if (class->usage_mask & lock_flag(bit + 2))
+                        c = '?';
         }
 
-        if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
-                *c4 = '-';
-        if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) {
-                *c4 = '+';
-                if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
-                        *c4 = '?';
-        }
+        return c;
+}
+
+void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS])
+{
+        int i = 0;
+
+#define LOCKDEP_STATE(__STATE)                                          \
+        usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE);     \
+        usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ);
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+
+        usage[i] = '\0';
 }
 
 static void print_lock_name(struct lock_class *class)
 {
-        char str[KSYM_NAME_LEN], c1, c2, c3, c4;
+        char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS];
         const char *name;
 
-        get_usage_chars(class, &c1, &c2, &c3, &c4);
+        get_usage_chars(class, usage);
 
         name = class->name;
         if (!name) {
@@ -513,7 +510,7 @@ static void print_lock_name(struct lock_class *class)
                 if (class->subclass)
                         printk("/%d", class->subclass);
         }
-        printk("){%c%c%c%c}", c1, c2, c3, c4);
+        printk("){%s}", usage);
 }
 
 static void print_lockdep_cache(struct lockdep_map *lock)
@@ -796,6 +793,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 
                 printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return NULL;
         }
         class = lock_classes + nr_lock_classes++;
@@ -859,6 +857,7 @@ static struct lock_list *alloc_list_entry(void)
 
                 printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return NULL;
         }
         return list_entries + nr_list_entries++;
@@ -1263,9 +1262,49 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
                         bit_backwards, bit_forwards, irqclass);
 }
 
-static int
-check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
-                struct held_lock *next)
+static const char *state_names[] = {
+#define LOCKDEP_STATE(__STATE) \
+        __stringify(__STATE),
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static const char *state_rnames[] = {
+#define LOCKDEP_STATE(__STATE) \
+        __stringify(__STATE)"-READ",
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static inline const char *state_name(enum lock_usage_bit bit)
+{
+        return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2];
+}
+
+static int exclusive_bit(int new_bit)
+{
+        /*
+         * USED_IN
+         * USED_IN_READ
+         * ENABLED
+         * ENABLED_READ
+         *
+         * bit 0 - write/read
+         * bit 1 - used_in/enabled
+         * bit 2+  state
+         */
+
+        int state = new_bit & ~3;
+        int dir = new_bit & 2;
+
+        /*
+         * keep state, bit flip the direction and strip read.
+         */
+        return state | (dir ^ 2);
+}
+
+static int check_irq_usage(struct task_struct *curr, struct held_lock *prev,
+                           struct held_lock *next, enum lock_usage_bit bit)
 {
         /*
          * Prove that the new dependency does not connect a hardirq-safe
@@ -1273,38 +1312,34 @@ check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
          * the backwards-subgraph starting at <prev>, and the
          * forwards-subgraph starting at <next>:
          */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
-                                        LOCK_ENABLED_HARDIRQS, "hard"))
+        if (!check_usage(curr, prev, next, bit,
+                           exclusive_bit(bit), state_name(bit)))
                 return 0;
 
+        bit++; /* _READ */
+
         /*
          * Prove that the new dependency does not connect a hardirq-safe-read
          * lock with a hardirq-unsafe lock - to achieve this we search
          * the backwards-subgraph starting at <prev>, and the
          * forwards-subgraph starting at <next>:
          */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
-                                        LOCK_ENABLED_HARDIRQS, "hard-read"))
+        if (!check_usage(curr, prev, next, bit,
+                           exclusive_bit(bit), state_name(bit)))
                 return 0;
 
-        /*
-         * Prove that the new dependency does not connect a softirq-safe
-         * lock with a softirq-unsafe lock - to achieve this we search
-         * the backwards-subgraph starting at <prev>, and the
-         * forwards-subgraph starting at <next>:
-         */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
-                                        LOCK_ENABLED_SOFTIRQS, "soft"))
-                return 0;
-        /*
-         * Prove that the new dependency does not connect a softirq-safe-read
-         * lock with a softirq-unsafe lock - to achieve this we search
-         * the backwards-subgraph starting at <prev>, and the
-         * forwards-subgraph starting at <next>:
-         */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
-                                        LOCK_ENABLED_SOFTIRQS, "soft"))
+        return 1;
+}
+
+static int
+check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
+                struct held_lock *next)
+{
+#define LOCKDEP_STATE(__STATE)                                          \
+        if (!check_irq_usage(curr, prev, next, LOCK_USED_IN_##__STATE)) \
                 return 0;
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
 
         return 1;
 }
@@ -1649,6 +1684,7 @@ cache_hit:
 
                 printk("BUG: MAX_LOCKDEP_CHAINS too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return 0;
         }
         chain = lock_chains + nr_lock_chains++;
@@ -1861,9 +1897,9 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
                 curr->comm, task_pid_nr(curr));
         print_lock(this);
         if (forwards)
-                printk("but this lock took another, %s-irq-unsafe lock in the past:\n", irqclass);
+                printk("but this lock took another, %s-unsafe lock in the past:\n", irqclass);
         else
-                printk("but this lock was taken by another, %s-irq-safe lock in the past:\n", irqclass);
+                printk("but this lock was taken by another, %s-safe lock in the past:\n", irqclass);
         print_lock_name(other);
         printk("\n\nand interrupts could create inverse lock ordering between them.\n\n");
 
@@ -1933,7 +1969,7 @@ void print_irqtrace_events(struct task_struct *curr)
         print_ip_sym(curr->softirq_disable_ip);
 }
 
-static int hardirq_verbose(struct lock_class *class)
+static int HARDIRQ_verbose(struct lock_class *class)
 {
 #if HARDIRQ_VERBOSE
         return class_filter(class);
@@ -1941,7 +1977,7 @@ static int hardirq_verbose(struct lock_class *class)
         return 0;
 }
 
-static int softirq_verbose(struct lock_class *class)
+static int SOFTIRQ_verbose(struct lock_class *class)
 {
 #if SOFTIRQ_VERBOSE
         return class_filter(class);
@@ -1949,185 +1985,95 @@ static int softirq_verbose(struct lock_class *class)
         return 0;
 }
 
+static int RECLAIM_FS_verbose(struct lock_class *class)
+{
+#if RECLAIM_VERBOSE
+        return class_filter(class);
+#endif
+        return 0;
+}
+
 #define STRICT_READ_CHECKS      1
 
-static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
+static int (*state_verbose_f[])(struct lock_class *class) = {
+#define LOCKDEP_STATE(__STATE) \
+        __STATE##_verbose,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static inline int state_verbose(enum lock_usage_bit bit,
+                                struct lock_class *class)
+{
+        return state_verbose_f[bit >> 2](class);
+}
+
+typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
+                             enum lock_usage_bit bit, const char *name);
+
+static int
+mark_lock_irq(struct task_struct *curr, struct held_lock *this,
                 enum lock_usage_bit new_bit)
 {
-        int ret = 1;
+        int excl_bit = exclusive_bit(new_bit);
+        int read = new_bit & 1;
+        int dir = new_bit & 2;
 
-        switch(new_bit) {
-        case LOCK_USED_IN_HARDIRQ:
-                if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
-                        return 0;
-                if (!valid_state(curr, this, new_bit,
-                                 LOCK_ENABLED_HARDIRQS_READ))
-                        return 0;
-                /*
-                 * just marked it hardirq-safe, check that this lock
-                 * took no hardirq-unsafe lock in the past:
-                 */
-                if (!check_usage_forwards(curr, this,
-                                          LOCK_ENABLED_HARDIRQS, "hard"))
-                        return 0;
-#if STRICT_READ_CHECKS
-                /*
-                 * just marked it hardirq-safe, check that this lock
-                 * took no hardirq-unsafe-read lock in the past:
-                 */
-                if (!check_usage_forwards(curr, this,
-                                LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
-                        return 0;
-#endif
-                if (hardirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_USED_IN_SOFTIRQ:
-                if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
-                        return 0;
-                if (!valid_state(curr, this, new_bit,
-                                 LOCK_ENABLED_SOFTIRQS_READ))
-                        return 0;
-                /*
-                 * just marked it softirq-safe, check that this lock
-                 * took no softirq-unsafe lock in the past:
-                 */
-                if (!check_usage_forwards(curr, this,
-                                          LOCK_ENABLED_SOFTIRQS, "soft"))
-                        return 0;
-#if STRICT_READ_CHECKS
-                /*
-                 * just marked it softirq-safe, check that this lock
-                 * took no softirq-unsafe-read lock in the past:
-                 */
-                if (!check_usage_forwards(curr, this,
-                                LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
-                        return 0;
-#endif
-                if (softirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_USED_IN_HARDIRQ_READ:
-                if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
-                        return 0;
-                /*
-                 * just marked it hardirq-read-safe, check that this lock
-                 * took no hardirq-unsafe lock in the past:
-                 */
-                if (!check_usage_forwards(curr, this,
-                                          LOCK_ENABLED_HARDIRQS, "hard"))
-                        return 0;
-                if (hardirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_USED_IN_SOFTIRQ_READ:
-                if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
-                        return 0;
-                /*
-                 * just marked it softirq-read-safe, check that this lock
-                 * took no softirq-unsafe lock in the past:
-                 */
-                if (!check_usage_forwards(curr, this,
-                                          LOCK_ENABLED_SOFTIRQS, "soft"))
-                        return 0;
-                if (softirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_ENABLED_HARDIRQS:
-                if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
-                        return 0;
-                if (!valid_state(curr, this, new_bit,
-                                 LOCK_USED_IN_HARDIRQ_READ))
-                        return 0;
-                /*
-                 * just marked it hardirq-unsafe, check that no hardirq-safe
-                 * lock in the system ever took it in the past:
-                 */
-                if (!check_usage_backwards(curr, this,
-                                           LOCK_USED_IN_HARDIRQ, "hard"))
-                        return 0;
-#if STRICT_READ_CHECKS
-                /*
-                 * just marked it hardirq-unsafe, check that no
-                 * hardirq-safe-read lock in the system ever took
-                 * it in the past:
-                 */
-                if (!check_usage_backwards(curr, this,
-                                   LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
-                        return 0;
-#endif
-                if (hardirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_ENABLED_SOFTIRQS:
-                if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
-                        return 0;
-                if (!valid_state(curr, this, new_bit,
-                                 LOCK_USED_IN_SOFTIRQ_READ))
-                        return 0;
-                /*
-                 * just marked it softirq-unsafe, check that no softirq-safe
-                 * lock in the system ever took it in the past:
-                 */
-                if (!check_usage_backwards(curr, this,
-                                           LOCK_USED_IN_SOFTIRQ, "soft"))
-                        return 0;
-#if STRICT_READ_CHECKS
-                /*
-                 * just marked it softirq-unsafe, check that no
-                 * softirq-safe-read lock in the system ever took
-                 * it in the past:
-                 */
-                if (!check_usage_backwards(curr, this,
-                                   LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
-                        return 0;
-#endif
-                if (softirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_ENABLED_HARDIRQS_READ:
-                if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
-                        return 0;
-#if STRICT_READ_CHECKS
-                /*
-                 * just marked it hardirq-read-unsafe, check that no
-                 * hardirq-safe lock in the system ever took it in the past:
-                 */
-                if (!check_usage_backwards(curr, this,
-                                           LOCK_USED_IN_HARDIRQ, "hard"))
-                        return 0;
-#endif
-                if (hardirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        case LOCK_ENABLED_SOFTIRQS_READ:
-                if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
+        /*
+         * mark USED_IN has to look forwards -- to ensure no dependency
+         * has ENABLED state, which would allow recursion deadlocks.
+         *
+         * mark ENABLED has to look backwards -- to ensure no dependee
+         * has USED_IN state, which, again, would allow  recursion deadlocks.
+         */
+        check_usage_f usage = dir ?
+                check_usage_backwards : check_usage_forwards;
+
+        /*
+         * Validate that this particular lock does not have conflicting
+         * usage states.
+         */
+        if (!valid_state(curr, this, new_bit, excl_bit))
+                return 0;
+
+        /*
+         * Validate that the lock dependencies don't have conflicting usage
+         * states.
+         */
+        if ((!read || !dir || STRICT_READ_CHECKS) &&
+                        !usage(curr, this, excl_bit, state_name(new_bit & ~1)))
+                return 0;
+
+        /*
+         * Check for read in write conflicts
+         */
+        if (!read) {
+                if (!valid_state(curr, this, new_bit, excl_bit + 1))
                         return 0;
-#if STRICT_READ_CHECKS
-                /*
-                 * just marked it softirq-read-unsafe, check that no
-                 * softirq-safe lock in the system ever took it in the past:
-                 */
-                if (!check_usage_backwards(curr, this,
-                                           LOCK_USED_IN_SOFTIRQ, "soft"))
+
+                if (STRICT_READ_CHECKS &&
+                        !usage(curr, this, excl_bit + 1,
+                                state_name(new_bit + 1)))
                         return 0;
-#endif
-                if (softirq_verbose(hlock_class(this)))
-                        ret = 2;
-                break;
-        default:
-                WARN_ON(1);
-                break;
         }
 
-        return ret;
+        if (state_verbose(new_bit, hlock_class(this)))
+                return 2;
+
+        return 1;
 }
 
+enum mark_type {
+#define LOCKDEP_STATE(__STATE)  __STATE,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
 /*
  * Mark all held locks with a usage bit:
  */
 static int
-mark_held_locks(struct task_struct *curr, int hardirq)
+mark_held_locks(struct task_struct *curr, enum mark_type mark)
 {
         enum lock_usage_bit usage_bit;
         struct held_lock *hlock;
@@ -2136,17 +2082,12 @@ mark_held_locks(struct task_struct *curr, int hardirq)
         for (i = 0; i < curr->lockdep_depth; i++) {
                 hlock = curr->held_locks + i;
 
-                if (hardirq) {
-                        if (hlock->read)
-                                usage_bit = LOCK_ENABLED_HARDIRQS_READ;
-                        else
-                                usage_bit = LOCK_ENABLED_HARDIRQS;
-                } else {
-                        if (hlock->read)
-                                usage_bit = LOCK_ENABLED_SOFTIRQS_READ;
-                        else
-                                usage_bit = LOCK_ENABLED_SOFTIRQS;
-                }
+                usage_bit = 2 + (mark << 2); /* ENABLED */
+                if (hlock->read)
+                        usage_bit += 1; /* READ */
+
+                BUG_ON(usage_bit >= LOCK_USAGE_STATES);
+
                 if (!mark_lock(curr, hlock, usage_bit))
                         return 0;
         }
@@ -2200,7 +2141,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
          * We are going to turn hardirqs on, so set the
          * usage bit for all held locks:
          */
-        if (!mark_held_locks(curr, 1))
+        if (!mark_held_locks(curr, HARDIRQ))
                 return;
         /*
          * If we have softirqs enabled, then set the usage
@@ -2208,7 +2149,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
          * this bit from being set before)
          */
         if (curr->softirqs_enabled)
-                if (!mark_held_locks(curr, 0))
+                if (!mark_held_locks(curr, SOFTIRQ))
                         return;
 
         curr->hardirq_enable_ip = ip;
@@ -2288,7 +2229,7 @@ void trace_softirqs_on(unsigned long ip)
          * enabled too:
          */
         if (curr->hardirqs_enabled)
-                mark_held_locks(curr, 0);
+                mark_held_locks(curr, SOFTIRQ);
 }
 
 /*
@@ -2317,6 +2258,48 @@ void trace_softirqs_off(unsigned long ip)
                 debug_atomic_inc(&redundant_softirqs_off);
 }
 
+static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags)
+{
+        struct task_struct *curr = current;
+
+        if (unlikely(!debug_locks))
+                return;
+
+        /* no reclaim without waiting on it */
+        if (!(gfp_mask & __GFP_WAIT))
+                return;
+
+        /* this guy won't enter reclaim */
+        if ((curr->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC))
+                return;
+
+        /* We're only interested __GFP_FS allocations for now */
+        if (!(gfp_mask & __GFP_FS))
+                return;
+
+        if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)))
+                return;
+
+        mark_held_locks(curr, RECLAIM_FS);
+}
+
+static void check_flags(unsigned long flags);
+
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+        unsigned long flags;
+
+        if (unlikely(current->lockdep_recursion))
+                return;
+
+        raw_local_irq_save(flags);
+        check_flags(flags);
+        current->lockdep_recursion = 1;
+        __lockdep_trace_alloc(gfp_mask, flags);
+        current->lockdep_recursion = 0;
+        raw_local_irq_restore(flags);
+}
+
 static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
 {
         /*
@@ -2345,19 +2328,35 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
         if (!hlock->hardirqs_off) {
                 if (hlock->read) {
                         if (!mark_lock(curr, hlock,
-                                        LOCK_ENABLED_HARDIRQS_READ))
+                                        LOCK_ENABLED_HARDIRQ_READ))
                                 return 0;
                         if (curr->softirqs_enabled)
                                 if (!mark_lock(curr, hlock,
-                                                LOCK_ENABLED_SOFTIRQS_READ))
+                                                LOCK_ENABLED_SOFTIRQ_READ))
                                         return 0;
                 } else {
                         if (!mark_lock(curr, hlock,
-                                        LOCK_ENABLED_HARDIRQS))
+                                        LOCK_ENABLED_HARDIRQ))
                                 return 0;
                         if (curr->softirqs_enabled)
                                 if (!mark_lock(curr, hlock,
-                                                LOCK_ENABLED_SOFTIRQS))
+                                                LOCK_ENABLED_SOFTIRQ))
+                                        return 0;
+                }
+        }
+
+        /*
+         * We reuse the irq context infrastructure more broadly as a general
+         * context checking code. This tests GFP_FS recursion (a lock taken
+         * during reclaim for a GFP_FS allocation is held over a GFP_FS
+         * allocation).
+         */
+        if (!hlock->trylock && (curr->lockdep_reclaim_gfp & __GFP_FS)) {
+                if (hlock->read) {
+                        if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS_READ))
+                                        return 0;
+                } else {
+                        if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS))
                                         return 0;
                 }
         }
@@ -2412,6 +2411,10 @@ static inline int separate_irq_context(struct task_struct *curr,
         return 0;
 }
 
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+}
+
 #endif
 
 /*
@@ -2445,14 +2448,13 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
                 return 0;
 
         switch (new_bit) {
-        case LOCK_USED_IN_HARDIRQ:
-        case LOCK_USED_IN_SOFTIRQ:
-        case LOCK_USED_IN_HARDIRQ_READ:
-        case LOCK_USED_IN_SOFTIRQ_READ:
-        case LOCK_ENABLED_HARDIRQS:
-        case LOCK_ENABLED_SOFTIRQS:
-        case LOCK_ENABLED_HARDIRQS_READ:
-        case LOCK_ENABLED_SOFTIRQS_READ:
+#define LOCKDEP_STATE(__STATE)                  \
+        case LOCK_USED_IN_##__STATE:            \
+        case LOCK_USED_IN_##__STATE##_READ:     \
+        case LOCK_ENABLED_##__STATE:            \
+        case LOCK_ENABLED_##__STATE##_READ:
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
                 ret = mark_lock_irq(curr, this, new_bit);
                 if (!ret)
                         return 0;
@@ -2488,13 +2490,20 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
 void lockdep_init_map(struct lockdep_map *lock, const char *name,
                       struct lock_class_key *key, int subclass)
 {
-        if (unlikely(!debug_locks))
+        lock->class_cache = NULL;
+#ifdef CONFIG_LOCK_STAT
+        lock->cpu = raw_smp_processor_id();
+#endif
+
+        if (DEBUG_LOCKS_WARN_ON(!name)) {
+                lock->name = "NULL";
                 return;
+        }
+
+        lock->name = name;
 
         if (DEBUG_LOCKS_WARN_ON(!key))
                 return;
-        if (DEBUG_LOCKS_WARN_ON(!name))
-                return;
         /*
          * Sanity check, the lock-class key must be persistent:
          */
@@ -2503,12 +2512,11 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
                 DEBUG_LOCKS_WARN_ON(1);
                 return;
         }
-        lock->name = name;
         lock->key = key;
-        lock->class_cache = NULL;
-#ifdef CONFIG_LOCK_STAT
-        lock->cpu = raw_smp_processor_id();
-#endif
+
+        if (unlikely(!debug_locks))
+                return;
+
         if (subclass)
                 register_lock_class(lock, subclass, 1);
 }
@@ -2542,6 +2550,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                 debug_locks_off();
                 printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return 0;
         }
 
@@ -2638,6 +2647,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                 debug_locks_off();
                 printk("BUG: MAX_LOCK_DEPTH too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return 0;
         }
 
@@ -2925,6 +2935,8 @@ void lock_set_class(struct lockdep_map *lock, const char *name,
 }
 EXPORT_SYMBOL_GPL(lock_set_class);
 
+DEFINE_TRACE(lock_acquire);
+
 /*
  * We are not always called with irqs disabled - do that here,
  * and also avoid lockdep recursion:
@@ -2935,6 +2947,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 {
         unsigned long flags;
 
+        trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
+
         if (unlikely(current->lockdep_recursion))
                 return;
 
@@ -2949,11 +2963,15 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 }
 EXPORT_SYMBOL_GPL(lock_acquire);
 
+DEFINE_TRACE(lock_release);
+
 void lock_release(struct lockdep_map *lock, int nested,
                           unsigned long ip)
 {
         unsigned long flags;
 
+        trace_lock_release(lock, nested, ip);
+
         if (unlikely(current->lockdep_recursion))
                 return;
 
@@ -2966,6 +2984,16 @@ void lock_release(struct lockdep_map *lock, int nested,
 }
 EXPORT_SYMBOL_GPL(lock_release);
 
+void lockdep_set_current_reclaim_state(gfp_t gfp_mask)
+{
+        current->lockdep_reclaim_gfp = gfp_mask;
+}
+
+void lockdep_clear_current_reclaim_state(void)
+{
+        current->lockdep_reclaim_gfp = 0;
+}
+
 #ifdef CONFIG_LOCK_STAT
 static int
 print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
@@ -3092,10 +3120,14 @@ found_it:
         lock->ip = ip;
 }
 
+DEFINE_TRACE(lock_contended);
+
 void lock_contended(struct lockdep_map *lock, unsigned long ip)
 {
         unsigned long flags;
 
+        trace_lock_contended(lock, ip);
+
         if (unlikely(!lock_stat))
                 return;
 
@@ -3111,10 +3143,14 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
 }
 EXPORT_SYMBOL_GPL(lock_contended);
 
+DEFINE_TRACE(lock_acquired);
+
 void lock_acquired(struct lockdep_map *lock, unsigned long ip)
 {
         unsigned long flags;
 
+        trace_lock_acquired(lock, ip);
+
         if (unlikely(!lock_stat))
                 return;