Merge branch 'linus' into locking-for-linus
[sfrench/cifs-2.6.git] / kernel / lockdep.c
index 06b0c3568f0b230a8c6b669d055c8c442a7eb790..981cd4854281458cc78e2e4730ee93df075287f4 100644 (file)
@@ -41,6 +41,7 @@
 #include <linux/utsname.h>
 #include <linux/hash.h>
 #include <linux/ftrace.h>
+#include <linux/stringify.h>
 
 #include <asm/sections.h>
 
@@ -310,12 +311,14 @@ 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 +433,24 @@ 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 +458,45 @@ 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 +509,7 @@ 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)
@@ -1263,9 +1259,49 @@ 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 +1309,34 @@ 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;
 }
@@ -1861,9 +1893,9 @@ 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 +1965,7 @@ 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 +1973,7 @@ 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 +1981,95 @@ 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 +2078,12 @@ 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 +2137,7 @@ 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 +2145,7 @@ 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 +2225,7 @@ 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 +2254,48 @@ 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 +2324,35 @@ 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 +2407,10 @@ static inline int separate_irq_context(struct task_struct *curr,
        return 0;
 }
 
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+}
+
 #endif
 
 /*
@@ -2445,14 +2444,13 @@ 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;
@@ -2966,6 +2964,16 @@ 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,