diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h index a83bbea62c67..0131a7058778 100644 --- a/arch/alpha/include/asm/rwsem.h +++ b/arch/alpha/include/asm/rwsem.h @@ -63,7 +63,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) return res >= 0 ? 1 : 0; } -static inline void __down_write(struct rw_semaphore *sem) +static inline long ___down_write(struct rw_semaphore *sem) { long oldcount; #ifndef CONFIG_SMP @@ -83,10 +83,24 @@ static inline void __down_write(struct rw_semaphore *sem) :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); #endif - if (unlikely(oldcount)) + return oldcount; +} + +static inline void __down_write(struct rw_semaphore *sem) +{ + if (unlikely(___down_write(sem))) rwsem_down_write_failed(sem); } +static inline int __down_write_killable(struct rw_semaphore *sem) +{ + if (unlikely(___down_write(sem))) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * trylock for writing -- returns 1 if successful, 0 if contention */ diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h index ce112472bdd6..8b23e070b844 100644 --- a/arch/ia64/include/asm/rwsem.h +++ b/arch/ia64/include/asm/rwsem.h @@ -49,8 +49,8 @@ __down_read (struct rw_semaphore *sem) /* * lock for writing */ -static inline void -__down_write (struct rw_semaphore *sem) +static inline long +___down_write (struct rw_semaphore *sem) { long old, new; @@ -59,10 +59,26 @@ __down_write (struct rw_semaphore *sem) new = old + RWSEM_ACTIVE_WRITE_BIAS; } while (cmpxchg_acq(&sem->count, old, new) != old); - if (old != 0) + return old; +} + +static inline void +__down_write (struct rw_semaphore *sem) +{ + if (___down_write(sem)) rwsem_down_write_failed(sem); } +static inline int +__down_write_killable (struct rw_semaphore *sem) +{ + if (___down_write(sem)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * unlock after reading */ diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h index fead491dfc28..c75e4471e618 100644 --- a/arch/s390/include/asm/rwsem.h +++ b/arch/s390/include/asm/rwsem.h @@ -90,7 +90,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) /* * lock for writing */ -static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) +static inline long ___down_write(struct rw_semaphore *sem) { signed long old, new, tmp; @@ -104,13 +104,23 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) : "=&d" (old), "=&d" (new), "=Q" (sem->count) : "Q" (sem->count), "m" (tmp) : "cc", "memory"); - if (old != 0) - rwsem_down_write_failed(sem); + + return old; } static inline void __down_write(struct rw_semaphore *sem) { - __down_write_nested(sem, 0); + if (___down_write(sem)) + rwsem_down_write_failed(sem); +} + +static inline int __down_write_killable(struct rw_semaphore *sem) +{ + if (___down_write(sem)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + + return 0; } /* diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild index a319745a7b63..751c3373a92c 100644 --- a/arch/sh/include/asm/Kbuild +++ b/arch/sh/include/asm/Kbuild @@ -26,6 +26,7 @@ generic-y += percpu.h generic-y += poll.h generic-y += preempt.h generic-y += resource.h +generic-y += rwsem.h generic-y += sembuf.h generic-y += serial.h generic-y += shmbuf.h diff --git a/arch/sh/include/asm/rwsem.h b/arch/sh/include/asm/rwsem.h deleted file mode 100644 index edab57265293..000000000000 --- a/arch/sh/include/asm/rwsem.h +++ /dev/null @@ -1,132 +0,0 @@ -/* - * include/asm-sh/rwsem.h: R/W semaphores for SH using the stuff - * in lib/rwsem.c. - */ - -#ifndef _ASM_SH_RWSEM_H -#define _ASM_SH_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" -#endif - -#ifdef __KERNEL__ - -#define RWSEM_UNLOCKED_VALUE 0x00000000 -#define RWSEM_ACTIVE_BIAS 0x00000001 -#define RWSEM_ACTIVE_MASK 0x0000ffff -#define RWSEM_WAITING_BIAS (-0x00010000) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -static inline void __down_read(struct rw_semaphore *sem) -{ - if (atomic_inc_return((atomic_t *)(&sem->count)) > 0) - smp_wmb(); - else - rwsem_down_read_failed(sem); -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - int tmp; - - while ((tmp = sem->count) >= 0) { - if (tmp == cmpxchg(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - smp_wmb(); - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write(struct rw_semaphore *sem) -{ - int tmp; - - tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic_t *)(&sem->count)); - if (tmp == RWSEM_ACTIVE_WRITE_BIAS) - smp_wmb(); - else - rwsem_down_write_failed(sem); -} - -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - int tmp; - - tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - smp_wmb(); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - int tmp; - - smp_wmb(); - tmp = atomic_dec_return((atomic_t *)(&sem->count)); - if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - smp_wmb(); - if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic_t *)(&sem->count)) < 0) - rwsem_wake(sem); -} - -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem) -{ - atomic_add(delta, (atomic_t *)(&sem->count)); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - int tmp; - - smp_wmb(); - tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count)); - if (tmp < 0) - rwsem_downgrade_wake(sem); -} - -static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) -{ - __down_write(sem); -} - -/* - * implement exchange and add functionality - */ -static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) -{ - smp_mb(); - return atomic_add_return(delta, (atomic_t *)(&sem->count)); -} - -#endif /* __KERNEL__ */ -#endif /* _ASM_SH_RWSEM_H */ diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild index e928618838bc..6024c26c0585 100644 --- a/arch/sparc/include/asm/Kbuild +++ b/arch/sparc/include/asm/Kbuild @@ -16,6 +16,7 @@ generic-y += mm-arch-hooks.h generic-y += module.h generic-y += mutex.h generic-y += preempt.h +generic-y += rwsem.h generic-y += serial.h generic-y += trace_clock.h generic-y += types.h diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h deleted file mode 100644 index 069bf4d663a1..000000000000 --- a/arch/sparc/include/asm/rwsem.h +++ /dev/null @@ -1,124 +0,0 @@ -/* - * rwsem.h: R/W semaphores implemented using CAS - * - * Written by David S. Miller (davem@redhat.com), 2001. - * Derived from asm-i386/rwsem.h - */ -#ifndef _SPARC64_RWSEM_H -#define _SPARC64_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" -#endif - -#ifdef __KERNEL__ - -#define RWSEM_UNLOCKED_VALUE 0x00000000L -#define RWSEM_ACTIVE_BIAS 0x00000001L -#define RWSEM_ACTIVE_MASK 0xffffffffL -#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -static inline void __down_read(struct rw_semaphore *sem) -{ - if (unlikely(atomic64_inc_return((atomic64_t *)(&sem->count)) <= 0L)) - rwsem_down_read_failed(sem); -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - long tmp; - - while ((tmp = sem->count) >= 0L) { - if (tmp == cmpxchg(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) -{ - long tmp; - - tmp = atomic64_add_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic64_t *)(&sem->count)); - if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) - rwsem_down_write_failed(sem); -} - -static inline void __down_write(struct rw_semaphore *sem) -{ - __down_write_nested(sem, 0); -} - -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - long tmp; - - tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic64_dec_return((atomic64_t *)(&sem->count)); - if (unlikely(tmp < -1L && (tmp & RWSEM_ACTIVE_MASK) == 0L)) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - if (unlikely(atomic64_sub_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic64_t *)(&sem->count)) < 0L)) - rwsem_wake(sem); -} - -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) -{ - atomic64_add(delta, (atomic64_t *)(&sem->count)); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic64_add_return(-RWSEM_WAITING_BIAS, (atomic64_t *)(&sem->count)); - if (tmp < 0L) - rwsem_downgrade_wake(sem); -} - -/* - * implement exchange and add functionality - */ -static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) -{ - return atomic64_add_return(delta, (atomic64_t *)(&sem->count)); -} - -#endif /* __KERNEL__ */ - -#endif /* _SPARC64_RWSEM_H */ diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index ceec86eb68e9..453744c1d347 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -99,26 +99,36 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) /* * lock for writing */ -static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) -{ - long tmp; - asm volatile("# beginning down_write\n\t" - LOCK_PREFIX " xadd %1,(%2)\n\t" - /* adds 0xffff0001, returns the old value */ - " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" - /* was the active mask 0 before? */ - " jz 1f\n" - " call call_rwsem_down_write_failed\n" - "1:\n" - "# ending down_write" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS) - : "memory", "cc"); -} +#define ____down_write(sem, slow_path) \ +({ \ + long tmp; \ + struct rw_semaphore* ret; \ + asm volatile("# beginning down_write\n\t" \ + LOCK_PREFIX " xadd %1,(%3)\n\t" \ + /* adds 0xffff0001, returns the old value */ \ + " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" \ + /* was the active mask 0 before? */\ + " jz 1f\n" \ + " call " slow_path "\n" \ + "1:\n" \ + "# ending down_write" \ + : "+m" (sem->count), "=d" (tmp), "=a" (ret) \ + : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS) \ + : "memory", "cc"); \ + ret; \ +}) static inline void __down_write(struct rw_semaphore *sem) { - __down_write_nested(sem, 0); + ____down_write(sem, "call_rwsem_down_write_failed"); +} + +static inline int __down_write_killable(struct rw_semaphore *sem) +{ + if (IS_ERR(____down_write(sem, "call_rwsem_down_write_failed_killable"))) + return -EINTR; + + return 0; } /* diff --git a/arch/x86/lib/rwsem.S b/arch/x86/lib/rwsem.S index be110efa0096..bf2c6074efd2 100644 --- a/arch/x86/lib/rwsem.S +++ b/arch/x86/lib/rwsem.S @@ -29,8 +29,10 @@ * there is contention on the semaphore. * * %eax contains the semaphore pointer on entry. Save the C-clobbered - * registers (%eax, %edx and %ecx) except %eax whish is either a return - * value or just clobbered.. + * registers (%eax, %edx and %ecx) except %eax which is either a return + * value or just gets clobbered. Same is true for %edx so make sure GCC + * reloads it after the slow path, by making it hold a temporary, for + * example see ____down_write(). */ #define save_common_regs \ @@ -106,6 +108,16 @@ ENTRY(call_rwsem_down_write_failed) ret ENDPROC(call_rwsem_down_write_failed) +ENTRY(call_rwsem_down_write_failed_killable) + FRAME_BEGIN + save_common_regs + movq %rax,%rdi + call rwsem_down_write_failed_killable + restore_common_regs + FRAME_END + ret +ENDPROC(call_rwsem_down_write_failed_killable) + ENTRY(call_rwsem_wake) FRAME_BEGIN /* do nothing if still outstanding active readers */ diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index b56855a1382a..28cf4c5d65ef 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -22,6 +22,7 @@ generic-y += mm-arch-hooks.h generic-y += percpu.h generic-y += preempt.h generic-y += resource.h +generic-y += rwsem.h generic-y += sections.h generic-y += siginfo.h generic-y += statfs.h diff --git a/arch/xtensa/include/asm/rwsem.h b/arch/xtensa/include/asm/rwsem.h deleted file mode 100644 index 249619e7e7f2..000000000000 --- a/arch/xtensa/include/asm/rwsem.h +++ /dev/null @@ -1,131 +0,0 @@ -/* - * include/asm-xtensa/rwsem.h - * - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - * - * Largely copied from include/asm-ppc/rwsem.h - * - * Copyright (C) 2001 - 2005 Tensilica Inc. - */ - -#ifndef _XTENSA_RWSEM_H -#define _XTENSA_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "Please don't include directly, use instead." -#endif - -#define RWSEM_UNLOCKED_VALUE 0x00000000 -#define RWSEM_ACTIVE_BIAS 0x00000001 -#define RWSEM_ACTIVE_MASK 0x0000ffff -#define RWSEM_WAITING_BIAS (-0x00010000) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -static inline void __down_read(struct rw_semaphore *sem) -{ - if (atomic_add_return(1,(atomic_t *)(&sem->count)) > 0) - smp_wmb(); - else - rwsem_down_read_failed(sem); -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - int tmp; - - while ((tmp = sem->count) >= 0) { - if (tmp == cmpxchg(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - smp_wmb(); - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write(struct rw_semaphore *sem) -{ - int tmp; - - tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic_t *)(&sem->count)); - if (tmp == RWSEM_ACTIVE_WRITE_BIAS) - smp_wmb(); - else - rwsem_down_write_failed(sem); -} - -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - int tmp; - - tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - smp_wmb(); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - int tmp; - - smp_wmb(); - tmp = atomic_sub_return(1,(atomic_t *)(&sem->count)); - if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - smp_wmb(); - if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic_t *)(&sem->count)) < 0) - rwsem_wake(sem); -} - -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem) -{ - atomic_add(delta, (atomic_t *)(&sem->count)); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - int tmp; - - smp_wmb(); - tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count)); - if (tmp < 0) - rwsem_downgrade_wake(sem); -} - -/* - * implement exchange and add functionality - */ -static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) -{ - smp_mb(); - return atomic_add_return(delta, (atomic_t *)(&sem->count)); -} - -#endif /* _XTENSA_RWSEM_H */ diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h index d6d5dc98d7da..3fc94a046bf5 100644 --- a/include/asm-generic/rwsem.h +++ b/include/asm-generic/rwsem.h @@ -53,7 +53,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) /* * lock for writing */ -static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) +static inline void __down_write(struct rw_semaphore *sem) { long tmp; @@ -63,9 +63,16 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) rwsem_down_write_failed(sem); } -static inline void __down_write(struct rw_semaphore *sem) +static inline int __down_write_killable(struct rw_semaphore *sem) { - __down_write_nested(sem, 0); + long tmp; + + tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, + (atomic_long_t *)&sem->count); + if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + return 0; } static inline int __down_write_trylock(struct rw_semaphore *sem) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index d10ef06971b5..f75222ea7f16 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -446,6 +446,18 @@ do { \ lock_acquired(&(_lock)->dep_map, _RET_IP_); \ } while (0) +#define LOCK_CONTENDED_RETURN(_lock, try, lock) \ +({ \ + int ____err = 0; \ + if (!try(_lock)) { \ + lock_contended(&(_lock)->dep_map, _RET_IP_); \ + ____err = lock(_lock); \ + } \ + if (!____err) \ + lock_acquired(&(_lock)->dep_map, _RET_IP_); \ + ____err; \ +}) + #else /* CONFIG_LOCK_STAT */ #define lock_contended(lockdep_map, ip) do {} while (0) @@ -454,6 +466,9 @@ do { \ #define LOCK_CONTENDED(_lock, try, lock) \ lock(_lock) +#define LOCK_CONTENDED_RETURN(_lock, try, lock) \ + lock(_lock) + #endif /* CONFIG_LOCK_STAT */ #ifdef CONFIG_LOCKDEP diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h index 561e8615528d..ae0528b834cd 100644 --- a/include/linux/rwsem-spinlock.h +++ b/include/linux/rwsem-spinlock.h @@ -34,7 +34,7 @@ struct rw_semaphore { extern void __down_read(struct rw_semaphore *sem); extern int __down_read_trylock(struct rw_semaphore *sem); extern void __down_write(struct rw_semaphore *sem); -extern void __down_write_nested(struct rw_semaphore *sem, int subclass); +extern int __must_check __down_write_killable(struct rw_semaphore *sem); extern int __down_write_trylock(struct rw_semaphore *sem); extern void __up_read(struct rw_semaphore *sem); extern void __up_write(struct rw_semaphore *sem); diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 8f498cdde280..d1c12d160ace 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -14,6 +14,7 @@ #include #include #include +#include #ifdef CONFIG_RWSEM_SPIN_ON_OWNER #include #endif @@ -43,6 +44,7 @@ struct rw_semaphore { extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem); extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem); +extern struct rw_semaphore *rwsem_down_write_failed_killable(struct rw_semaphore *sem); extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *); extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem); @@ -116,6 +118,7 @@ extern int down_read_trylock(struct rw_semaphore *sem); * lock for writing */ extern void down_write(struct rw_semaphore *sem); +extern int __must_check down_write_killable(struct rw_semaphore *sem); /* * trylock for writing -- returns 1 if successful, 0 if contention diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c index 3a5048572065..1591f6b3539f 100644 --- a/kernel/locking/rwsem-spinlock.c +++ b/kernel/locking/rwsem-spinlock.c @@ -191,11 +191,12 @@ int __down_read_trylock(struct rw_semaphore *sem) /* * get a write lock on the semaphore */ -void __sched __down_write_nested(struct rw_semaphore *sem, int subclass) +int __sched __down_write_common(struct rw_semaphore *sem, int state) { struct rwsem_waiter waiter; struct task_struct *tsk; unsigned long flags; + int ret = 0; raw_spin_lock_irqsave(&sem->wait_lock, flags); @@ -215,21 +216,33 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass) */ if (sem->count == 0) break; - set_task_state(tsk, TASK_UNINTERRUPTIBLE); + if (signal_pending_state(state, current)) { + ret = -EINTR; + goto out; + } + set_task_state(tsk, state); raw_spin_unlock_irqrestore(&sem->wait_lock, flags); schedule(); raw_spin_lock_irqsave(&sem->wait_lock, flags); } /* got the lock */ sem->count = -1; +out: list_del(&waiter.list); raw_spin_unlock_irqrestore(&sem->wait_lock, flags); + + return ret; } void __sched __down_write(struct rw_semaphore *sem) { - __down_write_nested(sem, 0); + __down_write_common(sem, TASK_UNINTERRUPTIBLE); +} + +int __sched __down_write_killable(struct rw_semaphore *sem) +{ + return __down_write_common(sem, TASK_KILLABLE); } /* diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index a4d4de05b2d1..09e30c6225e5 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -433,12 +433,13 @@ static inline bool rwsem_has_spinner(struct rw_semaphore *sem) /* * Wait until we successfully acquire the write lock */ -__visible -struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem) +static inline struct rw_semaphore * +__rwsem_down_write_failed_common(struct rw_semaphore *sem, int state) { long count; bool waiting = true; /* any queued threads before us */ struct rwsem_waiter waiter; + struct rw_semaphore *ret = sem; /* undo write bias from down_write operation, stop active locking */ count = rwsem_atomic_update(-RWSEM_ACTIVE_WRITE_BIAS, sem); @@ -478,7 +479,7 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem) count = rwsem_atomic_update(RWSEM_WAITING_BIAS, sem); /* wait until we successfully acquire the lock */ - set_current_state(TASK_UNINTERRUPTIBLE); + set_current_state(state); while (true) { if (rwsem_try_write_lock(count, sem)) break; @@ -486,21 +487,48 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem) /* Block until there are no active lockers. */ do { + if (signal_pending_state(state, current)) + goto out_nolock; + schedule(); - set_current_state(TASK_UNINTERRUPTIBLE); + set_current_state(state); } while ((count = sem->count) & RWSEM_ACTIVE_MASK); raw_spin_lock_irq(&sem->wait_lock); } __set_current_state(TASK_RUNNING); - list_del(&waiter.list); raw_spin_unlock_irq(&sem->wait_lock); - return sem; + return ret; + +out_nolock: + __set_current_state(TASK_RUNNING); + raw_spin_lock_irq(&sem->wait_lock); + list_del(&waiter.list); + if (list_empty(&sem->wait_list)) + rwsem_atomic_update(-RWSEM_WAITING_BIAS, sem); + else + __rwsem_do_wake(sem, RWSEM_WAKE_ANY); + raw_spin_unlock_irq(&sem->wait_lock); + + return ERR_PTR(-EINTR); +} + +__visible struct rw_semaphore * __sched +rwsem_down_write_failed(struct rw_semaphore *sem) +{ + return __rwsem_down_write_failed_common(sem, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(rwsem_down_write_failed); +__visible struct rw_semaphore * __sched +rwsem_down_write_failed_killable(struct rw_semaphore *sem) +{ + return __rwsem_down_write_failed_common(sem, TASK_KILLABLE); +} +EXPORT_SYMBOL(rwsem_down_write_failed_killable); + /* * handle waking up a waiter on the semaphore * - up_read/up_write has decremented the active part of count if we come here diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 205be0ce34de..c817216c1615 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -54,6 +54,25 @@ void __sched down_write(struct rw_semaphore *sem) EXPORT_SYMBOL(down_write); +/* + * lock for writing + */ +int __sched down_write_killable(struct rw_semaphore *sem) +{ + might_sleep(); + rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); + + if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) { + rwsem_release(&sem->dep_map, 1, _RET_IP_); + return -EINTR; + } + + rwsem_set_owner(sem); + return 0; +} + +EXPORT_SYMBOL(down_write_killable); + /* * trylock for writing -- returns 1 if successful, 0 if contention */