diff --git a/fs/aio.c b/fs/aio.c index d065b2c3273e..fc21c23b2387 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -34,7 +35,6 @@ #include #include -#include #if DEBUG > 1 #define dprintk printk @@ -594,51 +594,6 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id) return ret; } -/* - * use_mm - * Makes the calling kernel thread take on the specified - * mm context. - * Called by the retry thread execute retries within the - * iocb issuer's mm context, so that copy_from/to_user - * operations work seamlessly for aio. - * (Note: this routine is intended to be called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thread context) - */ -static void unuse_mm(struct mm_struct *mm) -{ - struct task_struct *tsk = current; - - task_lock(tsk); - tsk->mm = NULL; - /* active_mm is still 'mm' */ - enter_lazy_tlb(mm, tsk); - task_unlock(tsk); -} - /* * Queue up a kiocb to be retried. Assumes that the kiocb * has already been marked as kicked, and places it on diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h new file mode 100644 index 000000000000..70fffeba7495 --- /dev/null +++ b/include/linux/mmu_context.h @@ -0,0 +1,9 @@ +#ifndef _LINUX_MMU_CONTEXT_H +#define _LINUX_MMU_CONTEXT_H + +struct mm_struct; + +void use_mm(struct mm_struct *mm); +void unuse_mm(struct mm_struct *mm); + +#endif diff --git a/mm/Makefile b/mm/Makefile index a63bf59a0c77..728a9fde49d1 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -11,7 +11,7 @@ obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ maccess.o page_alloc.o page-writeback.o \ readahead.o swap.o truncate.o vmscan.o shmem.o \ prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \ - page_isolation.o mm_init.o $(mmu-y) + page_isolation.o mm_init.o mmu_context.o $(mmu-y) obj-y += init-mm.o obj-$(CONFIG_PROC_PAGE_MONITOR) += pagewalk.o diff --git a/mm/mmu_context.c b/mm/mmu_context.c new file mode 100644 index 000000000000..fd473b51c903 --- /dev/null +++ b/mm/mmu_context.c @@ -0,0 +1,55 @@ +/* Copyright (C) 2009 Red Hat, Inc. + * + * See ../COPYING for licensing terms. + */ + +#include +#include +#include + +#include + +/* + * use_mm + * Makes the calling kernel thread take on the specified + * mm context. + * Called by the retry thread execute retries within the + * iocb issuer's mm context, so that copy_from/to_user + * operations work seamlessly for aio. + * (Note: this routine is intended to be called only + * from a kernel thread context) + */ +void use_mm(struct mm_struct *mm) +{ + struct mm_struct *active_mm; + struct task_struct *tsk = current; + + task_lock(tsk); + active_mm = tsk->active_mm; + atomic_inc(&mm->mm_count); + tsk->mm = mm; + tsk->active_mm = mm; + switch_mm(active_mm, mm, tsk); + task_unlock(tsk); + + mmdrop(active_mm); +} + +/* + * unuse_mm + * Reverses the effect of use_mm, i.e. releases the + * specified mm context which was earlier taken on + * by the calling kernel thread + * (Note: this routine is intended to be called only + * from a kernel thread context) + */ +void unuse_mm(struct mm_struct *mm) +{ + struct task_struct *tsk = current; + + task_lock(tsk); + tsk->mm = NULL; + /* active_mm is still 'mm' */ + enter_lazy_tlb(mm, tsk); + task_unlock(tsk); +}