diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2009-09-21 17:03:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 07:17:42 -0700 |
| commit | 3d2d827f5ca5e32816194119d5c980c7e04474a6 (patch) | |
| tree | fe0e84669f5f20e1dff8e3dc6b191b4d5dfc0145 /fs/aio.c | |
| parent | 425fbf047cc70bb30dff368a6da02c8c2d229318 (diff) | |
| download | lwn-3d2d827f5ca5e32816194119d5c980c7e04474a6.tar.gz lwn-3d2d827f5ca5e32816194119d5c980c7e04474a6.zip | |
mm: move use_mm/unuse_mm from aio.c to mm/
Anyone who wants to do copy to/from user from a kernel thread, needs
use_mm (like what fs/aio has). Move that into mm/, to make reusing and
exporting easier down the line, and make aio use it. Next intended user,
besides aio, will be vhost-net.
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 47 |
1 files changed, 1 insertions, 46 deletions
@@ -24,6 +24,7 @@ #include <linux/file.h> #include <linux/mm.h> #include <linux/mman.h> +#include <linux/mmu_context.h> #include <linux/slab.h> #include <linux/timer.h> #include <linux/aio.h> @@ -34,7 +35,6 @@ #include <asm/kmap_types.h> #include <asm/uaccess.h> -#include <asm/mmu_context.h> #if DEBUG > 1 #define dprintk printk @@ -595,51 +595,6 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id) } /* - * 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 * the retry run list for the corresponding ioctx, if it |