dio: use get_user_pages_fast

Use get_user_pages_fast in the common/generic block and fs direct IO paths.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 8 deletions

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 9e81addbd6ea..9606ee848fd8 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -150,17 +150,11 @@ static int dio_refill_pages(struct dio *dio)
         int nr_pages;
 
         nr_pages = min(dio->total_pages - dio->curr_page, DIO_PAGES);
-        down_read(&current->mm->mmap_sem);
-        ret = get_user_pages(
-                current,                        /* Task for fault acounting */
-                current->mm,                    /* whose pages? */
+        ret = get_user_pages_fast(
                 dio->curr_user_address,         /* Where from? */
                 nr_pages,                       /* How many pages? */
                 dio->rw == READ,                /* Write to memory? */
-                0,                              /* force (?) */
-                &dio->pages[0],
-                NULL);                          /* vmas */
-        up_read(&current->mm->mmap_sem);
+                &dio->pages[0]);                /* Put results here */
 
         if (ret < 0 && dio->blocks_available && (dio->rw & WRITE)) {
                 struct page *page = ZERO_PAGE(0);