mm: gup: use get_user_pages_unlocked

This allows those get_user_pages calls to pass FAULT_FLAG_ALLOW_RETRY to
the page fault in order to release the mmap_sem during the I/O.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 6 insertions, 13 deletions

diff --git a/drivers/media/pci/ivtv/ivtv-udma.c b/drivers/media/pci/ivtv/ivtv-udma.c
index bee2329e0b2e..24152accc66c 100644
--- a/drivers/media/pci/ivtv/ivtv-udma.c
+++ b/drivers/media/pci/ivtv/ivtv-udma.c
@@ -124,10 +124,8 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
         }
 
         /* Get user pages for DMA Xfer */
-        down_read(&current->mm->mmap_sem);
-        err = get_user_pages(current, current->mm,
-                        user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
-        up_read(&current->mm->mmap_sem);
+        err = get_user_pages_unlocked(current, current->mm,
+                        user_dma.uaddr, user_dma.page_count, 0, 1, dma->map);
 
         if (user_dma.page_count != err) {
                 IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 128d3b55bdd9..9a1c34205254 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4551,18 +4551,15 @@ static int sgl_map_user_pages(struct st_buffer *STbp,
                 return -ENOMEM;
 
         /* Try to fault in all of the necessary pages */
-        down_read(&current->mm->mmap_sem);
         /* rw==READ means read from drive, write into memory area */
-        res = get_user_pages(
+        res = get_user_pages_unlocked(
                 current,
                 current->mm,
                 uaddr,
                 nr_pages,
                 rw == READ,
                 0, /* don't force */
-                pages,
-                NULL);
-        up_read(&current->mm->mmap_sem);
+                pages);
 
         /* Errors and no page mapped should return here */
         if (res < nr_pages)
diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c
index 7c74f58fc101..0e24eb9c219c 100644
--- a/drivers/video/fbdev/pvr2fb.c
+++ b/drivers/video/fbdev/pvr2fb.c
@@ -686,10 +686,8 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
         if (!pages)
                 return -ENOMEM;
 
-        down_read(&current->mm->mmap_sem);
-        ret = get_user_pages(current, current->mm, (unsigned long)buf,
-                             nr_pages, WRITE, 0, pages, NULL);
-        up_read(&current->mm->mmap_sem);
+        ret = get_user_pages_unlocked(current, current->mm, (unsigned long)buf,
+                                      nr_pages, WRITE, 0, pages);
 
         if (ret < nr_pages) {
                 nr_pages = ret;