The patch titled
Subject: mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote()
has been added to the -mm tree. Its filename is
mm-process_vm_access-set-foll_pin-via-pin_user_pages_remote.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-process_vm_access-set-foll_pin-via-pin_user_pages_remote.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-process_vm_access-set-foll_pin-via-pin_user_pages_remote.patch
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------------------------------------------------------
From: John Hubbard <jhubbard@xxxxxxxxxx>
Subject: mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote()
Convert process_vm_access to use the new pin_user_pages_remote() call,
which sets FOLL_PIN. Setting FOLL_PIN is now required for code that
requires tracking of pinned pages.
Also, release the pages via put_user_page*().
Also, rename "pages" to "pinned_pages", as this makes for easier reading
of process_vm_rw_single_vec().
Link: http://lkml.kernel.org/r/20200107224558.2362728-15-jhubbard@xxxxxxxxxx
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Jérôme Glisse <jglisse@xxxxxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Björn Töpel <bjorn.topel@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/process_vm_access.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
--- a/mm/process_vm_access.c~mm-process_vm_access-set-foll_pin-via-pin_user_pages_remote
+++ a/mm/process_vm_access.c
@@ -42,12 +42,11 @@ static int process_vm_rw_pages(struct pa
if (copy > len)
copy = len;
- if (vm_write) {
+ if (vm_write)
copied = copy_page_from_iter(page, offset, copy, iter);
- set_page_dirty_lock(page);
- } else {
+ else
copied = copy_page_to_iter(page, offset, copy, iter);
- }
+
len -= copied;
if (copied < copy && iov_iter_count(iter))
return -EFAULT;
@@ -96,7 +95,7 @@ static int process_vm_rw_single_vec(unsi
flags |= FOLL_WRITE;
while (!rc && nr_pages && iov_iter_count(iter)) {
- int pages = min(nr_pages, max_pages_per_loop);
+ int pinned_pages = min(nr_pages, max_pages_per_loop);
int locked = 1;
size_t bytes;
@@ -106,14 +105,15 @@ static int process_vm_rw_single_vec(unsi
* current/current->mm
*/
down_read(&mm->mmap_sem);
- pages = get_user_pages_remote(task, mm, pa, pages, flags,
- process_pages, NULL, &locked);
+ pinned_pages = pin_user_pages_remote(task, mm, pa, pinned_pages,
+ flags, process_pages,
+ NULL, &locked);
if (locked)
up_read(&mm->mmap_sem);
- if (pages <= 0)
+ if (pinned_pages <= 0)
return -EFAULT;
- bytes = pages * PAGE_SIZE - start_offset;
+ bytes = pinned_pages * PAGE_SIZE - start_offset;
if (bytes > len)
bytes = len;
@@ -122,10 +122,12 @@ static int process_vm_rw_single_vec(unsi
vm_write);
len -= bytes;
start_offset = 0;
- nr_pages -= pages;
- pa += pages * PAGE_SIZE;
- while (pages)
- put_page(process_pages[--pages]);
+ nr_pages -= pinned_pages;
+ pa += pinned_pages * PAGE_SIZE;
+
+ /* If vm_write is set, the pages need to be made dirty: */
+ put_user_pages_dirty_lock(process_pages, pinned_pages,
+ vm_write);
}
return rc;
_
Patches currently in -mm which might be from jhubbard@xxxxxxxxxx are
mm-gup-factor-out-duplicate-code-from-four-routines.patch
mm-gup-move-try_get_compound_head-to-top-fix-minor-issues.patch
mm-devmap-refactor-1-based-refcounting-for-zone_device-pages.patch
goldish_pipe-rename-local-pin_user_pages-routine.patch
mm-fix-get_user_pages_remotes-handling-of-foll_longterm.patch
vfio-fix-foll_longterm-use-simplify-get_user_pages_remote-call.patch
mm-gup-allow-foll_force-for-get_user_pages_fast.patch
ib-umem-use-get_user_pages_fast-to-pin-dma-pages.patch
media-v4l2-core-set-pages-dirty-upon-releasing-dma-buffers.patch
mm-gup-introduce-pin_user_pages-and-foll_pin.patch
goldish_pipe-convert-to-pin_user_pages-and-put_user_page.patch
ib-corehwumem-set-foll_pin-via-pin_user_pages-fix-up-odp.patch
mm-process_vm_access-set-foll_pin-via-pin_user_pages_remote.patch
drm-via-set-foll_pin-via-pin_user_pages_fast.patch
fs-io_uring-set-foll_pin-via-pin_user_pages.patch
net-xdp-set-foll_pin-via-pin_user_pages.patch
media-v4l2-core-pin_user_pages-foll_pin-and-put_user_page-conversion.patch
vfio-mm-pin_user_pages-foll_pin-and-put_user_page-conversion.patch
powerpc-book3s64-convert-to-pin_user_pages-and-put_user_page.patch
mm-gup_benchmark-use-proper-foll_write-flags-instead-of-hard-coding-1.patch
mm-tree-wide-rename-put_user_page-to-unpin_user_page.patch
