From: John Hubbard <jhubb...@nvidia.com>

For code that retains pages via get_user_pages*(),
release those pages via the new put_user_page(), or
put_user_pages*(), instead of put_page()

This prepares for eventually fixing the problem described
in [1], and is following a plan listed in [2], [3], [4].

[1] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()"

[2] https://lkml.kernel.org/r/20180709080554.21931-1-jhubb...@nvidia.com
    Proposed steps for fixing get_user_pages() + DMA problems.

[3]https://lkml.kernel.org/r/20180710082100.mkdwngdv5kkrc...@quack2.suse.cz
    Bounce buffers (otherwise [2] is not really viable).

[4] https://lkml.kernel.org/r/20181003162115.gg24...@quack2.suse.cz
    Follow-up discussions.

CC: Doug Ledford <dledf...@redhat.com>
CC: Jason Gunthorpe <j...@ziepe.ca>
CC: Mike Marciniszyn <mike.marcinis...@intel.com>
CC: Dennis Dalessandro <dennis.dalessan...@intel.com>
CC: Christian Benvenuti <be...@cisco.com>

CC: linux-r...@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux...@kvack.org

Reviewed-by: Jan Kara <j...@suse.cz>
Reviewed-by: Dennis Dalessandro <dennis.dalessan...@intel.com>
Acked-by: Jason Gunthorpe <j...@mellanox.com>
Signed-off-by: John Hubbard <jhubb...@nvidia.com>
---
 drivers/infiniband/core/umem.c              |  7 ++++---
 drivers/infiniband/core/umem_odp.c          |  2 +-
 drivers/infiniband/hw/hfi1/user_pages.c     | 11 ++++-------
 drivers/infiniband/hw/mthca/mthca_memfree.c |  6 +++---
 drivers/infiniband/hw/qib/qib_user_pages.c  | 11 ++++-------
 drivers/infiniband/hw/qib/qib_user_sdma.c   |  8 ++++----
 drivers/infiniband/hw/usnic/usnic_uiom.c    |  7 ++++---
 7 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index a41792dbae1f..7ab7a3a35eb4 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -58,9 +58,10 @@ static void __ib_umem_release(struct ib_device *dev, struct 
ib_umem *umem, int d
        for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) {
 
                page = sg_page(sg);
-               if (!PageDirty(page) && umem->writable && dirty)
-                       set_page_dirty_lock(page);
-               put_page(page);
+               if (umem->writable && dirty)
+                       put_user_pages_dirty_lock(&page, 1);
+               else
+                       put_user_page(page);
        }
 
        sg_free_table(&umem->sg_head);
diff --git a/drivers/infiniband/core/umem_odp.c 
b/drivers/infiniband/core/umem_odp.c
index 6ec748eccff7..6227b89cf05c 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -717,7 +717,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 
user_virt, u64 bcnt,
                                        ret = -EFAULT;
                                        break;
                                }
-                               put_page(local_page_list[j]);
+                               put_user_page(local_page_list[j]);
                                continue;
                        }
 
diff --git a/drivers/infiniband/hw/hfi1/user_pages.c 
b/drivers/infiniband/hw/hfi1/user_pages.c
index e341e6dcc388..99ccc0483711 100644
--- a/drivers/infiniband/hw/hfi1/user_pages.c
+++ b/drivers/infiniband/hw/hfi1/user_pages.c
@@ -121,13 +121,10 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, 
unsigned long vaddr, size_t np
 void hfi1_release_user_pages(struct mm_struct *mm, struct page **p,
                             size_t npages, bool dirty)
 {
-       size_t i;
-
-       for (i = 0; i < npages; i++) {
-               if (dirty)
-                       set_page_dirty_lock(p[i]);
-               put_page(p[i]);
-       }
+       if (dirty)
+               put_user_pages_dirty_lock(p, npages);
+       else
+               put_user_pages(p, npages);
 
        if (mm) { /* during close after signal, mm can be NULL */
                down_write(&mm->mmap_sem);
diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c 
b/drivers/infiniband/hw/mthca/mthca_memfree.c
index cc9c0c8ccba3..b8b12effd009 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -481,7 +481,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct 
mthca_uar *uar,
 
        ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
        if (ret < 0) {
-               put_page(pages[0]);
+               put_user_page(pages[0]);
                goto out;
        }
 
@@ -489,7 +489,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct 
mthca_uar *uar,
                                 mthca_uarc_virt(dev, uar, i));
        if (ret) {
                pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, 
PCI_DMA_TODEVICE);
-               put_page(sg_page(&db_tab->page[i].mem));
+               put_user_page(sg_page(&db_tab->page[i].mem));
                goto out;
        }
 
@@ -555,7 +555,7 @@ void mthca_cleanup_user_db_tab(struct mthca_dev *dev, 
struct mthca_uar *uar,
                if (db_tab->page[i].uvirt) {
                        mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1);
                        pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, 
PCI_DMA_TODEVICE);
-                       put_page(sg_page(&db_tab->page[i].mem));
+                       put_user_page(sg_page(&db_tab->page[i].mem));
                }
        }
 
diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c 
b/drivers/infiniband/hw/qib/qib_user_pages.c
index 16543d5e80c3..1a5c64c8695f 100644
--- a/drivers/infiniband/hw/qib/qib_user_pages.c
+++ b/drivers/infiniband/hw/qib/qib_user_pages.c
@@ -40,13 +40,10 @@
 static void __qib_release_user_pages(struct page **p, size_t num_pages,
                                     int dirty)
 {
-       size_t i;
-
-       for (i = 0; i < num_pages; i++) {
-               if (dirty)
-                       set_page_dirty_lock(p[i]);
-               put_page(p[i]);
-       }
+       if (dirty)
+               put_user_pages_dirty_lock(p, num_pages);
+       else
+               put_user_pages(p, num_pages);
 }
 
 /*
diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c 
b/drivers/infiniband/hw/qib/qib_user_sdma.c
index 926f3c8eba69..14f94d823907 100644
--- a/drivers/infiniband/hw/qib/qib_user_sdma.c
+++ b/drivers/infiniband/hw/qib/qib_user_sdma.c
@@ -266,7 +266,7 @@ static void qib_user_sdma_init_frag(struct 
qib_user_sdma_pkt *pkt,
        pkt->addr[i].length = len;
        pkt->addr[i].first_desc = first_desc;
        pkt->addr[i].last_desc = last_desc;
-       pkt->addr[i].put_page = put_page;
+       pkt->addr[i].put_page = put_user_page;
        pkt->addr[i].dma_mapped = dma_mapped;
        pkt->addr[i].page = page;
        pkt->addr[i].kvaddr = kvaddr;
@@ -321,7 +321,7 @@ static int qib_user_sdma_page_to_frags(const struct 
qib_devdata *dd,
                 * the caller can ignore this page.
                 */
                if (put) {
-                       put_page(page);
+                       put_user_page(page);
                } else {
                        /* coalesce case */
                        kunmap(page);
@@ -635,7 +635,7 @@ static void qib_user_sdma_free_pkt_frag(struct device *dev,
                        kunmap(pkt->addr[i].page);
 
                if (pkt->addr[i].put_page)
-                       put_page(pkt->addr[i].page);
+                       put_user_page(pkt->addr[i].page);
                else
                        __free_page(pkt->addr[i].page);
        } else if (pkt->addr[i].kvaddr) {
@@ -710,7 +710,7 @@ static int qib_user_sdma_pin_pages(const struct qib_devdata 
*dd,
        /* if error, return all pages not managed by pkt */
 free_pages:
        while (i < j)
-               put_page(pages[i++]);
+               put_user_page(pages[i++]);
 
 done:
        return ret;
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c 
b/drivers/infiniband/hw/usnic/usnic_uiom.c
index 9dd39daa602b..9e3615fd05f7 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -89,9 +89,10 @@ static void usnic_uiom_put_pages(struct list_head 
*chunk_list, int dirty)
                for_each_sg(chunk->page_list, sg, chunk->nents, i) {
                        page = sg_page(sg);
                        pa = sg_phys(sg);
-                       if (!PageDirty(page) && dirty)
-                               set_page_dirty_lock(page);
-                       put_page(page);
+                       if (dirty)
+                               put_user_pages_dirty_lock(&page, 1);
+                       else
+                               put_user_page(page);
                        usnic_dbg("pa: %pa\n", &pa);
                }
                kfree(chunk);
-- 
2.19.0

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