[PATCH v3 3/3] infiniband/mm: convert put_page() to put_user_page*()

john.hubbard
2018-10-06T02:50:01Z

From: John Hubbard <jhubbard@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-jhubbard@nvidia.com
Proposed steps for fixing get_user_pages() + DMA problems.

[3]https://lkml.kernel.org/r/20180710082100.mkdwngdv5kkrcz6n@quack2.suse.cz
Bounce buffers (otherwise [2] is not really viable).

[4] https://lkml.kernel.org/r/20181003162115.GG24030@quack2.suse.cz
Follow-up discussions.

CC: Doug Ledford <dledford@redhat.com>
CC: Jason Gunthorpe <jgg@ziepe.ca>
CC: Mike Marciniszyn <mike.marciniszyn@intel.com>
CC: Dennis Dalessandro <dennis.dalessandro@intel.com>
CC: Christian Benvenuti <benve@cisco.com>

CC: linux-rdma@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-mm@kvack.org
Signed-off-by: John Hubbard <jhubbard@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