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authorJohn Hubbard <jhubbard@nvidia.com>2020-05-17 04:23:36 +0300
committerDavid S. Miller <davem@davemloft.net>2020-05-17 22:37:45 +0300
commitdbfe7d74376e187f3c6eaff822e85176bc2cd06e (patch)
tree81d990e7cc2bf3e04dc61b5c8e96c208a7a65225 /net/rds/info.c
parent9740a7ae6d5208897bf3ef49e8595dc4cfd323ee (diff)
downloadlinux-dbfe7d74376e187f3c6eaff822e85176bc2cd06e.tar.xz
rds: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages_fast(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages_fast() + put_page() calls to pin_user_pages_fast() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: netdev@vger.kernel.org Cc: linux-rdma@vger.kernel.org Cc: rds-devel@oss.oracle.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/info.c')
-rw-r--r--net/rds/info.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/net/rds/info.c b/net/rds/info.c
index 03f6fd56d237..e1d63563e81c 100644
--- a/net/rds/info.c
+++ b/net/rds/info.c
@@ -162,7 +162,6 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval,
struct rds_info_lengths lens;
unsigned long nr_pages = 0;
unsigned long start;
- unsigned long i;
rds_info_func func;
struct page **pages = NULL;
int ret;
@@ -193,7 +192,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval,
ret = -ENOMEM;
goto out;
}
- ret = get_user_pages_fast(start, nr_pages, FOLL_WRITE, pages);
+ ret = pin_user_pages_fast(start, nr_pages, FOLL_WRITE, pages);
if (ret != nr_pages) {
if (ret > 0)
nr_pages = ret;
@@ -235,8 +234,7 @@ call_func:
ret = -EFAULT;
out:
- for (i = 0; pages && i < nr_pages; i++)
- put_page(pages[i]);
+ unpin_user_pages(pages, nr_pages);
kfree(pages);
return ret;