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| author | John Hubbard <jhubbard@nvidia.com> | 2020-05-16 18:23:36 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-05-17 12:37:45 -0700 |
| commit | dbfe7d74376e187f3c6eaff822e85176bc2cd06e (patch) | |
| tree | 81d990e7cc2bf3e04dc61b5c8e96c208a7a65225 | |
| parent | 9740a7ae6d5208897bf3ef49e8595dc4cfd323ee (diff) | |
| download | linux-dbfe7d74376e187f3c6eaff822e85176bc2cd06e.tar.gz linux-dbfe7d74376e187f3c6eaff822e85176bc2cd06e.tar.bz2 linux-dbfe7d74376e187f3c6eaff822e85176bc2cd06e.zip | |
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>
| -rw-r--r-- | net/rds/info.c | 6 |
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; |