diff options
| author | David Hildenbrand <[email protected]> | 2022-11-16 11:26:50 +0100 |
|---|---|---|
| committer | Andrew Morton <[email protected]> | 2022-11-30 15:58:58 -0800 |
| commit | a9d0284033e974a355b806fdb5fbabf8301bcd16 (patch) | |
| tree | 1083b1aeb23041c94db8620e9672a89ded6bf00c | |
| parent | b40656aa7d559adc1fe689396dc58b92a9a27286 (diff) | |
RDMA/usnic: remove FOLL_FORCE usage
GUP now supports reliable R/O long-term pinning in COW mappings, such
that we break COW early. MAP_SHARED VMAs only use the shared zeropage so
far in one corner case (DAXFS file with holes), which can be ignored
because GUP does not support long-term pinning in fsdax (see
check_vma_flags()).
Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required
for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop
using FOLL_FORCE, which is really only for ptrace access.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Cc: Christian Benvenuti <[email protected]>
Cc: Nelson Escobar <[email protected]>
Cc: Leon Romanovsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
| -rw-r--r-- | drivers/infiniband/hw/usnic/usnic_uiom.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 67923ced6e2d..c301b3be9f30 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -85,6 +85,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, int dmasync, struct usnic_uiom_reg *uiomr) { struct list_head *chunk_list = &uiomr->chunk_list; + unsigned int gup_flags = FOLL_LONGTERM; struct page **page_list; struct scatterlist *sg; struct usnic_uiom_chunk *chunk; @@ -96,7 +97,6 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, int off; int i; dma_addr_t pa; - unsigned int gup_flags; struct mm_struct *mm; /* @@ -131,8 +131,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, goto out; } - gup_flags = FOLL_WRITE; - gup_flags |= (writable) ? 0 : FOLL_FORCE; + if (writable) + gup_flags |= FOLL_WRITE; cur_base = addr & PAGE_MASK; ret = 0; @@ -140,8 +140,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, ret = pin_user_pages(cur_base, min_t(unsigned long, npages, PAGE_SIZE / sizeof(struct page *)), - gup_flags | FOLL_LONGTERM, - page_list, NULL); + gup_flags, page_list, NULL); if (ret < 0) goto out; |