diff options
| author | David Hildenbrand <david@redhat.com> | 2022-11-16 11:26:49 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-12-01 00:58:58 +0100 |
| commit | b40656aa7d559adc1fe689396dc58b92a9a27286 (patch) | |
| tree | fb4a86378ab328b46e4c37093942378fa8631e31 /drivers | |
| parent | mm/gup: reliable R/O long-term pinning in COW mappings (diff) | |
| download | linux-b40656aa7d559adc1fe689396dc58b92a9a27286.tar.xz linux-b40656aa7d559adc1fe689396dc58b92a9a27286.zip | |
RDMA/umem: 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/20221116102659.70287-11-david@redhat.com
Tested-by: Leon Romanovsky <leonro@nvidia.com> [over mlx4 and mlx5]
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/infiniband/core/umem.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 86d479772fbc..755a9c57db6f 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -156,7 +156,7 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, struct mm_struct *mm; unsigned long npages; int pinned, ret; - unsigned int gup_flags = FOLL_WRITE; + unsigned int gup_flags = FOLL_LONGTERM; /* * If the combination of the addr and size requested for this memory @@ -210,8 +210,8 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, cur_base = addr & PAGE_MASK; - if (!umem->writable) - gup_flags |= FOLL_FORCE; + if (umem->writable) + gup_flags |= FOLL_WRITE; while (npages) { cond_resched(); @@ -219,7 +219,7 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, min_t(unsigned long, npages, PAGE_SIZE / sizeof(struct page *)), - gup_flags | FOLL_LONGTERM, page_list); + gup_flags, page_list); if (pinned < 0) { ret = pinned; goto umem_release; |