Message ID | 20191121071354.456618-20-jhubbard@nvidia.com (mailing list archive) |
---|---|
State | Not Applicable |
Headers | show |
Series | mm/gup: track dma-pinned pages: FOLL_PIN | expand |
Context | Check | Description |
---|---|---|
snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (784eee1cc44801366d4f197e0ade7739ee8e1e83) |
snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 19 lines checked |
snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index c7a111ad9975..18aa36b56896 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -327,9 +327,8 @@ static int put_pfn(unsigned long pfn, int prot) { if (!is_invalid_reserved_pfn(pfn)) { struct page *page = pfn_to_page(pfn); - if (prot & IOMMU_WRITE) - SetPageDirty(page); - put_page(page); + + put_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE); return 1; } return 0; @@ -347,7 +346,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, flags |= FOLL_WRITE; down_read(&mm->mmap_sem); - ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, + ret = pin_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, page, NULL, NULL); if (ret == 1) { *pfn = page_to_pfn(page[0]);
1. Change vfio from get_user_pages_remote(), to pin_user_pages_remote(). 2. Because all FOLL_PIN-acquired pages must be released via put_user_page(), also convert the put_page() call over to put_user_pages_dirty_lock(). Note that this effectively changes the code's behavior in vfio_iommu_type1.c: put_pfn(): it now ultimately calls set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- drivers/vfio/vfio_iommu_type1.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)