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author | Dave Jiang <dave.jiang@intel.com> | 2018-08-17 15:43:40 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-17 16:20:27 -0700 |
commit | e1fb4a0864958fac2fb1b23f9f4562a9f90e3e8f (patch) | |
tree | 58c58654235f9432d77f73cfc14a1e07ae7bbcc6 /mm | |
parent | e36488c83b6d871b35dd555afb2d434bd61687cf (diff) | |
download | op-kernel-dev-e1fb4a0864958fac2fb1b23f9f4562a9f90e3e8f.zip op-kernel-dev-e1fb4a0864958fac2fb1b23f9f4562a9f90e3e8f.tar.gz |
dax: remove VM_MIXEDMAP for fsdax and device dax
This patch is reworked from an earlier patch that Dan has posted:
https://patchwork.kernel.org/patch/10131727/
VM_MIXEDMAP is used by dax to direct mm paths like vm_normal_page() that
the memory page it is dealing with is not typical memory from the linear
map. The get_user_pages_fast() path, since it does not resolve the vma,
is already using {pte,pmd}_devmap() as a stand-in for VM_MIXEDMAP, so we
use that as a VM_MIXEDMAP replacement in some locations. In the cases
where there is no pte to consult we fallback to using vma_is_dax() to
detect the VM_MIXEDMAP special case.
Now that we have explicit driver pfn_t-flag opt-in/opt-out for
get_user_pages() support for DAX we can stop setting VM_MIXEDMAP. This
also means we no longer need to worry about safely manipulating vm_flags
in a future where we support dynamically changing the dax mode of a
file.
DAX should also now be supported with madvise_behavior(), vma_merge(),
and copy_page_range().
This patch has been tested against ndctl unit test. It has also been
tested against xfstests commit: 625515d using fake pmem created by
memmap and no additional issues have been observed.
Link: http://lkml.kernel.org/r/152847720311.55924.16999195879201817653.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/hmm.c | 6 | ||||
-rw-r--r-- | mm/huge_memory.c | 4 | ||||
-rw-r--r-- | mm/ksm.c | 3 | ||||
-rw-r--r-- | mm/memory.c | 6 | ||||
-rw-r--r-- | mm/migrate.c | 3 | ||||
-rw-r--r-- | mm/mlock.c | 3 | ||||
-rw-r--r-- | mm/mmap.c | 9 |
7 files changed, 24 insertions, 10 deletions
@@ -676,7 +676,8 @@ int hmm_vma_get_pfns(struct hmm_range *range) return -EINVAL; /* FIXME support hugetlb fs */ - if (is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL)) { + if (is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL) || + vma_is_dax(vma)) { hmm_pfns_special(range); return -EINVAL; } @@ -849,7 +850,8 @@ int hmm_vma_fault(struct hmm_range *range, bool block) return -EINVAL; /* FIXME support hugetlb fs */ - if (is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL)) { + if (is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL) || + vma_is_dax(vma)) { hmm_pfns_special(range); return -EINVAL; } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index a9e1e09..1ce44e8 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -762,11 +762,11 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, * but we need to be consistent with PTEs and architectures that * can't support a 'special' bit. */ - BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))); + BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && + !pfn_t_devmap(pfn)); BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == (VM_PFNMAP|VM_MIXEDMAP)); BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); - BUG_ON(!pfn_t_devmap(pfn)); if (addr < vma->vm_start || addr >= vma->vm_end) return VM_FAULT_SIGBUS; @@ -2430,6 +2430,9 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, VM_HUGETLB | VM_MIXEDMAP)) return 0; /* just ignore the advice */ + if (vma_is_dax(vma)) + return 0; + #ifdef VM_SAO if (*vm_flags & VM_SAO) return 0; diff --git a/mm/memory.c b/mm/memory.c index 348279f..7c3bd11 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -859,6 +859,10 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr, return NULL; } } + + if (pte_devmap(pte)) + return NULL; + print_bad_pte(vma, addr, pte, NULL); return NULL; } @@ -923,6 +927,8 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, } } + if (pmd_devmap(pmd)) + return NULL; if (is_zero_pfn(pfn)) return NULL; if (unlikely(pfn > highest_memmap_pfn)) diff --git a/mm/migrate.c b/mm/migrate.c index 8c0af0f..4a83268 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2951,7 +2951,8 @@ int migrate_vma(const struct migrate_vma_ops *ops, /* Sanity check the arguments */ start &= PAGE_MASK; end &= PAGE_MASK; - if (!vma || is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL)) + if (!vma || is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_SPECIAL) || + vma_is_dax(vma)) return -EINVAL; if (start < vma->vm_start || start >= vma->vm_end) return -EINVAL; @@ -527,7 +527,8 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, vm_flags_t old_flags = vma->vm_flags; if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) || - is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm)) + is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) || + vma_is_dax(vma)) /* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */ goto out; @@ -1796,11 +1796,12 @@ out: vm_stat_account(mm, vm_flags, len >> PAGE_SHIFT); if (vm_flags & VM_LOCKED) { - if (!((vm_flags & VM_SPECIAL) || is_vm_hugetlb_page(vma) || - vma == get_gate_vma(current->mm))) - mm->locked_vm += (len >> PAGE_SHIFT); - else + if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) || + is_vm_hugetlb_page(vma) || + vma == get_gate_vma(current->mm)) vma->vm_flags &= VM_LOCKED_CLEAR_MASK; + else + mm->locked_vm += (len >> PAGE_SHIFT); } if (file) |