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authorDave Jiang <dave.jiang@intel.com>2018-08-18 01:43:40 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-18 02:20:27 +0300
commite1fb4a0864958fac2fb1b23f9f4562a9f90e3e8f (patch)
tree58c58654235f9432d77f73cfc14a1e07ae7bbcc6 /mm
parente36488c83b6d871b35dd555afb2d434bd61687cf (diff)
downloadlinux-e1fb4a0864958fac2fb1b23f9f4562a9f90e3e8f.tar.xz
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.c6
-rw-r--r--mm/huge_memory.c4
-rw-r--r--mm/ksm.c3
-rw-r--r--mm/memory.c6
-rw-r--r--mm/migrate.c3
-rw-r--r--mm/mlock.c3
-rw-r--r--mm/mmap.c9
7 files changed, 24 insertions, 10 deletions
diff --git a/mm/hmm.c b/mm/hmm.c
index de7b6bf77201..f40e8add84b5 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -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 a9e1e093df51..1ce44e87f494 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;
diff --git a/mm/ksm.c b/mm/ksm.c
index a6d43cf9a982..9b855a8b0f2d 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -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 348279ff6e51..7c3bd119fcca 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 8c0af0f7cab1..4a83268e23c2 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;
diff --git a/mm/mlock.c b/mm/mlock.c
index 74e5a6547c3d..41cc47e28ad6 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -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;
diff --git a/mm/mmap.c b/mm/mmap.c
index 17bbf4d3e24f..8d6449e74431 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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)