@@ -587,6 +587,56 @@ extern long faultin_vma_page_range(struct vm_area_struct *vma,
bool write, int *locked);
extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
unsigned long bytes);
+
+/*
+ * NOTE: This function can't tell whether the folio is "fully mapped" in the
+ * range.
+ * "fully mapped" means all the pages of folio is associated with the page
+ * table of range while this function just check whether the folio range is
+ * within the range [start, end). Funcation caller nees to do page table
+ * check if it cares about the page table association.
+ *
+ * Typical usage (like mlock or madvise) is:
+ * Caller knows at least 1 page of folio is associated with page table of VMA
+ * and the range [start, end) is intersect with the VMA range. Caller wants
+ * to know whether the folio is fully associated with the range. It calls
+ * this function to check whether the folio is in the range first. Then checks
+ * the page table to know whether the folio is fully mapped to the range.
+ */
+static inline bool
+folio_within_range(struct folio *folio, struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ pgoff_t pgoff, addr;
+ unsigned long vma_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+
+ VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio);
+ if (start > end)
+ return false;
+
+ if (start < vma->vm_start)
+ start = vma->vm_start;
+
+ if (end > vma->vm_end)
+ end = vma->vm_end;
+
+ pgoff = folio_pgoff(folio);
+
+ /* if folio start address is not in vma range */
+ if (!in_range(pgoff, vma->vm_pgoff, vma_pglen))
+ return false;
+
+ addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+
+ return !(addr < start || end - addr < folio_size(folio));
+}
+
+static inline bool
+folio_within_vma(struct folio *folio, struct vm_area_struct *vma)
+{
+ return folio_within_range(folio, vma, vma->vm_start, vma->vm_end);
+}
+
/*
* mlock_vma_folio() and munlock_vma_folio():
* should be called with vma's mmap_lock held for read or write,
It will be used to check whether the folio is mapped to specific VMA and whether the mapping address of folio is in the range. Also a helper function folio_within_vma() to check whether folio is in the range of vma based on folio_in_range(). Signed-off-by: Yin Fengwei <fengwei.yin@intel.com> --- mm/internal.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)