[PATCH] mm: unmap_vmas with inner ptlock
Remove the page_table_lock from around the calls to unmap_vmas, and replace
the pte_offset_map in zap_pte_range by pte_offset_map_lock: all callers are
now safe to descend without page_table_lock.
Don't attempt fancy locking for hugepages, just take page_table_lock in
unmap_hugepage_range. Which makes zap_hugepage_range, and the hugetlb test in
zap_page_range, redundant: unmap_vmas calls unmap_hugepage_range anyway. Nor
does unmap_vmas have much use for its mm arg now.
The tlb_start_vma and tlb_end_vma in unmap_page_range are now called without
page_table_lock: if they're implemented at all, they typically come down to
flush_cache_range (usually done outside page_table_lock) and flush_tlb_range
(which we already audited for the mprotect case).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index d664330..0cea162 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -16,7 +16,6 @@
int hugetlb_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int);
-void zap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long);
void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long);
int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
int hugetlb_report_meminfo(char *);
@@ -87,7 +86,6 @@
#define follow_huge_addr(mm, addr, write) ERR_PTR(-EINVAL)
#define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; })
#define hugetlb_prefault(mapping, vma) ({ BUG(); 0; })
-#define zap_hugepage_range(vma, start, len) BUG()
#define unmap_hugepage_range(vma, start, end) BUG()
#define is_hugepage_mem_enough(size) 0
#define hugetlb_report_meminfo(buf) 0
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d4c3512..972e2ce8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -682,7 +682,7 @@
unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *);
-unsigned long unmap_vmas(struct mmu_gather **tlb, struct mm_struct *mm,
+unsigned long unmap_vmas(struct mmu_gather **tlb,
struct vm_area_struct *start_vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *);