[PATCH 06/23] mm: Drop first_index/last_index in zap_details

Peter Xu
2021-03-23T00:50:17Z

The first_index/last_index parameters in zap_details are actually only used in
unmap_mapping_range_tree(). At the meantime, this function is only called by
unmap_mapping_pages() once. Instead of passing these two variables through the
whole stack of page zapping code, remove them from zap_details and let them
simply be parameters of unmap_mapping_range_tree(), which is inlined.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
include/linux/mm.h | 2 --
mm/memory.c | 20 ++++++++++----------
2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index b78306eb7a63..389dd91134f9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1707,8 +1707,6 @@ extern void user_shm_unlock(size_t, struct user_struct *);
*/
struct zap_details {
struct address_space *check_mapping; /* Check page->mapping if set */
- pgoff_t first_index; /* Lowest page->index to unmap */
- pgoff_t last_index; /* Highest page->index to unmap */
};

struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index b4ddba343abc..5e6175e00617 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3202,20 +3202,20 @@ static void unmap_mapping_range_vma(struct vm_area_struct *vma,
}

static inline void unmap_mapping_range_tree(struct rb_root_cached *root,
+ pgoff_t first_index,
+ pgoff_t last_index,
struct zap_details *details)
{
struct vm_area_struct *vma;
pgoff_t vba, vea, zba, zea;

- vma_interval_tree_foreach(vma, root,
- details->first_index, details->last_index) {
-
+ vma_interval_tree_foreach(vma, root, first_index, last_index) {
vba = vma->vm_pgoff;
vea = vba + vma_pages(vma) - 1;
- zba = details->first_index;
+ zba = first_index;
if (zba < vba)
zba = vba;
- zea = details->last_index;
+ zea = last_index;
if (zea > vea)
zea = vea;

@@ -3241,17 +3241,17 @@ static inline void unmap_mapping_range_tree(struct rb_root_cached *root,
void unmap_mapping_pages(struct address_space *mapping, pgoff_t start,
pgoff_t nr, bool even_cows)
{
+ pgoff_t first_index = start, last_index = start + nr - 1;
struct zap_details details = { };

details.check_mapping = even_cows ? NULL : mapping;
- details.first_index = start;
- details.last_index = start + nr - 1;
- if (details.last_index < details.first_index)
- details.last_index = ULONG_MAX;
+ if (last_index < first_index)
+ last_index = ULONG_MAX;

i_mmap_lock_write(mapping);
if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root)))
- unmap_mapping_range_tree(&mapping->i_mmap, &details);
+ unmap_mapping_range_tree(&mapping->i_mmap, first_index,
+ last_index, &details);
i_mmap_unlock_write(mapping);
}

--
2.26.2