[PATCH 09/23] mm: Pass zap_flags into unmap_mapping_pages()
From: Peter Xu <peterx@redhat.com>
Date: 2021-03-23 00:50:48
Also in:
lkml
Subsystem:
filesystem direct access (dax), filesystems (vfs and infrastructure), memory management, memory management - core, memory management - thp (transparent huge page), page cache, the rest · Maintainers:
Dan Williams, Alexander Viro, Christian Brauner, Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Matthew Wilcox, Linus Torvalds
Give unmap_mapping_pages() more power by allowing to specify a zap flag so that it can pass in more information than "whether we'd also like to zap cow pages". With the new flag, we can remove the even_cow parameter because even_cow==false equals to zap_flags==ZAP_FLAG_CHECK_MAPPING, while even_cow==true means a none zap flag to pass in (though in most cases we have had even_cow==false). No functional change intended. Signed-off-by: Peter Xu <peterx@redhat.com> --- fs/dax.c | 10 ++++++---- include/linux/mm.h | 4 ++-- mm/khugepaged.c | 3 ++- mm/memory.c | 15 ++++++++------- mm/truncate.c | 11 +++++++---- 5 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 177b7d305a52..dd90a35d38be 100644
--- a/fs/dax.c
+++ b/fs/dax.c@@ -514,7 +514,7 @@ static void *grab_mapping_entry(struct xa_state *xas, xas_unlock_irq(xas); unmap_mapping_pages(mapping, xas->xa_index & ~PG_PMD_COLOUR, - PG_PMD_NR, false); + PG_PMD_NR, ZAP_FLAG_CHECK_MAPPING); xas_reset(xas); xas_lock_irq(xas); }
@@ -609,7 +609,8 @@ struct page *dax_layout_busy_page_range(struct address_space *mapping, * guaranteed to either see new references or prevent new * references from being established. */ - unmap_mapping_pages(mapping, start_idx, end_idx - start_idx + 1, 0); + unmap_mapping_pages(mapping, start_idx, end_idx - start_idx + 1, + ZAP_FLAG_CHECK_MAPPING); xas_lock_irq(&xas); xas_for_each(&xas, entry, end_idx) {
@@ -740,9 +741,10 @@ static void *dax_insert_entry(struct xa_state *xas, /* we are replacing a zero page with block mapping */ if (dax_is_pmd_entry(entry)) unmap_mapping_pages(mapping, index & ~PG_PMD_COLOUR, - PG_PMD_NR, false); + PG_PMD_NR, ZAP_FLAG_CHECK_MAPPING); else /* pte entry */ - unmap_mapping_pages(mapping, index, 1, false); + unmap_mapping_pages(mapping, index, 1, + ZAP_FLAG_CHECK_MAPPING); } xas_reset(xas);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c11fbce0d557..d38cd23a08be 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -1784,7 +1784,7 @@ extern int fixup_user_fault(struct mm_struct *mm, unsigned long address, unsigned int fault_flags, bool *unlocked); void unmap_mapping_pages(struct address_space *mapping, - pgoff_t start, pgoff_t nr, bool even_cows); + pgoff_t start, pgoff_t nr, unsigned long zap_flags); void unmap_mapping_range(struct address_space *mapping, loff_t const holebegin, loff_t const holelen, int even_cows); #else
@@ -1804,7 +1804,7 @@ static inline int fixup_user_fault(struct mm_struct *mm, unsigned long address, return -EFAULT; } static inline void unmap_mapping_pages(struct address_space *mapping, - pgoff_t start, pgoff_t nr, bool even_cows) { } + pgoff_t start, pgoff_t nr, unsigned long zap_flags) { } static inline void unmap_mapping_range(struct address_space *mapping, loff_t const holebegin, loff_t const holelen, int even_cows) { } #endif
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 419a6acce326..7c75dff637e2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c@@ -1837,7 +1837,8 @@ static void collapse_file(struct mm_struct *mm, } if (page_mapped(page)) - unmap_mapping_pages(mapping, index, 1, false); + unmap_mapping_pages(mapping, index, 1, + ZAP_FLAG_CHECK_MAPPING); xas_lock_irq(&xas); xas_set(&xas, index);
diff --git a/mm/memory.c b/mm/memory.c
index a02c4d851cd4..36204b898894 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -3213,7 +3213,10 @@ static inline void unmap_mapping_range_tree(struct rb_root_cached *root, * @mapping: The address space containing pages to be unmapped. * @start: Index of first page to be unmapped. * @nr: Number of pages to be unmapped. 0 to unmap to end of file. - * @even_cows: Whether to unmap even private COWed pages. + * @zap_flags: Zap flags for the process. E.g., when ZAP_FLAG_CHECK_MAPPING is + * passed into it, we will only zap the pages that are in the same mapping + * specified in the @mapping parameter; otherwise we will not check mapping, + * IOW cow pages will be zapped too. * * Unmap the pages in this address space from any userspace process which * has them mmaped. Generally, you want to remove COWed pages as well when
@@ -3221,17 +3224,14 @@ static inline void unmap_mapping_range_tree(struct rb_root_cached *root, * cache. */ void unmap_mapping_pages(struct address_space *mapping, pgoff_t start, - pgoff_t nr, bool even_cows) + pgoff_t nr, unsigned long zap_flags) { pgoff_t first_index = start, last_index = start + nr - 1; struct zap_details details = { .zap_mapping = mapping, - .zap_flags = ZAP_FLAG_SKIP_SWAP, + .zap_flags = zap_flags | ZAP_FLAG_SKIP_SWAP, }; - if (!even_cows) - details.zap_flags |= ZAP_FLAG_CHECK_MAPPING; - if (last_index < first_index) last_index = ULONG_MAX;
@@ -3273,7 +3273,8 @@ void unmap_mapping_range(struct address_space *mapping, hlen = ULONG_MAX - hba + 1; } - unmap_mapping_pages(mapping, hba, hlen, even_cows); + unmap_mapping_pages(mapping, hba, hlen, even_cows ? + 0 : ZAP_FLAG_CHECK_MAPPING); } EXPORT_SYMBOL(unmap_mapping_range);
diff --git a/mm/truncate.c b/mm/truncate.c
index 95af244b112a..ba2cbe300e83 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c@@ -172,7 +172,8 @@ truncate_cleanup_page(struct address_space *mapping, struct page *page) { if (page_mapped(page)) { unsigned int nr = thp_nr_pages(page); - unmap_mapping_pages(mapping, page->index, nr, false); + unmap_mapping_pages(mapping, page->index, nr, + ZAP_FLAG_CHECK_MAPPING); } if (page_has_private(page))
@@ -652,14 +653,15 @@ int invalidate_inode_pages2_range(struct address_space *mapping, * Zap the rest of the file in one hit. */ unmap_mapping_pages(mapping, index, - (1 + end - index), false); + (1 + end - index), + ZAP_FLAG_CHECK_MAPPING); did_range_unmap = 1; } else { /* * Just zap this page */ unmap_mapping_pages(mapping, index, - 1, false); + 1, ZAP_FLAG_CHECK_MAPPING); } } BUG_ON(page_mapped(page));
@@ -685,7 +687,8 @@ int invalidate_inode_pages2_range(struct address_space *mapping, * get remapped later. */ if (dax_mapping(mapping)) { - unmap_mapping_pages(mapping, start, end - start + 1, false); + unmap_mapping_pages(mapping, start, end - start + 1, + ZAP_FLAG_CHECK_MAPPING); } out: cleancache_invalidate_inode(mapping);
--
2.26.2