7 files changed, 58 insertions, 92 deletions

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 41f9e268e3fb..24244a2f68cc 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -54,10 +54,7 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
 
         for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) {
                 page = sg_page_iter_page(&sg_iter);
-                if (umem->writable && dirty)
-                        put_user_pages_dirty_lock(&page, 1);
-                else
-                        put_user_page(page);
+                put_user_pages_dirty_lock(&page, 1, umem->writable && dirty);
         }
 
         sg_free_table(&umem->sg_head);
diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c
index b89a9b9aef7a..469acb961fbd 100644
--- a/drivers/infiniband/hw/hfi1/user_pages.c
+++ b/drivers/infiniband/hw/hfi1/user_pages.c
@@ -118,10 +118,7 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np
 void hfi1_release_user_pages(struct mm_struct *mm, struct page **p,
                              size_t npages, bool dirty)
 {
-        if (dirty)
-                put_user_pages_dirty_lock(p, npages);
-        else
-                put_user_pages(p, npages);
+        put_user_pages_dirty_lock(p, npages, dirty);
 
         if (mm) { /* during close after signal, mm can be NULL */
                 atomic64_sub(npages, &mm->pinned_vm);
diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c
index bfbfbb7e0ff4..6bf764e41891 100644
--- a/drivers/infiniband/hw/qib/qib_user_pages.c
+++ b/drivers/infiniband/hw/qib/qib_user_pages.c
@@ -40,10 +40,7 @@
 static void __qib_release_user_pages(struct page **p, size_t num_pages,
                                      int dirty)
 {
-        if (dirty)
-                put_user_pages_dirty_lock(p, num_pages);
-        else
-                put_user_pages(p, num_pages);
+        put_user_pages_dirty_lock(p, num_pages, dirty);
 }
 
 /**
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
index 0b0237d41613..62e6ffa9ad78 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -75,10 +75,7 @@ static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty)
                 for_each_sg(chunk->page_list, sg, chunk->nents, i) {
                         page = sg_page(sg);
                         pa = sg_phys(sg);
-                        if (dirty)
-                                put_user_pages_dirty_lock(&page, 1);
-                        else
-                                put_user_page(page);
+                        put_user_pages_dirty_lock(&page, 1, dirty);
                         usnic_dbg("pa: %pa\n", &pa);
                 }
                 kfree(chunk);
diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c
index 87a56039f0ef..e99983f07663 100644
--- a/drivers/infiniband/sw/siw/siw_mem.c
+++ b/drivers/infiniband/sw/siw/siw_mem.c
@@ -63,15 +63,7 @@ struct siw_mem *siw_mem_id2obj(struct siw_device *sdev, int stag_index)
 static void siw_free_plist(struct siw_page_chunk *chunk, int num_pages,
                            bool dirty)
 {
-        struct page **p = chunk->plist;
-
-        while (num_pages--) {
-                if (!PageDirty(*p) && dirty)
-                        put_user_pages_dirty_lock(p, 1);
-                else
-                        put_user_page(*p);
-                p++;
-        }
+        put_user_pages_dirty_lock(chunk->plist, num_pages, dirty);
 }
 
 void siw_umem_release(struct siw_umem *umem, bool dirty)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 69b7314c8d24..57a9fa34f159 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1075,8 +1075,9 @@ static inline void put_user_page(struct page *page)
         put_page(page);
 }
 
-void put_user_pages_dirty(struct page **pages, unsigned long npages);
-void put_user_pages_dirty_lock(struct page **pages, unsigned long npages);
+void put_user_pages_dirty_lock(struct page **pages, unsigned long npages,
+                               bool make_dirty);
+
 void put_user_pages(struct page **pages, unsigned long npages);
 
 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
diff --git a/mm/gup.c b/mm/gup.c
index 84a36d80dd2e..012060efddf1 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -29,85 +29,70 @@ struct follow_page_context {
         unsigned int page_mask;
 };
 
-typedef int (*set_dirty_func_t)(struct page *page);
-
-static void __put_user_pages_dirty(struct page **pages,
-                                   unsigned long npages,
-                                   set_dirty_func_t sdf)
-{
-        unsigned long index;
-
-        for (index = 0; index < npages; index++) {
-                struct page *page = compound_head(pages[index]);
-
-                /*
-                 * Checking PageDirty at this point may race with
-                 * clear_page_dirty_for_io(), but that's OK. Two key cases:
-                 *
-                 * 1) This code sees the page as already dirty, so it skips
-                 * the call to sdf(). That could happen because
-                 * clear_page_dirty_for_io() called page_mkclean(),
-                 * followed by set_page_dirty(). However, now the page is
-                 * going to get written back, which meets the original
-                 * intention of setting it dirty, so all is well:
-                 * clear_page_dirty_for_io() goes on to call
-                 * TestClearPageDirty(), and write the page back.
-                 *
-                 * 2) This code sees the page as clean, so it calls sdf().
-                 * The page stays dirty, despite being written back, so it
-                 * gets written back again in the next writeback cycle.
-                 * This is harmless.
-                 */
-                if (!PageDirty(page))
-                        sdf(page);
-
-                put_user_page(page);
-        }
-}
-
 /**
- * put_user_pages_dirty() - release and dirty an array of gup-pinned pages
- * @pages:  array of pages to be marked dirty and released.
+ * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages
+ * @pages:  array of pages to be maybe marked dirty, and definitely released.
  * @npages: number of pages in the @pages array.
+ * @make_dirty: whether to mark the pages dirty
  *
  * "gup-pinned page" refers to a page that has had one of the get_user_pages()
  * variants called on that page.
  *
  * For each page in the @pages array, make that page (or its head page, if a
- * compound page) dirty, if it was previously listed as clean. Then, release
- * the page using put_user_page().
+ * compound page) dirty, if @make_dirty is true, and if the page was previously
+ * listed as clean. In any case, releases all pages using put_user_page(),
+ * possibly via put_user_pages(), for the non-dirty case.
  *
  * Please see the put_user_page() documentation for details.
  *
- * set_page_dirty(), which does not lock the page, is used here.
- * Therefore, it is the caller's responsibility to ensure that this is
- * safe. If not, then put_user_pages_dirty_lock() should be called instead.
+ * set_page_dirty_lock() is used internally. If instead, set_page_dirty() is
+ * required, then the caller should a) verify that this is really correct,
+ * because _lock() is usually required, and b) hand code it:
+ * set_page_dirty_lock(), put_user_page().
  *
  */
-void put_user_pages_dirty(struct page **pages, unsigned long npages)
+void put_user_pages_dirty_lock(struct page **pages, unsigned long npages,
+                               bool make_dirty)
 {
-        __put_user_pages_dirty(pages, npages, set_page_dirty);
-}
-EXPORT_SYMBOL(put_user_pages_dirty);
+        unsigned long index;
 
-/**
- * put_user_pages_dirty_lock() - release and dirty an array of gup-pinned pages
- * @pages:  array of pages to be marked dirty and released.
- * @npages: number of pages in the @pages array.
- *
- * For each page in the @pages array, make that page (or its head page, if a
- * compound page) dirty, if it was previously listed as clean. Then, release
- * the page using put_user_page().
- *
- * Please see the put_user_page() documentation for details.
- *
- * This is just like put_user_pages_dirty(), except that it invokes
- * set_page_dirty_lock(), instead of set_page_dirty().
- *
- */
-void put_user_pages_dirty_lock(struct page **pages, unsigned long npages)
-{
-        __put_user_pages_dirty(pages, npages, set_page_dirty_lock);
+        /*
+         * TODO: this can be optimized for huge pages: if a series of pages is
+         * physically contiguous and part of the same compound page, then a
+         * single operation to the head page should suffice.
+         */
+
+        if (!make_dirty) {
+                put_user_pages(pages, npages);
+                return;
+        }
+
+        for (index = 0; index < npages; index++) {
+                struct page *page = compound_head(pages[index]);
+                /*
+                 * Checking PageDirty at this point may race with
+                 * clear_page_dirty_for_io(), but that's OK. Two key
+                 * cases:
+                 *
+                 * 1) This code sees the page as already dirty, so it
+                 * skips the call to set_page_dirty(). That could happen
+                 * because clear_page_dirty_for_io() called
+                 * page_mkclean(), followed by set_page_dirty().
+                 * However, now the page is going to get written back,
+                 * which meets the original intention of setting it
+                 * dirty, so all is well: clear_page_dirty_for_io() goes
+                 * on to call TestClearPageDirty(), and write the page
+                 * back.
+                 *
+                 * 2) This code sees the page as clean, so it calls
+                 * set_page_dirty(). The page stays dirty, despite being
+                 * written back, so it gets written back again in the
+                 * next writeback cycle. This is harmless.
+                 */
+                if (!PageDirty(page))
+                        set_page_dirty_lock(page);
+                put_user_page(page);
+        }
 }
 EXPORT_SYMBOL(put_user_pages_dirty_lock);