Merge tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszered...

[sfrench/cifs-2.6.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index 6ad346352a8c5e152411eac07f367e39ba4c5245..5b47834f2e1bb55cbea08131e725438b517a28c8 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -559,8 +559,11 @@ fallback:
 }
 
 /**
- * dax_layout_busy_page - find first pinned page in @mapping
+ * dax_layout_busy_page_range - find first pinned page in @mapping
  * @mapping: address space to scan for a page with ref count > 1
+ * @start: Starting offset. Page containing 'start' is included.
+ * @end: End offset. Page containing 'end' is included. If 'end' is LLONG_MAX,
+ *       pages from 'start' till the end of file are included.
  *
  * DAX requires ZONE_DEVICE mapped pages. These pages are never
  * 'onlined' to the page allocator so they are considered idle when
@@ -573,12 +576,15 @@ fallback:
  * to be able to run unmap_mapping_range() and subsequently not race
  * mapping_mapped() becoming true.
  */
-struct page *dax_layout_busy_page(struct address_space *mapping)
+struct page *dax_layout_busy_page_range(struct address_space *mapping,
+                                       loff_t start, loff_t end)
 {
-       XA_STATE(xas, &mapping->i_pages, 0);
        void *entry;
        unsigned int scanned = 0;
        struct page *page = NULL;
+       pgoff_t start_idx = start >> PAGE_SHIFT;
+       pgoff_t end_idx;
+       XA_STATE(xas, &mapping->i_pages, start_idx);
 
        /*
         * In the 'limited' case get_user_pages() for dax is disabled.
@@ -589,6 +595,11 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
        if (!dax_mapping(mapping) || !mapping_mapped(mapping))
                return NULL;
 
+       /* If end == LLONG_MAX, all pages from start to till end of file */
+       if (end == LLONG_MAX)
+               end_idx = ULONG_MAX;
+       else
+               end_idx = end >> PAGE_SHIFT;
        /*
         * If we race get_user_pages_fast() here either we'll see the
         * elevated page count in the iteration and wait, or
@@ -596,15 +607,15 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
         * against is no longer mapped in the page tables and bail to the
         * get_user_pages() slow path.  The slow path is protected by
         * pte_lock() and pmd_lock(). New references are not taken without
-        * holding those locks, and unmap_mapping_range() will not zero the
+        * holding those locks, and unmap_mapping_pages() will not zero the
         * pte or pmd without holding the respective lock, so we are
         * guaranteed to either see new references or prevent new
         * references from being established.
         */
-       unmap_mapping_range(mapping, 0, 0, 0);
+       unmap_mapping_pages(mapping, start_idx, end_idx - start_idx + 1, 0);
 
        xas_lock_irq(&xas);
-       xas_for_each(&xas, entry, ULONG_MAX) {
+       xas_for_each(&xas, entry, end_idx) {
                if (WARN_ON_ONCE(!xa_is_value(entry)))
                        continue;
                if (unlikely(dax_is_locked(entry)))
@@ -625,6 +636,12 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
        xas_unlock_irq(&xas);
        return page;
 }
+EXPORT_SYMBOL_GPL(dax_layout_busy_page_range);
+
+struct page *dax_layout_busy_page(struct address_space *mapping)
+{
+       return dax_layout_busy_page_range(mapping, 0, LLONG_MAX);
+}
 EXPORT_SYMBOL_GPL(dax_layout_busy_page);
 
 static int __dax_invalidate_entry(struct address_space *mapping,