diff options
Diffstat (limited to 'fs/dax.c')
| -rw-r--r-- | fs/dax.c | 29 |
1 files changed, 23 insertions, 6 deletions
@@ -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, |