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-rw-r--r--fs/dax.c44
1 files changed, 30 insertions, 14 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 95341af1a966..5b47834f2e1b 100644
--- 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,
@@ -1037,18 +1054,18 @@ static vm_fault_t dax_load_hole(struct xa_state *xas,
return ret;
}
-int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
- struct iomap *iomap)
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
{
sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
pgoff_t pgoff;
long rc, id;
void *kaddr;
bool page_aligned = false;
-
+ unsigned offset = offset_in_page(pos);
+ unsigned size = min_t(u64, PAGE_SIZE - offset, length);
if (IS_ALIGNED(sector << SECTOR_SHIFT, PAGE_SIZE) &&
- IS_ALIGNED(size, PAGE_SIZE))
+ (size == PAGE_SIZE))
page_aligned = true;
rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
@@ -1058,8 +1075,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
id = dax_read_lock();
if (page_aligned)
- rc = dax_zero_page_range(iomap->dax_dev, pgoff,
- size >> PAGE_SHIFT);
+ rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
else
rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
if (rc < 0) {
@@ -1072,7 +1088,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
dax_flush(iomap->dax_dev, kaddr + offset, size);
}
dax_read_unlock(id);
- return 0;
+ return size;
}
static loff_t
@@ -1367,7 +1383,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
ret = dax_load_hole(&xas, mapping, &entry, vmf);
goto finish_iomap;
}
- /*FALLTHRU*/
+ fallthrough;
default:
WARN_ON_ONCE(1);
error = -EIO;