#define RADIX_DAX_ZERO_PAGE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
#define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3))
-static unsigned long dax_radix_sector(void *entry)
+static unsigned long dax_radix_pfn(void *entry)
{
return (unsigned long)entry >> RADIX_DAX_SHIFT;
}
-static void *dax_radix_locked_entry(sector_t sector, unsigned long flags)
+static void *dax_radix_locked_entry(unsigned long pfn, unsigned long flags)
{
return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags |
- ((unsigned long)sector << RADIX_DAX_SHIFT) |
- RADIX_DAX_ENTRY_LOCK);
+ (pfn << RADIX_DAX_SHIFT) | RADIX_DAX_ENTRY_LOCK);
}
static unsigned int dax_radix_order(void *entry)
dax_wake_mapping_entry_waiter(mapping, index, entry, false);
}
+static unsigned long dax_entry_size(void *entry)
+{
+ if (dax_is_zero_entry(entry))
+ return 0;
+ else if (dax_is_empty_entry(entry))
+ return 0;
+ else if (dax_is_pmd_entry(entry))
+ return PMD_SIZE;
+ else
+ return PAGE_SIZE;
+}
+
+static unsigned long dax_radix_end_pfn(void *entry)
+{
+ return dax_radix_pfn(entry) + dax_entry_size(entry) / PAGE_SIZE;
+}
+
+/*
+ * Iterate through all mapped pfns represented by an entry, i.e. skip
+ * 'empty' and 'zero' entries.
+ */
+#define for_each_mapped_pfn(entry, pfn) \
+ for (pfn = dax_radix_pfn(entry); \
+ pfn < dax_radix_end_pfn(entry); pfn++)
+
+static void dax_associate_entry(void *entry, struct address_space *mapping)
+{
+ unsigned long pfn;
+
+ if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
+ return;
+
+ for_each_mapped_pfn(entry, pfn) {
+ struct page *page = pfn_to_page(pfn);
+
+ WARN_ON_ONCE(page->mapping);
+ page->mapping = mapping;
+ }
+}
+
+static void dax_disassociate_entry(void *entry, struct address_space *mapping,
+ bool trunc)
+{
+ unsigned long pfn;
+
+ if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
+ return;
+
+ for_each_mapped_pfn(entry, pfn) {
+ struct page *page = pfn_to_page(pfn);
+
+ WARN_ON_ONCE(trunc && page_ref_count(page) > 1);
+ WARN_ON_ONCE(page->mapping && page->mapping != mapping);
+ page->mapping = NULL;
+ }
+}
+
/*
* Find radix tree entry at given index. If it points to an exceptional entry,
* return it with the radix tree entry locked. If the radix tree doesn't
}
if (pmd_downgrade) {
+ dax_disassociate_entry(entry, mapping, false);
radix_tree_delete(&mapping->page_tree, index);
mapping->nrexceptional--;
dax_wake_mapping_entry_waiter(mapping, index, entry,
(radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_DIRTY) ||
radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE)))
goto out;
+ dax_disassociate_entry(entry, mapping, trunc);
radix_tree_delete(page_tree, index);
mapping->nrexceptional--;
ret = 1;
*/
static void *dax_insert_mapping_entry(struct address_space *mapping,
struct vm_fault *vmf,
- void *entry, sector_t sector,
+ void *entry, pfn_t pfn_t,
unsigned long flags, bool dirty)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
- void *new_entry;
+ unsigned long pfn = pfn_t_to_pfn(pfn_t);
pgoff_t index = vmf->pgoff;
+ void *new_entry;
if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
spin_lock_irq(&mapping->tree_lock);
- new_entry = dax_radix_locked_entry(sector, flags);
+ new_entry = dax_radix_locked_entry(pfn, flags);
+ if (dax_entry_size(entry) != dax_entry_size(new_entry)) {
+ dax_disassociate_entry(entry, mapping, false);
+ dax_associate_entry(new_entry, mapping);
+ }
if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) {
/*
i_mmap_unlock_read(mapping);
}
-static int dax_writeback_one(struct block_device *bdev,
- struct dax_device *dax_dev, struct address_space *mapping,
- pgoff_t index, void *entry)
+static int dax_writeback_one(struct dax_device *dax_dev,
+ struct address_space *mapping, pgoff_t index, void *entry)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
- void *entry2, **slot, *kaddr;
- long ret = 0, id;
- sector_t sector;
- pgoff_t pgoff;
+ void *entry2, **slot;
+ unsigned long pfn;
+ long ret = 0;
size_t size;
- pfn_t pfn;
/*
* A page got tagged dirty in DAX mapping? Something is seriously
goto put_unlocked;
/*
* Entry got reallocated elsewhere? No need to writeback. We have to
- * compare sectors as we must not bail out due to difference in lockbit
+ * compare pfns as we must not bail out due to difference in lockbit
* or entry type.
*/
- if (dax_radix_sector(entry2) != dax_radix_sector(entry))
+ if (dax_radix_pfn(entry2) != dax_radix_pfn(entry))
goto put_unlocked;
if (WARN_ON_ONCE(dax_is_empty_entry(entry) ||
dax_is_zero_entry(entry))) {
/*
* Even if dax_writeback_mapping_range() was given a wbc->range_start
* in the middle of a PMD, the 'index' we are given will be aligned to
- * the start index of the PMD, as will the sector we pull from
- * 'entry'. This allows us to flush for PMD_SIZE and not have to
- * worry about partial PMD writebacks.
+ * the start index of the PMD, as will the pfn we pull from 'entry'.
+ * This allows us to flush for PMD_SIZE and not have to worry about
+ * partial PMD writebacks.
*/
- sector = dax_radix_sector(entry);
+ pfn = dax_radix_pfn(entry);
size = PAGE_SIZE << dax_radix_order(entry);
- id = dax_read_lock();
- ret = bdev_dax_pgoff(bdev, sector, size, &pgoff);
- if (ret)
- goto dax_unlock;
-
- /*
- * dax_direct_access() may sleep, so cannot hold tree_lock over
- * its invocation.
- */
- ret = dax_direct_access(dax_dev, pgoff, size / PAGE_SIZE, &kaddr, &pfn);
- if (ret < 0)
- goto dax_unlock;
-
- if (WARN_ON_ONCE(ret < size / PAGE_SIZE)) {
- ret = -EIO;
- goto dax_unlock;
- }
-
- dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(pfn));
- dax_flush(dax_dev, kaddr, size);
+ dax_mapping_entry_mkclean(mapping, index, pfn);
+ dax_flush(dax_dev, page_address(pfn_to_page(pfn)), size);
/*
* After we have flushed the cache, we can clear the dirty tag. There
* cannot be new dirty data in the pfn after the flush has completed as
radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&mapping->tree_lock);
trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT);
- dax_unlock:
- dax_read_unlock(id);
put_locked_mapping_entry(mapping, index);
return ret;
break;
}
- ret = dax_writeback_one(bdev, dax_dev, mapping,
- indices[i], pvec.pages[i]);
+ ret = dax_writeback_one(dax_dev, mapping, indices[i],
+ pvec.pages[i]);
if (ret < 0) {
mapping_set_error(mapping, ret);
goto out;
int ret = VM_FAULT_NOPAGE;
struct page *zero_page;
void *entry2;
+ pfn_t pfn;
zero_page = ZERO_PAGE(0);
if (unlikely(!zero_page)) {
goto out;
}
- entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
+ pfn = page_to_pfn_t(zero_page);
+ entry2 = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(entry2)) {
ret = VM_FAULT_SIGBUS;
goto out;
}
- vm_insert_mixed(vmf->vma, vaddr, page_to_pfn_t(zero_page));
+ vm_insert_mixed(vmf->vma, vaddr, pfn);
out:
trace_dax_load_hole(inode, vmf, ret);
return ret;
if (error < 0)
goto error_finish_iomap;
- entry = dax_insert_mapping_entry(mapping, vmf, entry,
- dax_iomap_sector(&iomap, pos),
+ entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
0, write && !sync);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
void *ret = NULL;
spinlock_t *ptl;
pmd_t pmd_entry;
+ pfn_t pfn;
zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm);
if (unlikely(!zero_page))
goto fallback;
- ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
+ pfn = page_to_pfn_t(zero_page);
+ ret = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(ret))
goto fallback;
if (error < 0)
goto finish_iomap;
- entry = dax_insert_mapping_entry(mapping, vmf, entry,
- dax_iomap_sector(&iomap, pos),
+ entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
RADIX_DAX_PMD, write && !sync);
if (IS_ERR(entry))
goto finish_iomap;
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