fs_initcall(init_dax_wait_table);
/*
- * We use lowest available bit in exceptional entry for locking, one bit for
- * the entry size (PMD) and two more to tell us if the entry is a zero page or
- * an empty entry that is just used for locking. In total four special bits.
+ * DAX pagecache entries use XArray value entries so they can't be mistaken
+ * for pages. We use one bit for locking, one bit for the entry size (PMD)
+ * and two more to tell us if the entry is a zero page or an empty entry that
+ * is just used for locking. In total four special bits.
*
* If the PMD bit isn't set the entry has size PAGE_SIZE, and if the ZERO_PAGE
* and EMPTY bits aren't set the entry is a normal DAX entry with a filesystem
* block allocation.
*/
-#define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 4)
-#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
-#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
-#define RADIX_DAX_ZERO_PAGE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
-#define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3))
+#define DAX_SHIFT (4)
+#define DAX_LOCKED (1UL << 0)
+#define DAX_PMD (1UL << 1)
+#define DAX_ZERO_PAGE (1UL << 2)
+#define DAX_EMPTY (1UL << 3)
static unsigned long dax_radix_pfn(void *entry)
{
- return (unsigned long)entry >> RADIX_DAX_SHIFT;
+ return xa_to_value(entry) >> DAX_SHIFT;
}
static void *dax_radix_locked_entry(unsigned long pfn, unsigned long flags)
{
- return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags |
- (pfn << RADIX_DAX_SHIFT) | RADIX_DAX_ENTRY_LOCK);
+ return xa_mk_value(flags | ((unsigned long)pfn << DAX_SHIFT) |
+ DAX_LOCKED);
}
static unsigned int dax_radix_order(void *entry)
{
- if ((unsigned long)entry & RADIX_DAX_PMD)
+ if (xa_to_value(entry) & DAX_PMD)
return PMD_SHIFT - PAGE_SHIFT;
return 0;
}
static int dax_is_pmd_entry(void *entry)
{
- return (unsigned long)entry & RADIX_DAX_PMD;
+ return xa_to_value(entry) & DAX_PMD;
}
static int dax_is_pte_entry(void *entry)
{
- return !((unsigned long)entry & RADIX_DAX_PMD);
+ return !(xa_to_value(entry) & DAX_PMD);
}
static int dax_is_zero_entry(void *entry)
{
- return (unsigned long)entry & RADIX_DAX_ZERO_PAGE;
+ return xa_to_value(entry) & DAX_ZERO_PAGE;
}
static int dax_is_empty_entry(void *entry)
{
- return (unsigned long)entry & RADIX_DAX_EMPTY;
+ return xa_to_value(entry) & DAX_EMPTY;
}
/*
*/
static inline int slot_locked(struct address_space *mapping, void **slot)
{
- unsigned long entry = (unsigned long)
- radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
- return entry & RADIX_DAX_ENTRY_LOCK;
+ unsigned long entry = xa_to_value(
+ radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock));
+ return entry & DAX_LOCKED;
}
/*
*/
static inline void *lock_slot(struct address_space *mapping, void **slot)
{
- unsigned long entry = (unsigned long)
- radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
-
- entry |= RADIX_DAX_ENTRY_LOCK;
- radix_tree_replace_slot(&mapping->i_pages, slot, (void *)entry);
- return (void *)entry;
+ unsigned long v = xa_to_value(
+ radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock));
+ void *entry = xa_mk_value(v | DAX_LOCKED);
+ radix_tree_replace_slot(&mapping->i_pages, slot, entry);
+ return entry;
}
/*
*/
static inline void *unlock_slot(struct address_space *mapping, void **slot)
{
- unsigned long entry = (unsigned long)
- radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
-
- entry &= ~(unsigned long)RADIX_DAX_ENTRY_LOCK;
- radix_tree_replace_slot(&mapping->i_pages, slot, (void *)entry);
- return (void *)entry;
+ unsigned long v = xa_to_value(
+ radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock));
+ void *entry = xa_mk_value(v & ~DAX_LOCKED);
+ radix_tree_replace_slot(&mapping->i_pages, slot, entry);
+ return entry;
}
/*
* Lookup entry in radix tree, wait for it to become unlocked if it is
- * exceptional entry and return it. The caller must call
+ * a DAX entry and return it. The caller must call
* put_unlocked_mapping_entry() when he decided not to lock the entry or
* put_locked_mapping_entry() when he locked the entry and now wants to
* unlock it.
entry = __radix_tree_lookup(&mapping->i_pages, index, NULL,
&slot);
if (!entry ||
- WARN_ON_ONCE(!radix_tree_exceptional_entry(entry)) ||
+ WARN_ON_ONCE(!xa_is_value(entry)) ||
!slot_locked(mapping, slot)) {
if (slotp)
*slotp = slot;
xa_lock_irq(&mapping->i_pages);
entry = __radix_tree_lookup(&mapping->i_pages, index, NULL, &slot);
- if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) ||
+ if (WARN_ON_ONCE(!entry || !xa_is_value(entry) ||
!slot_locked(mapping, slot))) {
xa_unlock_irq(&mapping->i_pages);
return;
}
/*
- * 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
- * contain given index, create an empty exceptional entry for the index and
- * return with it locked.
+ * Find radix tree entry at given index. If it is a DAX entry, return it
+ * with the radix tree entry locked. If the radix tree doesn't contain the
+ * given index, create an empty entry for the index and return with it locked.
*
- * When requesting an entry with size RADIX_DAX_PMD, grab_mapping_entry() will
+ * When requesting an entry with size DAX_PMD, grab_mapping_entry() will
* either return that locked entry or will return an error. This error will
* happen if there are any 4k entries within the 2MiB range that we are
* requesting.
xa_lock_irq(&mapping->i_pages);
entry = get_unlocked_mapping_entry(mapping, index, &slot);
- if (WARN_ON_ONCE(entry && !radix_tree_exceptional_entry(entry))) {
+ if (WARN_ON_ONCE(entry && !xa_is_value(entry))) {
entry = ERR_PTR(-EIO);
goto out_unlock;
}
if (entry) {
- if (size_flag & RADIX_DAX_PMD) {
+ if (size_flag & DAX_PMD) {
if (dax_is_pte_entry(entry)) {
put_unlocked_mapping_entry(mapping, index,
entry);
true);
}
- entry = dax_radix_locked_entry(0, size_flag | RADIX_DAX_EMPTY);
+ entry = dax_radix_locked_entry(0, size_flag | DAX_EMPTY);
err = __radix_tree_insert(&mapping->i_pages, index,
dax_radix_order(entry), entry);
if (index >= end)
break;
- if (WARN_ON_ONCE(
- !radix_tree_exceptional_entry(pvec_ent)))
+ if (WARN_ON_ONCE(!xa_is_value(pvec_ent)))
continue;
xa_lock_irq(&mapping->i_pages);
xa_lock_irq(pages);
entry = get_unlocked_mapping_entry(mapping, index, NULL);
- if (!entry || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry)))
+ if (!entry || WARN_ON_ONCE(!xa_is_value(entry)))
goto out;
if (!trunc &&
(radix_tree_tag_get(pages, index, PAGECACHE_TAG_DIRTY) ||
return ret;
}
/*
- * Delete exceptional DAX entry at @index from @mapping. Wait for radix tree
- * entry to get unlocked before deleting it.
+ * Delete DAX entry at @index from @mapping. Wait for it
+ * to be unlocked before deleting it.
*/
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index)
{
* This gets called from truncate / punch_hole path. As such, the caller
* must hold locks protecting against concurrent modifications of the
* radix tree (usually fs-private i_mmap_sem for writing). Since the
- * caller has seen exceptional entry for this index, we better find it
+ * caller has seen a DAX entry for this index, we better find it
* at that index as well...
*/
WARN_ON_ONCE(!ret);
}
/*
- * Invalidate exceptional DAX entry if it is clean.
+ * Invalidate DAX entry if it is clean.
*/
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index)
if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
- if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
+ if (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE)) {
/* we are replacing a zero page with block mapping */
if (dax_is_pmd_entry(entry))
unmap_mapping_pages(mapping, index & ~PG_PMD_COLOUR,
* A page got tagged dirty in DAX mapping? Something is seriously
* wrong.
*/
- if (WARN_ON(!radix_tree_exceptional_entry(entry)))
+ if (WARN_ON(!xa_is_value(entry)))
return -EIO;
xa_lock_irq(pages);
entry2 = get_unlocked_mapping_entry(mapping, index, &slot);
/* Entry got punched out / reallocated? */
- if (!entry2 || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry2)))
+ if (!entry2 || WARN_ON_ONCE(!xa_is_value(entry2)))
goto put_unlocked;
/*
* Entry got reallocated elsewhere? No need to writeback. We have to
pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr));
vm_fault_t ret;
- dax_insert_mapping_entry(mapping, vmf, entry, pfn, RADIX_DAX_ZERO_PAGE,
- false);
+ dax_insert_mapping_entry(mapping, vmf, entry, pfn,
+ DAX_ZERO_PAGE, false);
+
ret = vmf_insert_mixed(vmf->vma, vaddr, pfn);
trace_dax_load_hole(inode, vmf, ret);
return ret;
pfn = page_to_pfn_t(zero_page);
ret = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
- RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
+ DAX_PMD | DAX_ZERO_PAGE, false);
ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd);
if (!pmd_none(*(vmf->pmd))) {
* is already in the tree, for instance), it will return -EEXIST and
* we just fall back to 4k entries.
*/
- entry = grab_mapping_entry(mapping, pgoff, RADIX_DAX_PMD);
+ entry = grab_mapping_entry(mapping, pgoff, DAX_PMD);
if (IS_ERR(entry))
goto fallback;
goto finish_iomap;
entry = dax_insert_mapping_entry(mapping, vmf, entry, pfn,
- RADIX_DAX_PMD, write && !sync);
+ DAX_PMD, write && !sync);
/*
* If we are doing synchronous page fault and inode needs fsync,
git.samba.org / sfrench / cifs-2.6.git / blobdiff