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-rw-r--r--fs/dax.c71
1 files changed, 61 insertions, 10 deletions
diff --git a/fs/dax.c b/fs/dax.c
index a8732fbed381..bcfedd184860 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -451,16 +451,37 @@ void dax_wake_mapping_entry_waiter(struct address_space *mapping,
__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
}
+static int __dax_invalidate_mapping_entry(struct address_space *mapping,
+ pgoff_t index, bool trunc)
+{
+ int ret = 0;
+ void *entry;
+ struct radix_tree_root *page_tree = &mapping->page_tree;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = get_unlocked_mapping_entry(mapping, index, NULL);
+ if (!entry || !radix_tree_exceptional_entry(entry))
+ goto out;
+ if (!trunc &&
+ (radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_DIRTY) ||
+ radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE)))
+ goto out;
+ radix_tree_delete(page_tree, index);
+ mapping->nrexceptional--;
+ ret = 1;
+out:
+ put_unlocked_mapping_entry(mapping, index, entry);
+ spin_unlock_irq(&mapping->tree_lock);
+ return ret;
+}
/*
* Delete exceptional DAX entry at @index from @mapping. Wait for radix tree
* entry to get unlocked before deleting it.
*/
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index)
{
- void *entry;
+ int ret = __dax_invalidate_mapping_entry(mapping, index, true);
- spin_lock_irq(&mapping->tree_lock);
- entry = get_unlocked_mapping_entry(mapping, index, NULL);
/*
* This gets called from truncate / punch_hole path. As such, the caller
* must hold locks protecting against concurrent modifications of the
@@ -468,16 +489,46 @@ int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index)
* caller has seen exceptional entry for this index, we better find it
* at that index as well...
*/
- if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry))) {
- spin_unlock_irq(&mapping->tree_lock);
- return 0;
- }
- radix_tree_delete(&mapping->page_tree, index);
+ WARN_ON_ONCE(!ret);
+ return ret;
+}
+
+/*
+ * Invalidate exceptional DAX entry if easily possible. This handles DAX
+ * entries for invalidate_inode_pages() so we evict the entry only if we can
+ * do so without blocking.
+ */
+int dax_invalidate_mapping_entry(struct address_space *mapping, pgoff_t index)
+{
+ int ret = 0;
+ void *entry, **slot;
+ struct radix_tree_root *page_tree = &mapping->page_tree;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = __radix_tree_lookup(page_tree, index, NULL, &slot);
+ if (!entry || !radix_tree_exceptional_entry(entry) ||
+ slot_locked(mapping, slot))
+ goto out;
+ if (radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_DIRTY) ||
+ radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
+ goto out;
+ radix_tree_delete(page_tree, index);
mapping->nrexceptional--;
+ ret = 1;
+out:
spin_unlock_irq(&mapping->tree_lock);
- dax_wake_mapping_entry_waiter(mapping, index, entry, true);
+ if (ret)
+ dax_wake_mapping_entry_waiter(mapping, index, entry, true);
+ return ret;
+}
- return 1;
+/*
+ * Invalidate exceptional DAX entry if it is clean.
+ */
+int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
+ pgoff_t index)
+{
+ return __dax_invalidate_mapping_entry(mapping, index, false);
}
/*