dax: Hash on XArray instead of mapping (ec4907ff) · Commits · 戴 / test

fs/dax.c

+15 −14

Original line number	Diff line number	Diff line
		@@ -116,7 +116,7 @@ static int dax_is_empty_entry(void *entry)
		* DAX page cache entry locking
		*/
		struct exceptional_entry_key {
		struct address_space *mapping;
		struct xarray *xa;
		pgoff_t entry_start;
		};

		@@ -125,7 +125,7 @@ struct wait_exceptional_entry_queue {
		struct exceptional_entry_key key;
		};

		static wait_queue_head_t dax_entry_waitqueue(struct address_space mapping,
		static wait_queue_head_t dax_entry_waitqueue(struct xarray xa,
		pgoff_t index, void entry, struct exceptional_entry_key key)
		{
		unsigned long hash;
		@@ -138,21 +138,21 @@ static wait_queue_head_t dax_entry_waitqueue(struct address_space mapping,
		if (dax_is_pmd_entry(entry))
		index &= ~PG_PMD_COLOUR;

		key->mapping = mapping;
		key->xa = xa;
		key->entry_start = index;

		hash = hash_long((unsigned long)mapping ^ index, DAX_WAIT_TABLE_BITS);
		hash = hash_long((unsigned long)xa ^ index, DAX_WAIT_TABLE_BITS);
		return wait_table + hash;
		}

		static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mode,
		int sync, void *keyp)
		static int wake_exceptional_entry_func(wait_queue_entry_t *wait,
		unsigned int mode, int sync, void *keyp)
		{
		struct exceptional_entry_key *key = keyp;
		struct wait_exceptional_entry_queue *ewait =
		container_of(wait, struct wait_exceptional_entry_queue, wait);

		if (key->mapping != ewait->key.mapping \|\|
		if (key->xa != ewait->key.xa \|\|
		key->entry_start != ewait->key.entry_start)
		return 0;
		return autoremove_wake_function(wait, mode, sync, NULL);
		@@ -163,13 +163,13 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo
		* The important information it's conveying is whether the entry at
		* this index used to be a PMD entry.
		*/
		static void dax_wake_mapping_entry_waiter(struct address_space *mapping,
		static void dax_wake_mapping_entry_waiter(struct xarray *xa,
		pgoff_t index, void *entry, bool wake_all)
		{
		struct exceptional_entry_key key;
		wait_queue_head_t *wq;

		wq = dax_entry_waitqueue(mapping, index, entry, &key);
		wq = dax_entry_waitqueue(xa, index, entry, &key);

		/*
		* Checking for locked entry and prepare_to_wait_exclusive() happens
		@@ -248,7 +248,8 @@ static void __get_unlocked_mapping_entry(struct address_space mapping,
		return entry;
		}

		wq = dax_entry_waitqueue(mapping, index, entry, &ewait.key);
		wq = dax_entry_waitqueue(&mapping->i_pages, index, entry,
		&ewait.key);
		prepare_to_wait_exclusive(wq, &ewait.wait,
		TASK_UNINTERRUPTIBLE);
		xa_unlock_irq(&mapping->i_pages);
		@@ -289,7 +290,7 @@ static void unlock_mapping_entry(struct address_space *mapping, pgoff_t index)
		}
		unlock_slot(mapping, slot);
		xa_unlock_irq(&mapping->i_pages);
		dax_wake_mapping_entry_waiter(mapping, index, entry, false);
		dax_wake_mapping_entry_waiter(&mapping->i_pages, index, entry, false);
		}

		static void put_locked_mapping_entry(struct address_space *mapping,
		@@ -309,7 +310,7 @@ static void put_unlocked_mapping_entry(struct address_space *mapping,
		return;

		/* We have to wake up next waiter for the page cache entry lock */
		dax_wake_mapping_entry_waiter(mapping, index, entry, false);
		dax_wake_mapping_entry_waiter(&mapping->i_pages, index, entry, false);
		}

		static unsigned long dax_entry_size(void *entry)
		@@ -578,8 +579,8 @@ restart:
		dax_disassociate_entry(entry, mapping, false);
		radix_tree_delete(&mapping->i_pages, index);
		mapping->nrexceptional--;
		dax_wake_mapping_entry_waiter(mapping, index, entry,
		true);
		dax_wake_mapping_entry_waiter(&mapping->i_pages,
		index, entry, true);
		}

		entry = dax_make_locked(0, size_flag \| DAX_EMPTY);

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