Merge tag 'for-6.9/dm-vdo' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper VDO target from Mike Snitzer:
 "Introduce the DM vdo target which provides block-level deduplication,
  compression, and thin provisioning. Please see:

      Documentation/admin-guide/device-mapper/vdo.rst
      Documentation/admin-guide/device-mapper/vdo-design.rst

  The DM vdo target handles its concurrency by pinning an IO, and
  subsequent stages of handling that IO, to a particular VDO thread.
  This aspect of VDO is "unique" but its overall implementation is very
  tightly coupled to its mostly lockless threading model. As such, VDO
  is not easily changed to use more traditional finer-grained locking
  and Linux workqueues. Please see the "Zones and Threading" section of
  vdo-design.rst

  The DM vdo target has been used in production for many years but has
  seen significant changes over the past ~6 years to prepare it for
  upstream inclusion. The codebase is still large but it is isolated to
  drivers/md/dm-vdo/ and has been made considerably more approachable
  and maintainable.

  Matt Sakai has been added to the MAINTAINERS file to reflect that he
  will send VDO changes upstream through the DM subsystem maintainers"

* tag 'for-6.9/dm-vdo' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (142 commits)
  dm vdo: document minimum metadata size requirements
  dm vdo: remove meaningless version number constant
  dm vdo: remove vdo_perform_once
  dm vdo block-map: Remove stray semicolon
  dm vdo string-utils: change from uds_ to vdo_ namespace
  dm vdo logger: change from uds_ to vdo_ namespace
  dm vdo funnel-queue: change from uds_ to vdo_ namespace
  dm vdo indexer: fix use after free
  dm vdo logger: remove log level to string conversion code
  dm vdo: document log_level parameter
  dm vdo: add 'log_level' module parameter
  dm vdo: remove all sysfs interfaces
  dm vdo target: eliminate inappropriate uses of UDS_SUCCESS
  dm vdo indexer: update ASSERT and ASSERT_LOG_ONLY usage
  dm vdo encodings: update some stale comments
  dm vdo permassert: audit all of ASSERT to test for VDO_SUCCESS
  dm-vdo funnel-workqueue: return VDO_SUCCESS from make_simple_work_queue
  dm vdo thread-utils: return VDO_SUCCESS on vdo_create_thread success
  dm vdo int-map: return VDO_SUCCESS on success
  dm vdo: check for VDO_SUCCESS return value from memory-alloc functions
  ...

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/memory-alloc.h b/drivers/md/dm-vdo/memory-alloc.h
new file mode 100644
index 000000000000..0093d9f940d9
--- /dev/null
+++ b/drivers/md/dm-vdo/memory-alloc.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef VDO_MEMORY_ALLOC_H
+#define VDO_MEMORY_ALLOC_H
+
+#include <linux/cache.h>
+#include <linux/io.h> /* for PAGE_SIZE */
+
+#include "permassert.h"
+#include "thread-registry.h"
+
+/* Custom memory allocation function that tracks memory usage */
+int __must_check vdo_allocate_memory(size_t size, size_t align, const char *what, void *ptr);
+
+/*
+ * Allocate storage based on element counts, sizes, and alignment.
+ *
+ * This is a generalized form of our allocation use case: It allocates an array of objects,
+ * optionally preceded by one object of another type (i.e., a struct with trailing variable-length
+ * array), with the alignment indicated.
+ *
+ * Why is this inline? The sizes and alignment will always be constant, when invoked through the
+ * macros below, and often the count will be a compile-time constant 1 or the number of extra bytes
+ * will be a compile-time constant 0. So at least some of the arithmetic can usually be optimized
+ * away, and the run-time selection between allocation functions always can. In many cases, it'll
+ * boil down to just a function call with a constant size.
+ *
+ * @count: The number of objects to allocate
+ * @size: The size of an object
+ * @extra: The number of additional bytes to allocate
+ * @align: The required alignment
+ * @what: What is being allocated (for error logging)
+ * @ptr: A pointer to hold the allocated memory
+ *
+ * Return: VDO_SUCCESS or an error code
+ */
+static inline int __vdo_do_allocation(size_t count, size_t size, size_t extra,
+				      size_t align, const char *what, void *ptr)
+{
+	size_t total_size = count * size + extra;
+
+	/* Overflow check: */
+	if ((size > 0) && (count > ((SIZE_MAX - extra) / size))) {
+		/*
+		 * This is kind of a hack: We rely on the fact that SIZE_MAX would cover the entire
+		 * address space (minus one byte) and thus the system can never allocate that much
+		 * and the call will always fail. So we can report an overflow as "out of memory"
+		 * by asking for "merely" SIZE_MAX bytes.
+		 */
+		total_size = SIZE_MAX;
+	}
+
+	return vdo_allocate_memory(total_size, align, what, ptr);
+}
+
+/*
+ * Allocate one or more elements of the indicated type, logging an error if the allocation fails.
+ * The memory will be zeroed.
+ *
+ * @COUNT: The number of objects to allocate
+ * @TYPE: The type of objects to allocate. This type determines the alignment of the allocation.
+ * @WHAT: What is being allocated (for error logging)
+ * @PTR: A pointer to hold the allocated memory
+ *
+ * Return: VDO_SUCCESS or an error code
+ */
+#define vdo_allocate(COUNT, TYPE, WHAT, PTR) \
+	__vdo_do_allocation(COUNT, sizeof(TYPE), 0, __alignof__(TYPE), WHAT, PTR)
+
+/*
+ * Allocate one object of an indicated type, followed by one or more elements of a second type,
+ * logging an error if the allocation fails. The memory will be zeroed.
+ *
+ * @TYPE1: The type of the primary object to allocate. This type determines the alignment of the
+ *         allocated memory.
+ * @COUNT: The number of objects to allocate
+ * @TYPE2: The type of array objects to allocate
+ * @WHAT: What is being allocated (for error logging)
+ * @PTR: A pointer to hold the allocated memory
+ *
+ * Return: VDO_SUCCESS or an error code
+ */
+#define vdo_allocate_extended(TYPE1, COUNT, TYPE2, WHAT, PTR)		\
+	__extension__({							\
+		int _result;						\
+		TYPE1 **_ptr = (PTR);					\
+		BUILD_BUG_ON(__alignof__(TYPE1) < __alignof__(TYPE2));	\
+		_result = __vdo_do_allocation(COUNT,			\
+					      sizeof(TYPE2),		\
+					      sizeof(TYPE1),		\
+					      __alignof__(TYPE1),	\
+					      WHAT,			\
+					      _ptr);			\
+		_result;						\
+	})
+
+/*
+ * Allocate memory starting on a cache line boundary, logging an error if the allocation fails. The
+ * memory will be zeroed.
+ *
+ * @size: The number of bytes to allocate
+ * @what: What is being allocated (for error logging)
+ * @ptr: A pointer to hold the allocated memory
+ *
+ * Return: VDO_SUCCESS or an error code
+ */
+static inline int __must_check vdo_allocate_cache_aligned(size_t size, const char *what, void *ptr)
+{
+	return vdo_allocate_memory(size, L1_CACHE_BYTES, what, ptr);
+}
+
+/*
+ * Allocate one element of the indicated type immediately, failing if the required memory is not
+ * immediately available.
+ *
+ * @size: The number of bytes to allocate
+ * @what: What is being allocated (for error logging)
+ *
+ * Return: pointer to the memory, or NULL if the memory is not available.
+ */
+void *__must_check vdo_allocate_memory_nowait(size_t size, const char *what);
+
+int __must_check vdo_reallocate_memory(void *ptr, size_t old_size, size_t size,
+				       const char *what, void *new_ptr);
+
+int __must_check vdo_duplicate_string(const char *string, const char *what,
+				      char **new_string);
+
+/* Free memory allocated with vdo_allocate(). */
+void vdo_free(void *ptr);
+
+static inline void *__vdo_forget(void **ptr_ptr)
+{
+	void *ptr = *ptr_ptr;
+
+	*ptr_ptr = NULL;
+	return ptr;
+}
+
+/*
+ * Null out a pointer and return a copy to it. This macro should be used when passing a pointer to
+ * a function for which it is not safe to access the pointer once the function returns.
+ */
+#define vdo_forget(ptr) __vdo_forget((void **) &(ptr))
+
+void vdo_memory_init(void);
+
+void vdo_memory_exit(void);
+
+void vdo_register_allocating_thread(struct registered_thread *new_thread,
+				    const bool *flag_ptr);
+
+void vdo_unregister_allocating_thread(void);
+
+void vdo_get_memory_stats(u64 *bytes_used, u64 *peak_bytes_used);
+
+void vdo_report_memory_usage(void);
+
+#endif /* VDO_MEMORY_ALLOC_H */