ftl: vss emulation

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Kozlowski Mateusz <mateusz.kozlowski@intel.com>
Change-Id: If22933834d640606526dec9185e849df367ac789
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/13311
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

lib/ftl/Makefile

@@ -9,6 +9,10 @@ include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 SO_VER := 5
 SO_MINOR := 0
 
+ifdef SPDK_FTL_VSS_EMU
+CFLAGS += -DSPDK_FTL_VSS_EMU
+endif
+
 ifneq ($(strip $(SPDK_FTL_ZONE_EMU_BLOCKS)),)
 CFLAGS += -DSPDK_FTL_ZONE_EMU_BLOCKS=$(SPDK_FTL_ZONE_EMU_BLOCKS)
 endif

lib/ftl/ftl_layout.c

@@ -27,6 +27,21 @@ blocks2mib(uint64_t blocks)
 #define FTL_LAYOUT_REGION_ALIGNMENT_BLOCKS 32ULL
 #define FTL_LAYOUT_REGION_ALIGNMENT_BYTES (FTL_LAYOUT_REGION_ALIGNMENT_BLOCKS * FTL_BLOCK_SIZE)
 
+#ifdef SPDK_FTL_VSS_EMU
+static inline uint64_t
+blocks_region(uint64_t bytes)
+{
+	const uint64_t alignment = FTL_LAYOUT_REGION_ALIGNMENT_BYTES;
+	uint64_t result;
+
+	result = spdk_divide_round_up(bytes, alignment);
+	result *= alignment;
+	result /= FTL_BLOCK_SIZE;
+
+	return result;
+}
+#endif
+
 static void
 dump_region(struct spdk_ftl_dev *dev, struct ftl_layout_region *region)
 {
@@ -111,6 +126,16 @@ setup_layout_nvc(struct spdk_ftl_dev *dev)
 	struct ftl_layout *layout = &dev->layout;
 	struct ftl_layout_region *region;
 
+#ifdef SPDK_FTL_VSS_EMU
+	/* Skip the already init`d VSS region */
+	region = &layout->region[FTL_LAYOUT_REGION_TYPE_VSS];
+	offset += region->current.blocks;
+
+	if (offset >= layout->nvc.total_blocks) {
+		goto error;
+	}
+#endif
+
 	region = &layout->region[FTL_LAYOUT_REGION_TYPE_DATA_NVC];
 	region->type = FTL_LAYOUT_REGION_TYPE_DATA_NVC;
 	region->name = "data_nvc";
@@ -208,6 +233,36 @@ ftl_layout_setup(struct spdk_ftl_dev *dev)
 	return 0;
 }
 
+#ifdef SPDK_FTL_VSS_EMU
+void
+ftl_layout_setup_vss_emu(struct spdk_ftl_dev *dev)
+{
+	const struct spdk_bdev *bdev;
+	struct ftl_layout *layout = &dev->layout;
+	struct ftl_layout_region *region = &layout->region[FTL_LAYOUT_REGION_TYPE_VSS];
+
+	assert(layout->md[FTL_LAYOUT_REGION_TYPE_VSS] == NULL);
+
+	region = &layout->region[FTL_LAYOUT_REGION_TYPE_VSS];
+	region->type = FTL_LAYOUT_REGION_TYPE_VSS;
+	region->name = "vss";
+	region->current.version = region->prev.version = 0;
+	region->current.offset = 0;
+
+	bdev = spdk_bdev_desc_get_bdev(dev->cache_bdev_desc);
+	layout->nvc.total_blocks = spdk_bdev_get_num_blocks(bdev);
+	region->current.blocks = blocks_region(dev->cache_md_size * layout->nvc.total_blocks);
+
+	region->vss_blksz = 0;
+	region->bdev_desc = dev->cache_bdev_desc;
+	region->ioch = dev->cache_ioch;
+
+	assert(region->bdev_desc != NULL);
+	assert(region->ioch != NULL);
+}
+#endif
+
+
 void
 ftl_layout_dump(struct spdk_ftl_dev *dev)
 {

lib/ftl/ftl_layout.h

@@ -12,6 +12,10 @@ struct spdk_ftl_dev;
 struct ftl_md;
 
 enum ftl_layout_region_type {
+#ifdef SPDK_FTL_VSS_EMU
+	/** VSS region for NV cache VSS emulation */
+	FTL_LAYOUT_REGION_TYPE_VSS,
+#endif
 	/* User data region on the nv cache device */
 	FTL_LAYOUT_REGION_TYPE_DATA_NVC,
 
@@ -111,6 +115,13 @@ struct ftl_layout {
  */
 int ftl_layout_setup(struct spdk_ftl_dev *dev);
 
+#ifdef SPDK_FTL_VSS_EMU
+/**
+ * @brief Setup FTL layout of VSS emu
+ */
+void ftl_layout_setup_vss_emu(struct spdk_ftl_dev *dev);
+#endif
+
 void ftl_layout_dump(struct spdk_ftl_dev *dev);
 int ftl_validate_regions(struct spdk_ftl_dev *dev, struct ftl_layout *layout);
 

lib/ftl/ftl_nv_cache_io.h

@@ -9,6 +9,8 @@
 #include "spdk/bdev.h"
 #include "ftl_core.h"
 
+#ifndef SPDK_FTL_VSS_EMU
+
 static inline int
 ftl_nv_cache_bdev_readv_blocks_with_md(struct spdk_ftl_dev *dev,
 				       struct spdk_bdev_desc *desc,
@@ -61,4 +63,116 @@ ftl_nv_cache_bdev_write_blocks_with_md(struct spdk_ftl_dev *dev,
 					      cb, cb_arg);
 }
 
+#else
+
+/* TODO: Maybe we can add a non-power-fail-safe support for VSS in AIO bdev and get rid of this */
+static inline void
+ftl_nv_cache_bdev_get_md(struct spdk_ftl_dev *dev,
+			 uint64_t offset_blocks, uint64_t num_blocks,
+			 void *md_buf)
+{
+	struct ftl_md *vss = dev->layout.md[FTL_LAYOUT_REGION_TYPE_VSS];
+	union ftl_md_vss *src;
+	union ftl_md_vss *dst = md_buf;
+	union ftl_md_vss *dst_end = dst + num_blocks;
+
+	assert(offset_blocks + num_blocks <= dev->layout.nvc.total_blocks);
+
+	if (!md_buf) {
+		return;
+	}
+
+	src = ftl_md_get_buffer(vss);
+	src += offset_blocks;
+	while (dst < dst_end) {
+		*dst = *src;
+		dst++;
+		src++;
+	}
+}
+
+static inline int
+ftl_nv_cache_bdev_readv_blocks_with_md(struct spdk_ftl_dev *dev,
+				       struct spdk_bdev_desc *desc,
+				       struct spdk_io_channel *ch,
+				       struct iovec *iov, int iovcnt, void *md,
+				       uint64_t offset_blocks, uint64_t num_blocks,
+				       spdk_bdev_io_completion_cb cb, void *cb_arg)
+{
+	assert(desc == dev->cache_bdev_desc);
+	ftl_nv_cache_bdev_get_md(dev, offset_blocks, num_blocks, md);
+	return spdk_bdev_readv_blocks(desc, ch, iov, iovcnt, offset_blocks,
+				      num_blocks, cb, cb_arg);
+}
+
+static inline void
+ftl_nv_cache_bdev_set_md(struct spdk_ftl_dev *dev,
+			 uint64_t offset_blocks, uint64_t num_blocks,
+			 void *md_buf)
+{
+	struct ftl_md *vss = dev->layout.md[FTL_LAYOUT_REGION_TYPE_VSS];
+	union ftl_md_vss *src = md_buf;
+	union ftl_md_vss *src_end = src + num_blocks;
+	union ftl_md_vss *dst;
+
+	assert(offset_blocks + num_blocks <= dev->layout.nvc.total_blocks);
+
+	if (!md_buf) {
+		return;
+	}
+
+	dst = ftl_md_get_buffer(vss);
+	dst += offset_blocks;
+	while (src < src_end) {
+		*dst = *src;
+		dst++;
+		src++;
+	}
+}
+
+static inline int
+ftl_nv_cache_bdev_writev_blocks_with_md(struct spdk_ftl_dev *dev,
+					struct spdk_bdev_desc *desc,
+					struct spdk_io_channel *ch,
+					struct iovec *iov, int iovcnt, void *md_buf,
+					uint64_t offset_blocks, uint64_t num_blocks,
+					spdk_bdev_io_completion_cb cb, void *cb_arg)
+{
+	assert(desc == dev->cache_bdev_desc);
+	ftl_nv_cache_bdev_set_md(dev, offset_blocks, num_blocks, md_buf);
+	return spdk_bdev_writev_blocks(desc, ch, iov, iovcnt,
+				       offset_blocks, num_blocks,
+				       cb, cb_arg);
+}
+
+static inline int
+ftl_nv_cache_bdev_read_blocks_with_md(struct spdk_ftl_dev *dev,
+				      struct spdk_bdev_desc *desc,
+				      struct spdk_io_channel *ch,
+				      void *buf, void *md,
+				      uint64_t offset_blocks, uint64_t num_blocks,
+				      spdk_bdev_io_completion_cb cb, void *cb_arg)
+{
+	assert(desc == dev->cache_bdev_desc);
+	ftl_nv_cache_bdev_get_md(dev, offset_blocks, num_blocks, md);
+	return spdk_bdev_read_blocks(desc, ch, buf, offset_blocks,
+				     num_blocks, cb, cb_arg);
+}
+
+static inline int
+ftl_nv_cache_bdev_write_blocks_with_md(struct spdk_ftl_dev *dev,
+				       struct spdk_bdev_desc *desc,
+				       struct spdk_io_channel *ch,
+				       void *buf, void *md,
+				       uint64_t offset_blocks, uint64_t num_blocks,
+				       spdk_bdev_io_completion_cb cb, void *cb_arg)
+{
+	assert(desc == dev->cache_bdev_desc);
+	ftl_nv_cache_bdev_set_md(dev, offset_blocks, num_blocks, md);
+	return spdk_bdev_write_blocks(desc, ch, buf,
+				      offset_blocks, num_blocks,
+				      cb, cb_arg);
+}
+
+#endif
 #endif /* FTL_NV_CACHE_IO_H */

lib/ftl/mngt/ftl_mngt_bdev.c

@@ -203,6 +203,7 @@ ftl_mngt_open_cache_bdev(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt
 		goto error;
 	}
 
+#ifndef SPDK_FTL_VSS_EMU
 	if (!spdk_bdev_is_md_separate(bdev)) {
 		FTL_ERRLOG(dev, "Bdev %s doesn't support separate metadata buffer IO\n",
 			   spdk_bdev_get_name(bdev));
@@ -233,6 +234,15 @@ ftl_mngt_open_cache_bdev(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt
 			   spdk_bdev_get_name(bdev));
 		goto error;
 	}
+#else
+	if (spdk_bdev_is_md_separate(bdev)) {
+		FTL_ERRLOG(dev, "FTL VSS emulation but NV cache supports VSS\n");
+		goto error;
+	}
+
+	dev->cache_md_size = 64;
+	FTL_NOTICELOG(dev, "FTL uses VSS emulation\n");
+#endif
 
 	ftl_mngt_next_step(mngt);
 	return;

lib/ftl/mngt/ftl_mngt_md.c

@@ -26,6 +26,9 @@ static bool
 is_buffer_needed(enum ftl_layout_region_type type)
 {
 	switch (type) {
+#ifdef SPDK_FTL_VSS_EMU
+	case FTL_LAYOUT_REGION_TYPE_VSS:
+#endif
 	case FTL_LAYOUT_REGION_TYPE_DATA_NVC:
 	case FTL_LAYOUT_REGION_TYPE_DATA_BASE:
 		return false;
@@ -79,3 +82,37 @@ ftl_mngt_deinit_md(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt)
 
 	ftl_mngt_next_step(mngt);
 }
+
+#ifdef SPDK_FTL_VSS_EMU
+void
+ftl_mngt_md_init_vss_emu(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt)
+{
+	struct ftl_layout *layout = &dev->layout;
+	struct ftl_layout_region *region = &layout->region[FTL_LAYOUT_REGION_TYPE_VSS];
+
+	/* Initialize VSS layout */
+	ftl_layout_setup_vss_emu(dev);
+
+	/* Allocate md buf */
+	layout->md[FTL_LAYOUT_REGION_TYPE_VSS] = ftl_md_create(dev, region->current.blocks,
+			region->vss_blksz, NULL, 0, region);
+	if (NULL == layout->md[FTL_LAYOUT_REGION_TYPE_VSS]) {
+		ftl_mngt_fail_step(mngt);
+		return;
+	}
+	ftl_mngt_next_step(mngt);
+}
+
+void
+ftl_mngt_md_deinit_vss_emu(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt)
+{
+	struct ftl_layout *layout = &dev->layout;
+
+	if (layout->md[FTL_LAYOUT_REGION_TYPE_VSS]) {
+		ftl_md_destroy(layout->md[FTL_LAYOUT_REGION_TYPE_VSS]);
+		layout->md[FTL_LAYOUT_REGION_TYPE_VSS] = NULL;
+	}
+
+	ftl_mngt_next_step(mngt);
+}
+#endif

lib/ftl/mngt/ftl_mngt_startup.c

@@ -42,6 +42,13 @@ static const struct ftl_mngt_process_desc desc_startup = {
 			.action = ftl_mngt_open_cache_bdev,
 			.cleanup = ftl_mngt_close_cache_bdev
 		},
+#ifdef SPDK_FTL_VSS_EMU
+		{
+			.name = "Initialize VSS emu",
+			.action = ftl_mngt_md_init_vss_emu,
+			.cleanup = ftl_mngt_md_deinit_vss_emu
+		},
+#endif
 		{
 			.name = "Register IO device",
 			.action = ftl_mngt_register_io_device,

lib/ftl/mngt/ftl_mngt_steps.h

@@ -14,6 +14,12 @@ void ftl_mngt_open_base_bdev(struct spdk_ftl_dev *dev, struct ftl_mngt_process *
 
 void ftl_mngt_close_base_bdev(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
 
+#ifdef SPDK_FTL_VSS_EMU
+void ftl_mngt_md_init_vss_emu(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
+
+void ftl_mngt_md_deinit_vss_emu(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
+#endif
+
 void ftl_mngt_open_cache_bdev(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
 
 void ftl_mngt_close_cache_bdev(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);