Adding upstream version 14.2.21.upstream/14.2.21upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2617 insertions, 0 deletions

diff --git a/src/spdk/lib/blobfs/blobfs.c b/src/spdk/lib/blobfs/blobfs.c
new file mode 100644
index 00000000..48e9f481
--- /dev/null
+++ b/src/spdk/lib/blobfs/blobfs.c
@@ -0,0 +1,2617 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "spdk/stdinc.h"
+
+#include "spdk/blobfs.h"
+#include "spdk/conf.h"
+#include "blobfs_internal.h"
+
+#include "spdk/queue.h"
+#include "spdk/thread.h"
+#include "spdk/assert.h"
+#include "spdk/env.h"
+#include "spdk/util.h"
+#include "spdk_internal/log.h"
+
+#define BLOBFS_TRACE(file, str, args...) \
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s " str, file->name, ##args)
+
+#define BLOBFS_TRACE_RW(file, str, args...) \
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS_RW, "file=%s " str, file->name, ##args)
+
+#define BLOBFS_DEFAULT_CACHE_SIZE (4ULL * 1024 * 1024 * 1024)
+#define SPDK_BLOBFS_DEFAULT_OPTS_CLUSTER_SZ (1024 * 1024)
+
+static uint64_t g_fs_cache_size = BLOBFS_DEFAULT_CACHE_SIZE;
+static struct spdk_mempool *g_cache_pool;
+static TAILQ_HEAD(, spdk_file) g_caches;
+static int g_fs_count = 0;
+static pthread_mutex_t g_cache_init_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_spinlock_t g_caches_lock;
+
+void
+spdk_cache_buffer_free(struct cache_buffer *cache_buffer)
+{
+	spdk_mempool_put(g_cache_pool, cache_buffer->buf);
+	free(cache_buffer);
+}
+
+#define CACHE_READAHEAD_THRESHOLD	(128 * 1024)
+
+struct spdk_file {
+	struct spdk_filesystem	*fs;
+	struct spdk_blob	*blob;
+	char			*name;
+	uint64_t		length;
+	bool                    is_deleted;
+	bool			open_for_writing;
+	uint64_t		length_flushed;
+	uint64_t		append_pos;
+	uint64_t		seq_byte_count;
+	uint64_t		next_seq_offset;
+	uint32_t		priority;
+	TAILQ_ENTRY(spdk_file)	tailq;
+	spdk_blob_id		blobid;
+	uint32_t		ref_count;
+	pthread_spinlock_t	lock;
+	struct cache_buffer	*last;
+	struct cache_tree	*tree;
+	TAILQ_HEAD(open_requests_head, spdk_fs_request) open_requests;
+	TAILQ_HEAD(sync_requests_head, spdk_fs_request) sync_requests;
+	TAILQ_ENTRY(spdk_file)	cache_tailq;
+};
+
+struct spdk_deleted_file {
+	spdk_blob_id	id;
+	TAILQ_ENTRY(spdk_deleted_file)	tailq;
+};
+
+struct spdk_filesystem {
+	struct spdk_blob_store	*bs;
+	TAILQ_HEAD(, spdk_file)	files;
+	struct spdk_bs_opts	bs_opts;
+	struct spdk_bs_dev	*bdev;
+	fs_send_request_fn	send_request;
+
+	struct {
+		uint32_t		max_ops;
+		struct spdk_io_channel	*sync_io_channel;
+		struct spdk_fs_channel	*sync_fs_channel;
+	} sync_target;
+
+	struct {
+		uint32_t		max_ops;
+		struct spdk_io_channel	*md_io_channel;
+		struct spdk_fs_channel	*md_fs_channel;
+	} md_target;
+
+	struct {
+		uint32_t		max_ops;
+	} io_target;
+};
+
+struct spdk_fs_cb_args {
+	union {
+		spdk_fs_op_with_handle_complete		fs_op_with_handle;
+		spdk_fs_op_complete			fs_op;
+		spdk_file_op_with_handle_complete	file_op_with_handle;
+		spdk_file_op_complete			file_op;
+		spdk_file_stat_op_complete		stat_op;
+	} fn;
+	void *arg;
+	sem_t *sem;
+	struct spdk_filesystem *fs;
+	struct spdk_file *file;
+	int rc;
+	bool from_request;
+	union {
+		struct {
+			TAILQ_HEAD(, spdk_deleted_file)	deleted_files;
+		} fs_load;
+		struct {
+			uint64_t	length;
+		} truncate;
+		struct {
+			struct spdk_io_channel	*channel;
+			void		*user_buf;
+			void		*pin_buf;
+			int		is_read;
+			off_t		offset;
+			size_t		length;
+			uint64_t	start_lba;
+			uint64_t	num_lba;
+			uint32_t	blocklen;
+		} rw;
+		struct {
+			const char	*old_name;
+			const char	*new_name;
+		} rename;
+		struct {
+			struct cache_buffer	*cache_buffer;
+			uint64_t		length;
+		} flush;
+		struct {
+			struct cache_buffer	*cache_buffer;
+			uint64_t		length;
+			uint64_t		offset;
+		} readahead;
+		struct {
+			uint64_t			offset;
+			TAILQ_ENTRY(spdk_fs_request)	tailq;
+			bool				xattr_in_progress;
+		} sync;
+		struct {
+			uint32_t			num_clusters;
+		} resize;
+		struct {
+			const char	*name;
+			uint32_t	flags;
+			TAILQ_ENTRY(spdk_fs_request)	tailq;
+		} open;
+		struct {
+			const char		*name;
+			struct spdk_blob	*blob;
+		} create;
+		struct {
+			const char	*name;
+		} delete;
+		struct {
+			const char	*name;
+		} stat;
+	} op;
+};
+
+static void cache_free_buffers(struct spdk_file *file);
+
+void
+spdk_fs_opts_init(struct spdk_blobfs_opts *opts)
+{
+	opts->cluster_sz = SPDK_BLOBFS_DEFAULT_OPTS_CLUSTER_SZ;
+}
+
+static void
+__initialize_cache(void)
+{
+	assert(g_cache_pool == NULL);
+
+	g_cache_pool = spdk_mempool_create("spdk_fs_cache",
+					   g_fs_cache_size / CACHE_BUFFER_SIZE,
+					   CACHE_BUFFER_SIZE,
+					   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
+					   SPDK_ENV_SOCKET_ID_ANY);
+	if (!g_cache_pool) {
+		SPDK_ERRLOG("Create mempool failed, you may "
+			    "increase the memory and try again\n");
+		assert(false);
+	}
+	TAILQ_INIT(&g_caches);
+	pthread_spin_init(&g_caches_lock, 0);
+}
+
+static void
+__free_cache(void)
+{
+	assert(g_cache_pool != NULL);
+
+	spdk_mempool_free(g_cache_pool);
+	g_cache_pool = NULL;
+}
+
+static uint64_t
+__file_get_blob_size(struct spdk_file *file)
+{
+	uint64_t cluster_sz;
+
+	cluster_sz = file->fs->bs_opts.cluster_sz;
+	return cluster_sz * spdk_blob_get_num_clusters(file->blob);
+}
+
+struct spdk_fs_request {
+	struct spdk_fs_cb_args		args;
+	TAILQ_ENTRY(spdk_fs_request)	link;
+	struct spdk_fs_channel		*channel;
+};
+
+struct spdk_fs_channel {
+	struct spdk_fs_request		*req_mem;
+	TAILQ_HEAD(, spdk_fs_request)	reqs;
+	sem_t				sem;
+	struct spdk_filesystem		*fs;
+	struct spdk_io_channel		*bs_channel;
+	fs_send_request_fn		send_request;
+	bool				sync;
+	pthread_spinlock_t		lock;
+};
+
+static struct spdk_fs_request *
+alloc_fs_request(struct spdk_fs_channel *channel)
+{
+	struct spdk_fs_request *req;
+
+	if (channel->sync) {
+		pthread_spin_lock(&channel->lock);
+	}
+
+	req = TAILQ_FIRST(&channel->reqs);
+	if (req) {
+		TAILQ_REMOVE(&channel->reqs, req, link);
+	}
+
+	if (channel->sync) {
+		pthread_spin_unlock(&channel->lock);
+	}
+
+	if (req == NULL) {
+		return NULL;
+	}
+	memset(req, 0, sizeof(*req));
+	req->channel = channel;
+	req->args.from_request = true;
+
+	return req;
+}
+
+static void
+free_fs_request(struct spdk_fs_request *req)
+{
+	struct spdk_fs_channel *channel = req->channel;
+
+	if (channel->sync) {
+		pthread_spin_lock(&channel->lock);
+	}
+
+	TAILQ_INSERT_HEAD(&req->channel->reqs, req, link);
+
+	if (channel->sync) {
+		pthread_spin_unlock(&channel->lock);
+	}
+}
+
+static int
+_spdk_fs_channel_create(struct spdk_filesystem *fs, struct spdk_fs_channel *channel,
+			uint32_t max_ops)
+{
+	uint32_t i;
+
+	channel->req_mem = calloc(max_ops, sizeof(struct spdk_fs_request));
+	if (!channel->req_mem) {
+		return -1;
+	}
+
+	TAILQ_INIT(&channel->reqs);
+	sem_init(&channel->sem, 0, 0);
+
+	for (i = 0; i < max_ops; i++) {
+		TAILQ_INSERT_TAIL(&channel->reqs, &channel->req_mem[i], link);
+	}
+
+	channel->fs = fs;
+
+	return 0;
+}
+
+static int
+_spdk_fs_md_channel_create(void *io_device, void *ctx_buf)
+{
+	struct spdk_filesystem		*fs;
+	struct spdk_fs_channel		*channel = ctx_buf;
+
+	fs = SPDK_CONTAINEROF(io_device, struct spdk_filesystem, md_target);
+
+	return _spdk_fs_channel_create(fs, channel, fs->md_target.max_ops);
+}
+
+static int
+_spdk_fs_sync_channel_create(void *io_device, void *ctx_buf)
+{
+	struct spdk_filesystem		*fs;
+	struct spdk_fs_channel		*channel = ctx_buf;
+
+	fs = SPDK_CONTAINEROF(io_device, struct spdk_filesystem, sync_target);
+
+	return _spdk_fs_channel_create(fs, channel, fs->sync_target.max_ops);
+}
+
+static int
+_spdk_fs_io_channel_create(void *io_device, void *ctx_buf)
+{
+	struct spdk_filesystem		*fs;
+	struct spdk_fs_channel		*channel = ctx_buf;
+
+	fs = SPDK_CONTAINEROF(io_device, struct spdk_filesystem, io_target);
+
+	return _spdk_fs_channel_create(fs, channel, fs->io_target.max_ops);
+}
+
+static void
+_spdk_fs_channel_destroy(void *io_device, void *ctx_buf)
+{
+	struct spdk_fs_channel *channel = ctx_buf;
+
+	free(channel->req_mem);
+	if (channel->bs_channel != NULL) {
+		spdk_bs_free_io_channel(channel->bs_channel);
+	}
+}
+
+static void
+__send_request_direct(fs_request_fn fn, void *arg)
+{
+	fn(arg);
+}
+
+static void
+common_fs_bs_init(struct spdk_filesystem *fs, struct spdk_blob_store *bs)
+{
+	fs->bs = bs;
+	fs->bs_opts.cluster_sz = spdk_bs_get_cluster_size(bs);
+	fs->md_target.md_fs_channel->bs_channel = spdk_bs_alloc_io_channel(fs->bs);
+	fs->md_target.md_fs_channel->send_request = __send_request_direct;
+	fs->sync_target.sync_fs_channel->bs_channel = spdk_bs_alloc_io_channel(fs->bs);
+	fs->sync_target.sync_fs_channel->send_request = __send_request_direct;
+
+	pthread_mutex_lock(&g_cache_init_lock);
+	if (g_fs_count == 0) {
+		__initialize_cache();
+	}
+	g_fs_count++;
+	pthread_mutex_unlock(&g_cache_init_lock);
+}
+
+static void
+init_cb(void *ctx, struct spdk_blob_store *bs, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_filesystem *fs = args->fs;
+
+	if (bserrno == 0) {
+		common_fs_bs_init(fs, bs);
+	} else {
+		free(fs);
+		fs = NULL;
+	}
+
+	args->fn.fs_op_with_handle(args->arg, fs, bserrno);
+	free_fs_request(req);
+}
+
+static void
+fs_conf_parse(void)
+{
+	struct spdk_conf_section *sp;
+
+	sp = spdk_conf_find_section(NULL, "Blobfs");
+	if (sp == NULL) {
+		g_fs_cache_buffer_shift = CACHE_BUFFER_SHIFT_DEFAULT;
+		return;
+	}
+
+	g_fs_cache_buffer_shift = spdk_conf_section_get_intval(sp, "CacheBufferShift");
+	if (g_fs_cache_buffer_shift <= 0) {
+		g_fs_cache_buffer_shift = CACHE_BUFFER_SHIFT_DEFAULT;
+	}
+}
+
+static struct spdk_filesystem *
+fs_alloc(struct spdk_bs_dev *dev, fs_send_request_fn send_request_fn)
+{
+	struct spdk_filesystem *fs;
+
+	fs = calloc(1, sizeof(*fs));
+	if (fs == NULL) {
+		return NULL;
+	}
+
+	fs->bdev = dev;
+	fs->send_request = send_request_fn;
+	TAILQ_INIT(&fs->files);
+
+	fs->md_target.max_ops = 512;
+	spdk_io_device_register(&fs->md_target, _spdk_fs_md_channel_create, _spdk_fs_channel_destroy,
+				sizeof(struct spdk_fs_channel), "blobfs_md");
+	fs->md_target.md_io_channel = spdk_get_io_channel(&fs->md_target);
+	fs->md_target.md_fs_channel = spdk_io_channel_get_ctx(fs->md_target.md_io_channel);
+
+	fs->sync_target.max_ops = 512;
+	spdk_io_device_register(&fs->sync_target, _spdk_fs_sync_channel_create, _spdk_fs_channel_destroy,
+				sizeof(struct spdk_fs_channel), "blobfs_sync");
+	fs->sync_target.sync_io_channel = spdk_get_io_channel(&fs->sync_target);
+	fs->sync_target.sync_fs_channel = spdk_io_channel_get_ctx(fs->sync_target.sync_io_channel);
+
+	fs->io_target.max_ops = 512;
+	spdk_io_device_register(&fs->io_target, _spdk_fs_io_channel_create, _spdk_fs_channel_destroy,
+				sizeof(struct spdk_fs_channel), "blobfs_io");
+
+	return fs;
+}
+
+static void
+__wake_caller(void *arg, int fserrno)
+{
+	struct spdk_fs_cb_args *args = arg;
+
+	args->rc = fserrno;
+	sem_post(args->sem);
+}
+
+void
+spdk_fs_init(struct spdk_bs_dev *dev, struct spdk_blobfs_opts *opt,
+	     fs_send_request_fn send_request_fn,
+	     spdk_fs_op_with_handle_complete cb_fn, void *cb_arg)
+{
+	struct spdk_filesystem *fs;
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	struct spdk_bs_opts opts = {};
+
+	fs = fs_alloc(dev, send_request_fn);
+	if (fs == NULL) {
+		cb_fn(cb_arg, NULL, -ENOMEM);
+		return;
+	}
+
+	fs_conf_parse();
+
+	req = alloc_fs_request(fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		spdk_put_io_channel(fs->md_target.md_io_channel);
+		spdk_io_device_unregister(&fs->md_target, NULL);
+		spdk_put_io_channel(fs->sync_target.sync_io_channel);
+		spdk_io_device_unregister(&fs->sync_target, NULL);
+		spdk_io_device_unregister(&fs->io_target, NULL);
+		free(fs);
+		cb_fn(cb_arg, NULL, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.fs_op_with_handle = cb_fn;
+	args->arg = cb_arg;
+	args->fs = fs;
+
+	spdk_bs_opts_init(&opts);
+	snprintf(opts.bstype.bstype, sizeof(opts.bstype.bstype), "BLOBFS");
+	if (opt) {
+		opts.cluster_sz = opt->cluster_sz;
+	}
+	spdk_bs_init(dev, &opts, init_cb, req);
+}
+
+static struct spdk_file *
+file_alloc(struct spdk_filesystem *fs)
+{
+	struct spdk_file *file;
+
+	file = calloc(1, sizeof(*file));
+	if (file == NULL) {
+		return NULL;
+	}
+
+	file->tree = calloc(1, sizeof(*file->tree));
+	if (file->tree == NULL) {
+		free(file);
+		return NULL;
+	}
+
+	file->fs = fs;
+	TAILQ_INIT(&file->open_requests);
+	TAILQ_INIT(&file->sync_requests);
+	pthread_spin_init(&file->lock, 0);
+	TAILQ_INSERT_TAIL(&fs->files, file, tailq);
+	file->priority = SPDK_FILE_PRIORITY_LOW;
+	return file;
+}
+
+static void fs_load_done(void *ctx, int bserrno);
+
+static int
+_handle_deleted_files(struct spdk_fs_request *req)
+{
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_filesystem *fs = args->fs;
+
+	if (!TAILQ_EMPTY(&args->op.fs_load.deleted_files)) {
+		struct spdk_deleted_file *deleted_file;
+
+		deleted_file = TAILQ_FIRST(&args->op.fs_load.deleted_files);
+		TAILQ_REMOVE(&args->op.fs_load.deleted_files, deleted_file, tailq);
+		spdk_bs_delete_blob(fs->bs, deleted_file->id, fs_load_done, req);
+		free(deleted_file);
+		return 0;
+	}
+
+	return 1;
+}
+
+static void
+fs_load_done(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_filesystem *fs = args->fs;
+
+	/* The filesystem has been loaded.  Now check if there are any files that
+	 *  were marked for deletion before last unload.  Do not complete the
+	 *  fs_load callback until all of them have been deleted on disk.
+	 */
+	if (_handle_deleted_files(req) == 0) {
+		/* We found a file that's been marked for deleting but not actually
+		 *  deleted yet.  This function will get called again once the delete
+		 *  operation is completed.
+		 */
+		return;
+	}
+
+	args->fn.fs_op_with_handle(args->arg, fs, 0);
+	free_fs_request(req);
+
+}
+
+static void
+iter_cb(void *ctx, struct spdk_blob *blob, int rc)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_filesystem *fs = args->fs;
+	uint64_t *length;
+	const char *name;
+	uint32_t *is_deleted;
+	size_t value_len;
+
+	if (rc < 0) {
+		args->fn.fs_op_with_handle(args->arg, fs, rc);
+		free_fs_request(req);
+		return;
+	}
+
+	rc = spdk_blob_get_xattr_value(blob, "name", (const void **)&name, &value_len);
+	if (rc < 0) {
+		args->fn.fs_op_with_handle(args->arg, fs, rc);
+		free_fs_request(req);
+		return;
+	}
+
+	rc = spdk_blob_get_xattr_value(blob, "length", (const void **)&length, &value_len);
+	if (rc < 0) {
+		args->fn.fs_op_with_handle(args->arg, fs, rc);
+		free_fs_request(req);
+		return;
+	}
+
+	assert(value_len == 8);
+
+	/* This file could be deleted last time without close it, then app crashed, so we delete it now */
+	rc = spdk_blob_get_xattr_value(blob, "is_deleted", (const void **)&is_deleted, &value_len);
+	if (rc < 0) {
+		struct spdk_file *f;
+
+		f = file_alloc(fs);
+		if (f == NULL) {
+			args->fn.fs_op_with_handle(args->arg, fs, -ENOMEM);
+			free_fs_request(req);
+			return;
+		}
+
+		f->name = strdup(name);
+		f->blobid = spdk_blob_get_id(blob);
+		f->length = *length;
+		f->length_flushed = *length;
+		f->append_pos = *length;
+		SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "added file %s length=%ju\n", f->name, f->length);
+	} else {
+		struct spdk_deleted_file *deleted_file;
+
+		deleted_file = calloc(1, sizeof(*deleted_file));
+		if (deleted_file == NULL) {
+			args->fn.fs_op_with_handle(args->arg, fs, -ENOMEM);
+			free_fs_request(req);
+			return;
+		}
+		deleted_file->id = spdk_blob_get_id(blob);
+		TAILQ_INSERT_TAIL(&args->op.fs_load.deleted_files, deleted_file, tailq);
+	}
+}
+
+static void
+load_cb(void *ctx, struct spdk_blob_store *bs, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_filesystem *fs = args->fs;
+	struct spdk_bs_type bstype;
+	static const struct spdk_bs_type blobfs_type = {"BLOBFS"};
+	static const struct spdk_bs_type zeros;
+
+	if (bserrno != 0) {
+		args->fn.fs_op_with_handle(args->arg, NULL, bserrno);
+		free_fs_request(req);
+		free(fs);
+		return;
+	}
+
+	bstype = spdk_bs_get_bstype(bs);
+
+	if (!memcmp(&bstype, &zeros, sizeof(bstype))) {
+		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "assigning bstype\n");
+		spdk_bs_set_bstype(bs, blobfs_type);
+	} else if (memcmp(&bstype, &blobfs_type, sizeof(bstype))) {
+		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "not blobfs\n");
+		SPDK_TRACEDUMP(SPDK_LOG_BLOB, "bstype", &bstype, sizeof(bstype));
+		args->fn.fs_op_with_handle(args->arg, NULL, bserrno);
+		free_fs_request(req);
+		free(fs);
+		return;
+	}
+
+	common_fs_bs_init(fs, bs);
+	fs_load_done(req, 0);
+}
+
+static void
+spdk_fs_io_device_unregister(struct spdk_filesystem *fs)
+{
+	assert(fs != NULL);
+	spdk_io_device_unregister(&fs->md_target, NULL);
+	spdk_io_device_unregister(&fs->sync_target, NULL);
+	spdk_io_device_unregister(&fs->io_target, NULL);
+	free(fs);
+}
+
+static void
+spdk_fs_free_io_channels(struct spdk_filesystem *fs)
+{
+	assert(fs != NULL);
+	spdk_fs_free_io_channel(fs->md_target.md_io_channel);
+	spdk_fs_free_io_channel(fs->sync_target.sync_io_channel);
+}
+
+void
+spdk_fs_load(struct spdk_bs_dev *dev, fs_send_request_fn send_request_fn,
+	     spdk_fs_op_with_handle_complete cb_fn, void *cb_arg)
+{
+	struct spdk_filesystem *fs;
+	struct spdk_fs_cb_args *args;
+	struct spdk_fs_request *req;
+	struct spdk_bs_opts	bs_opts;
+
+	fs = fs_alloc(dev, send_request_fn);
+	if (fs == NULL) {
+		cb_fn(cb_arg, NULL, -ENOMEM);
+		return;
+	}
+
+	fs_conf_parse();
+
+	req = alloc_fs_request(fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		spdk_fs_free_io_channels(fs);
+		spdk_fs_io_device_unregister(fs);
+		cb_fn(cb_arg, NULL, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.fs_op_with_handle = cb_fn;
+	args->arg = cb_arg;
+	args->fs = fs;
+	TAILQ_INIT(&args->op.fs_load.deleted_files);
+	spdk_bs_opts_init(&bs_opts);
+	bs_opts.iter_cb_fn = iter_cb;
+	bs_opts.iter_cb_arg = req;
+	spdk_bs_load(dev, &bs_opts, load_cb, req);
+}
+
+static void
+unload_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_filesystem *fs = args->fs;
+	struct spdk_file *file, *tmp;
+
+	TAILQ_FOREACH_SAFE(file, &fs->files, tailq, tmp) {
+		TAILQ_REMOVE(&fs->files, file, tailq);
+		cache_free_buffers(file);
+		free(file->name);
+		free(file->tree);
+		free(file);
+	}
+
+	pthread_mutex_lock(&g_cache_init_lock);
+	g_fs_count--;
+	if (g_fs_count == 0) {
+		__free_cache();
+	}
+	pthread_mutex_unlock(&g_cache_init_lock);
+
+	args->fn.fs_op(args->arg, bserrno);
+	free(req);
+
+	spdk_fs_io_device_unregister(fs);
+}
+
+void
+spdk_fs_unload(struct spdk_filesystem *fs, spdk_fs_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	/*
+	 * We must free the md_channel before unloading the blobstore, so just
+	 *  allocate this request from the general heap.
+	 */
+	req = calloc(1, sizeof(*req));
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.fs_op = cb_fn;
+	args->arg = cb_arg;
+	args->fs = fs;
+
+	spdk_fs_free_io_channels(fs);
+	spdk_bs_unload(fs->bs, unload_cb, req);
+}
+
+static struct spdk_file *
+fs_find_file(struct spdk_filesystem *fs, const char *name)
+{
+	struct spdk_file *file;
+
+	TAILQ_FOREACH(file, &fs->files, tailq) {
+		if (!strncmp(name, file->name, SPDK_FILE_NAME_MAX)) {
+			return file;
+		}
+	}
+
+	return NULL;
+}
+
+void
+spdk_fs_file_stat_async(struct spdk_filesystem *fs, const char *name,
+			spdk_file_stat_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_file_stat stat;
+	struct spdk_file *f = NULL;
+
+	if (strnlen(name, SPDK_FILE_NAME_MAX + 1) == SPDK_FILE_NAME_MAX + 1) {
+		cb_fn(cb_arg, NULL, -ENAMETOOLONG);
+		return;
+	}
+
+	f = fs_find_file(fs, name);
+	if (f != NULL) {
+		stat.blobid = f->blobid;
+		stat.size = f->append_pos >= f->length ? f->append_pos : f->length;
+		cb_fn(cb_arg, &stat, 0);
+		return;
+	}
+
+	cb_fn(cb_arg, NULL, -ENOENT);
+}
+
+static void
+__copy_stat(void *arg, struct spdk_file_stat *stat, int fserrno)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	args->rc = fserrno;
+	if (fserrno == 0) {
+		memcpy(args->arg, stat, sizeof(*stat));
+	}
+	sem_post(args->sem);
+}
+
+static void
+__file_stat(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	spdk_fs_file_stat_async(args->fs, args->op.stat.name,
+				args->fn.stat_op, req);
+}
+
+int
+spdk_fs_file_stat(struct spdk_filesystem *fs, struct spdk_io_channel *_channel,
+		  const char *name, struct spdk_file_stat *stat)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	int rc;
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	req->args.fs = fs;
+	req->args.op.stat.name = name;
+	req->args.fn.stat_op = __copy_stat;
+	req->args.arg = stat;
+	req->args.sem = &channel->sem;
+	channel->send_request(__file_stat, req);
+	sem_wait(&channel->sem);
+
+	rc = req->args.rc;
+	free_fs_request(req);
+
+	return rc;
+}
+
+static void
+fs_create_blob_close_cb(void *ctx, int bserrno)
+{
+	int rc;
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	rc = args->rc ? args->rc : bserrno;
+	args->fn.file_op(args->arg, rc);
+	free_fs_request(req);
+}
+
+static void
+fs_create_blob_resize_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *f = args->file;
+	struct spdk_blob *blob = args->op.create.blob;
+	uint64_t length = 0;
+
+	args->rc = bserrno;
+	if (bserrno) {
+		spdk_blob_close(blob, fs_create_blob_close_cb, args);
+		return;
+	}
+
+	spdk_blob_set_xattr(blob, "name", f->name, strlen(f->name) + 1);
+	spdk_blob_set_xattr(blob, "length", &length, sizeof(length));
+
+	spdk_blob_close(blob, fs_create_blob_close_cb, args);
+}
+
+static void
+fs_create_blob_open_cb(void *ctx, struct spdk_blob *blob, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	if (bserrno) {
+		args->fn.file_op(args->arg, bserrno);
+		free_fs_request(req);
+		return;
+	}
+
+	args->op.create.blob = blob;
+	spdk_blob_resize(blob, 1, fs_create_blob_resize_cb, req);
+}
+
+static void
+fs_create_blob_create_cb(void *ctx, spdk_blob_id blobid, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *f = args->file;
+
+	if (bserrno) {
+		args->fn.file_op(args->arg, bserrno);
+		free_fs_request(req);
+		return;
+	}
+
+	f->blobid = blobid;
+	spdk_bs_open_blob(f->fs->bs, blobid, fs_create_blob_open_cb, req);
+}
+
+void
+spdk_fs_create_file_async(struct spdk_filesystem *fs, const char *name,
+			  spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_file *file;
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	if (strnlen(name, SPDK_FILE_NAME_MAX + 1) == SPDK_FILE_NAME_MAX + 1) {
+		cb_fn(cb_arg, -ENAMETOOLONG);
+		return;
+	}
+
+	file = fs_find_file(fs, name);
+	if (file != NULL) {
+		cb_fn(cb_arg, -EEXIST);
+		return;
+	}
+
+	file = file_alloc(fs);
+	if (file == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	req = alloc_fs_request(fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->file = file;
+	args->fn.file_op = cb_fn;
+	args->arg = cb_arg;
+
+	file->name = strdup(name);
+	spdk_bs_create_blob(fs->bs, fs_create_blob_create_cb, args);
+}
+
+static void
+__fs_create_file_done(void *arg, int fserrno)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	args->rc = fserrno;
+	sem_post(args->sem);
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", args->op.create.name);
+}
+
+static void
+__fs_create_file(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", args->op.create.name);
+	spdk_fs_create_file_async(args->fs, args->op.create.name, __fs_create_file_done, req);
+}
+
+int
+spdk_fs_create_file(struct spdk_filesystem *fs, struct spdk_io_channel *_channel, const char *name)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	int rc;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", name);
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	args = &req->args;
+	args->fs = fs;
+	args->op.create.name = name;
+	args->sem = &channel->sem;
+	fs->send_request(__fs_create_file, req);
+	sem_wait(&channel->sem);
+	rc = args->rc;
+	free_fs_request(req);
+
+	return rc;
+}
+
+static void
+fs_open_blob_done(void *ctx, struct spdk_blob *blob, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *f = args->file;
+
+	f->blob = blob;
+	while (!TAILQ_EMPTY(&f->open_requests)) {
+		req = TAILQ_FIRST(&f->open_requests);
+		args = &req->args;
+		TAILQ_REMOVE(&f->open_requests, req, args.op.open.tailq);
+		args->fn.file_op_with_handle(args->arg, f, bserrno);
+		free_fs_request(req);
+	}
+}
+
+static void
+fs_open_blob_create_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *file = args->file;
+	struct spdk_filesystem *fs = args->fs;
+
+	if (file == NULL) {
+		/*
+		 * This is from an open with CREATE flag - the file
+		 *  is now created so look it up in the file list for this
+		 *  filesystem.
+		 */
+		file = fs_find_file(fs, args->op.open.name);
+		assert(file != NULL);
+		args->file = file;
+	}
+
+	file->ref_count++;
+	TAILQ_INSERT_TAIL(&file->open_requests, req, args.op.open.tailq);
+	if (file->ref_count == 1) {
+		assert(file->blob == NULL);
+		spdk_bs_open_blob(fs->bs, file->blobid, fs_open_blob_done, req);
+	} else if (file->blob != NULL) {
+		fs_open_blob_done(req, file->blob, 0);
+	} else {
+		/*
+		 * The blob open for this file is in progress due to a previous
+		 *  open request.  When that open completes, it will invoke the
+		 *  open callback for this request.
+		 */
+	}
+}
+
+void
+spdk_fs_open_file_async(struct spdk_filesystem *fs, const char *name, uint32_t flags,
+			spdk_file_op_with_handle_complete cb_fn, void *cb_arg)
+{
+	struct spdk_file *f = NULL;
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	if (strnlen(name, SPDK_FILE_NAME_MAX + 1) == SPDK_FILE_NAME_MAX + 1) {
+		cb_fn(cb_arg, NULL, -ENAMETOOLONG);
+		return;
+	}
+
+	f = fs_find_file(fs, name);
+	if (f == NULL && !(flags & SPDK_BLOBFS_OPEN_CREATE)) {
+		cb_fn(cb_arg, NULL, -ENOENT);
+		return;
+	}
+
+	if (f != NULL && f->is_deleted == true) {
+		cb_fn(cb_arg, NULL, -ENOENT);
+		return;
+	}
+
+	req = alloc_fs_request(fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, NULL, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.file_op_with_handle = cb_fn;
+	args->arg = cb_arg;
+	args->file = f;
+	args->fs = fs;
+	args->op.open.name = name;
+
+	if (f == NULL) {
+		spdk_fs_create_file_async(fs, name, fs_open_blob_create_cb, req);
+	} else {
+		fs_open_blob_create_cb(req, 0);
+	}
+}
+
+static void
+__fs_open_file_done(void *arg, struct spdk_file *file, int bserrno)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	args->file = file;
+	__wake_caller(args, bserrno);
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", args->op.open.name);
+}
+
+static void
+__fs_open_file(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", args->op.open.name);
+	spdk_fs_open_file_async(args->fs, args->op.open.name, args->op.open.flags,
+				__fs_open_file_done, req);
+}
+
+int
+spdk_fs_open_file(struct spdk_filesystem *fs, struct spdk_io_channel *_channel,
+		  const char *name, uint32_t flags, struct spdk_file **file)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	int rc;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", name);
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	args = &req->args;
+	args->fs = fs;
+	args->op.open.name = name;
+	args->op.open.flags = flags;
+	args->sem = &channel->sem;
+	fs->send_request(__fs_open_file, req);
+	sem_wait(&channel->sem);
+	rc = args->rc;
+	if (rc == 0) {
+		*file = args->file;
+	} else {
+		*file = NULL;
+	}
+	free_fs_request(req);
+
+	return rc;
+}
+
+static void
+fs_rename_blob_close_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	args->fn.fs_op(args->arg, bserrno);
+	free_fs_request(req);
+}
+
+static void
+fs_rename_blob_open_cb(void *ctx, struct spdk_blob *blob, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	const char *new_name = args->op.rename.new_name;
+
+	spdk_blob_set_xattr(blob, "name", new_name, strlen(new_name) + 1);
+	spdk_blob_close(blob, fs_rename_blob_close_cb, req);
+}
+
+static void
+__spdk_fs_md_rename_file(struct spdk_fs_request *req)
+{
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *f;
+
+	f = fs_find_file(args->fs, args->op.rename.old_name);
+	if (f == NULL) {
+		args->fn.fs_op(args->arg, -ENOENT);
+		free_fs_request(req);
+		return;
+	}
+
+	free(f->name);
+	f->name = strdup(args->op.rename.new_name);
+	args->file = f;
+	spdk_bs_open_blob(args->fs->bs, f->blobid, fs_rename_blob_open_cb, req);
+}
+
+static void
+fs_rename_delete_done(void *arg, int fserrno)
+{
+	__spdk_fs_md_rename_file(arg);
+}
+
+void
+spdk_fs_rename_file_async(struct spdk_filesystem *fs,
+			  const char *old_name, const char *new_name,
+			  spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_file *f;
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "old=%s new=%s\n", old_name, new_name);
+	if (strnlen(new_name, SPDK_FILE_NAME_MAX + 1) == SPDK_FILE_NAME_MAX + 1) {
+		cb_fn(cb_arg, -ENAMETOOLONG);
+		return;
+	}
+
+	req = alloc_fs_request(fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.fs_op = cb_fn;
+	args->fs = fs;
+	args->arg = cb_arg;
+	args->op.rename.old_name = old_name;
+	args->op.rename.new_name = new_name;
+
+	f = fs_find_file(fs, new_name);
+	if (f == NULL) {
+		__spdk_fs_md_rename_file(req);
+		return;
+	}
+
+	/*
+	 * The rename overwrites an existing file.  So delete the existing file, then
+	 *  do the actual rename.
+	 */
+	spdk_fs_delete_file_async(fs, new_name, fs_rename_delete_done, req);
+}
+
+static void
+__fs_rename_file_done(void *arg, int fserrno)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	__wake_caller(args, fserrno);
+}
+
+static void
+__fs_rename_file(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	spdk_fs_rename_file_async(args->fs, args->op.rename.old_name, args->op.rename.new_name,
+				  __fs_rename_file_done, req);
+}
+
+int
+spdk_fs_rename_file(struct spdk_filesystem *fs, struct spdk_io_channel *_channel,
+		    const char *old_name, const char *new_name)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	int rc;
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	args = &req->args;
+
+	args->fs = fs;
+	args->op.rename.old_name = old_name;
+	args->op.rename.new_name = new_name;
+	args->sem = &channel->sem;
+	fs->send_request(__fs_rename_file, req);
+	sem_wait(&channel->sem);
+	rc = args->rc;
+	free_fs_request(req);
+	return rc;
+}
+
+static void
+blob_delete_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	args->fn.file_op(args->arg, bserrno);
+	free_fs_request(req);
+}
+
+void
+spdk_fs_delete_file_async(struct spdk_filesystem *fs, const char *name,
+			  spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_file *f;
+	spdk_blob_id blobid;
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s\n", name);
+
+	if (strnlen(name, SPDK_FILE_NAME_MAX + 1) == SPDK_FILE_NAME_MAX + 1) {
+		cb_fn(cb_arg, -ENAMETOOLONG);
+		return;
+	}
+
+	f = fs_find_file(fs, name);
+	if (f == NULL) {
+		cb_fn(cb_arg, -ENOENT);
+		return;
+	}
+
+	req = alloc_fs_request(fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.file_op = cb_fn;
+	args->arg = cb_arg;
+
+	if (f->ref_count > 0) {
+		/* If the ref > 0, we mark the file as deleted and delete it when we close it. */
+		f->is_deleted = true;
+		spdk_blob_set_xattr(f->blob, "is_deleted", &f->is_deleted, sizeof(bool));
+		spdk_blob_sync_md(f->blob, blob_delete_cb, args);
+		return;
+	}
+
+	TAILQ_REMOVE(&fs->files, f, tailq);
+
+	cache_free_buffers(f);
+
+	blobid = f->blobid;
+
+	free(f->name);
+	free(f->tree);
+	free(f);
+
+	spdk_bs_delete_blob(fs->bs, blobid, blob_delete_cb, req);
+}
+
+static void
+__fs_delete_file_done(void *arg, int fserrno)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	__wake_caller(args, fserrno);
+}
+
+static void
+__fs_delete_file(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	spdk_fs_delete_file_async(args->fs, args->op.delete.name, __fs_delete_file_done, req);
+}
+
+int
+spdk_fs_delete_file(struct spdk_filesystem *fs, struct spdk_io_channel *_channel,
+		    const char *name)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	int rc;
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	args = &req->args;
+	args->fs = fs;
+	args->op.delete.name = name;
+	args->sem = &channel->sem;
+	fs->send_request(__fs_delete_file, req);
+	sem_wait(&channel->sem);
+	rc = args->rc;
+	free_fs_request(req);
+
+	return rc;
+}
+
+spdk_fs_iter
+spdk_fs_iter_first(struct spdk_filesystem *fs)
+{
+	struct spdk_file *f;
+
+	f = TAILQ_FIRST(&fs->files);
+	return f;
+}
+
+spdk_fs_iter
+spdk_fs_iter_next(spdk_fs_iter iter)
+{
+	struct spdk_file *f = iter;
+
+	if (f == NULL) {
+		return NULL;
+	}
+
+	f = TAILQ_NEXT(f, tailq);
+	return f;
+}
+
+const char *
+spdk_file_get_name(struct spdk_file *file)
+{
+	return file->name;
+}
+
+uint64_t
+spdk_file_get_length(struct spdk_file *file)
+{
+	assert(file != NULL);
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s length=0x%jx\n", file->name, file->length);
+	return file->length;
+}
+
+static void
+fs_truncate_complete_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	args->fn.file_op(args->arg, bserrno);
+	free_fs_request(req);
+}
+
+static void
+fs_truncate_resize_cb(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *file = args->file;
+	uint64_t *length = &args->op.truncate.length;
+
+	if (bserrno) {
+		args->fn.file_op(args->arg, bserrno);
+		free_fs_request(req);
+		return;
+	}
+
+	spdk_blob_set_xattr(file->blob, "length", length, sizeof(*length));
+
+	file->length = *length;
+	if (file->append_pos > file->length) {
+		file->append_pos = file->length;
+	}
+
+	spdk_blob_sync_md(file->blob, fs_truncate_complete_cb, args);
+}
+
+static uint64_t
+__bytes_to_clusters(uint64_t length, uint64_t cluster_sz)
+{
+	return (length + cluster_sz - 1) / cluster_sz;
+}
+
+void
+spdk_file_truncate_async(struct spdk_file *file, uint64_t length,
+			 spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_filesystem *fs;
+	size_t num_clusters;
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s old=0x%jx new=0x%jx\n", file->name, file->length, length);
+	if (length == file->length) {
+		cb_fn(cb_arg, 0);
+		return;
+	}
+
+	req = alloc_fs_request(file->fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->fn.file_op = cb_fn;
+	args->arg = cb_arg;
+	args->file = file;
+	args->op.truncate.length = length;
+	fs = file->fs;
+
+	num_clusters = __bytes_to_clusters(length, fs->bs_opts.cluster_sz);
+
+	spdk_blob_resize(file->blob, num_clusters, fs_truncate_resize_cb, req);
+}
+
+static void
+__truncate(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	spdk_file_truncate_async(args->file, args->op.truncate.length,
+				 args->fn.file_op, args);
+}
+
+int
+spdk_file_truncate(struct spdk_file *file, struct spdk_io_channel *_channel,
+		   uint64_t length)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	int rc;
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	args = &req->args;
+
+	args->file = file;
+	args->op.truncate.length = length;
+	args->fn.file_op = __wake_caller;
+	args->sem = &channel->sem;
+
+	channel->send_request(__truncate, req);
+	sem_wait(&channel->sem);
+	rc = args->rc;
+	free_fs_request(req);
+
+	return rc;
+}
+
+static void
+__rw_done(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	spdk_dma_free(args->op.rw.pin_buf);
+	args->fn.file_op(args->arg, bserrno);
+	free_fs_request(req);
+}
+
+static void
+__read_done(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	assert(req != NULL);
+	if (args->op.rw.is_read) {
+		memcpy(args->op.rw.user_buf,
+		       args->op.rw.pin_buf + (args->op.rw.offset & (args->op.rw.blocklen - 1)),
+		       args->op.rw.length);
+		__rw_done(req, 0);
+	} else {
+		memcpy(args->op.rw.pin_buf + (args->op.rw.offset & (args->op.rw.blocklen - 1)),
+		       args->op.rw.user_buf,
+		       args->op.rw.length);
+		spdk_blob_io_write(args->file->blob, args->op.rw.channel,
+				   args->op.rw.pin_buf,
+				   args->op.rw.start_lba, args->op.rw.num_lba,
+				   __rw_done, req);
+	}
+}
+
+static void
+__do_blob_read(void *ctx, int fserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	if (fserrno) {
+		__rw_done(req, fserrno);
+		return;
+	}
+	spdk_blob_io_read(args->file->blob, args->op.rw.channel,
+			  args->op.rw.pin_buf,
+			  args->op.rw.start_lba, args->op.rw.num_lba,
+			  __read_done, req);
+}
+
+static void
+__get_page_parameters(struct spdk_file *file, uint64_t offset, uint64_t length,
+		      uint64_t *start_lba, uint32_t *lba_size, uint64_t *num_lba)
+{
+	uint64_t end_lba;
+
+	*lba_size = spdk_bs_get_io_unit_size(file->fs->bs);
+	*start_lba = offset / *lba_size;
+	end_lba = (offset + length - 1) / *lba_size;
+	*num_lba = (end_lba - *start_lba + 1);
+}
+
+static void
+__readwrite(struct spdk_file *file, struct spdk_io_channel *_channel,
+	    void *payload, uint64_t offset, uint64_t length,
+	    spdk_file_op_complete cb_fn, void *cb_arg, int is_read)
+{
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	uint64_t start_lba, num_lba, pin_buf_length;
+	uint32_t lba_size;
+
+	if (is_read && offset + length > file->length) {
+		cb_fn(cb_arg, -EINVAL);
+		return;
+	}
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	__get_page_parameters(file, offset, length, &start_lba, &lba_size, &num_lba);
+
+	args = &req->args;
+	args->fn.file_op = cb_fn;
+	args->arg = cb_arg;
+	args->file = file;
+	args->op.rw.channel = channel->bs_channel;
+	args->op.rw.user_buf = payload;
+	args->op.rw.is_read = is_read;
+	args->op.rw.offset = offset;
+	args->op.rw.length = length;
+	args->op.rw.blocklen = lba_size;
+
+	pin_buf_length = num_lba * lba_size;
+	args->op.rw.pin_buf = spdk_dma_malloc(pin_buf_length, lba_size, NULL);
+	if (args->op.rw.pin_buf == NULL) {
+		SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "Failed to allocate buf for: file=%s offset=%jx length=%jx\n",
+			      file->name, offset, length);
+		free_fs_request(req);
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args->op.rw.start_lba = start_lba;
+	args->op.rw.num_lba = num_lba;
+
+	if (!is_read && file->length < offset + length) {
+		spdk_file_truncate_async(file, offset + length, __do_blob_read, req);
+	} else {
+		__do_blob_read(req, 0);
+	}
+}
+
+void
+spdk_file_write_async(struct spdk_file *file, struct spdk_io_channel *channel,
+		      void *payload, uint64_t offset, uint64_t length,
+		      spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	__readwrite(file, channel, payload, offset, length, cb_fn, cb_arg, 0);
+}
+
+void
+spdk_file_read_async(struct spdk_file *file, struct spdk_io_channel *channel,
+		     void *payload, uint64_t offset, uint64_t length,
+		     spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "file=%s offset=%jx length=%jx\n",
+		      file->name, offset, length);
+	__readwrite(file, channel, payload, offset, length, cb_fn, cb_arg, 1);
+}
+
+struct spdk_io_channel *
+spdk_fs_alloc_io_channel(struct spdk_filesystem *fs)
+{
+	struct spdk_io_channel *io_channel;
+	struct spdk_fs_channel *fs_channel;
+
+	io_channel = spdk_get_io_channel(&fs->io_target);
+	fs_channel = spdk_io_channel_get_ctx(io_channel);
+	fs_channel->bs_channel = spdk_bs_alloc_io_channel(fs->bs);
+	fs_channel->send_request = __send_request_direct;
+
+	return io_channel;
+}
+
+struct spdk_io_channel *
+spdk_fs_alloc_io_channel_sync(struct spdk_filesystem *fs)
+{
+	struct spdk_io_channel *io_channel;
+	struct spdk_fs_channel *fs_channel;
+
+	io_channel = spdk_get_io_channel(&fs->io_target);
+	fs_channel = spdk_io_channel_get_ctx(io_channel);
+	fs_channel->send_request = fs->send_request;
+	fs_channel->sync = 1;
+	pthread_spin_init(&fs_channel->lock, 0);
+
+	return io_channel;
+}
+
+void
+spdk_fs_free_io_channel(struct spdk_io_channel *channel)
+{
+	spdk_put_io_channel(channel);
+}
+
+void
+spdk_fs_set_cache_size(uint64_t size_in_mb)
+{
+	g_fs_cache_size = size_in_mb * 1024 * 1024;
+}
+
+uint64_t
+spdk_fs_get_cache_size(void)
+{
+	return g_fs_cache_size / (1024 * 1024);
+}
+
+static void __file_flush(void *_args);
+
+static void *
+alloc_cache_memory_buffer(struct spdk_file *context)
+{
+	struct spdk_file *file;
+	void *buf;
+
+	buf = spdk_mempool_get(g_cache_pool);
+	if (buf != NULL) {
+		return buf;
+	}
+
+	pthread_spin_lock(&g_caches_lock);
+	TAILQ_FOREACH(file, &g_caches, cache_tailq) {
+		if (!file->open_for_writing &&
+		    file->priority == SPDK_FILE_PRIORITY_LOW &&
+		    file != context) {
+			break;
+		}
+	}
+	pthread_spin_unlock(&g_caches_lock);
+	if (file != NULL) {
+		cache_free_buffers(file);
+		buf = spdk_mempool_get(g_cache_pool);
+		if (buf != NULL) {
+			return buf;
+		}
+	}
+
+	pthread_spin_lock(&g_caches_lock);
+	TAILQ_FOREACH(file, &g_caches, cache_tailq) {
+		if (!file->open_for_writing && file != context) {
+			break;
+		}
+	}
+	pthread_spin_unlock(&g_caches_lock);
+	if (file != NULL) {
+		cache_free_buffers(file);
+		buf = spdk_mempool_get(g_cache_pool);
+		if (buf != NULL) {
+			return buf;
+		}
+	}
+
+	pthread_spin_lock(&g_caches_lock);
+	TAILQ_FOREACH(file, &g_caches, cache_tailq) {
+		if (file != context) {
+			break;
+		}
+	}
+	pthread_spin_unlock(&g_caches_lock);
+	if (file != NULL) {
+		cache_free_buffers(file);
+		buf = spdk_mempool_get(g_cache_pool);
+		if (buf != NULL) {
+			return buf;
+		}
+	}
+
+	return NULL;
+}
+
+static struct cache_buffer *
+cache_insert_buffer(struct spdk_file *file, uint64_t offset)
+{
+	struct cache_buffer *buf;
+	int count = 0;
+
+	buf = calloc(1, sizeof(*buf));
+	if (buf == NULL) {
+		SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "calloc failed\n");
+		return NULL;
+	}
+
+	buf->buf = alloc_cache_memory_buffer(file);
+	while (buf->buf == NULL) {
+		/*
+		 * TODO: alloc_cache_memory_buffer() should eventually free
+		 *  some buffers.  Need a more sophisticated check here, instead
+		 *  of just bailing if 100 tries does not result in getting a
+		 *  free buffer.  This will involve using the sync channel's
+		 *  semaphore to block until a buffer becomes available.
+		 */
+		if (count++ == 100) {
+			SPDK_ERRLOG("could not allocate cache buffer\n");
+			assert(false);
+			free(buf);
+			return NULL;
+		}
+		buf->buf = alloc_cache_memory_buffer(file);
+	}
+
+	buf->buf_size = CACHE_BUFFER_SIZE;
+	buf->offset = offset;
+
+	pthread_spin_lock(&g_caches_lock);
+	if (file->tree->present_mask == 0) {
+		TAILQ_INSERT_TAIL(&g_caches, file, cache_tailq);
+	}
+	file->tree = spdk_tree_insert_buffer(file->tree, buf);
+	pthread_spin_unlock(&g_caches_lock);
+
+	return buf;
+}
+
+static struct cache_buffer *
+cache_append_buffer(struct spdk_file *file)
+{
+	struct cache_buffer *last;
+
+	assert(file->last == NULL || file->last->bytes_filled == file->last->buf_size);
+	assert((file->append_pos % CACHE_BUFFER_SIZE) == 0);
+
+	last = cache_insert_buffer(file, file->append_pos);
+	if (last == NULL) {
+		SPDK_DEBUGLOG(SPDK_LOG_BLOBFS, "cache_insert_buffer failed\n");
+		return NULL;
+	}
+
+	file->last = last;
+
+	return last;
+}
+
+static void __check_sync_reqs(struct spdk_file *file);
+
+static void
+__file_cache_finish_sync(void *ctx, int bserrno)
+{
+	struct spdk_file *file = ctx;
+	struct spdk_fs_request *sync_req;
+	struct spdk_fs_cb_args *sync_args;
+
+	pthread_spin_lock(&file->lock);
+	sync_req = TAILQ_FIRST(&file->sync_requests);
+	sync_args = &sync_req->args;
+	assert(sync_args->op.sync.offset <= file->length_flushed);
+	BLOBFS_TRACE(file, "sync done offset=%jx\n", sync_args->op.sync.offset);
+	TAILQ_REMOVE(&file->sync_requests, sync_req, args.op.sync.tailq);
+	pthread_spin_unlock(&file->lock);
+
+	sync_args->fn.file_op(sync_args->arg, bserrno);
+	__check_sync_reqs(file);
+
+	pthread_spin_lock(&file->lock);
+	free_fs_request(sync_req);
+	pthread_spin_unlock(&file->lock);
+}
+
+static void
+__free_args(struct spdk_fs_cb_args *args)
+{
+	struct spdk_fs_request *req;
+
+	if (!args->from_request) {
+		free(args);
+	} else {
+		/* Depends on args being at the start of the spdk_fs_request structure. */
+		req = (struct spdk_fs_request *)args;
+		free_fs_request(req);
+	}
+}
+
+static void
+__check_sync_reqs(struct spdk_file *file)
+{
+	struct spdk_fs_request *sync_req;
+
+	pthread_spin_lock(&file->lock);
+
+	TAILQ_FOREACH(sync_req, &file->sync_requests, args.op.sync.tailq) {
+		if (sync_req->args.op.sync.offset <= file->length_flushed) {
+			break;
+		}
+	}
+
+	if (sync_req != NULL && !sync_req->args.op.sync.xattr_in_progress) {
+		BLOBFS_TRACE(file, "set xattr length 0x%jx\n", file->length_flushed);
+		sync_req->args.op.sync.xattr_in_progress = true;
+		spdk_blob_set_xattr(file->blob, "length", &file->length_flushed,
+				    sizeof(file->length_flushed));
+
+		pthread_spin_unlock(&file->lock);
+		spdk_blob_sync_md(file->blob, __file_cache_finish_sync, file);
+	} else {
+		pthread_spin_unlock(&file->lock);
+	}
+}
+
+static void
+__file_flush_done(void *arg, int bserrno)
+{
+	struct spdk_fs_cb_args *args = arg;
+	struct spdk_file *file = args->file;
+	struct cache_buffer *next = args->op.flush.cache_buffer;
+
+	BLOBFS_TRACE(file, "length=%jx\n", args->op.flush.length);
+
+	pthread_spin_lock(&file->lock);
+	next->in_progress = false;
+	next->bytes_flushed += args->op.flush.length;
+	file->length_flushed += args->op.flush.length;
+	if (file->length_flushed > file->length) {
+		file->length = file->length_flushed;
+	}
+	if (next->bytes_flushed == next->buf_size) {
+		BLOBFS_TRACE(file, "write buffer fully flushed 0x%jx\n", file->length_flushed);
+		next = spdk_tree_find_buffer(file->tree, file->length_flushed);
+	}
+
+	/*
+	 * Assert that there is no cached data that extends past the end of the underlying
+	 *  blob.
+	 */
+	assert(next == NULL || next->offset < __file_get_blob_size(file) ||
+	       next->bytes_filled == 0);
+
+	pthread_spin_unlock(&file->lock);
+
+	__check_sync_reqs(file);
+
+	__file_flush(args);
+}
+
+static void
+__file_flush(void *_args)
+{
+	struct spdk_fs_cb_args *args = _args;
+	struct spdk_file *file = args->file;
+	struct cache_buffer *next;
+	uint64_t offset, length, start_lba, num_lba;
+	uint32_t lba_size;
+
+	pthread_spin_lock(&file->lock);
+	next = spdk_tree_find_buffer(file->tree, file->length_flushed);
+	if (next == NULL || next->in_progress) {
+		/*
+		 * There is either no data to flush, or a flush I/O is already in
+		 *  progress.  So return immediately - if a flush I/O is in
+		 *  progress we will flush more data after that is completed.
+		 */
+		__free_args(args);
+		if (next == NULL) {
+			/*
+			 * For cases where a file's cache was evicted, and then the
+			 *  file was later appended, we will write the data directly
+			 *  to disk and bypass cache.  So just update length_flushed
+			 *  here to reflect that all data was already written to disk.
+			 */
+			file->length_flushed = file->append_pos;
+		}
+		pthread_spin_unlock(&file->lock);
+		if (next == NULL) {
+			/*
+			 * There is no data to flush, but we still need to check for any
+			 *  outstanding sync requests to make sure metadata gets updated.
+			 */
+			__check_sync_reqs(file);
+		}
+		return;
+	}
+
+	offset = next->offset + next->bytes_flushed;
+	length = next->bytes_filled - next->bytes_flushed;
+	if (length == 0) {
+		__free_args(args);
+		pthread_spin_unlock(&file->lock);
+		return;
+	}
+	args->op.flush.length = length;
+	args->op.flush.cache_buffer = next;
+
+	__get_page_parameters(file, offset, length, &start_lba, &lba_size, &num_lba);
+
+	next->in_progress = true;
+	BLOBFS_TRACE(file, "offset=%jx length=%jx page start=%jx num=%jx\n",
+		     offset, length, start_lba, num_lba);
+	pthread_spin_unlock(&file->lock);
+	spdk_blob_io_write(file->blob, file->fs->sync_target.sync_fs_channel->bs_channel,
+			   next->buf + (start_lba * lba_size) - next->offset,
+			   start_lba, num_lba, __file_flush_done, args);
+}
+
+static void
+__file_extend_done(void *arg, int bserrno)
+{
+	struct spdk_fs_cb_args *args = arg;
+
+	__wake_caller(args, bserrno);
+}
+
+static void
+__file_extend_resize_cb(void *_args, int bserrno)
+{
+	struct spdk_fs_cb_args *args = _args;
+	struct spdk_file *file = args->file;
+
+	if (bserrno) {
+		__wake_caller(args, bserrno);
+		return;
+	}
+
+	spdk_blob_sync_md(file->blob, __file_extend_done, args);
+}
+
+static void
+__file_extend_blob(void *_args)
+{
+	struct spdk_fs_cb_args *args = _args;
+	struct spdk_file *file = args->file;
+
+	spdk_blob_resize(file->blob, args->op.resize.num_clusters, __file_extend_resize_cb, args);
+}
+
+static void
+__rw_from_file_done(void *arg, int bserrno)
+{
+	struct spdk_fs_cb_args *args = arg;
+
+	__wake_caller(args, bserrno);
+	__free_args(args);
+}
+
+static void
+__rw_from_file(void *_args)
+{
+	struct spdk_fs_cb_args *args = _args;
+	struct spdk_file *file = args->file;
+
+	if (args->op.rw.is_read) {
+		spdk_file_read_async(file, file->fs->sync_target.sync_io_channel, args->op.rw.user_buf,
+				     args->op.rw.offset, args->op.rw.length,
+				     __rw_from_file_done, args);
+	} else {
+		spdk_file_write_async(file, file->fs->sync_target.sync_io_channel, args->op.rw.user_buf,
+				      args->op.rw.offset, args->op.rw.length,
+				      __rw_from_file_done, args);
+	}
+}
+
+static int
+__send_rw_from_file(struct spdk_file *file, sem_t *sem, void *payload,
+		    uint64_t offset, uint64_t length, bool is_read)
+{
+	struct spdk_fs_cb_args *args;
+
+	args = calloc(1, sizeof(*args));
+	if (args == NULL) {
+		sem_post(sem);
+		return -ENOMEM;
+	}
+
+	args->file = file;
+	args->sem = sem;
+	args->op.rw.user_buf = payload;
+	args->op.rw.offset = offset;
+	args->op.rw.length = length;
+	args->op.rw.is_read = is_read;
+	file->fs->send_request(__rw_from_file, args);
+	return 0;
+}
+
+int
+spdk_file_write(struct spdk_file *file, struct spdk_io_channel *_channel,
+		void *payload, uint64_t offset, uint64_t length)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_cb_args *args;
+	uint64_t rem_length, copy, blob_size, cluster_sz;
+	uint32_t cache_buffers_filled = 0;
+	uint8_t *cur_payload;
+	struct cache_buffer *last;
+
+	BLOBFS_TRACE_RW(file, "offset=%jx length=%jx\n", offset, length);
+
+	if (length == 0) {
+		return 0;
+	}
+
+	if (offset != file->append_pos) {
+		BLOBFS_TRACE(file, " error offset=%jx append_pos=%jx\n", offset, file->append_pos);
+		return -EINVAL;
+	}
+
+	pthread_spin_lock(&file->lock);
+	file->open_for_writing = true;
+
+	if (file->last == NULL) {
+		if (file->append_pos % CACHE_BUFFER_SIZE == 0) {
+			cache_append_buffer(file);
+		} else {
+			int rc;
+
+			file->append_pos += length;
+			pthread_spin_unlock(&file->lock);
+			rc = __send_rw_from_file(file, &channel->sem, payload,
+						 offset, length, false);
+			sem_wait(&channel->sem);
+			return rc;
+		}
+	}
+
+	blob_size = __file_get_blob_size(file);
+
+	if ((offset + length) > blob_size) {
+		struct spdk_fs_cb_args extend_args = {};
+
+		cluster_sz = file->fs->bs_opts.cluster_sz;
+		extend_args.sem = &channel->sem;
+		extend_args.op.resize.num_clusters = __bytes_to_clusters((offset + length), cluster_sz);
+		extend_args.file = file;
+		BLOBFS_TRACE(file, "start resize to %u clusters\n", extend_args.op.resize.num_clusters);
+		pthread_spin_unlock(&file->lock);
+		file->fs->send_request(__file_extend_blob, &extend_args);
+		sem_wait(&channel->sem);
+		if (extend_args.rc) {
+			return extend_args.rc;
+		}
+	}
+
+	last = file->last;
+	rem_length = length;
+	cur_payload = payload;
+	while (rem_length > 0) {
+		copy = last->buf_size - last->bytes_filled;
+		if (copy > rem_length) {
+			copy = rem_length;
+		}
+		BLOBFS_TRACE_RW(file, "  fill offset=%jx length=%jx\n", file->append_pos, copy);
+		memcpy(&last->buf[last->bytes_filled], cur_payload, copy);
+		file->append_pos += copy;
+		if (file->length < file->append_pos) {
+			file->length = file->append_pos;
+		}
+		cur_payload += copy;
+		last->bytes_filled += copy;
+		rem_length -= copy;
+		if (last->bytes_filled == last->buf_size) {
+			cache_buffers_filled++;
+			last = cache_append_buffer(file);
+			if (last == NULL) {
+				BLOBFS_TRACE(file, "nomem\n");
+				pthread_spin_unlock(&file->lock);
+				return -ENOMEM;
+			}
+		}
+	}
+
+	pthread_spin_unlock(&file->lock);
+
+	if (cache_buffers_filled == 0) {
+		return 0;
+	}
+
+	args = calloc(1, sizeof(*args));
+	if (args == NULL) {
+		return -ENOMEM;
+	}
+
+	args->file = file;
+	file->fs->send_request(__file_flush, args);
+	return 0;
+}
+
+static void
+__readahead_done(void *arg, int bserrno)
+{
+	struct spdk_fs_cb_args *args = arg;
+	struct cache_buffer *cache_buffer = args->op.readahead.cache_buffer;
+	struct spdk_file *file = args->file;
+
+	BLOBFS_TRACE(file, "offset=%jx\n", cache_buffer->offset);
+
+	pthread_spin_lock(&file->lock);
+	cache_buffer->bytes_filled = args->op.readahead.length;
+	cache_buffer->bytes_flushed = args->op.readahead.length;
+	cache_buffer->in_progress = false;
+	pthread_spin_unlock(&file->lock);
+
+	__free_args(args);
+}
+
+static void
+__readahead(void *_args)
+{
+	struct spdk_fs_cb_args *args = _args;
+	struct spdk_file *file = args->file;
+	uint64_t offset, length, start_lba, num_lba;
+	uint32_t lba_size;
+
+	offset = args->op.readahead.offset;
+	length = args->op.readahead.length;
+	assert(length > 0);
+
+	__get_page_parameters(file, offset, length, &start_lba, &lba_size, &num_lba);
+
+	BLOBFS_TRACE(file, "offset=%jx length=%jx page start=%jx num=%jx\n",
+		     offset, length, start_lba, num_lba);
+	spdk_blob_io_read(file->blob, file->fs->sync_target.sync_fs_channel->bs_channel,
+			  args->op.readahead.cache_buffer->buf,
+			  start_lba, num_lba, __readahead_done, args);
+}
+
+static uint64_t
+__next_cache_buffer_offset(uint64_t offset)
+{
+	return (offset + CACHE_BUFFER_SIZE) & ~(CACHE_TREE_LEVEL_MASK(0));
+}
+
+static void
+check_readahead(struct spdk_file *file, uint64_t offset)
+{
+	struct spdk_fs_cb_args *args;
+
+	offset = __next_cache_buffer_offset(offset);
+	if (spdk_tree_find_buffer(file->tree, offset) != NULL || file->length <= offset) {
+		return;
+	}
+
+	args = calloc(1, sizeof(*args));
+	if (args == NULL) {
+		return;
+	}
+
+	BLOBFS_TRACE(file, "offset=%jx\n", offset);
+
+	args->file = file;
+	args->op.readahead.offset = offset;
+	args->op.readahead.cache_buffer = cache_insert_buffer(file, offset);
+	if (!args->op.readahead.cache_buffer) {
+		BLOBFS_TRACE(file, "Cannot allocate buf for offset=%jx\n", offset);
+		free(args);
+		return;
+	}
+
+	args->op.readahead.cache_buffer->in_progress = true;
+	if (file->length < (offset + CACHE_BUFFER_SIZE)) {
+		args->op.readahead.length = file->length & (CACHE_BUFFER_SIZE - 1);
+	} else {
+		args->op.readahead.length = CACHE_BUFFER_SIZE;
+	}
+	file->fs->send_request(__readahead, args);
+}
+
+static int
+__file_read(struct spdk_file *file, void *payload, uint64_t offset, uint64_t length, sem_t *sem)
+{
+	struct cache_buffer *buf;
+	int rc;
+
+	buf = spdk_tree_find_filled_buffer(file->tree, offset);
+	if (buf == NULL) {
+		pthread_spin_unlock(&file->lock);
+		rc = __send_rw_from_file(file, sem, payload, offset, length, true);
+		pthread_spin_lock(&file->lock);
+		return rc;
+	}
+
+	if ((offset + length) > (buf->offset + buf->bytes_filled)) {
+		length = buf->offset + buf->bytes_filled - offset;
+	}
+	BLOBFS_TRACE(file, "read %p offset=%ju length=%ju\n", payload, offset, length);
+	memcpy(payload, &buf->buf[offset - buf->offset], length);
+	if ((offset + length) % CACHE_BUFFER_SIZE == 0) {
+		pthread_spin_lock(&g_caches_lock);
+		spdk_tree_remove_buffer(file->tree, buf);
+		if (file->tree->present_mask == 0) {
+			TAILQ_REMOVE(&g_caches, file, cache_tailq);
+		}
+		pthread_spin_unlock(&g_caches_lock);
+	}
+
+	sem_post(sem);
+	return 0;
+}
+
+int64_t
+spdk_file_read(struct spdk_file *file, struct spdk_io_channel *_channel,
+	       void *payload, uint64_t offset, uint64_t length)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	uint64_t final_offset, final_length;
+	uint32_t sub_reads = 0;
+	int rc = 0;
+
+	pthread_spin_lock(&file->lock);
+
+	BLOBFS_TRACE_RW(file, "offset=%ju length=%ju\n", offset, length);
+
+	file->open_for_writing = false;
+
+	if (length == 0 || offset >= file->append_pos) {
+		pthread_spin_unlock(&file->lock);
+		return 0;
+	}
+
+	if (offset + length > file->append_pos) {
+		length = file->append_pos - offset;
+	}
+
+	if (offset != file->next_seq_offset) {
+		file->seq_byte_count = 0;
+	}
+	file->seq_byte_count += length;
+	file->next_seq_offset = offset + length;
+	if (file->seq_byte_count >= CACHE_READAHEAD_THRESHOLD) {
+		check_readahead(file, offset);
+		check_readahead(file, offset + CACHE_BUFFER_SIZE);
+	}
+
+	final_length = 0;
+	final_offset = offset + length;
+	while (offset < final_offset) {
+		length = NEXT_CACHE_BUFFER_OFFSET(offset) - offset;
+		if (length > (final_offset - offset)) {
+			length = final_offset - offset;
+		}
+		rc = __file_read(file, payload, offset, length, &channel->sem);
+		if (rc == 0) {
+			final_length += length;
+		} else {
+			break;
+		}
+		payload += length;
+		offset += length;
+		sub_reads++;
+	}
+	pthread_spin_unlock(&file->lock);
+	while (sub_reads-- > 0) {
+		sem_wait(&channel->sem);
+	}
+	if (rc == 0) {
+		return final_length;
+	} else {
+		return rc;
+	}
+}
+
+static void
+_file_sync(struct spdk_file *file, struct spdk_fs_channel *channel,
+	   spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_fs_request *sync_req;
+	struct spdk_fs_request *flush_req;
+	struct spdk_fs_cb_args *sync_args;
+	struct spdk_fs_cb_args *flush_args;
+
+	BLOBFS_TRACE(file, "offset=%jx\n", file->append_pos);
+
+	pthread_spin_lock(&file->lock);
+	if (file->append_pos <= file->length_flushed) {
+		BLOBFS_TRACE(file, "done - no data to flush\n");
+		pthread_spin_unlock(&file->lock);
+		cb_fn(cb_arg, 0);
+		return;
+	}
+
+	sync_req = alloc_fs_request(channel);
+	if (!sync_req) {
+		pthread_spin_unlock(&file->lock);
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+	sync_args = &sync_req->args;
+
+	flush_req = alloc_fs_request(channel);
+	if (!flush_req) {
+		pthread_spin_unlock(&file->lock);
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+	flush_args = &flush_req->args;
+
+	sync_args->file = file;
+	sync_args->fn.file_op = cb_fn;
+	sync_args->arg = cb_arg;
+	sync_args->op.sync.offset = file->append_pos;
+	sync_args->op.sync.xattr_in_progress = false;
+	TAILQ_INSERT_TAIL(&file->sync_requests, sync_req, args.op.sync.tailq);
+	pthread_spin_unlock(&file->lock);
+
+	flush_args->file = file;
+	channel->send_request(__file_flush, flush_args);
+}
+
+int
+spdk_file_sync(struct spdk_file *file, struct spdk_io_channel *_channel)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_cb_args args = {};
+
+	args.sem = &channel->sem;
+	_file_sync(file, channel, __wake_caller, &args);
+	sem_wait(&channel->sem);
+
+	return args.rc;
+}
+
+void
+spdk_file_sync_async(struct spdk_file *file, struct spdk_io_channel *_channel,
+		     spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+
+	_file_sync(file, channel, cb_fn, cb_arg);
+}
+
+void
+spdk_file_set_priority(struct spdk_file *file, uint32_t priority)
+{
+	BLOBFS_TRACE(file, "priority=%u\n", priority);
+	file->priority = priority;
+
+}
+
+/*
+ * Close routines
+ */
+
+static void
+__file_close_async_done(void *ctx, int bserrno)
+{
+	struct spdk_fs_request *req = ctx;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *file = args->file;
+
+	if (file->is_deleted) {
+		spdk_fs_delete_file_async(file->fs, file->name, blob_delete_cb, ctx);
+		return;
+	}
+
+	args->fn.file_op(args->arg, bserrno);
+	free_fs_request(req);
+}
+
+static void
+__file_close_async(struct spdk_file *file, struct spdk_fs_request *req)
+{
+	struct spdk_blob *blob;
+
+	pthread_spin_lock(&file->lock);
+	if (file->ref_count == 0) {
+		pthread_spin_unlock(&file->lock);
+		__file_close_async_done(req, -EBADF);
+		return;
+	}
+
+	file->ref_count--;
+	if (file->ref_count > 0) {
+		pthread_spin_unlock(&file->lock);
+		req->args.fn.file_op(req->args.arg, 0);
+		free_fs_request(req);
+		return;
+	}
+
+	pthread_spin_unlock(&file->lock);
+
+	blob = file->blob;
+	file->blob = NULL;
+	spdk_blob_close(blob, __file_close_async_done, req);
+}
+
+static void
+__file_close_async__sync_done(void *arg, int fserrno)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+
+	__file_close_async(args->file, req);
+}
+
+void
+spdk_file_close_async(struct spdk_file *file, spdk_file_op_complete cb_fn, void *cb_arg)
+{
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	req = alloc_fs_request(file->fs->md_target.md_fs_channel);
+	if (req == NULL) {
+		cb_fn(cb_arg, -ENOMEM);
+		return;
+	}
+
+	args = &req->args;
+	args->file = file;
+	args->fn.file_op = cb_fn;
+	args->arg = cb_arg;
+
+	spdk_file_sync_async(file, file->fs->md_target.md_io_channel, __file_close_async__sync_done, req);
+}
+
+static void
+__file_close(void *arg)
+{
+	struct spdk_fs_request *req = arg;
+	struct spdk_fs_cb_args *args = &req->args;
+	struct spdk_file *file = args->file;
+
+	__file_close_async(file, req);
+}
+
+int
+spdk_file_close(struct spdk_file *file, struct spdk_io_channel *_channel)
+{
+	struct spdk_fs_channel *channel = spdk_io_channel_get_ctx(_channel);
+	struct spdk_fs_request *req;
+	struct spdk_fs_cb_args *args;
+
+	req = alloc_fs_request(channel);
+	if (req == NULL) {
+		return -ENOMEM;
+	}
+
+	args = &req->args;
+
+	spdk_file_sync(file, _channel);
+	BLOBFS_TRACE(file, "name=%s\n", file->name);
+	args->file = file;
+	args->sem = &channel->sem;
+	args->fn.file_op = __wake_caller;
+	args->arg = req;
+	channel->send_request(__file_close, req);
+	sem_wait(&channel->sem);
+
+	return args->rc;
+}
+
+int
+spdk_file_get_id(struct spdk_file *file, void *id, size_t size)
+{
+	if (size < sizeof(spdk_blob_id)) {
+		return -EINVAL;
+	}
+
+	memcpy(id, &file->blobid, sizeof(spdk_blob_id));
+
+	return sizeof(spdk_blob_id);
+}
+
+static void
+cache_free_buffers(struct spdk_file *file)
+{
+	BLOBFS_TRACE(file, "free=%s\n", file->name);
+	pthread_spin_lock(&file->lock);
+	pthread_spin_lock(&g_caches_lock);
+	if (file->tree->present_mask == 0) {
+		pthread_spin_unlock(&g_caches_lock);
+		pthread_spin_unlock(&file->lock);
+		return;
+	}
+	spdk_tree_free_buffers(file->tree);
+
+	TAILQ_REMOVE(&g_caches, file, cache_tailq);
+	/* If not freed, put it in the end of the queue */
+	if (file->tree->present_mask != 0) {
+		TAILQ_INSERT_TAIL(&g_caches, file, cache_tailq);
+	}
+	file->last = NULL;
+	pthread_spin_unlock(&g_caches_lock);
+	pthread_spin_unlock(&file->lock);
+}
+
+SPDK_LOG_REGISTER_COMPONENT("blobfs", SPDK_LOG_BLOBFS)
+SPDK_LOG_REGISTER_COMPONENT("blobfs_rw", SPDK_LOG_BLOBFS_RW)