diff options
Diffstat (limited to 'src/spdk/module/bdev/delay/vbdev_delay.c')
| -rw-r--r-- | src/spdk/module/bdev/delay/vbdev_delay.c | 851 |
1 files changed, 851 insertions, 0 deletions
diff --git a/src/spdk/module/bdev/delay/vbdev_delay.c b/src/spdk/module/bdev/delay/vbdev_delay.c new file mode 100644 index 000000000..b4ea1b413 --- /dev/null +++ b/src/spdk/module/bdev/delay/vbdev_delay.c @@ -0,0 +1,851 @@ +/*- + * 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 "vbdev_delay.h" +#include "spdk/rpc.h" +#include "spdk/env.h" +#include "spdk/conf.h" +#include "spdk/endian.h" +#include "spdk/string.h" +#include "spdk/thread.h" +#include "spdk/util.h" + +#include "spdk/bdev_module.h" +#include "spdk_internal/log.h" + + +static int vbdev_delay_init(void); +static int vbdev_delay_get_ctx_size(void); +static void vbdev_delay_examine(struct spdk_bdev *bdev); +static void vbdev_delay_finish(void); +static int vbdev_delay_config_json(struct spdk_json_write_ctx *w); + +static struct spdk_bdev_module delay_if = { + .name = "delay", + .module_init = vbdev_delay_init, + .config_text = NULL, + .get_ctx_size = vbdev_delay_get_ctx_size, + .examine_config = vbdev_delay_examine, + .module_fini = vbdev_delay_finish, + .config_json = vbdev_delay_config_json +}; + +SPDK_BDEV_MODULE_REGISTER(delay, &delay_if) + +/* Associative list to be used in examine */ +struct bdev_association { + char *vbdev_name; + char *bdev_name; + uint64_t avg_read_latency; + uint64_t p99_read_latency; + uint64_t avg_write_latency; + uint64_t p99_write_latency; + TAILQ_ENTRY(bdev_association) link; +}; +static TAILQ_HEAD(, bdev_association) g_bdev_associations = TAILQ_HEAD_INITIALIZER( + g_bdev_associations); + +/* List of virtual bdevs and associated info for each. */ +struct vbdev_delay { + struct spdk_bdev *base_bdev; /* the thing we're attaching to */ + struct spdk_bdev_desc *base_desc; /* its descriptor we get from open */ + struct spdk_bdev delay_bdev; /* the delay virtual bdev */ + uint64_t average_read_latency_ticks; /* the average read delay */ + uint64_t p99_read_latency_ticks; /* the p99 read delay */ + uint64_t average_write_latency_ticks; /* the average write delay */ + uint64_t p99_write_latency_ticks; /* the p99 write delay */ + TAILQ_ENTRY(vbdev_delay) link; + struct spdk_thread *thread; /* thread where base device is opened */ +}; +static TAILQ_HEAD(, vbdev_delay) g_delay_nodes = TAILQ_HEAD_INITIALIZER(g_delay_nodes); + +struct delay_bdev_io { + int status; + + uint64_t completion_tick; + + enum delay_io_type type; + + struct spdk_io_channel *ch; + + struct spdk_bdev_io_wait_entry bdev_io_wait; + + STAILQ_ENTRY(delay_bdev_io) link; +}; + +struct delay_io_channel { + struct spdk_io_channel *base_ch; /* IO channel of base device */ + STAILQ_HEAD(, delay_bdev_io) avg_read_io; + STAILQ_HEAD(, delay_bdev_io) p99_read_io; + STAILQ_HEAD(, delay_bdev_io) avg_write_io; + STAILQ_HEAD(, delay_bdev_io) p99_write_io; + struct spdk_poller *io_poller; + unsigned int rand_seed; +}; + +static void +vbdev_delay_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io); + + +/* Callback for unregistering the IO device. */ +static void +_device_unregister_cb(void *io_device) +{ + struct vbdev_delay *delay_node = io_device; + + /* Done with this delay_node. */ + free(delay_node->delay_bdev.name); + free(delay_node); +} + +static void +_vbdev_delay_destruct(void *ctx) +{ + struct spdk_bdev_desc *desc = ctx; + + spdk_bdev_close(desc); +} + +static int +vbdev_delay_destruct(void *ctx) +{ + struct vbdev_delay *delay_node = (struct vbdev_delay *)ctx; + + /* It is important to follow this exact sequence of steps for destroying + * a vbdev... + */ + + TAILQ_REMOVE(&g_delay_nodes, delay_node, link); + + /* Unclaim the underlying bdev. */ + spdk_bdev_module_release_bdev(delay_node->base_bdev); + + /* Close the underlying bdev on its same opened thread. */ + if (delay_node->thread && delay_node->thread != spdk_get_thread()) { + spdk_thread_send_msg(delay_node->thread, _vbdev_delay_destruct, delay_node->base_desc); + } else { + spdk_bdev_close(delay_node->base_desc); + } + + /* Unregister the io_device. */ + spdk_io_device_unregister(delay_node, _device_unregister_cb); + + return 0; +} + +static int +_process_io_stailq(void *arg, uint64_t ticks) +{ + STAILQ_HEAD(, delay_bdev_io) *head = arg; + struct delay_bdev_io *io_ctx, *tmp; + int completions = 0; + + STAILQ_FOREACH_SAFE(io_ctx, head, link, tmp) { + if (io_ctx->completion_tick <= ticks) { + STAILQ_REMOVE(head, io_ctx, delay_bdev_io, link); + spdk_bdev_io_complete(spdk_bdev_io_from_ctx(io_ctx), io_ctx->status); + completions++; + } else { + /* In the general case, I/O will become ready in an fifo order. When timeouts are dynamically + * changed, this is not necessarily the case. However, the normal behavior will be restored + * after the outstanding I/O at the time of the change have been completed. + * This essentially means that moving from a high to low latency creates a dam for the new I/O + * submitted after the latency change. This is considered desirable behavior for the use case where + * we are trying to trigger a pre-defined timeout on an initiator. + */ + break; + } + } + + return completions; +} + +static int +_delay_finish_io(void *arg) +{ + struct delay_io_channel *delay_ch = arg; + uint64_t ticks = spdk_get_ticks(); + int completions = 0; + + completions += _process_io_stailq(&delay_ch->avg_read_io, ticks); + completions += _process_io_stailq(&delay_ch->avg_write_io, ticks); + completions += _process_io_stailq(&delay_ch->p99_read_io, ticks); + completions += _process_io_stailq(&delay_ch->p99_write_io, ticks); + + return completions == 0 ? SPDK_POLLER_IDLE : SPDK_POLLER_BUSY; +} + +/* Completion callback for IO that were issued from this bdev. The original bdev_io + * is passed in as an arg so we'll complete that one with the appropriate status + * and then free the one that this module issued. + */ +static void +_delay_complete_io(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg) +{ + struct spdk_bdev_io *orig_io = cb_arg; + struct vbdev_delay *delay_node = SPDK_CONTAINEROF(orig_io->bdev, struct vbdev_delay, delay_bdev); + struct delay_bdev_io *io_ctx = (struct delay_bdev_io *)orig_io->driver_ctx; + struct delay_io_channel *delay_ch = spdk_io_channel_get_ctx(io_ctx->ch); + + io_ctx->status = success ? SPDK_BDEV_IO_STATUS_SUCCESS : SPDK_BDEV_IO_STATUS_FAILED; + spdk_bdev_free_io(bdev_io); + + /* Put the I/O into the proper list for processing by the channel poller. */ + switch (io_ctx->type) { + case DELAY_AVG_READ: + io_ctx->completion_tick = spdk_get_ticks() + delay_node->average_read_latency_ticks; + STAILQ_INSERT_TAIL(&delay_ch->avg_read_io, io_ctx, link); + break; + case DELAY_AVG_WRITE: + io_ctx->completion_tick = spdk_get_ticks() + delay_node->average_write_latency_ticks; + STAILQ_INSERT_TAIL(&delay_ch->avg_write_io, io_ctx, link); + break; + case DELAY_P99_READ: + io_ctx->completion_tick = spdk_get_ticks() + delay_node->p99_read_latency_ticks; + STAILQ_INSERT_TAIL(&delay_ch->p99_read_io, io_ctx, link); + break; + case DELAY_P99_WRITE: + io_ctx->completion_tick = spdk_get_ticks() + delay_node->p99_write_latency_ticks; + STAILQ_INSERT_TAIL(&delay_ch->p99_write_io, io_ctx, link); + break; + case DELAY_NONE: + default: + spdk_bdev_io_complete(orig_io, io_ctx->status); + break; + } +} + +static void +vbdev_delay_resubmit_io(void *arg) +{ + struct spdk_bdev_io *bdev_io = (struct spdk_bdev_io *)arg; + struct delay_bdev_io *io_ctx = (struct delay_bdev_io *)bdev_io->driver_ctx; + + vbdev_delay_submit_request(io_ctx->ch, bdev_io); +} + +static void +vbdev_delay_queue_io(struct spdk_bdev_io *bdev_io) +{ + struct delay_bdev_io *io_ctx = (struct delay_bdev_io *)bdev_io->driver_ctx; + struct delay_io_channel *delay_ch = spdk_io_channel_get_ctx(io_ctx->ch); + int rc; + + io_ctx->bdev_io_wait.bdev = bdev_io->bdev; + io_ctx->bdev_io_wait.cb_fn = vbdev_delay_resubmit_io; + io_ctx->bdev_io_wait.cb_arg = bdev_io; + + rc = spdk_bdev_queue_io_wait(bdev_io->bdev, delay_ch->base_ch, &io_ctx->bdev_io_wait); + if (rc != 0) { + SPDK_ERRLOG("Queue io failed in vbdev_delay_queue_io, rc=%d.\n", rc); + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED); + } +} + +static void +delay_read_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success) +{ + struct vbdev_delay *delay_node = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_delay, + delay_bdev); + struct delay_io_channel *delay_ch = spdk_io_channel_get_ctx(ch); + int rc; + + if (!success) { + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED); + return; + } + + rc = spdk_bdev_readv_blocks(delay_node->base_desc, delay_ch->base_ch, bdev_io->u.bdev.iovs, + bdev_io->u.bdev.iovcnt, bdev_io->u.bdev.offset_blocks, + bdev_io->u.bdev.num_blocks, _delay_complete_io, + bdev_io); + + if (rc == -ENOMEM) { + SPDK_ERRLOG("No memory, start to queue io for delay.\n"); + vbdev_delay_queue_io(bdev_io); + } else if (rc != 0) { + SPDK_ERRLOG("ERROR on bdev_io submission!\n"); + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED); + } +} + +static void +vbdev_delay_reset_dev(struct spdk_io_channel_iter *i, int status) +{ + struct spdk_bdev_io *bdev_io = spdk_io_channel_iter_get_ctx(i); + struct spdk_io_channel *ch = spdk_io_channel_iter_get_channel(i); + struct delay_io_channel *delay_ch = spdk_io_channel_get_ctx(ch); + struct vbdev_delay *delay_node = spdk_io_channel_iter_get_io_device(i); + int rc; + + rc = spdk_bdev_reset(delay_node->base_desc, delay_ch->base_ch, + _delay_complete_io, bdev_io); + + if (rc == -ENOMEM) { + SPDK_ERRLOG("No memory, start to queue io for delay.\n"); + vbdev_delay_queue_io(bdev_io); + } else if (rc != 0) { + SPDK_ERRLOG("ERROR on bdev_io submission!\n"); + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED); + } +} + +static void +_abort_all_delayed_io(void *arg) +{ + STAILQ_HEAD(, delay_bdev_io) *head = arg; + struct delay_bdev_io *io_ctx, *tmp; + + STAILQ_FOREACH_SAFE(io_ctx, head, link, tmp) { + STAILQ_REMOVE(head, io_ctx, delay_bdev_io, link); + spdk_bdev_io_complete(spdk_bdev_io_from_ctx(io_ctx), SPDK_BDEV_IO_STATUS_ABORTED); + } +} + +static void +vbdev_delay_reset_channel(struct spdk_io_channel_iter *i) +{ + struct spdk_io_channel *ch = spdk_io_channel_iter_get_channel(i); + struct delay_io_channel *delay_ch = spdk_io_channel_get_ctx(ch); + + _abort_all_delayed_io(&delay_ch->avg_read_io); + _abort_all_delayed_io(&delay_ch->avg_write_io); + _abort_all_delayed_io(&delay_ch->p99_read_io); + _abort_all_delayed_io(&delay_ch->p99_write_io); + + spdk_for_each_channel_continue(i, 0); +} + +static bool +abort_delayed_io(void *_head, struct spdk_bdev_io *bio_to_abort) +{ + STAILQ_HEAD(, delay_bdev_io) *head = _head; + struct delay_bdev_io *io_ctx_to_abort = (struct delay_bdev_io *)bio_to_abort->driver_ctx; + struct delay_bdev_io *io_ctx; + + STAILQ_FOREACH(io_ctx, head, link) { + if (io_ctx == io_ctx_to_abort) { + STAILQ_REMOVE(head, io_ctx_to_abort, delay_bdev_io, link); + spdk_bdev_io_complete(bio_to_abort, SPDK_BDEV_IO_STATUS_ABORTED); + return true; + } + } + + return false; +} + +static int +vbdev_delay_abort(struct vbdev_delay *delay_node, struct delay_io_channel *delay_ch, + struct spdk_bdev_io *bdev_io) +{ + struct spdk_bdev_io *bio_to_abort = bdev_io->u.abort.bio_to_abort; + + if (abort_delayed_io(&delay_ch->avg_read_io, bio_to_abort) || + abort_delayed_io(&delay_ch->avg_write_io, bio_to_abort) || + abort_delayed_io(&delay_ch->p99_read_io, bio_to_abort) || + abort_delayed_io(&delay_ch->p99_write_io, bio_to_abort)) { + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS); + return 0; + } + + return spdk_bdev_abort(delay_node->base_desc, delay_ch->base_ch, bio_to_abort, + _delay_complete_io, bdev_io); +} + +static void +vbdev_delay_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io) +{ + struct vbdev_delay *delay_node = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_delay, delay_bdev); + struct delay_io_channel *delay_ch = spdk_io_channel_get_ctx(ch); + struct delay_bdev_io *io_ctx = (struct delay_bdev_io *)bdev_io->driver_ctx; + int rc = 0; + bool is_p99; + + is_p99 = rand_r(&delay_ch->rand_seed) % 100 == 0 ? true : false; + + io_ctx->ch = ch; + io_ctx->type = DELAY_NONE; + + switch (bdev_io->type) { + case SPDK_BDEV_IO_TYPE_READ: + io_ctx->type = is_p99 ? DELAY_P99_READ : DELAY_AVG_READ; + spdk_bdev_io_get_buf(bdev_io, delay_read_get_buf_cb, + bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen); + break; + case SPDK_BDEV_IO_TYPE_WRITE: + io_ctx->type = is_p99 ? DELAY_P99_WRITE : DELAY_AVG_WRITE; + rc = spdk_bdev_writev_blocks(delay_node->base_desc, delay_ch->base_ch, bdev_io->u.bdev.iovs, + bdev_io->u.bdev.iovcnt, bdev_io->u.bdev.offset_blocks, + bdev_io->u.bdev.num_blocks, _delay_complete_io, + bdev_io); + break; + case SPDK_BDEV_IO_TYPE_WRITE_ZEROES: + rc = spdk_bdev_write_zeroes_blocks(delay_node->base_desc, delay_ch->base_ch, + bdev_io->u.bdev.offset_blocks, + bdev_io->u.bdev.num_blocks, + _delay_complete_io, bdev_io); + break; + case SPDK_BDEV_IO_TYPE_UNMAP: + rc = spdk_bdev_unmap_blocks(delay_node->base_desc, delay_ch->base_ch, + bdev_io->u.bdev.offset_blocks, + bdev_io->u.bdev.num_blocks, + _delay_complete_io, bdev_io); + break; + case SPDK_BDEV_IO_TYPE_FLUSH: + rc = spdk_bdev_flush_blocks(delay_node->base_desc, delay_ch->base_ch, + bdev_io->u.bdev.offset_blocks, + bdev_io->u.bdev.num_blocks, + _delay_complete_io, bdev_io); + break; + case SPDK_BDEV_IO_TYPE_RESET: + /* During reset, the generic bdev layer aborts all new I/Os and queues all new resets. + * Hence we can simply abort all I/Os delayed to complete. + */ + spdk_for_each_channel(delay_node, vbdev_delay_reset_channel, bdev_io, + vbdev_delay_reset_dev); + break; + case SPDK_BDEV_IO_TYPE_ABORT: + rc = vbdev_delay_abort(delay_node, delay_ch, bdev_io); + break; + default: + SPDK_ERRLOG("delay: unknown I/O type %d\n", bdev_io->type); + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED); + return; + } + + if (rc == -ENOMEM) { + SPDK_ERRLOG("No memory, start to queue io for delay.\n"); + vbdev_delay_queue_io(bdev_io); + } else if (rc != 0) { + SPDK_ERRLOG("ERROR on bdev_io submission!\n"); + spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED); + } +} + +static bool +vbdev_delay_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type) +{ + struct vbdev_delay *delay_node = (struct vbdev_delay *)ctx; + + if (io_type == SPDK_BDEV_IO_TYPE_ZCOPY) { + return false; + } else { + return spdk_bdev_io_type_supported(delay_node->base_bdev, io_type); + } +} + +static struct spdk_io_channel * +vbdev_delay_get_io_channel(void *ctx) +{ + struct vbdev_delay *delay_node = (struct vbdev_delay *)ctx; + struct spdk_io_channel *delay_ch = NULL; + + delay_ch = spdk_get_io_channel(delay_node); + + return delay_ch; +} + +static void +_delay_write_conf_values(struct vbdev_delay *delay_node, struct spdk_json_write_ctx *w) +{ + spdk_json_write_named_string(w, "name", spdk_bdev_get_name(&delay_node->delay_bdev)); + spdk_json_write_named_string(w, "base_bdev_name", spdk_bdev_get_name(delay_node->base_bdev)); + spdk_json_write_named_int64(w, "avg_read_latency", + delay_node->average_read_latency_ticks * SPDK_SEC_TO_USEC / spdk_get_ticks_hz()); + spdk_json_write_named_int64(w, "p99_read_latency", + delay_node->p99_read_latency_ticks * SPDK_SEC_TO_USEC / spdk_get_ticks_hz()); + spdk_json_write_named_int64(w, "avg_write_latency", + delay_node->average_write_latency_ticks * SPDK_SEC_TO_USEC / spdk_get_ticks_hz()); + spdk_json_write_named_int64(w, "p99_write_latency", + delay_node->p99_write_latency_ticks * SPDK_SEC_TO_USEC / spdk_get_ticks_hz()); +} + +static int +vbdev_delay_dump_info_json(void *ctx, struct spdk_json_write_ctx *w) +{ + struct vbdev_delay *delay_node = (struct vbdev_delay *)ctx; + + spdk_json_write_name(w, "delay"); + spdk_json_write_object_begin(w); + _delay_write_conf_values(delay_node, w); + spdk_json_write_object_end(w); + + return 0; +} + +/* This is used to generate JSON that can configure this module to its current state. */ +static int +vbdev_delay_config_json(struct spdk_json_write_ctx *w) +{ + struct vbdev_delay *delay_node; + + TAILQ_FOREACH(delay_node, &g_delay_nodes, link) { + spdk_json_write_object_begin(w); + spdk_json_write_named_string(w, "method", "bdev_delay_create"); + spdk_json_write_named_object_begin(w, "params"); + _delay_write_conf_values(delay_node, w); + spdk_json_write_object_end(w); + } + return 0; +} + +/* We provide this callback for the SPDK channel code to create a channel using + * the channel struct we provided in our module get_io_channel() entry point. Here + * we get and save off an underlying base channel of the device below us so that + * we can communicate with the base bdev on a per channel basis. If we needed + * our own poller for this vbdev, we'd register it here. + */ +static int +delay_bdev_ch_create_cb(void *io_device, void *ctx_buf) +{ + struct delay_io_channel *delay_ch = ctx_buf; + struct vbdev_delay *delay_node = io_device; + + STAILQ_INIT(&delay_ch->avg_read_io); + STAILQ_INIT(&delay_ch->p99_read_io); + STAILQ_INIT(&delay_ch->avg_write_io); + STAILQ_INIT(&delay_ch->p99_write_io); + + delay_ch->io_poller = SPDK_POLLER_REGISTER(_delay_finish_io, delay_ch, 0); + delay_ch->base_ch = spdk_bdev_get_io_channel(delay_node->base_desc); + delay_ch->rand_seed = time(NULL); + + return 0; +} + +/* We provide this callback for the SPDK channel code to destroy a channel + * created with our create callback. We just need to undo anything we did + * when we created. If this bdev used its own poller, we'd unregsiter it here. + */ +static void +delay_bdev_ch_destroy_cb(void *io_device, void *ctx_buf) +{ + struct delay_io_channel *delay_ch = ctx_buf; + + spdk_poller_unregister(&delay_ch->io_poller); + spdk_put_io_channel(delay_ch->base_ch); +} + +/* Create the delay association from the bdev and vbdev name and insert + * on the global list. */ +static int +vbdev_delay_insert_association(const char *bdev_name, const char *vbdev_name, + uint64_t avg_read_latency, uint64_t p99_read_latency, + uint64_t avg_write_latency, uint64_t p99_write_latency) +{ + struct bdev_association *assoc; + + TAILQ_FOREACH(assoc, &g_bdev_associations, link) { + if (strcmp(vbdev_name, assoc->vbdev_name) == 0) { + SPDK_ERRLOG("delay bdev %s already exists\n", vbdev_name); + return -EEXIST; + } + } + + assoc = calloc(1, sizeof(struct bdev_association)); + if (!assoc) { + SPDK_ERRLOG("could not allocate bdev_association\n"); + return -ENOMEM; + } + + assoc->bdev_name = strdup(bdev_name); + if (!assoc->bdev_name) { + SPDK_ERRLOG("could not allocate assoc->bdev_name\n"); + free(assoc); + return -ENOMEM; + } + + assoc->vbdev_name = strdup(vbdev_name); + if (!assoc->vbdev_name) { + SPDK_ERRLOG("could not allocate assoc->vbdev_name\n"); + free(assoc->bdev_name); + free(assoc); + return -ENOMEM; + } + + assoc->avg_read_latency = avg_read_latency; + assoc->p99_read_latency = p99_read_latency; + assoc->avg_write_latency = avg_write_latency; + assoc->p99_write_latency = p99_write_latency; + + TAILQ_INSERT_TAIL(&g_bdev_associations, assoc, link); + + return 0; +} + +int +vbdev_delay_update_latency_value(char *delay_name, uint64_t latency_us, enum delay_io_type type) +{ + struct spdk_bdev *delay_bdev; + struct vbdev_delay *delay_node; + uint64_t ticks_mhz = spdk_get_ticks_hz() / SPDK_SEC_TO_USEC; + + delay_bdev = spdk_bdev_get_by_name(delay_name); + if (delay_bdev == NULL) { + return -ENODEV; + } else if (delay_bdev->module != &delay_if) { + return -EINVAL; + } + + delay_node = SPDK_CONTAINEROF(delay_bdev, struct vbdev_delay, delay_bdev); + + switch (type) { + case DELAY_AVG_READ: + delay_node->average_read_latency_ticks = ticks_mhz * latency_us; + break; + case DELAY_AVG_WRITE: + delay_node->average_write_latency_ticks = ticks_mhz * latency_us; + break; + case DELAY_P99_READ: + delay_node->p99_read_latency_ticks = ticks_mhz * latency_us; + break; + case DELAY_P99_WRITE: + delay_node->p99_write_latency_ticks = ticks_mhz * latency_us; + break; + default: + return -EINVAL; + } + + return 0; +} + +static int +vbdev_delay_init(void) +{ + /* Not allowing for .ini style configuration. */ + return 0; +} + +static void +vbdev_delay_finish(void) +{ + struct bdev_association *assoc; + + while ((assoc = TAILQ_FIRST(&g_bdev_associations))) { + TAILQ_REMOVE(&g_bdev_associations, assoc, link); + free(assoc->bdev_name); + free(assoc->vbdev_name); + free(assoc); + } +} + +static int +vbdev_delay_get_ctx_size(void) +{ + return sizeof(struct delay_bdev_io); +} + +static void +vbdev_delay_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w) +{ + /* No config per bdev needed */ +} + +/* When we register our bdev this is how we specify our entry points. */ +static const struct spdk_bdev_fn_table vbdev_delay_fn_table = { + .destruct = vbdev_delay_destruct, + .submit_request = vbdev_delay_submit_request, + .io_type_supported = vbdev_delay_io_type_supported, + .get_io_channel = vbdev_delay_get_io_channel, + .dump_info_json = vbdev_delay_dump_info_json, + .write_config_json = vbdev_delay_write_config_json, +}; + +/* Called when the underlying base bdev goes away. */ +static void +vbdev_delay_base_bdev_hotremove_cb(void *ctx) +{ + struct vbdev_delay *delay_node, *tmp; + struct spdk_bdev *bdev_find = ctx; + + TAILQ_FOREACH_SAFE(delay_node, &g_delay_nodes, link, tmp) { + if (bdev_find == delay_node->base_bdev) { + spdk_bdev_unregister(&delay_node->delay_bdev, NULL, NULL); + } + } +} + +/* Create and register the delay vbdev if we find it in our list of bdev names. + * This can be called either by the examine path or RPC method. + */ +static int +vbdev_delay_register(struct spdk_bdev *bdev) +{ + struct bdev_association *assoc; + struct vbdev_delay *delay_node; + uint64_t ticks_mhz = spdk_get_ticks_hz() / SPDK_SEC_TO_USEC; + int rc = 0; + + /* Check our list of names from config versus this bdev and if + * there's a match, create the delay_node & bdev accordingly. + */ + TAILQ_FOREACH(assoc, &g_bdev_associations, link) { + if (strcmp(assoc->bdev_name, bdev->name) != 0) { + continue; + } + + delay_node = calloc(1, sizeof(struct vbdev_delay)); + if (!delay_node) { + rc = -ENOMEM; + SPDK_ERRLOG("could not allocate delay_node\n"); + break; + } + + /* The base bdev that we're attaching to. */ + delay_node->base_bdev = bdev; + delay_node->delay_bdev.name = strdup(assoc->vbdev_name); + if (!delay_node->delay_bdev.name) { + rc = -ENOMEM; + SPDK_ERRLOG("could not allocate delay_bdev name\n"); + free(delay_node); + break; + } + delay_node->delay_bdev.product_name = "delay"; + + delay_node->delay_bdev.write_cache = bdev->write_cache; + delay_node->delay_bdev.required_alignment = bdev->required_alignment; + delay_node->delay_bdev.optimal_io_boundary = bdev->optimal_io_boundary; + delay_node->delay_bdev.blocklen = bdev->blocklen; + delay_node->delay_bdev.blockcnt = bdev->blockcnt; + + delay_node->delay_bdev.ctxt = delay_node; + delay_node->delay_bdev.fn_table = &vbdev_delay_fn_table; + delay_node->delay_bdev.module = &delay_if; + + /* Store the number of ticks you need to add to get the I/O expiration time. */ + delay_node->average_read_latency_ticks = ticks_mhz * assoc->avg_read_latency; + delay_node->p99_read_latency_ticks = ticks_mhz * assoc->p99_read_latency; + delay_node->average_write_latency_ticks = ticks_mhz * assoc->avg_write_latency; + delay_node->p99_write_latency_ticks = ticks_mhz * assoc->p99_write_latency; + + spdk_io_device_register(delay_node, delay_bdev_ch_create_cb, delay_bdev_ch_destroy_cb, + sizeof(struct delay_io_channel), + assoc->vbdev_name); + + rc = spdk_bdev_open(bdev, true, vbdev_delay_base_bdev_hotremove_cb, + bdev, &delay_node->base_desc); + if (rc) { + SPDK_ERRLOG("could not open bdev %s\n", spdk_bdev_get_name(bdev)); + goto error_unregister; + } + + /* Save the thread where the base device is opened */ + delay_node->thread = spdk_get_thread(); + + rc = spdk_bdev_module_claim_bdev(bdev, delay_node->base_desc, delay_node->delay_bdev.module); + if (rc) { + SPDK_ERRLOG("could not claim bdev %s\n", spdk_bdev_get_name(bdev)); + goto error_close; + } + + rc = spdk_bdev_register(&delay_node->delay_bdev); + if (rc) { + SPDK_ERRLOG("could not register delay_bdev\n"); + spdk_bdev_module_release_bdev(delay_node->base_bdev); + goto error_close; + } + + TAILQ_INSERT_TAIL(&g_delay_nodes, delay_node, link); + } + + return rc; + +error_close: + spdk_bdev_close(delay_node->base_desc); +error_unregister: + spdk_io_device_unregister(delay_node, NULL); + free(delay_node->delay_bdev.name); + free(delay_node); + return rc; +} + +int +create_delay_disk(const char *bdev_name, const char *vbdev_name, uint64_t avg_read_latency, + uint64_t p99_read_latency, uint64_t avg_write_latency, uint64_t p99_write_latency) +{ + struct spdk_bdev *bdev = NULL; + int rc = 0; + + if (p99_read_latency < avg_read_latency || p99_write_latency < avg_write_latency) { + SPDK_ERRLOG("Unable to create a delay bdev where p99 latency is less than average latency.\n"); + return -EINVAL; + } + + rc = vbdev_delay_insert_association(bdev_name, vbdev_name, avg_read_latency, p99_read_latency, + avg_write_latency, p99_write_latency); + if (rc) { + return rc; + } + + bdev = spdk_bdev_get_by_name(bdev_name); + if (!bdev) { + return 0; + } + + return vbdev_delay_register(bdev); +} + +void +delete_delay_disk(struct spdk_bdev *bdev, spdk_bdev_unregister_cb cb_fn, void *cb_arg) +{ + struct bdev_association *assoc; + + if (!bdev || bdev->module != &delay_if) { + cb_fn(cb_arg, -ENODEV); + return; + } + + TAILQ_FOREACH(assoc, &g_bdev_associations, link) { + if (strcmp(assoc->vbdev_name, bdev->name) == 0) { + TAILQ_REMOVE(&g_bdev_associations, assoc, link); + free(assoc->bdev_name); + free(assoc->vbdev_name); + free(assoc); + break; + } + } + + spdk_bdev_unregister(bdev, cb_fn, cb_arg); +} + +static void +vbdev_delay_examine(struct spdk_bdev *bdev) +{ + vbdev_delay_register(bdev); + + spdk_bdev_module_examine_done(&delay_if); +} + +SPDK_LOG_REGISTER_COMPONENT("vbdev_delay", SPDK_LOG_VBDEV_DELAY) |