/*- * BSD LICENSE * * Copyright (C) 2008-2012 Daisuke Aoyama . * 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. */ /** \file * Block Device Module Interface */ #ifndef SPDK_INTERNAL_BDEV_H #define SPDK_INTERNAL_BDEV_H #include "spdk/stdinc.h" #include "spdk/bdev.h" #include "spdk/queue.h" #include "spdk/scsi_spec.h" /** \page block_backend_modules Block Device Backend Modules * * To implement a backend block device driver, a number of functions * dictated by struct spdk_bdev_fn_table must be provided. * * The module should register itself using SPDK_BDEV_MODULE_REGISTER to * define the parameters for the module. * *
* * In the module initialization code, the config file sections can be parsed to * acquire custom configuration parameters. For example, if the config file has * a section such as below: * 
 * [MyBE]
 * MyParam 1234
 *
* * The value can be extracted as the example below: * 
 * struct spdk_conf_section *sp = spdk_conf_find_section(NULL, "MyBe");
 * int my_param = spdk_conf_section_get_intval(sp, "MyParam");
 *
* * The backend initialization routine also need to create "disks". A virtual * representation of each LUN must be constructed. Mainly a struct spdk_bdev * must be passed to the bdev database via spdk_bdev_register(). */ /** Block device module */ struct spdk_bdev_module_if { /** * Initialization function for the module. Called by the spdk * application during startup. * * Modules are required to define this function. */ int (*module_init)(void); /** * Finish function for the module. Called by the spdk application * before the spdk application exits to perform any necessary cleanup. * * Modules are not required to define this function. */ void (*module_fini)(void); /** * Function called to return a text string representing the * module's configuration options for inclusion in a configuration file. */ void (*config_text)(FILE *fp); /** Name for the modules being defined. */ const char *name; /** * Returns the allocation size required for the backend for uses such as local * command structs, local SGL, iovecs, or other user context. */ int (*get_ctx_size)(void); /** * Notification that a bdev should be examined by a virtual bdev module. * Virtual bdev modules may use this to examine newly-added bdevs and automatically * create their own vbdevs. */ void (*examine)(struct spdk_bdev *bdev); /** * Count of bdev examinations in progress. Used by generic bdev layer and must * not be modified by bdev modules. */ uint32_t examine_in_progress; TAILQ_ENTRY(spdk_bdev_module_if) tailq; }; /** * Function table for a block device backend. * * The backend block device function table provides a set of APIs to allow * communication with a backend. The main commands are read/write API * calls for I/O via submit_request. */ struct spdk_bdev_fn_table { /** Destroy the backend block device object */ int (*destruct)(void *ctx); /** Process the IO. */ void (*submit_request)(struct spdk_io_channel *ch, struct spdk_bdev_io *); /** Check if the block device supports a specific I/O type. */ bool (*io_type_supported)(void *ctx, enum spdk_bdev_io_type); /** Get an I/O channel for the specific bdev for the calling thread. */ struct spdk_io_channel *(*get_io_channel)(void *ctx); /** * Output driver-specific configuration to a JSON stream. Optional - may be NULL. * * The JSON write context will be initialized with an open object, so the bdev * driver should write a name (based on the driver name) followed by a JSON value * (most likely another nested object). */ int (*dump_config_json)(void *ctx, struct spdk_json_write_ctx *w); /** Get spin-time per I/O channel in microseconds. * Optional - may be NULL. */ uint64_t (*get_spin_time)(struct spdk_io_channel *ch); }; /** bdev I/O completion status */ enum spdk_bdev_io_status { SPDK_BDEV_IO_STATUS_SCSI_ERROR = -3, SPDK_BDEV_IO_STATUS_NVME_ERROR = -2, SPDK_BDEV_IO_STATUS_FAILED = -1, SPDK_BDEV_IO_STATUS_PENDING = 0, SPDK_BDEV_IO_STATUS_SUCCESS = 1, }; struct spdk_bdev { /** User context passed in by the backend */ void *ctxt; /** Unique name for this block device. */ char *name; /** Unique product name for this kind of block device. */ char *product_name; /** Size in bytes of a logical block for the backend */ uint32_t blocklen; /** Number of blocks */ uint64_t blockcnt; /** write cache enabled, not used at the moment */ int write_cache; /** * This is used to make sure buffers are sector aligned. * This causes double buffering on writes. */ int need_aligned_buffer; /** * Pointer to the bdev module that registered this bdev. */ struct spdk_bdev_module_if *module; /** function table for all LUN ops */ const struct spdk_bdev_fn_table *fn_table; /** Represents maximum unmap block descriptor count */ uint32_t max_unmap_bdesc_count; /** generation value used by block device reset */ uint32_t gencnt; /** Mutex protecting claimed */ pthread_mutex_t mutex; /** The bdev status */ enum spdk_bdev_status status; /** The list of block devices that this block device is built on top of (if any). */ TAILQ_HEAD(, spdk_bdev) base_bdevs; TAILQ_ENTRY(spdk_bdev) base_bdev_link; /** The list of virtual block devices built on top of this block device. */ TAILQ_HEAD(, spdk_bdev) vbdevs; TAILQ_ENTRY(spdk_bdev) vbdev_link; bool bdev_opened_for_write; /** * Pointer to the module that has claimed this bdev for purposes of creating virtual * bdevs on top of it. Set to NULL if the bdev has not been claimed. */ struct spdk_bdev_module_if *claim_module; /** List of open descriptors for this block device. */ TAILQ_HEAD(, spdk_bdev_desc) open_descs; TAILQ_ENTRY(spdk_bdev) link; /** denotes if a reset is currently in progress on this bdev */ bool reset_in_progress; TAILQ_HEAD(, spdk_bdev_io) queued_resets; }; typedef void (*spdk_bdev_io_get_buf_cb)(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io); struct spdk_bdev_io { /** The block device that this I/O belongs to. */ struct spdk_bdev *bdev; /** The bdev I/O channel that this was submitted on. */ struct spdk_bdev_channel *ch; /** bdev allocated memory associated with this request */ void *buf; /** Callback for when buf is allocated */ spdk_bdev_io_get_buf_cb get_buf_cb; /** Entry to the list need_buf of struct spdk_bdev. */ TAILQ_ENTRY(spdk_bdev_io) buf_link; /** Generation value for each I/O. */ uint32_t gencnt; /** Enumerated value representing the I/O type. */ enum spdk_bdev_io_type type; union { struct { /** For basic read case, use our own iovec element. */ struct iovec iov; /** For SG buffer cases, array of iovecs to transfer. */ struct iovec *iovs; /** For SG buffer cases, number of iovecs in iovec array. */ int iovcnt; /** Total size of data to be transferred. */ size_t len; /** Starting offset (in bytes) of the bdev for this I/O. */ uint64_t offset; } read; struct { /** For basic write case, use our own iovec element */ struct iovec iov; /** For SG buffer cases, array of iovecs to transfer. */ struct iovec *iovs; /** For SG buffer cases, number of iovecs in iovec array. */ int iovcnt; /** Total size of data to be transferred. */ size_t len; /** Starting offset (in bytes) of the bdev for this I/O. */ uint64_t offset; } write; struct { /** Represents the unmap block descriptors. */ struct spdk_scsi_unmap_bdesc *unmap_bdesc; /** Count of unmap block descriptors. */ uint16_t bdesc_count; } unmap; struct { /** Represents starting offset in bytes of the range to be flushed. */ uint64_t offset; /** Represents the number of bytes to be flushed, starting at offset. */ uint64_t length; } flush; struct { /* The NVMe command to execute */ struct spdk_nvme_cmd cmd; /* The data buffer to transfer */ void *buf; /* The number of bytes to transfer */ size_t nbytes; } nvme_passthru; } u; /** Status for the IO */ enum spdk_bdev_io_status status; /** Error information from a device */ union { /** Only valid when status is SPDK_BDEV_IO_STATUS_NVME_ERROR */ struct { /** NVMe status code type */ int sct; /** NVMe status code */ int sc; } nvme; /** Only valid when status is SPDK_BDEV_IO_STATUS_SCSI_ERROR */ struct { /** SCSI status code */ enum spdk_scsi_status sc; /** SCSI sense key */ enum spdk_scsi_sense sk; /** SCSI additional sense code */ uint8_t asc; /** SCSI additional sense code qualifier */ uint8_t ascq; } scsi; } error; /** User function that will be called when this completes */ spdk_bdev_io_completion_cb cb; /** Context that will be passed to the completion callback */ void *caller_ctx; /** * Set to true while the bdev module submit_request function is in progress. * * This is used to decide whether spdk_bdev_io_complete() can complete the I/O directly * or if completion must be deferred via an event. */ bool in_submit_request; /** Member used for linking child I/Os together. */ TAILQ_ENTRY(spdk_bdev_io) link; /** It may be used by modules to put the bdev_io into its own list. */ TAILQ_ENTRY(spdk_bdev_io) module_link; /** * Per I/O context for use by the bdev module. * * Note that vbdev modules may not use this field if modifying a bdev_io and resubmitting * to the next lower bdev. */ uint8_t driver_ctx[0]; /* No members may be added after driver_ctx! */ }; void spdk_bdev_register(struct spdk_bdev *bdev); void spdk_bdev_unregister(struct spdk_bdev *bdev); void spdk_vbdev_register(struct spdk_bdev *vbdev, struct spdk_bdev **base_bdevs, int base_bdev_count); void spdk_vbdev_unregister(struct spdk_bdev *vbdev); void spdk_bdev_module_examine_done(struct spdk_bdev_module_if *module); int spdk_bdev_module_claim_bdev(struct spdk_bdev *bdev, struct spdk_bdev_desc *desc, struct spdk_bdev_module_if *module); void spdk_bdev_module_release_bdev(struct spdk_bdev *bdev); void spdk_bdev_poller_start(struct spdk_bdev_poller **ppoller, spdk_bdev_poller_fn fn, void *arg, uint32_t lcore, uint64_t period_microseconds); void spdk_bdev_poller_stop(struct spdk_bdev_poller **ppoller); void spdk_bdev_io_get_buf(struct spdk_bdev_io *bdev_io, spdk_bdev_io_get_buf_cb cb); struct spdk_bdev_io *spdk_bdev_get_io(void); void spdk_bdev_io_resubmit(struct spdk_bdev_io *bdev_io, struct spdk_bdev_desc *new_bdev_desc); void spdk_bdev_io_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status status); /** * Complete a bdev_io with an NVMe status code. * * \param bdev_io I/O to complete. * \param sct NVMe Status Code Type. * \param sc NVMe Status Code. */ void spdk_bdev_io_complete_nvme_status(struct spdk_bdev_io *bdev_io, int sct, int sc); /** * Complete a bdev_io with a SCSI status code. * * \param bdev_io I/O to complete. * \param sc SCSI Status Code. * \param sk SCSI Sense Key. * \param asc SCSI Additional Sense Code. * \param ascq SCSI Additional Sense Code Qualifier. */ void spdk_bdev_io_complete_scsi_status(struct spdk_bdev_io *bdev_io, enum spdk_scsi_status sc, enum spdk_scsi_sense sk, uint8_t asc, uint8_t ascq); void spdk_scsi_nvme_translate(const struct spdk_bdev_io *bdev_io, int *sc, int *sk, int *asc, int *ascq); void spdk_bdev_module_list_add(struct spdk_bdev_module_if *bdev_module); static inline struct spdk_bdev_io * spdk_bdev_io_from_ctx(void *ctx) { return (struct spdk_bdev_io *) ((uintptr_t)ctx - offsetof(struct spdk_bdev_io, driver_ctx)); } #define SPDK_BDEV_MODULE_REGISTER(_name, init_fn, fini_fn, config_fn, ctx_size_fn, examine_fn)\ static struct spdk_bdev_module_if _name ## _if = { \ .name = #_name, \ .module_init = init_fn, \ .module_fini = fini_fn, \ .config_text = config_fn, \ .get_ctx_size = ctx_size_fn, \ .examine = examine_fn, \ }; \ __attribute__((constructor)) static void _name ## _init(void) \ { \ spdk_bdev_module_list_add(&_name ## _if); \ } #define SPDK_GET_BDEV_MODULE(name) &name ## _if /* * Modules are not required to use this macro. It allows modules to reference the module with * SPDK_GET_BDEV_MODULE() before it is defined by SPDK_BDEV_MODULE_REGISTER. */ #define SPDK_DECLARE_BDEV_MODULE(name) \ static struct spdk_bdev_module_if name ## _if; #endif /* SPDK_INTERNAL_BDEV_H */