// SPDX-License-Identifier: GPL-2.0 /* * Functions related to sysfs handling */ #include #include #include #include #include #include #include #include #include "blk.h" #include "blk-mq.h" #include "blk-mq-debugfs.h" #include "blk-mq-sched.h" #include "blk-rq-qos.h" #include "blk-wbt.h" #include "blk-cgroup.h" #include "blk-throttle.h" struct queue_sysfs_entry { struct attribute attr; ssize_t (*show)(struct gendisk *disk, char *page); ssize_t (*store)(struct gendisk *disk, const char *page, size_t count); void (*load_module)(struct gendisk *disk, const char *page, size_t count); }; static ssize_t queue_var_show(unsigned long var, char *page) { return sysfs_emit(page, "%lu\n", var); } static ssize_t queue_var_store(unsigned long *var, const char *page, size_t count) { int err; unsigned long v; err = kstrtoul(page, 10, &v); if (err || v > UINT_MAX) return -EINVAL; *var = v; return count; } static ssize_t queue_requests_show(struct gendisk *disk, char *page) { return queue_var_show(disk->queue->nr_requests, page); } static ssize_t queue_requests_store(struct gendisk *disk, const char *page, size_t count) { unsigned long nr; int ret, err; if (!queue_is_mq(disk->queue)) return -EINVAL; ret = queue_var_store(&nr, page, count); if (ret < 0) return ret; if (nr < BLKDEV_MIN_RQ) nr = BLKDEV_MIN_RQ; err = blk_mq_update_nr_requests(disk->queue, nr); if (err) return err; return ret; } static ssize_t queue_ra_show(struct gendisk *disk, char *page) { return queue_var_show(disk->bdi->ra_pages << (PAGE_SHIFT - 10), page); } static ssize_t queue_ra_store(struct gendisk *disk, const char *page, size_t count) { unsigned long ra_kb; ssize_t ret; ret = queue_var_store(&ra_kb, page, count); if (ret < 0) return ret; disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10); return ret; } #define QUEUE_SYSFS_LIMIT_SHOW(_field) \ static ssize_t queue_##_field##_show(struct gendisk *disk, char *page) \ { \ return queue_var_show(disk->queue->limits._field, page); \ } QUEUE_SYSFS_LIMIT_SHOW(max_segments) QUEUE_SYSFS_LIMIT_SHOW(max_discard_segments) QUEUE_SYSFS_LIMIT_SHOW(max_integrity_segments) QUEUE_SYSFS_LIMIT_SHOW(max_segment_size) QUEUE_SYSFS_LIMIT_SHOW(logical_block_size) QUEUE_SYSFS_LIMIT_SHOW(physical_block_size) QUEUE_SYSFS_LIMIT_SHOW(chunk_sectors) QUEUE_SYSFS_LIMIT_SHOW(io_min) QUEUE_SYSFS_LIMIT_SHOW(io_opt) QUEUE_SYSFS_LIMIT_SHOW(discard_granularity) QUEUE_SYSFS_LIMIT_SHOW(zone_write_granularity) QUEUE_SYSFS_LIMIT_SHOW(virt_boundary_mask) QUEUE_SYSFS_LIMIT_SHOW(dma_alignment) QUEUE_SYSFS_LIMIT_SHOW(max_open_zones) QUEUE_SYSFS_LIMIT_SHOW(max_active_zones) QUEUE_SYSFS_LIMIT_SHOW(atomic_write_unit_min) QUEUE_SYSFS_LIMIT_SHOW(atomic_write_unit_max) #define QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(_field) \ static ssize_t queue_##_field##_show(struct gendisk *disk, char *page) \ { \ return sysfs_emit(page, "%llu\n", \ (unsigned long long)disk->queue->limits._field << \ SECTOR_SHIFT); \ } QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_discard_sectors) QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_hw_discard_sectors) QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_write_zeroes_sectors) QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(atomic_write_max_sectors) QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(atomic_write_boundary_sectors) QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_zone_append_sectors) #define QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(_field) \ static ssize_t queue_##_field##_show(struct gendisk *disk, char *page) \ { \ return queue_var_show(disk->queue->limits._field >> 1, page); \ } QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(max_sectors) QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(max_hw_sectors) #define QUEUE_SYSFS_SHOW_CONST(_name, _val) \ static ssize_t queue_##_name##_show(struct gendisk *disk, char *page) \ { \ return sysfs_emit(page, "%d\n", _val); \ } /* deprecated fields */ QUEUE_SYSFS_SHOW_CONST(discard_zeroes_data, 0) QUEUE_SYSFS_SHOW_CONST(write_same_max, 0) QUEUE_SYSFS_SHOW_CONST(poll_delay, -1) static ssize_t queue_max_discard_sectors_store(struct gendisk *disk, const char *page, size_t count) { unsigned long max_discard_bytes; struct queue_limits lim; ssize_t ret; int err; ret = queue_var_store(&max_discard_bytes, page, count); if (ret < 0) return ret; if (max_discard_bytes & (disk->queue->limits.discard_granularity - 1)) return -EINVAL; if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX) return -EINVAL; lim = queue_limits_start_update(disk->queue); lim.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT; err = queue_limits_commit_update(disk->queue, &lim); if (err) return err; return ret; } static ssize_t queue_max_sectors_store(struct gendisk *disk, const char *page, size_t count) { unsigned long max_sectors_kb; struct queue_limits lim; ssize_t ret; int err; ret = queue_var_store(&max_sectors_kb, page, count); if (ret < 0) return ret; lim = queue_limits_start_update(disk->queue); lim.max_user_sectors = max_sectors_kb << 1; err = queue_limits_commit_update(disk->queue, &lim); if (err) return err; return ret; } static ssize_t queue_feature_store(struct gendisk *disk, const char *page, size_t count, blk_features_t feature) { struct queue_limits lim; unsigned long val; ssize_t ret; ret = queue_var_store(&val, page, count); if (ret < 0) return ret; lim = queue_limits_start_update(disk->queue); if (val) lim.features |= feature; else lim.features &= ~feature; ret = queue_limits_commit_update(disk->queue, &lim); if (ret) return ret; return count; } #define QUEUE_SYSFS_FEATURE(_name, _feature) \ static ssize_t queue_##_name##_show(struct gendisk *disk, char *page) \ { \ return sysfs_emit(page, "%u\n", \ !!(disk->queue->limits.features & _feature)); \ } \ static ssize_t queue_##_name##_store(struct gendisk *disk, \ const char *page, size_t count) \ { \ return queue_feature_store(disk, page, count, _feature); \ } QUEUE_SYSFS_FEATURE(rotational, BLK_FEAT_ROTATIONAL) QUEUE_SYSFS_FEATURE(add_random, BLK_FEAT_ADD_RANDOM) QUEUE_SYSFS_FEATURE(iostats, BLK_FEAT_IO_STAT) QUEUE_SYSFS_FEATURE(stable_writes, BLK_FEAT_STABLE_WRITES); #define QUEUE_SYSFS_FEATURE_SHOW(_name, _feature) \ static ssize_t queue_##_name##_show(struct gendisk *disk, char *page) \ { \ return sysfs_emit(page, "%u\n", \ !!(disk->queue->limits.features & _feature)); \ } QUEUE_SYSFS_FEATURE_SHOW(poll, BLK_FEAT_POLL); QUEUE_SYSFS_FEATURE_SHOW(fua, BLK_FEAT_FUA); QUEUE_SYSFS_FEATURE_SHOW(dax, BLK_FEAT_DAX); static ssize_t queue_zoned_show(struct gendisk *disk, char *page) { if (blk_queue_is_zoned(disk->queue)) return sysfs_emit(page, "host-managed\n"); return sysfs_emit(page, "none\n"); } static ssize_t queue_nr_zones_show(struct gendisk *disk, char *page) { return queue_var_show(disk_nr_zones(disk), page); } static ssize_t queue_iostats_passthrough_show(struct gendisk *disk, char *page) { return queue_var_show(blk_queue_passthrough_stat(disk->queue), page); } static ssize_t queue_iostats_passthrough_store(struct gendisk *disk, const char *page, size_t count) { struct queue_limits lim; unsigned long ios; ssize_t ret; ret = queue_var_store(&ios, page, count); if (ret < 0) return ret; lim = queue_limits_start_update(disk->queue); if (ios) lim.flags |= BLK_FLAG_IOSTATS_PASSTHROUGH; else lim.flags &= ~BLK_FLAG_IOSTATS_PASSTHROUGH; ret = queue_limits_commit_update(disk->queue, &lim); if (ret) return ret; return count; } static ssize_t queue_nomerges_show(struct gendisk *disk, char *page) { return queue_var_show((blk_queue_nomerges(disk->queue) << 1) | blk_queue_noxmerges(disk->queue), page); } static ssize_t queue_nomerges_store(struct gendisk *disk, const char *page, size_t count) { unsigned long nm; ssize_t ret = queue_var_store(&nm, page, count); if (ret < 0) return ret; blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, disk->queue); blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, disk->queue); if (nm == 2) blk_queue_flag_set(QUEUE_FLAG_NOMERGES, disk->queue); else if (nm) blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, disk->queue); return ret; } static ssize_t queue_rq_affinity_show(struct gendisk *disk, char *page) { bool set = test_bit(QUEUE_FLAG_SAME_COMP, &disk->queue->queue_flags); bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &disk->queue->queue_flags); return queue_var_show(set << force, page); } static ssize_t queue_rq_affinity_store(struct gendisk *disk, const char *page, size_t count) { ssize_t ret = -EINVAL; #ifdef CONFIG_SMP struct request_queue *q = disk->queue; unsigned long val; ret = queue_var_store(&val, page, count); if (ret < 0) return ret; if (val == 2) { blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); } else if (val == 1) { blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); } else if (val == 0) { blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); } #endif return ret; } static ssize_t queue_poll_delay_store(struct gendisk *disk, const char *page, size_t count) { return count; } static ssize_t queue_poll_store(struct gendisk *disk, const char *page, size_t count) { if (!(disk->queue->limits.features & BLK_FEAT_POLL)) return -EINVAL; pr_info_ratelimited("writes to the poll attribute are ignored.\n"); pr_info_ratelimited("please use driver specific parameters instead.\n"); return count; } static ssize_t queue_io_timeout_show(struct gendisk *disk, char *page) { return sysfs_emit(page, "%u\n", jiffies_to_msecs(disk->queue->rq_timeout)); } static ssize_t queue_io_timeout_store(struct gendisk *disk, const char *page, size_t count) { unsigned int val; int err; err = kstrtou32(page, 10, &val); if (err || val == 0) return -EINVAL; blk_queue_rq_timeout(disk->queue, msecs_to_jiffies(val)); return count; } static ssize_t queue_wc_show(struct gendisk *disk, char *page) { if (blk_queue_write_cache(disk->queue)) return sysfs_emit(page, "write back\n"); return sysfs_emit(page, "write through\n"); } static ssize_t queue_wc_store(struct gendisk *disk, const char *page, size_t count) { struct queue_limits lim; bool disable; int err; if (!strncmp(page, "write back", 10)) { disable = false; } else if (!strncmp(page, "write through", 13) || !strncmp(page, "none", 4)) { disable = true; } else { return -EINVAL; } lim = queue_limits_start_update(disk->queue); if (disable) lim.flags |= BLK_FLAG_WRITE_CACHE_DISABLED; else lim.flags &= ~BLK_FLAG_WRITE_CACHE_DISABLED; err = queue_limits_commit_update(disk->queue, &lim); if (err) return err; return count; } #define QUEUE_RO_ENTRY(_prefix, _name) \ static struct queue_sysfs_entry _prefix##_entry = { \ .attr = { .name = _name, .mode = 0444 }, \ .show = _prefix##_show, \ }; #define QUEUE_RW_ENTRY(_prefix, _name) \ static struct queue_sysfs_entry _prefix##_entry = { \ .attr = { .name = _name, .mode = 0644 }, \ .show = _prefix##_show, \ .store = _prefix##_store, \ }; #define QUEUE_RW_LOAD_MODULE_ENTRY(_prefix, _name) \ static struct queue_sysfs_entry _prefix##_entry = { \ .attr = { .name = _name, .mode = 0644 }, \ .show = _prefix##_show, \ .load_module = _prefix##_load_module, \ .store = _prefix##_store, \ } QUEUE_RW_ENTRY(queue_requests, "nr_requests"); QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); QUEUE_RW_LOAD_MODULE_ENTRY(elv_iosched, "scheduler"); QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); QUEUE_RO_ENTRY(queue_max_hw_discard_sectors, "discard_max_hw_bytes"); QUEUE_RW_ENTRY(queue_max_discard_sectors, "discard_max_bytes"); QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); QUEUE_RO_ENTRY(queue_atomic_write_max_sectors, "atomic_write_max_bytes"); QUEUE_RO_ENTRY(queue_atomic_write_boundary_sectors, "atomic_write_boundary_bytes"); QUEUE_RO_ENTRY(queue_atomic_write_unit_max, "atomic_write_unit_max_bytes"); QUEUE_RO_ENTRY(queue_atomic_write_unit_min, "atomic_write_unit_min_bytes"); QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); QUEUE_RO_ENTRY(queue_max_write_zeroes_sectors, "write_zeroes_max_bytes"); QUEUE_RO_ENTRY(queue_max_zone_append_sectors, "zone_append_max_bytes"); QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); QUEUE_RO_ENTRY(queue_zoned, "zoned"); QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); QUEUE_RW_ENTRY(queue_iostats_passthrough, "iostats_passthrough"); QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); QUEUE_RW_ENTRY(queue_poll, "io_poll"); QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); QUEUE_RW_ENTRY(queue_wc, "write_cache"); QUEUE_RO_ENTRY(queue_fua, "fua"); QUEUE_RO_ENTRY(queue_dax, "dax"); QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask"); QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment"); /* legacy alias for logical_block_size: */ static struct queue_sysfs_entry queue_hw_sector_size_entry = { .attr = {.name = "hw_sector_size", .mode = 0444 }, .show = queue_logical_block_size_show, }; QUEUE_RW_ENTRY(queue_rotational, "rotational"); QUEUE_RW_ENTRY(queue_iostats, "iostats"); QUEUE_RW_ENTRY(queue_add_random, "add_random"); QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes"); #ifdef CONFIG_BLK_WBT static ssize_t queue_var_store64(s64 *var, const char *page) { int err; s64 v; err = kstrtos64(page, 10, &v); if (err < 0) return err; *var = v; return 0; } static ssize_t queue_wb_lat_show(struct gendisk *disk, char *page) { if (!wbt_rq_qos(disk->queue)) return -EINVAL; if (wbt_disabled(disk->queue)) return sysfs_emit(page, "0\n"); return sysfs_emit(page, "%llu\n", div_u64(wbt_get_min_lat(disk->queue), 1000)); } static ssize_t queue_wb_lat_store(struct gendisk *disk, const char *page, size_t count) { struct request_queue *q = disk->queue; struct rq_qos *rqos; ssize_t ret; s64 val; ret = queue_var_store64(&val, page); if (ret < 0) return ret; if (val < -1) return -EINVAL; rqos = wbt_rq_qos(q); if (!rqos) { ret = wbt_init(disk); if (ret) return ret; } if (val == -1) val = wbt_default_latency_nsec(q); else if (val >= 0) val *= 1000ULL; if (wbt_get_min_lat(q) == val) return count; /* * Ensure that the queue is idled, in case the latency update * ends up either enabling or disabling wbt completely. We can't * have IO inflight if that happens. */ blk_mq_quiesce_queue(q); wbt_set_min_lat(q, val); blk_mq_unquiesce_queue(q); return count; } QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); #endif /* Common attributes for bio-based and request-based queues. */ static struct attribute *queue_attrs[] = { &queue_ra_entry.attr, &queue_max_hw_sectors_entry.attr, &queue_max_sectors_entry.attr, &queue_max_segments_entry.attr, &queue_max_discard_segments_entry.attr, &queue_max_integrity_segments_entry.attr, &queue_max_segment_size_entry.attr, &queue_hw_sector_size_entry.attr, &queue_logical_block_size_entry.attr, &queue_physical_block_size_entry.attr, &queue_chunk_sectors_entry.attr, &queue_io_min_entry.attr, &queue_io_opt_entry.attr, &queue_discard_granularity_entry.attr, &queue_max_discard_sectors_entry.attr, &queue_max_hw_discard_sectors_entry.attr, &queue_discard_zeroes_data_entry.attr, &queue_atomic_write_max_sectors_entry.attr, &queue_atomic_write_boundary_sectors_entry.attr, &queue_atomic_write_unit_min_entry.attr, &queue_atomic_write_unit_max_entry.attr, &queue_write_same_max_entry.attr, &queue_max_write_zeroes_sectors_entry.attr, &queue_max_zone_append_sectors_entry.attr, &queue_zone_write_granularity_entry.attr, &queue_rotational_entry.attr, &queue_zoned_entry.attr, &queue_nr_zones_entry.attr, &queue_max_open_zones_entry.attr, &queue_max_active_zones_entry.attr, &queue_nomerges_entry.attr, &queue_iostats_passthrough_entry.attr, &queue_iostats_entry.attr, &queue_stable_writes_entry.attr, &queue_add_random_entry.attr, &queue_poll_entry.attr, &queue_wc_entry.attr, &queue_fua_entry.attr, &queue_dax_entry.attr, &queue_poll_delay_entry.attr, &queue_virt_boundary_mask_entry.attr, &queue_dma_alignment_entry.attr, NULL, }; /* Request-based queue attributes that are not relevant for bio-based queues. */ static struct attribute *blk_mq_queue_attrs[] = { &queue_requests_entry.attr, &elv_iosched_entry.attr, &queue_rq_affinity_entry.attr, &queue_io_timeout_entry.attr, #ifdef CONFIG_BLK_WBT &queue_wb_lat_entry.attr, #endif NULL, }; static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr, int n) { struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); struct request_queue *q = disk->queue; if ((attr == &queue_max_open_zones_entry.attr || attr == &queue_max_active_zones_entry.attr) && !blk_queue_is_zoned(q)) return 0; return attr->mode; } static umode_t blk_mq_queue_attr_visible(struct kobject *kobj, struct attribute *attr, int n) { struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); struct request_queue *q = disk->queue; if (!queue_is_mq(q)) return 0; if (attr == &queue_io_timeout_entry.attr && !q->mq_ops->timeout) return 0; return attr->mode; } static struct attribute_group queue_attr_group = { .attrs = queue_attrs, .is_visible = queue_attr_visible, }; static struct attribute_group blk_mq_queue_attr_group = { .attrs = blk_mq_queue_attrs, .is_visible = blk_mq_queue_attr_visible, }; #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) static ssize_t queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) { struct queue_sysfs_entry *entry = to_queue(attr); struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); ssize_t res; if (!entry->show) return -EIO; mutex_lock(&disk->queue->sysfs_lock); res = entry->show(disk, page); mutex_unlock(&disk->queue->sysfs_lock); return res; } static ssize_t queue_attr_store(struct kobject *kobj, struct attribute *attr, const char *page, size_t length) { struct queue_sysfs_entry *entry = to_queue(attr); struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); struct request_queue *q = disk->queue; ssize_t res; if (!entry->store) return -EIO; /* * If the attribute needs to load a module, do it before freezing the * queue to ensure that the module file can be read when the request * queue is the one for the device storing the module file. */ if (entry->load_module) entry->load_module(disk, page, length); blk_mq_freeze_queue(q); mutex_lock(&q->sysfs_lock); res = entry->store(disk, page, length); mutex_unlock(&q->sysfs_lock); blk_mq_unfreeze_queue(q); return res; } static const struct sysfs_ops queue_sysfs_ops = { .show = queue_attr_show, .store = queue_attr_store, }; static const struct attribute_group *blk_queue_attr_groups[] = { &queue_attr_group, &blk_mq_queue_attr_group, NULL }; static void blk_queue_release(struct kobject *kobj) { /* nothing to do here, all data is associated with the parent gendisk */ } static const struct kobj_type blk_queue_ktype = { .default_groups = blk_queue_attr_groups, .sysfs_ops = &queue_sysfs_ops, .release = blk_queue_release, }; static void blk_debugfs_remove(struct gendisk *disk) { struct request_queue *q = disk->queue; mutex_lock(&q->debugfs_mutex); blk_trace_shutdown(q); debugfs_remove_recursive(q->debugfs_dir); q->debugfs_dir = NULL; q->sched_debugfs_dir = NULL; q->rqos_debugfs_dir = NULL; mutex_unlock(&q->debugfs_mutex); } /** * blk_register_queue - register a block layer queue with sysfs * @disk: Disk of which the request queue should be registered with sysfs. */ int blk_register_queue(struct gendisk *disk) { struct request_queue *q = disk->queue; int ret; mutex_lock(&q->sysfs_dir_lock); kobject_init(&disk->queue_kobj, &blk_queue_ktype); ret = kobject_add(&disk->queue_kobj, &disk_to_dev(disk)->kobj, "queue"); if (ret < 0) goto out_put_queue_kobj; if (queue_is_mq(q)) { ret = blk_mq_sysfs_register(disk); if (ret) goto out_put_queue_kobj; } mutex_lock(&q->sysfs_lock); mutex_lock(&q->debugfs_mutex); q->debugfs_dir = debugfs_create_dir(disk->disk_name, blk_debugfs_root); if (queue_is_mq(q)) blk_mq_debugfs_register(q); mutex_unlock(&q->debugfs_mutex); ret = disk_register_independent_access_ranges(disk); if (ret) goto out_debugfs_remove; if (q->elevator) { ret = elv_register_queue(q, false); if (ret) goto out_unregister_ia_ranges; } ret = blk_crypto_sysfs_register(disk); if (ret) goto out_elv_unregister; blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); wbt_enable_default(disk); /* Now everything is ready and send out KOBJ_ADD uevent */ kobject_uevent(&disk->queue_kobj, KOBJ_ADD); if (q->elevator) kobject_uevent(&q->elevator->kobj, KOBJ_ADD); mutex_unlock(&q->sysfs_lock); mutex_unlock(&q->sysfs_dir_lock); /* * SCSI probing may synchronously create and destroy a lot of * request_queues for non-existent devices. Shutting down a fully * functional queue takes measureable wallclock time as RCU grace * periods are involved. To avoid excessive latency in these * cases, a request_queue starts out in a degraded mode which is * faster to shut down and is made fully functional here as * request_queues for non-existent devices never get registered. */ if (!blk_queue_init_done(q)) { blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q); percpu_ref_switch_to_percpu(&q->q_usage_counter); } return ret; out_elv_unregister: elv_unregister_queue(q); out_unregister_ia_ranges: disk_unregister_independent_access_ranges(disk); out_debugfs_remove: blk_debugfs_remove(disk); mutex_unlock(&q->sysfs_lock); out_put_queue_kobj: kobject_put(&disk->queue_kobj); mutex_unlock(&q->sysfs_dir_lock); return ret; } /** * blk_unregister_queue - counterpart of blk_register_queue() * @disk: Disk of which the request queue should be unregistered from sysfs. * * Note: the caller is responsible for guaranteeing that this function is called * after blk_register_queue() has finished. */ void blk_unregister_queue(struct gendisk *disk) { struct request_queue *q = disk->queue; if (WARN_ON(!q)) return; /* Return early if disk->queue was never registered. */ if (!blk_queue_registered(q)) return; /* * Since sysfs_remove_dir() prevents adding new directory entries * before removal of existing entries starts, protect against * concurrent elv_iosched_store() calls. */ mutex_lock(&q->sysfs_lock); blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q); mutex_unlock(&q->sysfs_lock); mutex_lock(&q->sysfs_dir_lock); /* * Remove the sysfs attributes before unregistering the queue data * structures that can be modified through sysfs. */ if (queue_is_mq(q)) blk_mq_sysfs_unregister(disk); blk_crypto_sysfs_unregister(disk); mutex_lock(&q->sysfs_lock); elv_unregister_queue(q); disk_unregister_independent_access_ranges(disk); mutex_unlock(&q->sysfs_lock); /* Now that we've deleted all child objects, we can delete the queue. */ kobject_uevent(&disk->queue_kobj, KOBJ_REMOVE); kobject_del(&disk->queue_kobj); mutex_unlock(&q->sysfs_dir_lock); blk_debugfs_remove(disk); }