// SPDX-License-Identifier: GPL-2.0 /* * Functions related to setting various queue properties from drivers */ #include #include #include #include #include #include #include #include #include #include #include #include #include "blk.h" #include "blk-rq-qos.h" #include "blk-wbt.h" void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) { q->rq_timeout = timeout; } EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); /** * blk_set_stacking_limits - set default limits for stacking devices * @lim: the queue_limits structure to reset * * Prepare queue limits for applying limits from underlying devices using * blk_stack_limits(). */ void blk_set_stacking_limits(struct queue_limits *lim) { memset(lim, 0, sizeof(*lim)); lim->logical_block_size = SECTOR_SIZE; lim->physical_block_size = SECTOR_SIZE; lim->io_min = SECTOR_SIZE; lim->discard_granularity = SECTOR_SIZE; lim->dma_alignment = SECTOR_SIZE - 1; lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; /* Inherit limits from component devices */ lim->max_segments = USHRT_MAX; lim->max_discard_segments = USHRT_MAX; lim->max_hw_sectors = UINT_MAX; lim->max_segment_size = UINT_MAX; lim->max_sectors = UINT_MAX; lim->max_dev_sectors = UINT_MAX; lim->max_write_zeroes_sectors = UINT_MAX; lim->max_zone_append_sectors = UINT_MAX; lim->max_user_discard_sectors = UINT_MAX; } EXPORT_SYMBOL(blk_set_stacking_limits); void blk_apply_bdi_limits(struct backing_dev_info *bdi, struct queue_limits *lim) { /* * For read-ahead of large files to be effective, we need to read ahead * at least twice the optimal I/O size. */ bdi->ra_pages = max(lim->io_opt * 2 / PAGE_SIZE, VM_READAHEAD_PAGES); bdi->io_pages = lim->max_sectors >> PAGE_SECTORS_SHIFT; } static int blk_validate_zoned_limits(struct queue_limits *lim) { if (!(lim->features & BLK_FEAT_ZONED)) { if (WARN_ON_ONCE(lim->max_open_zones) || WARN_ON_ONCE(lim->max_active_zones) || WARN_ON_ONCE(lim->zone_write_granularity) || WARN_ON_ONCE(lim->max_zone_append_sectors)) return -EINVAL; return 0; } if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED))) return -EINVAL; /* * Given that active zones include open zones, the maximum number of * open zones cannot be larger than the maximum number of active zones. */ if (lim->max_active_zones && lim->max_open_zones > lim->max_active_zones) return -EINVAL; if (lim->zone_write_granularity < lim->logical_block_size) lim->zone_write_granularity = lim->logical_block_size; if (lim->max_zone_append_sectors) { /* * The Zone Append size is limited by the maximum I/O size * and the zone size given that it can't span zones. */ lim->max_zone_append_sectors = min3(lim->max_hw_sectors, lim->max_zone_append_sectors, lim->chunk_sectors); } return 0; } static int blk_validate_integrity_limits(struct queue_limits *lim) { struct blk_integrity *bi = &lim->integrity; if (!bi->tuple_size) { if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE || bi->tag_size || ((bi->flags & BLK_INTEGRITY_REF_TAG))) { pr_warn("invalid PI settings.\n"); return -EINVAL; } return 0; } if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) { pr_warn("integrity support disabled.\n"); return -EINVAL; } if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE && (bi->flags & BLK_INTEGRITY_REF_TAG)) { pr_warn("ref tag not support without checksum.\n"); return -EINVAL; } if (!bi->interval_exp) bi->interval_exp = ilog2(lim->logical_block_size); return 0; } /* * Returns max guaranteed bytes which we can fit in a bio. * * We request that an atomic_write is ITER_UBUF iov_iter (so a single vector), * so we assume that we can fit in at least PAGE_SIZE in a segment, apart from * the first and last segments. */ static unsigned int blk_queue_max_guaranteed_bio(struct queue_limits *lim) { unsigned int max_segments = min(BIO_MAX_VECS, lim->max_segments); unsigned int length; length = min(max_segments, 2) * lim->logical_block_size; if (max_segments > 2) length += (max_segments - 2) * PAGE_SIZE; return length; } static void blk_atomic_writes_update_limits(struct queue_limits *lim) { unsigned int unit_limit = min(lim->max_hw_sectors << SECTOR_SHIFT, blk_queue_max_guaranteed_bio(lim)); unit_limit = rounddown_pow_of_two(unit_limit); lim->atomic_write_max_sectors = min(lim->atomic_write_hw_max >> SECTOR_SHIFT, lim->max_hw_sectors); lim->atomic_write_unit_min = min(lim->atomic_write_hw_unit_min, unit_limit); lim->atomic_write_unit_max = min(lim->atomic_write_hw_unit_max, unit_limit); lim->atomic_write_boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT; } static void blk_validate_atomic_write_limits(struct queue_limits *lim) { unsigned int boundary_sectors; if (!lim->atomic_write_hw_max) goto unsupported; boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT; if (boundary_sectors) { /* * A feature of boundary support is that it disallows bios to * be merged which would result in a merged request which * crosses either a chunk sector or atomic write HW boundary, * even though chunk sectors may be just set for performance. * For simplicity, disallow atomic writes for a chunk sector * which is non-zero and smaller than atomic write HW boundary. * Furthermore, chunk sectors must be a multiple of atomic * write HW boundary. Otherwise boundary support becomes * complicated. * Devices which do not conform to these rules can be dealt * with if and when they show up. */ if (WARN_ON_ONCE(lim->chunk_sectors % boundary_sectors)) goto unsupported; /* * The boundary size just needs to be a multiple of unit_max * (and not necessarily a power-of-2), so this following check * could be relaxed in future. * Furthermore, if needed, unit_max could even be reduced so * that it is compliant with a !power-of-2 boundary. */ if (!is_power_of_2(boundary_sectors)) goto unsupported; } blk_atomic_writes_update_limits(lim); return; unsupported: lim->atomic_write_max_sectors = 0; lim->atomic_write_boundary_sectors = 0; lim->atomic_write_unit_min = 0; lim->atomic_write_unit_max = 0; } /* * Check that the limits in lim are valid, initialize defaults for unset * values, and cap values based on others where needed. */ static int blk_validate_limits(struct queue_limits *lim) { unsigned int max_hw_sectors; unsigned int logical_block_sectors; int err; /* * Unless otherwise specified, default to 512 byte logical blocks and a * physical block size equal to the logical block size. */ if (!lim->logical_block_size) lim->logical_block_size = SECTOR_SIZE; else if (blk_validate_block_size(lim->logical_block_size)) { pr_warn("Invalid logical block size (%d)\n", lim->logical_block_size); return -EINVAL; } if (lim->physical_block_size < lim->logical_block_size) lim->physical_block_size = lim->logical_block_size; /* * The minimum I/O size defaults to the physical block size unless * explicitly overridden. */ if (lim->io_min < lim->physical_block_size) lim->io_min = lim->physical_block_size; /* * max_hw_sectors has a somewhat weird default for historical reason, * but driver really should set their own instead of relying on this * value. * * The block layer relies on the fact that every driver can * handle at lest a page worth of data per I/O, and needs the value * aligned to the logical block size. */ if (!lim->max_hw_sectors) lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; if (WARN_ON_ONCE(lim->max_hw_sectors < PAGE_SECTORS)) return -EINVAL; logical_block_sectors = lim->logical_block_size >> SECTOR_SHIFT; if (WARN_ON_ONCE(logical_block_sectors > lim->max_hw_sectors)) return -EINVAL; lim->max_hw_sectors = round_down(lim->max_hw_sectors, logical_block_sectors); /* * The actual max_sectors value is a complex beast and also takes the * max_dev_sectors value (set by SCSI ULPs) and a user configurable * value into account. The ->max_sectors value is always calculated * from these, so directly setting it won't have any effect. */ max_hw_sectors = min_not_zero(lim->max_hw_sectors, lim->max_dev_sectors); if (lim->max_user_sectors) { if (lim->max_user_sectors < PAGE_SIZE / SECTOR_SIZE) return -EINVAL; lim->max_sectors = min(max_hw_sectors, lim->max_user_sectors); } else if (lim->io_opt > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) { lim->max_sectors = min(max_hw_sectors, lim->io_opt >> SECTOR_SHIFT); } else if (lim->io_min > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) { lim->max_sectors = min(max_hw_sectors, lim->io_min >> SECTOR_SHIFT); } else { lim->max_sectors = min(max_hw_sectors, BLK_DEF_MAX_SECTORS_CAP); } lim->max_sectors = round_down(lim->max_sectors, logical_block_sectors); /* * Random default for the maximum number of segments. Driver should not * rely on this and set their own. */ if (!lim->max_segments) lim->max_segments = BLK_MAX_SEGMENTS; lim->max_discard_sectors = min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors); if (!lim->max_discard_segments) lim->max_discard_segments = 1; if (lim->discard_granularity < lim->physical_block_size) lim->discard_granularity = lim->physical_block_size; /* * By default there is no limit on the segment boundary alignment, * but if there is one it can't be smaller than the page size as * that would break all the normal I/O patterns. */ if (!lim->seg_boundary_mask) lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; if (WARN_ON_ONCE(lim->seg_boundary_mask < PAGE_SIZE - 1)) return -EINVAL; /* * Stacking device may have both virtual boundary and max segment * size limit, so allow this setting now, and long-term the two * might need to move out of stacking limits since we have immutable * bvec and lower layer bio splitting is supposed to handle the two * correctly. */ if (lim->virt_boundary_mask) { if (!lim->max_segment_size) lim->max_segment_size = UINT_MAX; } else { /* * The maximum segment size has an odd historic 64k default that * drivers probably should override. Just like the I/O size we * require drivers to at least handle a full page per segment. */ if (!lim->max_segment_size) lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; if (WARN_ON_ONCE(lim->max_segment_size < PAGE_SIZE)) return -EINVAL; } /* * We require drivers to at least do logical block aligned I/O, but * historically could not check for that due to the separate calls * to set the limits. Once the transition is finished the check * below should be narrowed down to check the logical block size. */ if (!lim->dma_alignment) lim->dma_alignment = SECTOR_SIZE - 1; if (WARN_ON_ONCE(lim->dma_alignment > PAGE_SIZE)) return -EINVAL; if (lim->alignment_offset) { lim->alignment_offset &= (lim->physical_block_size - 1); lim->flags &= ~BLK_FLAG_MISALIGNED; } if (!(lim->features & BLK_FEAT_WRITE_CACHE)) lim->features &= ~BLK_FEAT_FUA; blk_validate_atomic_write_limits(lim); err = blk_validate_integrity_limits(lim); if (err) return err; return blk_validate_zoned_limits(lim); } /* * Set the default limits for a newly allocated queue. @lim contains the * initial limits set by the driver, which could be no limit in which case * all fields are cleared to zero. */ int blk_set_default_limits(struct queue_limits *lim) { /* * Most defaults are set by capping the bounds in blk_validate_limits, * but max_user_discard_sectors is special and needs an explicit * initialization to the max value here. */ lim->max_user_discard_sectors = UINT_MAX; return blk_validate_limits(lim); } /** * queue_limits_commit_update - commit an atomic update of queue limits * @q: queue to update * @lim: limits to apply * * Apply the limits in @lim that were obtained from queue_limits_start_update() * and updated by the caller to @q. * * Returns 0 if successful, else a negative error code. */ int queue_limits_commit_update(struct request_queue *q, struct queue_limits *lim) { int error; error = blk_validate_limits(lim); if (error) goto out_unlock; #ifdef CONFIG_BLK_INLINE_ENCRYPTION if (q->crypto_profile && lim->integrity.tag_size) { pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together.\n"); error = -EINVAL; goto out_unlock; } #endif q->limits = *lim; if (q->disk) blk_apply_bdi_limits(q->disk->bdi, lim); out_unlock: mutex_unlock(&q->limits_lock); return error; } EXPORT_SYMBOL_GPL(queue_limits_commit_update); /** * queue_limits_set - apply queue limits to queue * @q: queue to update * @lim: limits to apply * * Apply the limits in @lim that were freshly initialized to @q. * To update existing limits use queue_limits_start_update() and * queue_limits_commit_update() instead. * * Returns 0 if successful, else a negative error code. */ int queue_limits_set(struct request_queue *q, struct queue_limits *lim) { mutex_lock(&q->limits_lock); return queue_limits_commit_update(q, lim); } EXPORT_SYMBOL_GPL(queue_limits_set); /** * blk_limits_io_min - set minimum request size for a device * @limits: the queue limits * @min: smallest I/O size in bytes * * Description: * Some devices have an internal block size bigger than the reported * hardware sector size. This function can be used to signal the * smallest I/O the device can perform without incurring a performance * penalty. */ void blk_limits_io_min(struct queue_limits *limits, unsigned int min) { limits->io_min = min; if (limits->io_min < limits->logical_block_size) limits->io_min = limits->logical_block_size; if (limits->io_min < limits->physical_block_size) limits->io_min = limits->physical_block_size; } EXPORT_SYMBOL(blk_limits_io_min); /** * blk_limits_io_opt - set optimal request size for a device * @limits: the queue limits * @opt: smallest I/O size in bytes * * Description: * Storage devices may report an optimal I/O size, which is the * device's preferred unit for sustained I/O. This is rarely reported * for disk drives. For RAID arrays it is usually the stripe width or * the internal track size. A properly aligned multiple of * optimal_io_size is the preferred request size for workloads where * sustained throughput is desired. */ void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt) { limits->io_opt = opt; } EXPORT_SYMBOL(blk_limits_io_opt); static int queue_limit_alignment_offset(const struct queue_limits *lim, sector_t sector) { unsigned int granularity = max(lim->physical_block_size, lim->io_min); unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT) << SECTOR_SHIFT; return (granularity + lim->alignment_offset - alignment) % granularity; } static unsigned int queue_limit_discard_alignment( const struct queue_limits *lim, sector_t sector) { unsigned int alignment, granularity, offset; if (!lim->max_discard_sectors) return 0; /* Why are these in bytes, not sectors? */ alignment = lim->discard_alignment >> SECTOR_SHIFT; granularity = lim->discard_granularity >> SECTOR_SHIFT; if (!granularity) return 0; /* Offset of the partition start in 'granularity' sectors */ offset = sector_div(sector, granularity); /* And why do we do this modulus *again* in blkdev_issue_discard()? */ offset = (granularity + alignment - offset) % granularity; /* Turn it back into bytes, gaah */ return offset << SECTOR_SHIFT; } static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs) { sectors = round_down(sectors, lbs >> SECTOR_SHIFT); if (sectors < PAGE_SIZE >> SECTOR_SHIFT) sectors = PAGE_SIZE >> SECTOR_SHIFT; return sectors; } /** * blk_stack_limits - adjust queue_limits for stacked devices * @t: the stacking driver limits (top device) * @b: the underlying queue limits (bottom, component device) * @start: first data sector within component device * * Description: * This function is used by stacking drivers like MD and DM to ensure * that all component devices have compatible block sizes and * alignments. The stacking driver must provide a queue_limits * struct (top) and then iteratively call the stacking function for * all component (bottom) devices. The stacking function will * attempt to combine the values and ensure proper alignment. * * Returns 0 if the top and bottom queue_limits are compatible. The * top device's block sizes and alignment offsets may be adjusted to * ensure alignment with the bottom device. If no compatible sizes * and alignments exist, -1 is returned and the resulting top * queue_limits will have the misaligned flag set to indicate that * the alignment_offset is undefined. */ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, sector_t start) { unsigned int top, bottom, alignment, ret = 0; t->features |= (b->features & BLK_FEAT_INHERIT_MASK); /* * BLK_FEAT_NOWAIT and BLK_FEAT_POLL need to be supported both by the * stacking driver and all underlying devices. The stacking driver sets * the flags before stacking the limits, and this will clear the flags * if any of the underlying devices does not support it. */ if (!(b->features & BLK_FEAT_NOWAIT)) t->features &= ~BLK_FEAT_NOWAIT; if (!(b->features & BLK_FEAT_POLL)) t->features &= ~BLK_FEAT_POLL; t->flags |= (b->flags & BLK_FLAG_MISALIGNED); t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); t->max_user_sectors = min_not_zero(t->max_user_sectors, b->max_user_sectors); t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, b->max_write_zeroes_sectors); t->max_zone_append_sectors = min(queue_limits_max_zone_append_sectors(t), queue_limits_max_zone_append_sectors(b)); t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, b->seg_boundary_mask); t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, b->virt_boundary_mask); t->max_segments = min_not_zero(t->max_segments, b->max_segments); t->max_discard_segments = min_not_zero(t->max_discard_segments, b->max_discard_segments); t->max_integrity_segments = min_not_zero(t->max_integrity_segments, b->max_integrity_segments); t->max_segment_size = min_not_zero(t->max_segment_size, b->max_segment_size); alignment = queue_limit_alignment_offset(b, start); /* Bottom device has different alignment. Check that it is * compatible with the current top alignment. */ if (t->alignment_offset != alignment) { top = max(t->physical_block_size, t->io_min) + t->alignment_offset; bottom = max(b->physical_block_size, b->io_min) + alignment; /* Verify that top and bottom intervals line up */ if (max(top, bottom) % min(top, bottom)) { t->flags |= BLK_FLAG_MISALIGNED; ret = -1; } } t->logical_block_size = max(t->logical_block_size, b->logical_block_size); t->physical_block_size = max(t->physical_block_size, b->physical_block_size); t->io_min = max(t->io_min, b->io_min); t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); t->dma_alignment = max(t->dma_alignment, b->dma_alignment); /* Set non-power-of-2 compatible chunk_sectors boundary */ if (b->chunk_sectors) t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors); /* Physical block size a multiple of the logical block size? */ if (t->physical_block_size & (t->logical_block_size - 1)) { t->physical_block_size = t->logical_block_size; t->flags |= BLK_FLAG_MISALIGNED; ret = -1; } /* Minimum I/O a multiple of the physical block size? */ if (t->io_min & (t->physical_block_size - 1)) { t->io_min = t->physical_block_size; t->flags |= BLK_FLAG_MISALIGNED; ret = -1; } /* Optimal I/O a multiple of the physical block size? */ if (t->io_opt & (t->physical_block_size - 1)) { t->io_opt = 0; t->flags |= BLK_FLAG_MISALIGNED; ret = -1; } /* chunk_sectors a multiple of the physical block size? */ if ((t->chunk_sectors << 9) & (t->physical_block_size - 1)) { t->chunk_sectors = 0; t->flags |= BLK_FLAG_MISALIGNED; ret = -1; } /* Find lowest common alignment_offset */ t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) % max(t->physical_block_size, t->io_min); /* Verify that new alignment_offset is on a logical block boundary */ if (t->alignment_offset & (t->logical_block_size - 1)) { t->flags |= BLK_FLAG_MISALIGNED; ret = -1; } t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size); t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size); t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size); /* Discard alignment and granularity */ if (b->discard_granularity) { alignment = queue_limit_discard_alignment(b, start); t->max_discard_sectors = min_not_zero(t->max_discard_sectors, b->max_discard_sectors); t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, b->max_hw_discard_sectors); t->discard_granularity = max(t->discard_granularity, b->discard_granularity); t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % t->discard_granularity; } t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors, b->max_secure_erase_sectors); t->zone_write_granularity = max(t->zone_write_granularity, b->zone_write_granularity); if (!(t->features & BLK_FEAT_ZONED)) { t->zone_write_granularity = 0; t->max_zone_append_sectors = 0; } return ret; } EXPORT_SYMBOL(blk_stack_limits); /** * queue_limits_stack_bdev - adjust queue_limits for stacked devices * @t: the stacking driver limits (top device) * @bdev: the underlying block device (bottom) * @offset: offset to beginning of data within component device * @pfx: prefix to use for warnings logged * * Description: * This function is used by stacking drivers like MD and DM to ensure * that all component devices have compatible block sizes and * alignments. The stacking driver must provide a queue_limits * struct (top) and then iteratively call the stacking function for * all component (bottom) devices. The stacking function will * attempt to combine the values and ensure proper alignment. */ void queue_limits_stack_bdev(struct queue_limits *t, struct block_device *bdev, sector_t offset, const char *pfx) { if (blk_stack_limits(t, &bdev_get_queue(bdev)->limits, get_start_sect(bdev) + offset)) pr_notice("%s: Warning: Device %pg is misaligned\n", pfx, bdev); } EXPORT_SYMBOL_GPL(queue_limits_stack_bdev); /** * queue_limits_stack_integrity - stack integrity profile * @t: target queue limits * @b: base queue limits * * Check if the integrity profile in the @b can be stacked into the * target @t. Stacking is possible if either: * * a) does not have any integrity information stacked into it yet * b) the integrity profile in @b is identical to the one in @t * * If @b can be stacked into @t, return %true. Else return %false and clear the * integrity information in @t. */ bool queue_limits_stack_integrity(struct queue_limits *t, struct queue_limits *b) { struct blk_integrity *ti = &t->integrity; struct blk_integrity *bi = &b->integrity; if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) return true; if (!ti->tuple_size) { /* inherit the settings from the first underlying device */ if (!(ti->flags & BLK_INTEGRITY_STACKED)) { ti->flags = BLK_INTEGRITY_DEVICE_CAPABLE | (bi->flags & BLK_INTEGRITY_REF_TAG); ti->csum_type = bi->csum_type; ti->tuple_size = bi->tuple_size; ti->pi_offset = bi->pi_offset; ti->interval_exp = bi->interval_exp; ti->tag_size = bi->tag_size; goto done; } if (!bi->tuple_size) goto done; } if (ti->tuple_size != bi->tuple_size) goto incompatible; if (ti->interval_exp != bi->interval_exp) goto incompatible; if (ti->tag_size != bi->tag_size) goto incompatible; if (ti->csum_type != bi->csum_type) goto incompatible; if ((ti->flags & BLK_INTEGRITY_REF_TAG) != (bi->flags & BLK_INTEGRITY_REF_TAG)) goto incompatible; done: ti->flags |= BLK_INTEGRITY_STACKED; return true; incompatible: memset(ti, 0, sizeof(*ti)); return false; } EXPORT_SYMBOL_GPL(queue_limits_stack_integrity); /** * blk_set_queue_depth - tell the block layer about the device queue depth * @q: the request queue for the device * @depth: queue depth * */ void blk_set_queue_depth(struct request_queue *q, unsigned int depth) { q->queue_depth = depth; rq_qos_queue_depth_changed(q); } EXPORT_SYMBOL(blk_set_queue_depth); int bdev_alignment_offset(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); if (q->limits.flags & BLK_FLAG_MISALIGNED) return -1; if (bdev_is_partition(bdev)) return queue_limit_alignment_offset(&q->limits, bdev->bd_start_sect); return q->limits.alignment_offset; } EXPORT_SYMBOL_GPL(bdev_alignment_offset); unsigned int bdev_discard_alignment(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); if (bdev_is_partition(bdev)) return queue_limit_discard_alignment(&q->limits, bdev->bd_start_sect); return q->limits.discard_alignment; } EXPORT_SYMBOL_GPL(bdev_discard_alignment);