diff options
Diffstat (limited to 'block/blk-settings.c')
| -rw-r--r-- | block/blk-settings.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index b0f547c..5649f34 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -309,9 +309,94 @@ EXPORT_SYMBOL(blk_queue_max_segment_size); void blk_queue_logical_block_size(struct request_queue *q, unsigned short size) { q->limits.logical_block_size = size; + + if (q->limits.physical_block_size < size) + q->limits.physical_block_size = size; + + if (q->limits.io_min < q->limits.physical_block_size) + q->limits.io_min = q->limits.physical_block_size; } EXPORT_SYMBOL(blk_queue_logical_block_size); +/** + * blk_queue_physical_block_size - set physical block size for the queue + * @q: the request queue for the device + * @size: the physical block size, in bytes + * + * Description: + * This should be set to the lowest possible sector size that the + * hardware can operate on without reverting to read-modify-write + * operations. + */ +void blk_queue_physical_block_size(struct request_queue *q, unsigned short size) +{ + q->limits.physical_block_size = size; + + if (q->limits.physical_block_size < q->limits.logical_block_size) + q->limits.physical_block_size = q->limits.logical_block_size; + + if (q->limits.io_min < q->limits.physical_block_size) + q->limits.io_min = q->limits.physical_block_size; +} +EXPORT_SYMBOL(blk_queue_physical_block_size); + +/** + * blk_queue_alignment_offset - set physical block alignment offset + * @q: the request queue for the device + * @alignment: alignment offset in bytes + * + * Description: + * Some devices are naturally misaligned to compensate for things like + * the legacy DOS partition table 63-sector offset. Low-level drivers + * should call this function for devices whose first sector is not + * naturally aligned. + */ +void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) +{ + q->limits.alignment_offset = + offset & (q->limits.physical_block_size - 1); + q->limits.misaligned = 0; +} +EXPORT_SYMBOL(blk_queue_alignment_offset); + +/** + * blk_queue_io_min - set minimum request size for the queue + * @q: the request queue for the device + * @io_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_queue_io_min(struct request_queue *q, unsigned int min) +{ + q->limits.io_min = min; + + if (q->limits.io_min < q->limits.logical_block_size) + q->limits.io_min = q->limits.logical_block_size; + + if (q->limits.io_min < q->limits.physical_block_size) + q->limits.io_min = q->limits.physical_block_size; +} +EXPORT_SYMBOL(blk_queue_io_min); + +/** + * blk_queue_io_opt - set optimal request size for the queue + * @q: the request queue for the device + * @io_opt: optimal request size in bytes + * + * Description: + * Drivers can call this function to set the preferred I/O request + * size for devices that report such a value. + */ +void blk_queue_io_opt(struct request_queue *q, unsigned int opt) +{ + q->limits.io_opt = opt; +} +EXPORT_SYMBOL(blk_queue_io_opt); + /* * Returns the minimum that is _not_ zero, unless both are zero. */ @@ -358,6 +443,107 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) EXPORT_SYMBOL(blk_queue_stack_limits); /** + * blk_stack_limits - adjust queue_limits for stacked devices + * @t: the stacking driver limits (top) + * @bdev: the underlying queue limits (bottom) + * @offset: offset to beginning of data within component device + * + * Description: + * Merges two queue_limit structs. Returns 0 if alignment didn't + * change. Returns -1 if adding the bottom device caused + * misalignment. + */ +int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, + sector_t offset) +{ + t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); + t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); + + t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, + b->seg_boundary_mask); + + t->max_phys_segments = min_not_zero(t->max_phys_segments, + b->max_phys_segments); + + t->max_hw_segments = min_not_zero(t->max_hw_segments, + b->max_hw_segments); + + t->max_segment_size = min_not_zero(t->max_segment_size, + b->max_segment_size); + + 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->no_cluster |= b->no_cluster; + + /* Bottom device offset aligned? */ + if (offset && + (offset & (b->physical_block_size - 1)) != b->alignment_offset) { + t->misaligned = 1; + return -1; + } + + /* If top has no alignment offset, inherit from bottom */ + if (!t->alignment_offset) + t->alignment_offset = + b->alignment_offset & (b->physical_block_size - 1); + + /* Top device aligned on logical block boundary? */ + if (t->alignment_offset & (t->logical_block_size - 1)) { + t->misaligned = 1; + return -1; + } + + return 0; +} + +/** + * disk_stack_limits - adjust queue limits for stacked drivers + * @t: MD/DM gendisk (top) + * @bdev: the underlying block device (bottom) + * @offset: offset to beginning of data within component device + * + * Description: + * Merges the limits for two queues. Returns 0 if alignment + * didn't change. Returns -1 if adding the bottom device caused + * misalignment. + */ +void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, + sector_t offset) +{ + struct request_queue *t = disk->queue; + struct request_queue *b = bdev_get_queue(bdev); + + offset += get_start_sect(bdev) << 9; + + if (blk_stack_limits(&t->limits, &b->limits, offset) < 0) { + char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE]; + + disk_name(disk, 0, top); + bdevname(bdev, bottom); + + printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n", + top, bottom); + } + + if (!t->queue_lock) + WARN_ON_ONCE(1); + else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) { + unsigned long flags; + + spin_lock_irqsave(t->queue_lock, flags); + if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) + queue_flag_clear(QUEUE_FLAG_CLUSTER, t); + spin_unlock_irqrestore(t->queue_lock, flags); + } +} +EXPORT_SYMBOL(disk_stack_limits); + +/** * blk_queue_dma_pad - set pad mask * @q: the request queue for the device * @mask: pad mask |
