diff options
Diffstat (limited to 'block/blk-settings.c')
| -rw-r--r-- | block/blk-settings.c | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index d52d4ad..5eeb9e0 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -528,7 +528,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, sector_t offset) { sector_t alignment; - unsigned int top, bottom; + unsigned int top, bottom, ret = 0; 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); @@ -546,6 +546,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->max_segment_size = min_not_zero(t->max_segment_size, b->max_segment_size); + t->misaligned |= b->misaligned; + alignment = queue_limit_alignment_offset(b, offset); /* Bottom device has different alignment. Check that it is @@ -558,8 +560,10 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 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) - 1)) + if (max(top, bottom) & (min(top, bottom) - 1)) { t->misaligned = 1; + ret = -1; + } } t->logical_block_size = max(t->logical_block_size, @@ -578,18 +582,21 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, if (t->physical_block_size & (t->logical_block_size - 1)) { t->physical_block_size = t->logical_block_size; t->misaligned = 1; + 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->misaligned = 1; + 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->misaligned = 1; + ret = -1; } /* Find lowest common alignment_offset */ @@ -597,8 +604,10 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, & (max(t->physical_block_size, t->io_min) - 1); /* Verify that new alignment_offset is on a logical block boundary */ - if (t->alignment_offset & (t->logical_block_size - 1)) + if (t->alignment_offset & (t->logical_block_size - 1)) { t->misaligned = 1; + ret = -1; + } /* Discard alignment and granularity */ if (b->discard_granularity) { @@ -626,11 +635,33 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, (t->discard_granularity - 1); } - return t->misaligned ? -1 : 0; + return ret; } EXPORT_SYMBOL(blk_stack_limits); /** + * bdev_stack_limits - adjust queue limits for stacked drivers + * @t: the stacking driver limits (top device) + * @bdev: the component block_device (bottom) + * @start: first data sector within component device + * + * Description: + * Merges queue limits for a top device and a block_device. Returns + * 0 if alignment didn't change. Returns -1 if adding the bottom + * device caused misalignment. + */ +int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, + sector_t start) +{ + struct request_queue *bq = bdev_get_queue(bdev); + + start += get_start_sect(bdev); + + return blk_stack_limits(t, &bq->limits, start << 9); +} +EXPORT_SYMBOL(bdev_stack_limits); + +/** * disk_stack_limits - adjust queue limits for stacked drivers * @disk: MD/DM gendisk (top) * @bdev: the underlying block device (bottom) |
