BLK_STACK_LIMITS(9) Block Devices BLK_STACK_LIMITS(9)NAME
blk_stack_limits - adjust queue_limits for stacked devices
SYNOPSIS
int blk_stack_limits(struct queue_limits * t, struct queue_limits * b,
sector_t start);
ARGUMENTS
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
deviceĀ“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.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 BLK_STACK_LIMITS(9)