loop: Improve the hw_queue_depth kernel module parameter implementation
Make the following minor changes which were reported by colleagues while reviewing this code: - Remove the parentheses from around the LOOP_DEFAULT_HW_Q_DEPTH definition since these are superfluous. - Accept other number formats than decimal, e.g. hexadecimal. - Do not set hw_queue_depth to an out-of-range value, even if that value won't be used. - Use the LOOP_DEFAULT_HW_Q_DEPTH macro in the kernel module parameter description to prevent that the description gets out of sync. This patch has been tested as follows: # modprobe -r loop # modprobe loop hw_queue_depth=-1 modprobe: ERROR: could not insert 'loop': Invalid argument # modprobe loop hw_queue_depth=0 modprobe: ERROR: could not insert 'loop': Invalid argument # modprobe loop hw_queue_depth=1; cat /sys/module/loop/parameters/hw_queue_depth 1 # modprobe -r loop; modprobe loop; cat /sys/module/loop/parameters/hw_queue_depth hw_queue_depth=0x10 16 # modprobe -r loop; modprobe loop; cat /sys/module/loop/parameters/hw_queue_depth hw_queue_depth=128 128 # modprobe -r loop; modprobe loop hw_queue_depth=129; cat /sys/module/loop/parameters/hw_queue_depth 129 # modprobe -r loop; modprobe loop hw_queue_depth=$((1<<32)) modprobe: ERROR: could not insert 'loop': Numerical result out of range See also commit ef44c508 ("loop: allow user to set the queue depth"). Cc: Chaitanya Kulkarni <kch@nvidia.com> Cc: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20230130211347.832110-1-bvanassche@acm.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>
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