diff options
author | Bart Van Assche <bvanassche@acm.org> | 2023-01-31 00:13:47 +0300 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2023-02-01 18:16:11 +0300 |
commit | e152a05fa054170c05f1d5e04e93e2e75ea11405 (patch) | |
tree | 2167c4d6dc8f3c03551930737dff66269dea4987 | |
parent | 2d97930d74b12467fd5f48d8560e48c1cf5edcb1 (diff) | |
download | linux-e152a05fa054170c05f1d5e04e93e2e75ea11405.tar.xz |
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 ef44c50837ab ("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.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | drivers/block/loop.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 1518a6423279..5f04235e4ff7 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -90,7 +90,7 @@ struct loop_cmd { }; #define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ) -#define LOOP_DEFAULT_HW_Q_DEPTH (128) +#define LOOP_DEFAULT_HW_Q_DEPTH 128 static DEFINE_IDR(loop_index_idr); static DEFINE_MUTEX(loop_ctl_mutex); @@ -1792,9 +1792,15 @@ static int hw_queue_depth = LOOP_DEFAULT_HW_Q_DEPTH; static int loop_set_hw_queue_depth(const char *s, const struct kernel_param *p) { - int ret = kstrtoint(s, 10, &hw_queue_depth); + int qd, ret; - return (ret || (hw_queue_depth < 1)) ? -EINVAL : 0; + ret = kstrtoint(s, 0, &qd); + if (ret < 0) + return ret; + if (qd < 1) + return -EINVAL; + hw_queue_depth = qd; + return 0; } static const struct kernel_param_ops loop_hw_qdepth_param_ops = { @@ -1803,7 +1809,7 @@ static const struct kernel_param_ops loop_hw_qdepth_param_ops = { }; device_param_cb(hw_queue_depth, &loop_hw_qdepth_param_ops, &hw_queue_depth, 0444); -MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 128"); +MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: " __stringify(LOOP_DEFAULT_HW_Q_DEPTH)); MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); |