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authorBart Van Assche <bvanassche@acm.org>2023-01-30 13:13:47 -0800
committerJens Axboe <axboe@kernel.dk>2023-02-01 08:16:11 -0700
commite152a05fa054170c05f1d5e04e93e2e75ea11405 (patch)
tree2167c4d6dc8f3c03551930737dff66269dea4987 /drivers/block
parent2d97930d74b12467fd5f48d8560e48c1cf5edcb1 (diff)
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>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/loop.c14
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);