On 1/27/21 1:45 PM, Lee Duncan wrote:
On 1/18/21 12:34 PM, Mike Christie wrote:
This patch just breaks out the code that calculates the number
of scsi cmds that will be used for a scsi session. It also adds
a check that we don't go over the host's can_queue value.
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
---
drivers/scsi/libiscsi.c | 84 +++++++++++++++++++++++++----------------
include/scsi/libiscsi.h | 2 +
2 files changed, 54 insertions(+), 32 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index b271d3accd2a..195006a08e0d 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2648,6 +2648,54 @@ void iscsi_pool_free(struct iscsi_pool *q)
}
EXPORT_SYMBOL_GPL(iscsi_pool_free);
+int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
+ uint16_t requested_cmds_max)
+{
+ int scsi_cmds, total_cmds = requested_cmds_max;
+
+check:
+ if (!total_cmds)
+ total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
+ /*
+ * The iscsi layer needs some tasks for nop handling and tmfs,
+ * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
+ * + 1 command for scsi IO.
+ */
+ if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
+ printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
+ total_cmds, ISCSI_TOTAL_CMDS_MIN);
+ return -EINVAL;
+ }
+
+ if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
+ printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d.\n",
+ requested_cmds_max, ISCSI_TOTAL_CMDS_MAX);
+ total_cmds = ISCSI_TOTAL_CMDS_MAX;
+ }
+
+ if (!is_power_of_2(total_cmds)) {
+ printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2.\n",
+ total_cmds);
I don't like mixing KERN_ERR and KERN_INFO for the same event. Can we
make it just one KERN_INFO? (since we keep going)
I think INFO is good. This patch just copied the old code, but I'm not
sure why I used ERR for the other cases where I fix up the value for the
user. I'll fix those too like the one above this one, so we are consistent.
