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Allow sending TUR to consume all UAs during reconnect

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During reconnect we normally defer any SCSI commands that are issued
to be queued and sent later, once the re-connect has completed and we have
swapped the contexts.
This is what we want for almost all situations, except when we are
reconnecting very simple applications which request "no ua on reconnect".
For these applications we want to actually send the TURs that are used
during the login phase on the temporary context.

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
This commit is contained in:
Ronnie Sahlberg
2015-12-15 19:05:55 -08:00
parent cda985167d
commit 916fef6c03
1 changed files with 37 additions and 7 deletions
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44
lib/connect.c
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@@ -41,6 +41,33 @@ static void
iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_data _U_,
void *private_data);
/* During a reconnect all new SCSI commands are normally deferred to the
* old context and not actually issued until we have completed the re-connect
* and switched the contexts.
* This is what we want most of the time. However, IF we want to send TURs
* during the reconnect to eat all the UAs, then we want to send them out
* on this temporary context and NOT just queue them for until later.
* Hence this function.
*
* By setting ->old_iscsi temporarily to NULL when we are creating the TUR
* we avoid the check in iscsi_scsi_command_async() that otehrwise will try
* to defer this command until later.
*/
static struct scsi_task *
iscsi_testunitready_connect(struct iscsi_context *iscsi, int lun,
iscsi_command_cb cb, void *private_data)
{
struct scsi_task *task;
struct iscsi_context *old_iscsi = iscsi->old_iscsi;
iscsi->old_iscsi = NULL;
task = iscsi_testunitready_task(iscsi, lun, cb, private_data);
iscsi->old_iscsi = old_iscsi;
return task;
}
static void
iscsi_testunitready_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *private_data)
@@ -67,9 +94,9 @@ iscsi_testunitready_cb(struct iscsi_context *iscsi, int status,
scsi_free_scsi_task(task);
return;
}
if (iscsi_testunitready_task(iscsi, ct->lun,
iscsi_testunitready_cb,
ct) == NULL) {
if (iscsi_testunitready_connect(iscsi, ct->lun,
iscsi_testunitready_cb,
ct) == NULL) {
iscsi_set_error(iscsi, "iscsi_testunitready "
"failed.");
ct->cb(iscsi, SCSI_STATUS_ERROR, NULL,
@@ -135,8 +162,9 @@ iscsi_login_cb(struct iscsi_context *iscsi, int status, void *command_data _U_,
UAs that might be present.
*/
if (iscsi->no_ua_on_reconnect || (ct->lun != -1 && !iscsi->old_iscsi)) {
if (iscsi_testunitready_task(iscsi, ct->lun,
iscsi_testunitready_cb, ct) == NULL) {
if (iscsi_testunitready_connect(iscsi, ct->lun,
iscsi_testunitready_cb,
ct) == NULL) {
iscsi_set_error(iscsi, "iscsi_testunitready_async failed.");
ct->cb(iscsi, SCSI_STATUS_ERROR, NULL, ct->private_data);
iscsi_free(iscsi, ct);
@@ -269,6 +297,7 @@ void iscsi_reconnect_cb(struct iscsi_context *iscsi _U_, int status,
void *command_data _U_, void *private_data _U_)
{
int i;
if (status != SCSI_STATUS_GOOD) {
int backoff = ++iscsi->old_iscsi->retry_cnt;
if (backoff > 10) {
@@ -446,6 +475,7 @@ int iscsi_reconnect(struct iscsi_context *old_iscsi)
memcpy(old_iscsi, iscsi, sizeof(struct iscsi_context));
free(iscsi);
return iscsi_full_connect_async(old_iscsi, old_iscsi->portal,
old_iscsi->lun, iscsi_reconnect_cb, NULL);
return iscsi_full_connect_async(old_iscsi, old_iscsi->portal,
old_iscsi->lun, iscsi_reconnect_cb,
NULL);
}