ivampiresp/Spdk
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

vhost: ignore sessions that weren't ever started

Browse Source 
The previous patches described as optimizations also
fixed some issues. They seem sufficient to cover all
the error cases, but the real source of the problem
lies in foreach_session() initiated by the device backend,
which can use sessions that were never seen by the
backend.

The backends are only notified when a session is
*started*, but foreach_session() iterates through
all the sessions - even those that were never started.
Vhost SCSI, for example, in the foreach_session() callbacks
used to expect svsession->svdev to be always set, but
that field is only set when the session gets started.

A perfect solution would to introduce a new backend
callback to be called on new connection. Vhost SCSI
could set e.g. svsession->svdev inside. For now we go
with much easier solution that prevents sessions from
being used in foreach-session() unless they were
started at least once. (...and e.g. got their ->svdev set)

Change-Id: Ida30a1f27f99977360d08a71a64fc92931b25b75
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/449394
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
This commit is contained in:
Darek Stojaczyk 2019-03-27 14:59:45 +01:00 committed by Jim Harris
parent bf77d4b774
commit e051a5366e
2 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
lib/vhost/vhost.c
View File

@ -943,7 +943,7 @@ spdk_vhost_event_async_foreach_fn(void *arg1, void *arg2)
}
vsession = spdk_vhost_session_find_by_id(vdev, ctx->vsession_id);
if (vsession == NULL) {
if (vsession == NULL || !vsession->initialized) {
/* The session must have been removed in the meantime, so we
* just skip it in our foreach chain
*/
@ -1183,6 +1183,7 @@ start_device(int vid)
spdk_vhost_session_set_coalescing(vdev, vsession, NULL);
spdk_vhost_session_mem_register(vsession);
vsession->initialized = true;
rc = vdev->backend->start_session(vsession);
if (rc != 0) {
spdk_vhost_session_mem_unregister(vsession);
@ -1346,6 +1347,7 @@ new_connection(int vid)
vsession->id = vdev->vsessions_num++;
vsession->vid = vid;
vsession->lcore = -1;
vsession->initialized = false;
vsession->next_stats_check_time = 0;
vsession->stats_check_interval = SPDK_VHOST_STATS_CHECK_INTERVAL_MS *
spdk_get_ticks_hz() / 1000UL;
@ -1390,10 +1392,13 @@ spdk_vhost_external_event_foreach_continue(struct spdk_vhost_dev *vdev,
}
while (vsession->lcore == -1) {
rc = fn(vdev, vsession, arg);
if (rc < 0) {
return;
if (vsession->initialized) {
rc = fn(vdev, vsession, arg);
if (rc < 0) {
return;
}
}
vsession = spdk_vhost_session_next(vdev, vsession->id);
if (vsession == NULL) {
goto out_finish_foreach;

1
lib/vhost/vhost_internal.h
View File

@ -126,6 +126,7 @@ struct spdk_vhost_session {
int32_t lcore;
bool initialized;
bool needs_restart;
bool forced_polling;