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authorPeter Lieven <pl@kamp.de>2012-12-06 10:46:47 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2013-01-22 15:07:03 +0100
commit5b5d34ec9882b29b757f6808693308e52a8e8ba7 (patch)
tree205ceec23470140440d8dee9a7456f31b63b3b97 /block
parent4cc841b57c1dc91d71bafc25b53ffab4eff7959b (diff)
iscsi: add support for iSCSI NOPs [v2]
This patch will send NOP-Out PDUs every 5 seconds to the iSCSI target. If a consecutive number of NOP-In replies fail a reconnect is initiated. iSCSI NOPs help to ensure that the connection to the target is still operational. This should not, but in reality may be the case even if the TCP connection is still alive if there are bugs in either the target or the initiator implementation. v2: - track the NOPs inside libiscsi so libiscsi can reset the counter in case it initiates a reconnect. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/iscsi.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/block/iscsi.c b/block/iscsi.c
index 259192f535..249778986d 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -48,6 +48,7 @@ typedef struct IscsiLun {
int block_size;
uint64_t num_blocks;
int events;
+ QEMUTimer *nop_timer;
} IscsiLun;
typedef struct IscsiAIOCB {
@@ -66,6 +67,9 @@ typedef struct IscsiAIOCB {
#endif
} IscsiAIOCB;
+#define NOP_INTERVAL 5000
+#define MAX_NOP_FAILURES 3
+
static void
iscsi_bh_cb(void *p)
{
@@ -768,6 +772,26 @@ static char *parse_initiator_name(const char *target)
}
}
+#if defined(LIBISCSI_FEATURE_NOP_COUNTER)
+static void iscsi_nop_timed_event(void *opaque)
+{
+ IscsiLun *iscsilun = opaque;
+
+ if (iscsi_get_nops_in_flight(iscsilun->iscsi) > MAX_NOP_FAILURES) {
+ error_report("iSCSI: NOP timeout. Reconnecting...");
+ iscsi_reconnect(iscsilun->iscsi);
+ }
+
+ if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) {
+ error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages.");
+ return;
+ }
+
+ qemu_mod_timer(iscsilun->nop_timer, qemu_get_clock_ms(rt_clock) + NOP_INTERVAL);
+ iscsi_set_events(iscsilun);
+}
+#endif
+
/*
* We support iscsi url's on the form
* iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
@@ -928,6 +952,12 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
ret = 0;
+#if defined(LIBISCSI_FEATURE_NOP_COUNTER)
+ /* Set up a timer for sending out iSCSI NOPs */
+ iscsilun->nop_timer = qemu_new_timer_ms(rt_clock, iscsi_nop_timed_event, iscsilun);
+ qemu_mod_timer(iscsilun->nop_timer, qemu_get_clock_ms(rt_clock) + NOP_INTERVAL);
+#endif
+
out:
if (initiator_name != NULL) {
g_free(initiator_name);
@@ -953,6 +983,10 @@ static void iscsi_close(BlockDriverState *bs)
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
+ if (iscsilun->nop_timer) {
+ qemu_del_timer(iscsilun->nop_timer);
+ qemu_free_timer(iscsilun->nop_timer);
+ }
qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), NULL, NULL, NULL, NULL);
iscsi_destroy_context(iscsi);
memset(iscsilun, 0, sizeof(IscsiLun));
@@ -987,6 +1021,10 @@ static int iscsi_create(const char *filename, QEMUOptionParameter *options)
if (ret != 0) {
goto out;
}
+ if (iscsilun->nop_timer) {
+ qemu_del_timer(iscsilun->nop_timer);
+ qemu_free_timer(iscsilun->nop_timer);
+ }
if (iscsilun->type != TYPE_DISK) {
ret = -ENODEV;
goto out;