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authorJohn Soni Jose <sony.john@avagotech.com>2015-06-24 06:41:58 +0530
committerSasha Levin <sasha.levin@oracle.com>2015-09-17 01:30:30 -0400
commit20b38ab5b687df3dbb873cfb0efa946a021f890a (patch)
treece2ad87f2a9f6e2d8460fcdb69cefc578559ff1a
parent38da5ebc9d7b7ba9482f65cd4cf1c55bd6c28c72 (diff)
libiscsi: Fix host busy blocking during connection teardown
[ Upstream commit 660d0831d1494a6837b2f810d08b5be092c1f31d ] In case of hw iscsi offload, an host can have N-number of active connections. There can be IO's running on some connections which make host->host_busy always TRUE. Now if logout from a connection is tried then the code gets into an infinite loop as host->host_busy is always TRUE. iscsi_conn_teardown(....) { ......... /* * Block until all in-progress commands for this connection * time out or fail. */ for (;;) { spin_lock_irqsave(session->host->host_lock, flags); if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */ spin_unlock_irqrestore(session->host->host_lock, flags); break; } spin_unlock_irqrestore(session->host->host_lock, flags); msleep_interruptible(500); iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): " "host_busy %d host_failed %d\n", atomic_read(&session->host->host_busy), session->host->host_failed); ................ ............... } } This is not an issue with software-iscsi/iser as each cxn is a separate host. Fix: Acquiring eh_mutex in iscsi_conn_teardown() before setting session->state = ISCSI_STATE_TERMINATE. Signed-off-by: John Soni Jose <sony.john@avagotech.com> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Chris Leech <cleech@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--drivers/scsi/libiscsi.c25
1 files changed, 2 insertions, 23 deletions
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 0d8bc6c66650..7854584ebd59 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2960,10 +2960,10 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_session *session = conn->session;
- unsigned long flags;
del_timer_sync(&conn->transport_timer);
+ mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->frwd_lock);
conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
if (session->leadconn == conn) {
@@ -2975,28 +2975,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
}
spin_unlock_bh(&session->frwd_lock);
- /*
- * Block until all in-progress commands for this connection
- * time out or fail.
- */
- for (;;) {
- spin_lock_irqsave(session->host->host_lock, flags);
- if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
- spin_unlock_irqrestore(session->host->host_lock, flags);
- break;
- }
- spin_unlock_irqrestore(session->host->host_lock, flags);
- msleep_interruptible(500);
- iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
- "host_busy %d host_failed %d\n",
- atomic_read(&session->host->host_busy),
- session->host->host_failed);
- /*
- * force eh_abort() to unblock
- */
- wake_up(&conn->ehwait);
- }
-
/* flush queued up work because we free the connection below */
iscsi_suspend_tx(conn);
@@ -3013,6 +2991,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
if (session->leadconn == conn)
session->leadconn = NULL;
spin_unlock_bh(&session->frwd_lock);
+ mutex_unlock(&session->eh_mutex);
iscsi_destroy_conn(cls_conn);
}