Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 32/57] libiscsi: Fix host busy blocking during connection teardown | Date | Tue, 22 Sep 2015 10:48:21 -0700 |
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3.13.11-ckt27 -stable review patch. If anyone has any objections, please let me know.
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From: John Soni Jose <sony.john@avagotech.com>
commit 660d0831d1494a6837b2f810d08b5be092c1f31d upstream.
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> Signed-off-by: James Bottomley <JBottomley@Odin.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/scsi/libiscsi.c | 25 ++----------------------- 1 file changed, 2 insertions(+), 23 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index b69b233..dbf27d6 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -2911,10 +2911,10 @@ 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->lock); conn->c_stage = ISCSI_CONN_CLEANUP_WAIT; if (session->leadconn == conn) { @@ -2926,28 +2926,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) } spin_unlock_bh(&session->lock); - /* - * Block until all in-progress commands for this connection - * time out or fail. - */ - for (;;) { - spin_lock_irqsave(session->host->host_lock, flags); - if (!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", - 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); @@ -2960,6 +2938,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) if (session->leadconn == conn) session->leadconn = NULL; spin_unlock_bh(&session->lock); + mutex_unlock(&session->eh_mutex); iscsi_destroy_conn(cls_conn); } -- 1.9.1
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