From 8d4a690cd4f574bcb70c2cb89c227ba89a51351f Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Thu, 6 Oct 2011 03:56:57 -0500 Subject: [SCSI] iscsi class: Replace iscsi_get_next_target_id with IDA Replaced the iscsi_get_next_target_id with IDA to make target-id allocation efficient for iscsi offload drivers This patch should be applied after Jonathen Cameron Patch "ida : simplified functions for id allocation" Signed-off-by: John Soni Jose Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/scsi_transport_iscsi.c | 59 +++++++++++++++---------------------- 1 file changed, 23 insertions(+), 36 deletions(-) (limited to 'drivers') diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index c58f6766f4c7..d746c351588f 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -81,6 +82,7 @@ struct iscsi_internal { static atomic_t iscsi_session_nr; /* sysfs session id for next new session */ static struct workqueue_struct *iscsi_eh_timer_workq; +static DEFINE_IDA(iscsi_sess_ida); /* * list of registered transports and lock that must * be held while accessing list. The iscsi_transport_lock must @@ -990,6 +992,7 @@ static void __iscsi_unbind_session(struct work_struct *work) struct Scsi_Host *shost = iscsi_session_to_shost(session); struct iscsi_cls_host *ihost = shost->shost_data; unsigned long flags; + unsigned int target_id; ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n"); @@ -1001,10 +1004,15 @@ static void __iscsi_unbind_session(struct work_struct *work) mutex_unlock(&ihost->mutex); return; } + + target_id = session->target_id; session->target_id = ISCSI_MAX_TARGET; spin_unlock_irqrestore(&session->lock, flags); mutex_unlock(&ihost->mutex); + if (session->ida_used) + ida_simple_remove(&iscsi_sess_ida, target_id); + scsi_remove_target(&session->dev); iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION); ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n"); @@ -1045,59 +1053,36 @@ iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport, } EXPORT_SYMBOL_GPL(iscsi_alloc_session); -static int iscsi_get_next_target_id(struct device *dev, void *data) -{ - struct iscsi_cls_session *session; - unsigned long flags; - int err = 0; - - if (!iscsi_is_session_dev(dev)) - return 0; - - session = iscsi_dev_to_session(dev); - spin_lock_irqsave(&session->lock, flags); - if (*((unsigned int *) data) == session->target_id) - err = -EEXIST; - spin_unlock_irqrestore(&session->lock, flags); - return err; -} - int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id) { struct Scsi_Host *shost = iscsi_session_to_shost(session); struct iscsi_cls_host *ihost; unsigned long flags; - unsigned int id = target_id; + int id = 0; int err; ihost = shost->shost_data; session->sid = atomic_add_return(1, &iscsi_session_nr); - if (id == ISCSI_MAX_TARGET) { - for (id = 0; id < ISCSI_MAX_TARGET; id++) { - err = device_for_each_child(&shost->shost_gendev, &id, - iscsi_get_next_target_id); - if (!err) - break; - } + if (target_id == ISCSI_MAX_TARGET) { + id = ida_simple_get(&iscsi_sess_ida, 0, 0, GFP_KERNEL); - if (id == ISCSI_MAX_TARGET) { + if (id < 0) { iscsi_cls_session_printk(KERN_ERR, session, - "Too many iscsi targets. Max " - "number of targets is %d.\n", - ISCSI_MAX_TARGET - 1); - err = -EOVERFLOW; - goto release_host; + "Failure in Target ID Allocation\n"); + return id; } - } - session->target_id = id; + session->target_id = (unsigned int)id; + session->ida_used = true; + } else + session->target_id = target_id; dev_set_name(&session->dev, "session%u", session->sid); err = device_add(&session->dev); if (err) { iscsi_cls_session_printk(KERN_ERR, session, "could not register session's dev\n"); - goto release_host; + goto release_ida; } transport_register_device(&session->dev); @@ -1109,8 +1094,10 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id) ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n"); return 0; -release_host: - scsi_host_put(shost); +release_ida: + if (session->ida_used) + ida_simple_remove(&iscsi_sess_ida, session->target_id); + return err; } EXPORT_SYMBOL_GPL(iscsi_add_session); -- cgit v1.2.3