From 9709f0e05b827049733f439de82a4a1688b37b86 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 26 Nov 2010 13:13:06 -0500 Subject: [PATCH] IB/srp: consolidate state change code Signed-off-by: Bart Van Assche [ broken out and small cleanups by David Dillow ] Signed-off-by: David Dillow --- drivers/infiniband/ulp/srp/ib_srp.c | 45 +++++++++++++++-------------- 1 file changed, 24 insertions(+), 21 deletions(-) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 29429a13fd90..def9e6b38459 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -441,18 +441,28 @@ static void srp_disconnect_target(struct srp_target_port *target) wait_for_completion(&target->done); } +static bool srp_change_state(struct srp_target_port *target, + enum srp_target_state old, + enum srp_target_state new) +{ + bool changed = false; + + spin_lock_irq(target->scsi_host->host_lock); + if (target->state == old) { + target->state = new; + changed = true; + } + spin_unlock_irq(target->scsi_host->host_lock); + return changed; +} + static void srp_remove_work(struct work_struct *work) { struct srp_target_port *target = container_of(work, struct srp_target_port, work); - spin_lock_irq(target->scsi_host->host_lock); - if (target->state != SRP_TARGET_DEAD) { - spin_unlock_irq(target->scsi_host->host_lock); + if (!srp_change_state(target, SRP_TARGET_DEAD, SRP_TARGET_REMOVED)) return; - } - target->state = SRP_TARGET_REMOVED; - spin_unlock_irq(target->scsi_host->host_lock); spin_lock(&target->srp_host->target_lock); list_del(&target->list); @@ -560,13 +570,8 @@ static int srp_reconnect_target(struct srp_target_port *target) struct ib_wc wc; int ret; - spin_lock_irq(target->scsi_host->host_lock); - if (target->state != SRP_TARGET_LIVE) { - spin_unlock_irq(target->scsi_host->host_lock); + if (!srp_change_state(target, SRP_TARGET_LIVE, SRP_TARGET_CONNECTING)) return -EAGAIN; - } - target->state = SRP_TARGET_CONNECTING; - spin_unlock_irq(target->scsi_host->host_lock); srp_disconnect_target(target); /* @@ -605,13 +610,8 @@ static int srp_reconnect_target(struct srp_target_port *target) if (ret) goto err; - spin_lock_irq(target->scsi_host->host_lock); - if (target->state == SRP_TARGET_CONNECTING) { - ret = 0; - target->state = SRP_TARGET_LIVE; - } else + if (!srp_change_state(target, SRP_TARGET_CONNECTING, SRP_TARGET_LIVE)) ret = -EAGAIN; - spin_unlock_irq(target->scsi_host->host_lock); return ret; @@ -621,9 +621,12 @@ static int srp_reconnect_target(struct srp_target_port *target) /* * We couldn't reconnect, so kill our target port off. - * However, we have to defer the real removal because we might - * be in the context of the SCSI error handler now, which - * would deadlock if we call scsi_remove_host(). + * However, we have to defer the real removal because we + * are in the context of the SCSI error handler now, which + * will deadlock if we call scsi_remove_host(). + * + * Schedule our work inside the lock to avoid a race with + * the flush_scheduled_work() in srp_remove_one(). */ spin_lock_irq(target->scsi_host->host_lock); if (target->state == SRP_TARGET_CONNECTING) {