The connection uniqueness check is performed before a new connection is added to the target list. This patch protects both actions by a mutex such that simultaneous writes from two different threads into the "add_target" variable do not result in duplicate connections.
Signed-off-by: Bart Van Assche <[email protected]> Cc: Sagi Grimberg <[email protected]> Cc: Sebastian Riemer <[email protected]> Cc: Roland Dreier <[email protected]> --- drivers/infiniband/ulp/srp/ib_srp.c | 12 +++++++++--- drivers/infiniband/ulp/srp/ib_srp.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index b3ca4d6..7d9413e 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -2617,6 +2617,8 @@ static ssize_t srp_create_target(struct device *dev, target->tl_retry_count = 7; target->queue_size = SRP_DEFAULT_QUEUE_SIZE; + mutex_lock(&host->add_target_mutex); + ret = srp_parse_options(buf, target); if (ret) goto err; @@ -2683,7 +2685,11 @@ static ssize_t srp_create_target(struct device *dev, be64_to_cpu(target->service_id), target->path.sgid.raw, target->path.dgid.raw); - return count; + ret = count; + +out: + mutex_unlock(&host->add_target_mutex); + return ret; err_disconnect: srp_disconnect_target(target); @@ -2699,8 +2705,7 @@ err_free_mem: err: scsi_host_put(target_host); - - return ret; + goto out; } static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target); @@ -2736,6 +2741,7 @@ static struct srp_host *srp_add_port(struct srp_device *device, u8 port) INIT_LIST_HEAD(&host->target_list); spin_lock_init(&host->target_lock); init_completion(&host->released); + mutex_init(&host->add_target_mutex); host->srp_dev = device; host->port = port; diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h index 5756810..aad27b7 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.h +++ b/drivers/infiniband/ulp/srp/ib_srp.h @@ -105,6 +105,7 @@ struct srp_host { spinlock_t target_lock; struct completion released; struct list_head list; + struct mutex add_target_mutex; }; struct srp_request { -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
