Ping? It'd be nice to get some answers to these questions rather than merging this conversion with the questions still in the changelog ...
----- Forwarded message from Matthew Wilcox <[email protected]> ----- Date: Thu, 21 Jun 2018 14:28:27 -0700 From: Matthew Wilcox <[email protected]> To: [email protected] Cc: Matthew Wilcox <[email protected]>, "Nicholas A. Bellinger" <[email protected]>, Bart Van Assche <[email protected]>, Hannes Reinecke <[email protected]>, Kees Cook <[email protected]>, Varun Prakash <[email protected]>, Sagi Grimberg <[email protected]>, Philippe Ombredanne <[email protected]>, Greg Kroah-Hartman <[email protected]>, Kate Stewart <[email protected]>, Thomas Gleixner <[email protected]>, "David S. Miller" <[email protected]>, Denys Vlasenko <[email protected]>, [email protected], [email protected] Subject: [PATCH 18/26] target/iscsi: Allocate session IDs from an IDA X-Mailer: git-send-email 2.14.3 Since the session is never looked up by ID, we can use the more space-efficient IDA instead of the IDR. I think I found a bug where we never reuse session ID 0, but there may be a good reason for it, so I've merely documented it in this patch. Not reusing session ID 0 doesn't even leak memory. Signed-off-by: Matthew Wilcox <[email protected]> --- drivers/target/iscsi/iscsi_target.c | 10 ++-------- drivers/target/iscsi/iscsi_target.h | 4 +--- drivers/target/iscsi/iscsi_target_login.c | 20 ++++++-------------- 3 files changed, 9 insertions(+), 25 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 8e223799347a..94bad43c41ff 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -57,9 +57,8 @@ static DEFINE_SPINLOCK(tiqn_lock); static DEFINE_MUTEX(np_lock); static struct idr tiqn_idr; -struct idr sess_idr; +DEFINE_IDA(sess_ida); struct mutex auth_id_lock; -spinlock_t sess_idr_lock; struct iscsit_global *iscsit_global; @@ -700,9 +699,7 @@ static int __init iscsi_target_init_module(void) spin_lock_init(&iscsit_global->ts_bitmap_lock); mutex_init(&auth_id_lock); - spin_lock_init(&sess_idr_lock); idr_init(&tiqn_idr); - idr_init(&sess_idr); ret = target_register_template(&iscsi_ops); if (ret) @@ -4375,10 +4372,7 @@ int iscsit_close_session(struct iscsi_session *sess) pr_debug("Decremented number of active iSCSI Sessions on" " iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions); - spin_lock(&sess_idr_lock); - idr_remove(&sess_idr, sess->session_index); - spin_unlock(&sess_idr_lock); - + ida_free(&sess_ida, sess->session_index); kfree(sess->sess_ops); sess->sess_ops = NULL; spin_unlock_bh(&se_tpg->session_lock); diff --git a/drivers/target/iscsi/iscsi_target.h b/drivers/target/iscsi/iscsi_target.h index 42de1843aa40..48bac0acf8c7 100644 --- a/drivers/target/iscsi/iscsi_target.h +++ b/drivers/target/iscsi/iscsi_target.h @@ -55,9 +55,7 @@ extern struct kmem_cache *lio_ooo_cache; extern struct kmem_cache *lio_qr_cache; extern struct kmem_cache *lio_r2t_cache; -extern struct idr sess_idr; +extern struct ida sess_ida; extern struct mutex auth_id_lock; -extern spinlock_t sess_idr_lock; - #endif /*** ISCSI_TARGET_H ***/ diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index 99501785cdc1..561d2ad38989 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -336,22 +336,16 @@ static int iscsi_login_zero_tsih_s1( timer_setup(&sess->time2retain_timer, iscsit_handle_time2retain_timeout, 0); - idr_preload(GFP_KERNEL); - spin_lock_bh(&sess_idr_lock); - ret = idr_alloc(&sess_idr, NULL, 0, 0, GFP_NOWAIT); - if (ret >= 0) - sess->session_index = ret; - spin_unlock_bh(&sess_idr_lock); - idr_preload_end(); - + ret = ida_alloc(&sess_ida, GFP_KERNEL); if (ret < 0) { - pr_err("idr_alloc() for sess_idr failed\n"); + pr_err("Session ID allocation failed %d\n", ret); iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR, ISCSI_LOGIN_STATUS_NO_RESOURCES); kfree(sess); return -ENOMEM; } + sess->session_index = ret; sess->creation_time = get_jiffies_64(); /* * The FFP CmdSN window values will be allocated from the TPG's @@ -1163,11 +1157,9 @@ void iscsi_target_login_sess_out(struct iscsi_conn *conn, goto old_sess_out; if (conn->sess->se_sess) transport_free_session(conn->sess->se_sess); - if (conn->sess->session_index != 0) { - spin_lock_bh(&sess_idr_lock); - idr_remove(&sess_idr, conn->sess->session_index); - spin_unlock_bh(&sess_idr_lock); - } + /* Um, 0 is a valid ID. I suppose we never free it? */ + if (conn->sess->session_index != 0) + ida_free(&sess_ida, conn->sess->session_index); kfree(conn->sess->sess_ops); kfree(conn->sess); conn->sess = NULL; -- 2.17.1 ----- End forwarded message -----
