[PATCH 1/2] Convert target drivers to use sbitmap

From: Matthew Wilcox
Date: Tue May 15 2018 - 13:41:01 EST

From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

The sbitmap and the percpu_ida perform essentially the same task,
allocating tags for commands. Since the sbitmap is more used than
the percpu_ida, convert the percpu_ida users to the sbitmap API.

Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_target.c | 16 ++++++-----
drivers/target/iscsi/iscsi_target_util.c | 34 +++++++++++++++++++++---
drivers/target/sbp/sbp_target.c | 8 +++---
drivers/target/target_core_transport.c | 5 ++--
drivers/target/tcm_fc/tfc_cmd.c | 11 ++++----
drivers/usb/gadget/function/f_tcm.c | 8 +++---
drivers/vhost/scsi.c | 9 ++++---
drivers/xen/xen-scsiback.c | 8 +++---
include/target/iscsi/iscsi_target_core.h | 1 +
include/target/target_core_base.h | 5 ++--
10 files changed, 73 insertions(+), 32 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index 025dc2d3f3de..cdf671c2af61 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3719,7 +3719,8 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
return;
}
cmd->jiffies_at_free = get_jiffies_64();
- percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+ sbitmap_queue_clear(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+ cmd->se_cmd.map_cpu);
}
EXPORT_SYMBOL(qlt_free_cmd);

@@ -4084,7 +4085,8 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
qlt_send_term_exchange(qpair, NULL, &cmd->atio, 1, 0);

qlt_decr_num_pend_cmds(vha);
- percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+ sbitmap_queue_clear(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+ cmd->se_cmd.map_cpu);
spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);

spin_lock_irqsave(&ha->tgt.sess_lock, flags);
@@ -4215,9 +4217,9 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha,
{
struct se_session *se_sess = sess->se_sess;
struct qla_tgt_cmd *cmd;
- int tag;
+ int tag, cpu;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0)
return NULL;

@@ -4230,6 +4232,7 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha,
qlt_incr_num_pend_cmds(vha);
cmd->vha = vha;
cmd->se_cmd.map_tag = tag;
+ cmd->se_cmd.map_cpu = cpu;
cmd->sess = sess;
cmd->loop_id = sess->loop_id;
cmd->conf_compl_supported = sess->conf_compl_supported;
@@ -5212,7 +5215,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
struct fc_port *sess;
struct se_session *se_sess;
struct qla_tgt_cmd *cmd;
- int tag;
+ int tag, cpu;
unsigned long flags;

if (unlikely(tgt->tgt_stop)) {
@@ -5244,7 +5247,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,

se_sess = sess->se_sess;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0)
return;

@@ -5275,6 +5278,7 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
cmd->reset_count = ha->base_qpair->chip_reset;
cmd->q_full = 1;
cmd->qpair = ha->base_qpair;
+ cmd->se_cmd.map_cpu = cpu;

if (qfull) {
cmd->q_full = 1;
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 4435bf374d2d..28bcffae609f 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -17,7 +17,7 @@
******************************************************************************/

#include <linux/list.h>
-#include <linux/percpu_ida.h>
+#include <linux/sched/signal.h>
#include <net/ipv6.h> /* ipv6_addr_equal() */
#include <scsi/scsi_tcq.h>
#include <scsi/iscsi_proto.h>
@@ -147,6 +147,28 @@ void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
spin_unlock_bh(&cmd->r2t_lock);
}

+int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
+{
+ int tag = -1;
+ DEFINE_WAIT(wait);
+ struct sbq_wait_state *ws;
+
+ if (state == TASK_RUNNING)
+ return tag;
+
+ ws = &se_sess->sess_tag_pool.ws[0];
+ for (;;) {
+ prepare_to_wait_exclusive(&ws->wait, &wait, state);
+ if (signal_pending_state(state, current))
+ break;
+ schedule();
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, cpup);
+ }
+
+ finish_wait(&ws->wait, &wait);
+ return tag;
+}
+
/*
* May be called from software interrupt (timer) context for allocating
* iSCSI NopINs.
@@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
{
struct iscsi_cmd *cmd;
struct se_session *se_sess = conn->sess->se_sess;
- int size, tag;
+ int size, tag, cpu;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
+ if (tag < 0)
+ tag = iscsit_wait_for_tag(se_sess, state, &cpu);
if (tag < 0)
return NULL;

@@ -166,6 +190,7 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
memset(cmd, 0, size);

cmd->se_cmd.map_tag = tag;
+ cmd->se_cmd.map_cpu = cpu;
cmd->conn = conn;
cmd->data_direction = DMA_NONE;
INIT_LIST_HEAD(&cmd->i_conn_node);
@@ -711,7 +736,8 @@ void iscsit_release_cmd(struct iscsi_cmd *cmd)
kfree(cmd->iov_data);
kfree(cmd->text_in_ptr);

- percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
+ sbitmap_queue_clear(&sess->se_sess->sess_tag_pool, se_cmd->map_tag,
+ se_cmd->map_cpu);
}
EXPORT_SYMBOL(iscsit_release_cmd);

diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
index fb1003921d85..c58f9f04c6be 100644
--- a/drivers/target/sbp/sbp_target.c
+++ b/drivers/target/sbp/sbp_target.c
@@ -926,15 +926,16 @@ static struct sbp_target_request *sbp_mgt_get_req(struct sbp_session *sess,
{
struct se_session *se_sess = sess->se_sess;
struct sbp_target_request *req;
- int tag;
+ int tag, cpu;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0)
return ERR_PTR(-ENOMEM);

req = &((struct sbp_target_request *)se_sess->sess_cmd_map)[tag];
memset(req, 0, sizeof(*req));
req->se_cmd.map_tag = tag;
+ req->se_cmd.map_cpu = cpu;
req->se_cmd.tag = next_orb;

return req;
@@ -1460,7 +1461,8 @@ static void sbp_free_request(struct sbp_target_request *req)
kfree(req->pg_tbl);
kfree(req->cmd_buf);

- percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
+ sbitmap_queue_clear(&se_sess->sess_tag_pool, se_cmd->map_tag,
+ se_cmd->map_cpu);
}

static void sbp_mgt_agent_process(struct work_struct *work)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 4558f2e1fe1b..3103890ed109 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -260,7 +260,8 @@ int transport_alloc_session_tags(struct se_session *se_sess,
}
}

- rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
+ rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
+ false, GFP_KERNEL, NUMA_NO_NODE);
if (rc < 0) {
pr_err("Unable to init se_sess->sess_tag_pool,"
" tag_num: %u\n", tag_num);
@@ -547,7 +548,7 @@ void transport_free_session(struct se_session *se_sess)
target_put_nacl(se_nacl);
}
if (se_sess->sess_cmd_map) {
- percpu_ida_destroy(&se_sess->sess_tag_pool);
+ sbitmap_queue_free(&se_sess->sess_tag_pool);
kvfree(se_sess->sess_cmd_map);
}
kmem_cache_free(se_sess_cache, se_sess);
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index ec372860106f..b3e3364b7147 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -28,7 +28,6 @@
#include <linux/configfs.h>
#include <linux/ctype.h>
#include <linux/hash.h>
-#include <linux/percpu_ida.h>
#include <asm/unaligned.h>
#include <scsi/scsi_tcq.h>
#include <scsi/libfc.h>
@@ -92,7 +91,8 @@ static void ft_free_cmd(struct ft_cmd *cmd)
if (fr_seq(fp))
fc_seq_release(fr_seq(fp));
fc_frame_free(fp);
- percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
+ sbitmap_queue_clear(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag,
+ cmd->se_cmd.map_cpu);
ft_sess_put(sess); /* undo get from lookup at recv */
}

@@ -448,9 +448,9 @@ static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
struct ft_cmd *cmd;
struct fc_lport *lport = sess->tport->lport;
struct se_session *se_sess = sess->se_sess;
- int tag;
+ int tag, cpu;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0)
goto busy;

@@ -458,10 +458,11 @@ static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
memset(cmd, 0, sizeof(struct ft_cmd));

cmd->se_cmd.map_tag = tag;
+ cmd->se_cmd.map_cpu = cpu;
cmd->sess = sess;
cmd->seq = fc_seq_assign(lport, fp);
if (!cmd->seq) {
- percpu_ida_free(&se_sess->sess_tag_pool, tag);
+ sbitmap_queue_clear(&se_sess->sess_tag_pool, tag, cpu);
goto busy;
}
cmd->req_frame = fp; /* hold frame during cmd */
diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index d78dbb73bde8..b335f4f33bc3 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -1071,15 +1071,16 @@ static struct usbg_cmd *usbg_get_cmd(struct f_uas *fu,
{
struct se_session *se_sess = tv_nexus->tvn_se_sess;
struct usbg_cmd *cmd;
- int tag;
+ int tag, cpu;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0)
return ERR_PTR(-ENOMEM);

cmd = &((struct usbg_cmd *)se_sess->sess_cmd_map)[tag];
memset(cmd, 0, sizeof(*cmd));
cmd->se_cmd.map_tag = tag;
+ cmd->se_cmd.map_cpu = cpu;
cmd->se_cmd.tag = cmd->tag = scsi_tag;
cmd->fu = fu;

@@ -1288,7 +1289,8 @@ static void usbg_release_cmd(struct se_cmd *se_cmd)
struct se_session *se_sess = se_cmd->se_sess;

kfree(cmd->data_buf);
- percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
+ sbitmap_queue_clear(&se_sess->sess_tag_pool, se_cmd->map_tag,
+ se_cmd->map_cpu);
}

static u32 usbg_sess_get_index(struct se_session *se_sess)
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 7ad57094d736..1fadaa39f322 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -46,7 +46,6 @@
#include <linux/virtio_scsi.h>
#include <linux/llist.h>
#include <linux/bitmap.h>
-#include <linux/percpu_ida.h>

#include "vhost.h"

@@ -324,7 +323,8 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
}

vhost_scsi_put_inflight(tv_cmd->inflight);
- percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
+ sbitmap_queue_clear(&se_sess->sess_tag_pool, se_cmd->map_tag,
+ se_cmd->map_cpu);
}

static u32 vhost_scsi_sess_get_index(struct se_session *se_sess)
@@ -567,7 +567,7 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
struct se_session *se_sess;
struct scatterlist *sg, *prot_sg;
struct page **pages;
- int tag;
+ int tag, cpu;

tv_nexus = tpg->tpg_nexus;
if (!tv_nexus) {
@@ -576,7 +576,7 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
}
se_sess = tv_nexus->tvn_se_sess;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0) {
pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
return ERR_PTR(-ENOMEM);
@@ -591,6 +591,7 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
cmd->tvc_prot_sgl = prot_sg;
cmd->tvc_upages = pages;
cmd->tvc_se_cmd.map_tag = tag;
+ cmd->tvc_se_cmd.map_cpu = cpu;
cmd->tvc_tag = scsi_tag;
cmd->tvc_lun = lun;
cmd->tvc_task_attr = task_attr;
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 7bc88fd43cfc..d2c71b8608f0 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -654,9 +654,9 @@ static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring
struct scsiback_nexus *nexus = tpg->tpg_nexus;
struct se_session *se_sess = nexus->tvn_se_sess;
struct vscsibk_pend *req;
- int tag, i;
+ int tag, cpu, i;

- tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+ tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0) {
pr_err("Unable to obtain tag for vscsiif_request\n");
return ERR_PTR(-ENOMEM);
@@ -665,6 +665,7 @@ static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring
req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
memset(req, 0, sizeof(*req));
req->se_cmd.map_tag = tag;
+ req->se_cmd.map_cpu = cpu;

for (i = 0; i < VSCSI_MAX_GRANTS; i++)
req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
@@ -1379,7 +1380,8 @@ static void scsiback_release_cmd(struct se_cmd *se_cmd)
{
struct se_session *se_sess = se_cmd->se_sess;

- percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
+ sbitmap_queue_clear(&se_sess->sess_tag_pool, se_cmd->map_tag,
+ se_cmd->map_cpu);
}

static u32 scsiback_sess_get_index(struct se_session *se_sess)
diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h
index cf5f3fff1f1a..f2e6abea8490 100644
--- a/include/target/iscsi/iscsi_target_core.h
+++ b/include/target/iscsi/iscsi_target_core.h
@@ -4,6 +4,7 @@

#include <linux/dma-direction.h> /* enum dma_data_direction */
#include <linux/list.h> /* struct list_head */
+#include <linux/sched.h>
#include <linux/socket.h> /* struct sockaddr_storage */
#include <linux/types.h> /* u8 */
#include <scsi/iscsi_proto.h> /* itt_t */
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 9f9f5902af38..cd417b17fee6 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -4,7 +4,7 @@

#include <linux/configfs.h> /* struct config_group */
#include <linux/dma-direction.h> /* enum dma_data_direction */
-#include <linux/percpu_ida.h> /* struct percpu_ida */
+#include <linux/sbitmap.h>
#include <linux/percpu-refcount.h>
#include <linux/semaphore.h> /* struct semaphore */
#include <linux/completion.h>
@@ -454,6 +454,7 @@ struct se_cmd {
int sam_task_attr;
/* Used for se_sess->sess_tag_pool */
unsigned int map_tag;
+ int map_cpu;
/* Transport protocol dependent state, see transport_state_table */
enum transport_state_table t_state;
/* See se_cmd_flags_table */
@@ -607,7 +608,7 @@ struct se_session {
struct list_head sess_wait_list;
spinlock_t sess_cmd_lock;
void *sess_cmd_map;
- struct percpu_ida sess_tag_pool;
+ struct sbitmap_queue sess_tag_pool;
};

struct se_device;
--
2.17.0