From: Quinn Tran <qutran@xxxxxxxxxxx>
This patch uses kref to protect access between fcp_abort
path and nvme command and LS command completion path.
Stack trace below shows the abort path is accessing stale
memory (nvme_private->sp).
When command kref reaches 0, nvme_private & srb resource will
be disconnected from each other. Any subsequence nvme abort
request will not be able to reference the original srb.
[ 5631.003998] BUG: unable to handle kernel paging request at 00000010000005d8
[ 5631.004016] IP: [<ffffffffc087df92>] qla_nvme_abort_work+0x22/0x100 [qla2xxx]
[ 5631.004086] Workqueue: events qla_nvme_abort_work [qla2xxx]
[ 5631.004097] RIP: 0010:[<ffffffffc087df92>] [<ffffffffc087df92>] qla_nvme_abort_work+0x22/0x100 [qla2xxx]
[ 5631.004109] Call Trace:
[ 5631.004115] [<ffffffffaa4b8174>] ? pwq_dec_nr_in_flight+0x64/0xb0
[ 5631.004117] [<ffffffffaa4b9d4f>] process_one_work+0x17f/0x440
[ 5631.004120] [<ffffffffaa4bade6>] worker_thread+0x126/0x3c0
Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx>
Signed-off-by: Himanshu Madhani <hmadhani@xxxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_def.h | 3 +
drivers/scsi/qla2xxx/qla_nvme.c | 163 ++++++++++++++++++++++++++++------------
drivers/scsi/qla2xxx/qla_nvme.h | 1 +
3 files changed, 117 insertions(+), 50 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 602ed24bb806..c0d1b0715541 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -532,6 +532,8 @@ typedef struct srb {
uint8_t cmd_type;
uint8_t pad[3];
atomic_t ref_count;
+ struct kref cmd_kref; /* need to migrate ref_count over to this */
+ void *priv;
wait_queue_head_t nvme_ls_waitq;
struct fc_port *fcport;
struct scsi_qla_host *vha;
@@ -554,6 +556,7 @@ typedef struct srb {
} u;
void (*done)(void *, int);
void (*free)(void *);
+ void (*put_fn)(struct kref *kref);
} srb_t;
#define GET_CMD_SP(sp) (sp->u.scmd.cmd)
diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
index 8b3cb0fd307e..316aea085e6e 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.c
+++ b/drivers/scsi/qla2xxx/qla_nvme.c
@@ -123,53 +123,91 @@ static int qla_nvme_alloc_queue(struct nvme_fc_local_port *lport,
return 0;
}
+static void qla_nvme_release_fcp_cmd_kref(struct kref *kref)
+{
+ struct srb *sp = container_of(kref, struct srb, cmd_kref);
+ struct nvme_private *priv = (struct nvme_private *)sp->priv;
+ struct nvmefc_fcp_req *fd;
+ struct srb_iocb *nvme;
+ unsigned long flags;
+
+ if (!priv)
+ goto out;
+
+ nvme = &sp->u.iocb_cmd;
+ fd = nvme->u.nvme.desc;
+
+ spin_lock_irqsave(&priv->cmd_lock, flags);
+ priv->sp = NULL;
+ sp->priv = NULL;
+ if (priv->comp_status == QLA_SUCCESS) {
+ fd->rcv_rsplen = nvme->u.nvme.rsp_pyld_len;
+ } else {
+ fd->rcv_rsplen = 0;
+ fd->transferred_length = 0;
+ }
+ fd->status = 0;
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
+
+ fd->done(fd);
+out:
+ qla2xxx_rel_qpair_sp(sp->qpair, sp);
+}
+
+static void qla_nvme_release_ls_cmd_kref(struct kref *kref)
+{
+ struct srb *sp = container_of(kref, struct srb, cmd_kref);
+ struct nvme_private *priv = (struct nvme_private *)sp->priv;
+ struct nvmefc_ls_req *fd;
+ unsigned long flags;
+
+ if (!priv)
+ goto out;
+
+ spin_lock_irqsave(&priv->cmd_lock, flags);
+ priv->sp = NULL;
+ sp->priv = NULL;
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
+
+ fd = priv->fd;
+ fd->done(fd, priv->comp_status);
+out:
+ qla2x00_rel_sp(sp);
+}
+
+static void qla_nvme_ls_complete(struct work_struct *work)
+{
+ struct nvme_private *priv =
+ container_of(work, struct nvme_private, ls_work);
+
+ kref_put(&priv->sp->cmd_kref, qla_nvme_release_ls_cmd_kref);
+}
+
static void qla_nvme_sp_ls_done(void *ptr, int res)
{
srb_t *sp = ptr;
- struct srb_iocb *nvme;
- struct nvmefc_ls_req *fd;
struct nvme_private *priv;
- if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
+ if (WARN_ON_ONCE(kref_read(&sp->cmd_kref) == 0))
return;
- atomic_dec(&sp->ref_count);
-
if (res)
res = -EINVAL;
- nvme = &sp->u.iocb_cmd;
- fd = nvme->u.nvme.desc;
- priv = fd->private;
+ priv = (struct nvme_private *)sp->priv;
priv->comp_status = res;
+ INIT_WORK(&priv->ls_work, qla_nvme_ls_complete);
schedule_work(&priv->ls_work);
- /* work schedule doesn't need the sp */
- qla2x00_rel_sp(sp);
}
+/* it assumed that QPair lock is held. */
static void qla_nvme_sp_done(void *ptr, int res)
{
srb_t *sp = ptr;
- struct srb_iocb *nvme;
- struct nvmefc_fcp_req *fd;
+ struct nvme_private *priv = (struct nvme_private *)sp->priv;
- nvme = &sp->u.iocb_cmd;
- fd = nvme->u.nvme.desc;
-
- if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
- return;
-
- atomic_dec(&sp->ref_count);
-
- if (res == QLA_SUCCESS) {
- fd->rcv_rsplen = nvme->u.nvme.rsp_pyld_len;
- } else {
- fd->rcv_rsplen = 0;
- fd->transferred_length = 0;
- }
- fd->status = 0;
- fd->done(fd);
- qla2xxx_rel_qpair_sp(sp->qpair, sp);
+ priv->comp_status = res;
+ kref_put(&sp->cmd_kref, qla_nvme_release_fcp_cmd_kref);
return;
}
@@ -188,44 +226,50 @@ static void qla_nvme_abort_work(struct work_struct *work)
__func__, sp, sp->handle, fcport, fcport->deleted);
if (!ha->flags.fw_started && (fcport && fcport->deleted))
- return;
+ goto out;
if (ha->flags.host_shutting_down) {
ql_log(ql_log_info, sp->fcport->vha, 0xffff,
"%s Calling done on sp: %p, type: 0x%x, sp->ref_count: 0x%x\n",
__func__, sp, sp->type, atomic_read(&sp->ref_count));
sp->done(sp, 0);
- return;
+ goto out;
}
- if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
- return;
-
rval = ha->isp_ops->abort_command(sp);
ql_dbg(ql_dbg_io, fcport->vha, 0x212b,
"%s: %s command for sp=%p, handle=%x on fcport=%p rval=%x\n",
__func__, (rval != QLA_SUCCESS) ? "Failed to abort" : "Aborted",
sp, sp->handle, fcport, rval);
+
+out:
+ /* kref_get was done before work was schedule. */
+ kref_put(&sp->cmd_kref, sp->put_fn);
}
static void qla_nvme_ls_abort(struct nvme_fc_local_port *lport,
struct nvme_fc_remote_port *rport, struct nvmefc_ls_req *fd)
{
struct nvme_private *priv = fd->private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->cmd_lock, flags);
+ if (!priv->sp) {
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
+ return;
+ }
+
+ if (!kref_get_unless_zero(&priv->sp->cmd_kref)) {
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
INIT_WORK(&priv->abort_work, qla_nvme_abort_work);
schedule_work(&priv->abort_work);
}
-static void qla_nvme_ls_complete(struct work_struct *work)
-{
- struct nvme_private *priv =
- container_of(work, struct nvme_private, ls_work);
- struct nvmefc_ls_req *fd = priv->fd;
-
- fd->done(fd, priv->comp_status);
-}
static int qla_nvme_ls_req(struct nvme_fc_local_port *lport,
struct nvme_fc_remote_port *rport, struct nvmefc_ls_req *fd)
@@ -257,11 +301,13 @@ static int qla_nvme_ls_req(struct nvme_fc_local_port *lport,
sp->type = SRB_NVME_LS;
sp->name = "nvme_ls";
sp->done = qla_nvme_sp_ls_done;
- atomic_set(&sp->ref_count, 1);
- nvme = &sp->u.iocb_cmd;
+ sp->put_fn = qla_nvme_release_ls_cmd_kref;
+ sp->priv = (void *)priv;
priv->sp = sp;
+ kref_init(&sp->cmd_kref);
+ spin_lock_init(&priv->cmd_lock);
+ nvme = &sp->u.iocb_cmd;
priv->fd = fd;
- INIT_WORK(&priv->ls_work, qla_nvme_ls_complete);
nvme->u.nvme.desc = fd;
nvme->u.nvme.dir = 0;
nvme->u.nvme.dl = 0;
@@ -278,9 +324,10 @@ static int qla_nvme_ls_req(struct nvme_fc_local_port *lport,
if (rval != QLA_SUCCESS) {
ql_log(ql_log_warn, vha, 0x700e,
"qla2x00_start_sp failed = %d\n", rval);
- atomic_dec(&sp->ref_count);
wake_up(&sp->nvme_ls_waitq);
- sp->free(sp);
+ sp->priv = NULL;
+ priv->sp = NULL;
+ qla2x00_rel_sp(sp);
return rval;
}
@@ -292,6 +339,18 @@ static void qla_nvme_fcp_abort(struct nvme_fc_local_port *lport,
struct nvmefc_fcp_req *fd)
{
struct nvme_private *priv = fd->private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->cmd_lock, flags);
+ if (!priv->sp) {
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
+ return;
+ }
+ if (!kref_get_unless_zero(&priv->sp->cmd_kref)) {
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&priv->cmd_lock, flags);
INIT_WORK(&priv->abort_work, qla_nvme_abort_work);
schedule_work(&priv->abort_work);
@@ -515,12 +574,15 @@ static int qla_nvme_post_cmd(struct nvme_fc_local_port *lport,
if (!sp)
return -EBUSY;
- atomic_set(&sp->ref_count, 1);
init_waitqueue_head(&sp->nvme_ls_waitq);
+ kref_init(&sp->cmd_kref);
+ spin_lock_init(&priv->cmd_lock);
+ sp->priv = (void *)priv;
priv->sp = sp;
sp->type = SRB_NVME_CMD;
sp->name = "nvme_cmd";
sp->done = qla_nvme_sp_done;
+ sp->put_fn = qla_nvme_release_fcp_cmd_kref;
sp->qpair = qpair;
sp->vha = vha;
nvme = &sp->u.iocb_cmd;
@@ -530,9 +592,10 @@ static int qla_nvme_post_cmd(struct nvme_fc_local_port *lport,
if (rval != QLA_SUCCESS) {
ql_log(ql_log_warn, vha, 0x212d,
"qla2x00_start_nvme_mq failed = %d\n", rval);
- atomic_dec(&sp->ref_count);
wake_up(&sp->nvme_ls_waitq);
- sp->free(sp);
+ sp->priv = NULL;
+ priv->sp = NULL;
+ qla2xxx_rel_qpair_sp(sp->qpair, sp);
}
return rval;
diff --git a/drivers/scsi/qla2xxx/qla_nvme.h b/drivers/scsi/qla2xxx/qla_nvme.h
index 2d088add7011..67bb4a2a3742 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.h
+++ b/drivers/scsi/qla2xxx/qla_nvme.h
@@ -34,6 +34,7 @@ struct nvme_private {
struct work_struct ls_work;
struct work_struct abort_work;
int comp_status;
+ spinlock_t cmd_lock;
};
struct qla_nvme_rport {
--
2.12.0
