[PATCH v2 34/56] scsi: libfc: Enable lock context analysis

[Bart Van Assche <bvanassche@acm.org>]

Document locking requirements with __must_hold().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/libfc/Makefile  | 2 ++
 drivers/scsi/libfc/fc_disc.c | 6 +++++-
 drivers/scsi/libfc/fc_exch.c | 6 ++++++
 drivers/scsi/libfc/fc_fcp.c  | 4 ++++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/libfc/Makefile b/drivers/scsi/libfc/Makefile
index 65396f86c307..b265cf2a84a2 100644
--- a/drivers/scsi/libfc/Makefile
+++ b/drivers/scsi/libfc/Makefile
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 # $Id: Makefile
 
+CONTEXT_ANALYSIS := y
+
 obj-$(CONFIG_LIBFC) += libfc.o
 
 libfc-objs := \
diff --git a/drivers/scsi/libfc/fc_disc.c b/drivers/scsi/libfc/fc_disc.c
index 7792724d5b97..e2fd076ee15b 100644
--- a/drivers/scsi/libfc/fc_disc.c
+++ b/drivers/scsi/libfc/fc_disc.c
@@ -37,7 +37,7 @@
 #define FC_DISC_RETRY_LIMIT	3	/* max retries */
 #define FC_DISC_RETRY_DELAY	500UL	/* (msecs) delay */
 
-static void fc_disc_gpn_ft_req(struct fc_disc *);
+static void fc_disc_gpn_ft_req(struct fc_disc *disc) __must_hold(disc->disc_mutex);
 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
 static void fc_disc_timeout(struct work_struct *);
@@ -200,6 +200,7 @@ static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
  * @disc: The discovery object to be restarted
  */
 static void fc_disc_restart(struct fc_disc *disc)
+	__must_hold(disc->disc_mutex)
 {
 	lockdep_assert_held(&disc->disc_mutex);
 
@@ -250,6 +251,7 @@ static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
  * @event: The discovery completion status
  */
 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
+	__must_hold(disc->disc_mutex)
 {
 	struct fc_lport *lport = fc_disc_lport(disc);
 	struct fc_rport_priv *rdata;
@@ -294,6 +296,7 @@ static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
  * @fp:	  The error code encoded as a frame pointer
  */
 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
+	__must_hold(disc->disc_mutex)
 {
 	struct fc_lport *lport = fc_disc_lport(disc);
 	unsigned long delay = 0;
@@ -374,6 +377,7 @@ static void fc_disc_gpn_ft_req(struct fc_disc *disc)
  * Goes through the list of IDs and names resulting from a request.
  */
 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
+	__must_hold(disc->disc_mutex)
 {
 	struct fc_lport *lport;
 	struct fc_gpn_ft_resp *np;
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 9183a0e9568a..9057a95d8612 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -811,6 +811,7 @@ static void fc_exch_timeout(struct work_struct *work)
  */
 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
 					struct fc_exch_mgr *mp)
+	__context_unsafe(conditionally acquires &_res->ex_lock)
 {
 	struct fc_exch *ep;
 	unsigned int cpu;
@@ -904,6 +905,7 @@ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
  */
 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
 				     struct fc_frame *fp)
+	__context_unsafe(conditionally acquires &_res->ex_lock)
 {
 	struct fc_exch_mgr_anchor *ema;
 	struct fc_exch *ep;
@@ -996,6 +998,8 @@ static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
 
 	ep = fc_exch_alloc(lport, fp);
 	if (ep) {
+		/* Acquired by fc_exch_alloc(). */
+		__acquire(&ep->ex_lock);
 		ep->class = fc_frame_class(fp);
 
 		/*
@@ -2191,6 +2195,8 @@ struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
 		fc_frame_free(fp);
 		return NULL;
 	}
+	/* Acquired by fc_exch_alloc(). */
+	__acquire(&ep->ex_lock);
 	ep->esb_stat |= ESB_ST_SEQ_INIT;
 	fh = fc_frame_header_get(fp);
 	fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c
index a5139e43ca4c..9ba31a8a5250 100644
--- a/drivers/scsi/libfc/fc_fcp.c
+++ b/drivers/scsi/libfc/fc_fcp.c
@@ -207,6 +207,7 @@ static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
  * needed.
  */
 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
+	__cond_acquires(0, &fsp->scsi_pkt_lock)
 {
 	spin_lock_bh(&fsp->scsi_pkt_lock);
 	if (fsp->state & FC_SRB_COMPL) {
@@ -224,6 +225,7 @@ static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
  * @fsp: The FCP packet to be unlocked and decremented
  */
 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
+	__releases(&fsp->scsi_pkt_lock)
 {
 	spin_unlock_bh(&fsp->scsi_pkt_lock);
 	fc_fcp_pkt_release(fsp);
@@ -1242,6 +1244,7 @@ static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
  * Called to send an abort and then wait for abort completion
  */
 static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
+	__must_hold(&fsp->scsi_pkt_lock)
 {
 	int rc = FAILED;
 	unsigned long ticks_left;
@@ -1950,6 +1953,7 @@ EXPORT_SYMBOL(fc_queuecommand);
  * The fcp packet lock must be held when calling.
  */
 static void fc_io_compl(struct fc_fcp_pkt *fsp)
+	__must_hold(&fsp->scsi_pkt_lock)
 {
 	struct fc_fcp_internal *si;
 	struct scsi_cmnd *sc_cmd;