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Commit 0d228c0f authored by Abhijeet Joglekar's avatar Abhijeet Joglekar Committed by James Bottomley
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[SCSI] libfc: Hold disc mutex while processing gpn ft resp 



gpn_ft_resp processing currently does not hold the discovery lock.
disc_done() thus gets called from gpn_ft_resp or from gpn_ft_parse
without the lock held. This then sets disc->pending to zero or calls
gpn_ft_req() without disc_lock held.

- Hold disc mutex during gpn_ft resp processing
- In disc_done, release the disc mutex while calling lport callback

Signed-off-by: default avatarAbhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: default avatarRobert Love <robert.w.love@intel.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent a53922dd

drivers/scsi/libfc/fc_disc.c

+15 −3
Original line number Diff line number Diff line
@@ -461,21 +461,29 @@ static void fc_disc_del_target(struct fc_disc *disc, struct fc_rport *rport) 
/**

 * fc_disc_done() - Discovery has been completed

 * @disc: FC discovery context

 * Locking Note: This function expects that the disc mutex is locked before

 * it is called. The discovery callback is then made with the lock released,

 * and the lock is re-taken before returning from this function

 */

static void fc_disc_done(struct fc_disc *disc)

{

	struct fc_lport *lport = disc->lport;

	enum fc_disc_event event;



	FC_DEBUG_DISC("Discovery complete for port (%6x)\n",

		      fc_host_port_id(lport->host));



	disc->disc_callback(lport, disc->event);

	event = disc->event;

	disc->event = DISC_EV_NONE;



	if (disc->requested)

		fc_disc_gpn_ft_req(disc);

	else

		disc->pending = 0;



	mutex_unlock(&disc->disc_mutex);

	disc->disc_callback(lport, event);

	mutex_lock(&disc->disc_mutex);

}



/**
@@ -681,8 +689,8 @@ static void fc_disc_timeout(struct work_struct *work) 
 * @fp: response frame

 * @lp_arg: Fibre Channel host port instance

 *

 * Locking Note: This function expects that the disc_mutex is locked

 *		 before it is called.

 * Locking Note: This function is called without disc mutex held, and

 *		 should do all its processing with the mutex held

 */

static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,

				void *disc_arg)
@@ -695,11 +703,13 @@ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, 
	unsigned int len;

	int error;



	mutex_lock(&disc->disc_mutex);

	FC_DEBUG_DISC("Received a GPN_FT response on port (%6x)\n",

		      fc_host_port_id(disc->lport->host));



	if (IS_ERR(fp)) {

		fc_disc_error(disc, fp);

		mutex_unlock(&disc->disc_mutex);

		return;

	}
@@ -744,6 +754,8 @@ static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp, 
			disc->seq_count++;

	}

	fc_frame_free(fp);



	mutex_unlock(&disc->disc_mutex);

}



/**