+++ /dev/null
-From: Vasu Dev <vasu.dev@intel.com>
-Subject: libfc, fcoe: fixed locking issues with lport->lp_mutex around lport->link_status
-Patch-mainline: 6d235742e63f6b8912d8b200b75f9aa6d48f3e07
-References: bnc #468053
-
-The fcoe_xmit could call fc_pause in case the pending skb queue len is larger
-than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to
-change lport->link_status and that had these issues :-
-
-1. The fcoe_xmit was getting called with bh disabled, thus causing
-"BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled.
-
-2. fc_linkup and fc_linkdown function calls lport_enter function with
-lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send
-lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi
-req. In this case grabbing the same lport->lp_mutex again in fc_puase from
-fcoe_xmit would cause deadlock.
-
-The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but
-FC_PAUSE bit was not used anywhere beside just setting and clear this
-bit in lport->link_status, instead used a separate field qfull in fc_lport
-to eliminate need for lport->lp_mutex to track pending queue full condition
-and in turn avoid above described two locking issues.
-
-Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger
-SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds
-while lp->qfull is set.
-
-This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated
-fields in fc_lport for this, this simplified all related conditional
-code.
-
-Also removed fc_pause and fc_unpause functions and instead used newly added
-lport->qfull directly in fcoe.
-
-Also fixed a circular locking in fc_exch_recv_abts.
-
-These issues were blocking large file copy to a 2TB lun.
-
-Signed-off-by: Vasu Dev <vasu.dev@intel.com>
-Acked-by: Bernhard Walle <bwalle@suse.de>
----
- drivers/scsi/fcoe/fcoe_sw.c | 6 +++---
- drivers/scsi/fcoe/libfcoe.c | 41 +++++++++++++++++------------------------
- drivers/scsi/libfc/fc_exch.c | 2 +-
- drivers/scsi/libfc/fc_fcp.c | 6 +++---
- drivers/scsi/libfc/fc_lport.c | 38 +++++++-------------------------------
- drivers/scsi/libfc/fc_rport.c | 2 +-
- include/scsi/libfc.h | 12 ++----------
- 7 files changed, 34 insertions(+), 73 deletions(-)
-
---- a/drivers/scsi/fcoe/fcoe_sw.c
-+++ b/drivers/scsi/fcoe/fcoe_sw.c
-@@ -116,7 +116,8 @@ static int fcoe_sw_lport_config(struct f
- {
- int i = 0;
-
-- lp->link_status = 0;
-+ lp->link_up = 0;
-+ lp->qfull = 0;
- lp->max_retry_count = 3;
- lp->e_d_tov = 2 * 1000; /* FC-FS default */
- lp->r_a_tov = 2 * 2 * 1000;
-@@ -181,9 +182,8 @@ static int fcoe_sw_netdev_config(struct
- if (fc_set_mfs(lp, mfs))
- return -EINVAL;
-
-- lp->link_status = ~FC_PAUSE & ~FC_LINK_UP;
- if (!fcoe_link_ok(lp))
-- lp->link_status |= FC_LINK_UP;
-+ lp->link_up = 1;
-
- /* offload features support */
- if (fc->real_dev->features & NETIF_F_SG)
---- a/drivers/scsi/fcoe/libfcoe.c
-+++ b/drivers/scsi/fcoe/libfcoe.c
-@@ -505,7 +505,7 @@ int fcoe_xmit(struct fc_lport *lp, struc
- if (rc) {
- fcoe_insert_wait_queue(lp, skb);
- if (fc->fcoe_pending_queue.qlen > FCOE_MAX_QUEUE_DEPTH)
-- fc_pause(lp);
-+ lp->qfull = 1;
- }
-
- return 0;
-@@ -719,7 +719,7 @@ static void fcoe_recv_flogi(struct fcoe_
- * fcoe_watchdog - fcoe timer callback
- * @vp:
- *
-- * This checks the pending queue length for fcoe and put fcoe to be paused state
-+ * This checks the pending queue length for fcoe and set lport qfull
- * if the FCOE_MAX_QUEUE_DEPTH is reached. This is done for all fc_lport on the
- * fcoe_hostlist.
- *
-@@ -729,17 +729,17 @@ void fcoe_watchdog(ulong vp)
- {
- struct fc_lport *lp;
- struct fcoe_softc *fc;
-- int paused = 0;
-+ int qfilled = 0;
-
- read_lock(&fcoe_hostlist_lock);
- list_for_each_entry(fc, &fcoe_hostlist, list) {
- lp = fc->lp;
- if (lp) {
- if (fc->fcoe_pending_queue.qlen > FCOE_MAX_QUEUE_DEPTH)
-- paused = 1;
-+ qfilled = 1;
- if (fcoe_check_wait_queue(lp) < FCOE_MAX_QUEUE_DEPTH) {
-- if (paused)
-- fc_unpause(lp);
-+ if (qfilled)
-+ lp->qfull = 0;
- }
- }
- }
-@@ -768,8 +768,7 @@ void fcoe_watchdog(ulong vp)
- **/
- static int fcoe_check_wait_queue(struct fc_lport *lp)
- {
-- int rc, unpause = 0;
-- int paused = 0;
-+ int rc;
- struct sk_buff *skb;
- struct fcoe_softc *fc;
-
-@@ -777,10 +776,10 @@ static int fcoe_check_wait_queue(struct
- spin_lock_bh(&fc->fcoe_pending_queue.lock);
-
- /*
-- * is this interface paused?
-+ * if interface pending queue full then set qfull in lport.
- */
- if (fc->fcoe_pending_queue.qlen > FCOE_MAX_QUEUE_DEPTH)
-- paused = 1;
-+ lp->qfull = 1;
- if (fc->fcoe_pending_queue.qlen) {
- while ((skb = __skb_dequeue(&fc->fcoe_pending_queue)) != NULL) {
- spin_unlock_bh(&fc->fcoe_pending_queue.lock);
-@@ -792,11 +791,9 @@ static int fcoe_check_wait_queue(struct
- spin_lock_bh(&fc->fcoe_pending_queue.lock);
- }
- if (fc->fcoe_pending_queue.qlen < FCOE_MAX_QUEUE_DEPTH)
-- unpause = 1;
-+ lp->qfull = 0;
- }
- spin_unlock_bh(&fc->fcoe_pending_queue.lock);
-- if ((unpause) && (paused))
-- fc_unpause(lp);
- return fc->fcoe_pending_queue.qlen;
- }
-
-@@ -874,7 +871,7 @@ static int fcoe_device_notification(stru
- struct net_device *real_dev = ptr;
- struct fcoe_softc *fc;
- struct fcoe_dev_stats *stats;
-- u16 new_status;
-+ u32 new_link_up;
- u32 mfs;
- int rc = NOTIFY_OK;
-
-@@ -891,17 +888,15 @@ static int fcoe_device_notification(stru
- goto out;
- }
-
-- new_status = lp->link_status;
-+ new_link_up = lp->link_up;
- switch (event) {
- case NETDEV_DOWN:
- case NETDEV_GOING_DOWN:
-- new_status &= ~FC_LINK_UP;
-+ new_link_up = 0;
- break;
- case NETDEV_UP:
- case NETDEV_CHANGE:
-- new_status &= ~FC_LINK_UP;
-- if (!fcoe_link_ok(lp))
-- new_status |= FC_LINK_UP;
-+ new_link_up = !fcoe_link_ok(lp);
- break;
- case NETDEV_CHANGEMTU:
- mfs = fc->real_dev->mtu -
-@@ -909,17 +904,15 @@ static int fcoe_device_notification(stru
- sizeof(struct fcoe_crc_eof));
- if (mfs >= FC_MIN_MAX_FRAME)
- fc_set_mfs(lp, mfs);
-- new_status &= ~FC_LINK_UP;
-- if (!fcoe_link_ok(lp))
-- new_status |= FC_LINK_UP;
-+ new_link_up = !fcoe_link_ok(lp);
- break;
- case NETDEV_REGISTER:
- break;
- default:
- FC_DBG("unknown event %ld call", event);
- }
-- if (lp->link_status != new_status) {
-- if ((new_status & FC_LINK_UP) == FC_LINK_UP)
-+ if (lp->link_up != new_link_up) {
-+ if (new_link_up)
- fc_linkup(lp);
- else {
- stats = lp->dev_stats[smp_processor_id()];
---- a/drivers/scsi/libfc/fc_exch.c
-+++ b/drivers/scsi/libfc/fc_exch.c
-@@ -1096,7 +1096,7 @@ static void fc_exch_recv_abts(struct fc_
- ap->ba_high_seq_cnt = fh->fh_seq_cnt;
- ap->ba_low_seq_cnt = htons(sp->cnt);
- }
-- sp = fc_seq_start_next(sp);
-+ sp = fc_seq_start_next_locked(sp);
- spin_unlock_bh(&ep->ex_lock);
- fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
- fc_frame_free(rx_fp);
---- a/drivers/scsi/libfc/fc_fcp.c
-+++ b/drivers/scsi/libfc/fc_fcp.c
-@@ -20,13 +20,13 @@
- */
-
- #include <linux/module.h>
-+#include <linux/delay.h>
- #include <linux/kernel.h>
- #include <linux/types.h>
- #include <linux/spinlock.h>
- #include <linux/scatterlist.h>
- #include <linux/err.h>
- #include <linux/crc32.h>
--#include <linux/delay.h>
-
- #include <scsi/scsi_tcq.h>
- #include <scsi/scsi.h>
-@@ -1622,7 +1622,7 @@ out:
- static inline int fc_fcp_lport_queue_ready(struct fc_lport *lp)
- {
- /* lock ? */
-- return (lp->state == LPORT_ST_READY) && (lp->link_status & FC_LINK_UP);
-+ return (lp->state == LPORT_ST_READY) && lp->link_up && !lp->qfull;
- }
-
- /**
-@@ -1891,7 +1891,7 @@ int fc_eh_abort(struct scsi_cmnd *sc_cmd
- lp = shost_priv(sc_cmd->device->host);
- if (lp->state != LPORT_ST_READY)
- return rc;
-- else if (!(lp->link_status & FC_LINK_UP))
-+ else if (!lp->link_up)
- return rc;
-
- spin_lock_irqsave(lp->host->host_lock, flags);
---- a/drivers/scsi/libfc/fc_lport.c
-+++ b/drivers/scsi/libfc/fc_lport.c
-@@ -250,7 +250,7 @@ void fc_get_host_port_state(struct Scsi_
- {
- struct fc_lport *lp = shost_priv(shost);
-
-- if ((lp->link_status & FC_LINK_UP) == FC_LINK_UP)
-+ if (lp->link_up)
- fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
- else
- fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
-@@ -484,7 +484,7 @@ static void fc_lport_recv_rnid_req(struc
- * @sp: current sequence in the ADISC exchange
- * @fp: ADISC request frame
- *
-- * Locking Note: The lport lock is exected to be held before calling
-+ * Locking Note: The lport lock is expected to be held before calling
- * this function.
- */
- static void fc_lport_recv_adisc_req(struct fc_seq *sp, struct fc_frame *in_fp,
-@@ -577,8 +577,8 @@ void fc_linkup(struct fc_lport *lport)
- fc_host_port_id(lport->host));
-
- mutex_lock(&lport->lp_mutex);
-- if ((lport->link_status & FC_LINK_UP) != FC_LINK_UP) {
-- lport->link_status |= FC_LINK_UP;
-+ if (!lport->link_up) {
-+ lport->link_up = 1;
-
- if (lport->state == LPORT_ST_RESET)
- fc_lport_enter_flogi(lport);
-@@ -597,8 +597,8 @@ void fc_linkdown(struct fc_lport *lport)
- FC_DEBUG_LPORT("Link is down for port (%6x)\n",
- fc_host_port_id(lport->host));
-
-- if ((lport->link_status & FC_LINK_UP) == FC_LINK_UP) {
-- lport->link_status &= ~(FC_LINK_UP);
-+ if (lport->link_up) {
-+ lport->link_up = 0;
- fc_lport_enter_reset(lport);
- lport->tt.fcp_cleanup(lport);
- }
-@@ -607,30 +607,6 @@ void fc_linkdown(struct fc_lport *lport)
- EXPORT_SYMBOL(fc_linkdown);
-
- /**
-- * fc_pause - Pause the flow of frames
-- * @lport: The lport to be paused
-- */
--void fc_pause(struct fc_lport *lport)
--{
-- mutex_lock(&lport->lp_mutex);
-- lport->link_status |= FC_PAUSE;
-- mutex_unlock(&lport->lp_mutex);
--}
--EXPORT_SYMBOL(fc_pause);
--
--/**
-- * fc_unpause - Unpause the flow of frames
-- * @lport: The lport to be unpaused
-- */
--void fc_unpause(struct fc_lport *lport)
--{
-- mutex_lock(&lport->lp_mutex);
-- lport->link_status &= ~(FC_PAUSE);
-- mutex_unlock(&lport->lp_mutex);
--}
--EXPORT_SYMBOL(fc_unpause);
--
--/**
- * fc_fabric_logoff - Logout of the fabric
- * @lport: fc_lport pointer to logoff the fabric
- *
-@@ -977,7 +953,7 @@ static void fc_lport_enter_reset(struct
- fc_host_fabric_name(lport->host) = 0;
- fc_host_port_id(lport->host) = 0;
-
-- if ((lport->link_status & FC_LINK_UP) == FC_LINK_UP)
-+ if (lport->link_up)
- fc_lport_enter_flogi(lport);
- }
-
---- a/drivers/scsi/libfc/fc_rport.c
-+++ b/drivers/scsi/libfc/fc_rport.c
-@@ -425,7 +425,7 @@ static void fc_rport_error(struct fc_rpo
- PTR_ERR(fp), fc_rport_state(rport), rdata->retries);
-
- if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
-- /*
-+ /*
- * Memory allocation failure, or the exchange timed out.
- * Retry after delay
- */
---- a/include/scsi/libfc.h
-+++ b/include/scsi/libfc.h
-@@ -68,9 +68,6 @@
- /*
- * FC HBA status
- */
--#define FC_PAUSE (1 << 1)
--#define FC_LINK_UP (1 << 0)
--
- enum fc_lport_state {
- LPORT_ST_NONE = 0,
- LPORT_ST_FLOGI,
-@@ -603,7 +600,8 @@ struct fc_lport {
-
- /* Operational Information */
- struct libfc_function_template tt;
-- u16 link_status;
-+ u8 link_up;
-+ u8 qfull;
- enum fc_lport_state state;
- unsigned long boot_time;
-
-@@ -704,12 +702,6 @@ void fc_linkup(struct fc_lport *);
- void fc_linkdown(struct fc_lport *);
-
- /*
-- * Pause and unpause traffic.
-- */
--void fc_pause(struct fc_lport *);
--void fc_unpause(struct fc_lport *);
--
--/*
- * Configure the local port.
- */
- int fc_lport_config(struct fc_lport *);
projects / people / pmueller / ipfire-2.x.git / blobdiff