From: Vasu Dev <[email protected]> Modifies fcoe_hostlist_lock uses such that a new EM allocation in fcoe_em_config and adding new fcoe_softc using fcoe_hostlist_add are atomic, this is to ensure that a shared offload EM gets allocated only once per eth device for its all lports.
Signed-off-by: Vasu Dev <[email protected]> Signed-off-by: Robert Love <[email protected]> --- drivers/scsi/fcoe/fcoe.c | 26 ++++++++++++++++++-------- 1 files changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 7b6cc6e..7b3bd8d 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -420,6 +420,8 @@ static int fcoe_shost_config(struct fc_lport *lp, struct Scsi_Host *shost, * fcoe_em_config() - allocates em for this lport * @lp: the port that em is to allocated for * + * Called with write fcoe_hostlist_lock held. + * * Returns : 0 on success */ static inline int fcoe_em_config(struct fc_lport *lp) @@ -608,6 +610,13 @@ static int fcoe_if_create(struct net_device *netdev) goto out_lp_destroy; } + /* + * fcoe_em_alloc() and fcoe_hostlist_add() both + * need to be atomic under fcoe_hostlist_lock + * since fcoe_em_alloc() looks for an existing EM + * instance on host list updated by fcoe_hostlist_add(). + */ + write_lock(&fcoe_hostlist_lock); /* lport exch manager allocation */ rc = fcoe_em_config(lp); if (rc) { @@ -618,6 +627,7 @@ static int fcoe_if_create(struct net_device *netdev) /* add to lports list */ fcoe_hostlist_add(lp); + write_unlock(&fcoe_hostlist_lock); lp->boot_time = jiffies; @@ -1721,6 +1731,8 @@ int fcoe_reset(struct Scsi_Host *shost) * fcoe_hostlist_lookup_softc() - find the corresponding lport by a given device * @dev: this is currently ptr to net_device * + * Called with fcoe_hostlist_lock held. + * * Returns: NULL or the located fcoe_softc */ static struct fcoe_softc * @@ -1728,14 +1740,10 @@ fcoe_hostlist_lookup_softc(const struct net_device *dev) { struct fcoe_softc *fc; - read_lock(&fcoe_hostlist_lock); list_for_each_entry(fc, &fcoe_hostlist, list) { - if (fc->real_dev == dev) { - read_unlock(&fcoe_hostlist_lock); + if (fc->real_dev == dev) return fc; - } } - read_unlock(&fcoe_hostlist_lock); return NULL; } @@ -1749,7 +1757,9 @@ struct fc_lport *fcoe_hostlist_lookup(const struct net_device *netdev) { struct fcoe_softc *fc; + read_lock(&fcoe_hostlist_lock); fc = fcoe_hostlist_lookup_softc(netdev); + read_unlock(&fcoe_hostlist_lock); return (fc) ? fc->ctlr.lp : NULL; } @@ -1758,6 +1768,8 @@ struct fc_lport *fcoe_hostlist_lookup(const struct net_device *netdev) * fcoe_hostlist_add() - Add a lport to lports list * @lp: ptr to the fc_lport to be added * + * Called with write fcoe_hostlist_lock held. + * * Returns: 0 for success */ int fcoe_hostlist_add(const struct fc_lport *lp) @@ -1767,9 +1779,7 @@ int fcoe_hostlist_add(const struct fc_lport *lp) fc = fcoe_hostlist_lookup_softc(fcoe_netdev(lp)); if (!fc) { fc = lport_priv(lp); - write_lock_bh(&fcoe_hostlist_lock); list_add_tail(&fc->list, &fcoe_hostlist); - write_unlock_bh(&fcoe_hostlist_lock); } return 0; } @@ -1784,9 +1794,9 @@ int fcoe_hostlist_remove(const struct fc_lport *lp) { struct fcoe_softc *fc; + write_lock_bh(&fcoe_hostlist_lock); fc = fcoe_hostlist_lookup_softc(fcoe_netdev(lp)); BUG_ON(!fc); - write_lock_bh(&fcoe_hostlist_lock); list_del(&fc->list); write_unlock_bh(&fcoe_hostlist_lock); _______________________________________________ devel mailing list [email protected] http://www.open-fcoe.org/mailman/listinfo/devel
