From 9d34876f820d55c94bd0b2a2ed3d2e2976cbd997 Mon Sep 17 00:00:00 2001 From: Robert Love Date: Thu, 5 Sep 2013 07:47:27 +0000 Subject: libfcoe: Make fcoe_sysfs optional / fix fnic NULL exception fnic doesn't use any of the create/destroy/enable/disable interfaces either from the (legacy) module paramaters or the (new) fcoe_sysfs interfaces. When fcoe_sysfs was introduced fnic wasn't changed since it wasn't using the interfaces. libfcoe incorrectly assumed that that all of its users were using fcoe_sysfs and when adding and deleting FCFs would assume the existance of a fcoe_ctlr_device. fnic was not allocating this structure because it doesn't care about the standard user interfaces (fnic starts on link only). If/When libfcoe tried to use the fcoe_ctlr_device's lock for the first time a NULL pointer exception would be triggered. Since fnic doesn't care about sysfs or user interfaces, the solution is to drop libfcoe's assumption that all drivers are using fcoe_sysfs. This patch accomplishes this by changing some of the structure relationships. We need a way to determine when a LLD is using fcoe_sysfs or not and we can do that by checking for the existance of the fcoe_ctlr_device. Prior to this patch, it was assumed that the fcoe_ctlr structure was allocated with the fcoe_ctlr_device and immediately followed it in memory. To reach the fcoe_ctlr_device we would simply go back in memory from the fcoe_ctlr to get the fcoe_ctlr_device. Since fnic doesn't allocate the fcoe_ctlr_device, we cannot keep that assumption. This patch adds a pointer from the fcoe_ctlr to the fcoe_ctlr_device. For bnx2fc and fcoe we will continue to allocate the two structures together, but then we'll set the ctlr->cdev pointer to point at the fcoe_ctlr_device. fnic will not change and will continue to allocate the fcoe_ctlr itself, and ctlr->cdev will remain NULL. When libfcoe adds fcoe_fcf's to the fcoe_ctlr it will check if ctlr->cdev is set and only if so will it continue to interact with fcoe_sysfs. Signed-off-by: Robert Love Acked-by: Neil Horman Tested-by: Hiral Patel --- include/scsi/libfcoe.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/scsi/libfcoe.h') diff --git a/include/scsi/libfcoe.h b/include/scsi/libfcoe.h index 4427393..de7e3ee 100644 --- a/include/scsi/libfcoe.h +++ b/include/scsi/libfcoe.h @@ -90,6 +90,7 @@ enum fip_state { * @lp: &fc_lport: libfc local port. * @sel_fcf: currently selected FCF, or NULL. * @fcfs: list of discovered FCFs. + * @cdev: (Optional) pointer to sysfs fcoe_ctlr_device. * @fcf_count: number of discovered FCF entries. * @sol_time: time when a multicast solicitation was last sent. * @sel_time: time after which to select an FCF. @@ -127,6 +128,7 @@ struct fcoe_ctlr { struct fc_lport *lp; struct fcoe_fcf *sel_fcf; struct list_head fcfs; + struct fcoe_ctlr_device *cdev; u16 fcf_count; unsigned long sol_time; unsigned long sel_time; @@ -168,8 +170,11 @@ static inline void *fcoe_ctlr_priv(const struct fcoe_ctlr *ctlr) return (void *)(ctlr + 1); } +/* + * This assumes that the fcoe_ctlr (x) is allocated with the fcoe_ctlr_device. + */ #define fcoe_ctlr_to_ctlr_dev(x) \ - (struct fcoe_ctlr_device *)(((struct fcoe_ctlr_device *)(x)) - 1) + (x)->cdev /** * struct fcoe_fcf - Fibre-Channel Forwarder -- cgit v1.1