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author | Robert Love <robert.w.love@intel.com> | 2013-09-05 11:47:27 +0400 |
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committer | Robert Love <robert.w.love@intel.com> | 2013-10-12 00:25:40 +0400 |
commit | 9d34876f820d55c94bd0b2a2ed3d2e2976cbd997 (patch) | |
tree | ee7dd415c30b57215841214959d00c0470787e51 /drivers/scsi/fcoe/fcoe.c | |
parent | 1c2c1b4fbd413fd814807768d2aba9023722ed76 (diff) | |
download | linux-9d34876f820d55c94bd0b2a2ed3d2e2976cbd997.tar.xz |
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 <robert.w.love@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Tested-by: Hiral Patel <hiralpat@cisco.com>
Diffstat (limited to 'drivers/scsi/fcoe/fcoe.c')
-rw-r--r-- | drivers/scsi/fcoe/fcoe.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index dff40b2fccbd..8626988e12a5 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -408,6 +408,7 @@ static struct fcoe_interface *fcoe_interface_create(struct net_device *netdev, } ctlr = fcoe_ctlr_device_priv(ctlr_dev); + ctlr->cdev = ctlr_dev; fcoe = fcoe_ctlr_priv(ctlr); dev_hold(netdev); |