pnfs-obj: autologin: Add support for protocol autologin
The pnfs-objects protocol mandates that we autologin into devices not
present in the system, according to information specified in the
get_device_info returned from the server.
The Protocol specifies two login hints.
1. An IP address:port combination
2. A string URI which is constructed as a URL with a protocol prefix
followed by :// and a string as address. For each protocol prefix
the string-address format might be different.
We only support the second option. The first option is just redundant
to the second one.
NOTE: The Kernel part of autologin does not parse the URI string. It
just channels it to a user-mode script. So any new login protocols should
only update the user-mode script which is a part of the nfs-utils package,
but the Kernel need not change.
We implement the autologin by using the call_usermodehelper() API.
(Thanks to Steve Dickson <steved@redhat.com> for pointing it out)
So there is no running daemon needed, and/or special setup.
We Add the osd_login_prog Kernel module parameters which defaults to:
/sbin/osd_login
Kernel try's to upcall the program specified in osd_login_prog. If the file is
not found or the execution fails Kernel will disable any farther upcalls, by
zeroing out osd_login_prog, Until Admin re-enables it by setting the
osd_login_prog parameter to a proper program.
Also add text about the osd_login program command line API to:
Documentation/filesystems/nfs/pnfs.txt
and documentation of the new osd_login_prog module parameter to:
Documentation/kernel-parameters.txt
TODO: Add timeout option in the case osd_login program gets
stuck
Signed-off-by: Sachin Bhamare <sbhamare@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 3a621a2..4bff4a3 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -137,6 +137,7 @@
struct objio_dev_ent *ode;
struct osd_dev *od;
struct osd_dev_info odi;
+ bool retry_flag = true;
int err;
ode = _dev_list_find(NFS_SERVER(pnfslay->plh_inode), d_id);
@@ -171,10 +172,18 @@
goto out;
}
+retry_lookup:
od = osduld_info_lookup(&odi);
if (unlikely(IS_ERR(od))) {
err = PTR_ERR(od);
dprintk("%s: osduld_info_lookup => %d\n", __func__, err);
+ if (err == -ENODEV && retry_flag) {
+ err = objlayout_autologin(deviceaddr);
+ if (likely(!err)) {
+ retry_flag = false;
+ goto retry_lookup;
+ }
+ }
goto out;
}