From: Sachin Bhamare <sbhamare@xxxxxxxxxxx>
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@xxxxxxxxxx> 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@xxxxxxxxxxx>
Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
---
Documentation/filesystems/nfs/pnfs.txt | 54 +++++++++++++
Documentation/kernel-parameters.txt | 6 ++
fs/nfs/objlayout/objio_osd.c | 9 ++
fs/nfs/objlayout/objlayout.c | 134 ++++++++++++++++++++++++++++++++
fs/nfs/objlayout/objlayout.h | 2 +
5 files changed, 205 insertions(+), 0 deletions(-)
diff --git a/Documentation/filesystems/nfs/pnfs.txt b/Documentation/filesystems/nfs/pnfs.txt
index 983e14a..c7919c6 100644
--- a/Documentation/filesystems/nfs/pnfs.txt
+++ b/Documentation/filesystems/nfs/pnfs.txt
@@ -53,3 +53,57 @@ lseg maintains an extra reference corresponding to the NFS_LSEG_VALID
bit which holds it in the pnfs_layout_hdr's list. When the final lseg
is removed from the pnfs_layout_hdr's list, the NFS_LAYOUT_DESTROYED
bit is set, preventing any new lsegs from being added.
+
+layout drivers
+--------------
+
+PNFS utilizes what is called layout drivers. The STD defines 3 basic
+layout types: "files" "objects" and "blocks". For each of these types
+there is a layout-driver with a common function-vectors table which
+are called by the nfs-client pnfs-core to implement the different layout
+types.
+
+Files-layout-driver code is in: fs/nfs/nfs4filelayout.c && nfs4filelayoutdev.c
+Objects-layout-deriver code is in: fs/nfs/objlayout/.. directory
+Blocks-layout-deriver code is in: fs/nfs/blocklayout/.. directory
+
+objects-layout setup
+--------------------
+
+As part of the full STD implementation the objlayoutdriver.ko needs, at times,
+to automatically login to yet undiscovered iscsi/osd devices. For this the
+driver makes up-calles to a user-mode script called *osd_login*
+
+The path_name of the script to use is by default:
+ /sbin/osd_login.
+This name can be overridden by the Kernel module parameter:
+ objlayoutdriver.osd_login_prog
+
+If Kernel does not find the osd_login_prog path it will zero it out
+and will not attempt farther logins. An admin can then write new value
+to the objlayoutdriver.osd_login_prog Kernel parameter to re-enable it.
+
+The /sbin/osd_login is part of the nfs-utils package, and should usually
+be installed on distributions that support this Kernel version.
+
+The API to the login script is as follows:
+ Usage: $0 -u <URI> -o <OSDNAME> -s <SYSTEMID>
+ Options:
+ -u target uri e.g. iscsi://<ip>:<port>
+ (allways exists)
+ (More protocols can be defined in the future.
+ The client does not interpret this string it is
+ passed unchanged as recieved from the Server)
+ -o osdname of the requested target OSD
+ (Might be empty)
+ (A string which denotes the OSD name, there is a
+ limit of 64 chars on this string)
+ -s systemid of the requested target OSD
+ (Might be empty)
+ (This string, if not empty is always an hex
+ representation of the 20 bytes osd_system_id)
+
+blocks-layout setup
+-------------------
+
+TODO: Document the setup needs of the blocks layout driver
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 033d4e6..d5a2f09 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1670,6 +1670,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
back to using the idmapper.
To turn off this behaviour, set the value to '0'.
+ objlayoutdriver.osd_login_prog=
+ [NFS] [OBJLAYOUT] sets the pathname to the program which
+ is used to automatically discover and login into new
+ osd-targets. Please see:
+ Documentation/filesystems/pnfs.txt for more explanations
+
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 37a9269..5b2ac9e 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -137,6 +137,7 @@ static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay,
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 @@ static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay,
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;
}
diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index 71047c9..b158d1b 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -37,6 +37,9 @@
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#include <linux/kmod.h>
+#include <linux/moduleparam.h>
+#include <linux/ratelimit.h>
#include <scsi/osd_initiator.h>
#include "objlayout.h"
@@ -649,3 +652,134 @@ void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr)
__free_page(odi->page);
kfree(odi);
}
+
+enum {
+ OBJLAYOUT_MAX_URI_LEN = 256, OBJLAYOUT_MAX_OSDNAME_LEN = 64,
+ OBJLAYOUT_MAX_SYSID_HEX_LEN = OSD_SYSTEMID_LEN * 2 + 1,
+ OSD_LOGIN_UPCALL_PATHLEN = 256
+};
+
+static char osd_login_prog[OSD_LOGIN_UPCALL_PATHLEN] = "/sbin/osd_login";
+
+module_param_string(osd_login_prog, osd_login_prog, sizeof(osd_login_prog),
+ 0600);
+MODULE_PARM_DESC(osd_login_prog, "Path to the osd_login upcall program");
+
+struct __auto_login {
+ char uri[OBJLAYOUT_MAX_URI_LEN];
+ char osdname[OBJLAYOUT_MAX_OSDNAME_LEN];
+ char systemid_hex[OBJLAYOUT_MAX_SYSID_HEX_LEN];
+};
+
+static int __objlayout_upcall(struct __auto_login *login)
+{
+ static char *envp[] = { "HOME=/",
+ "TERM=linux",
+ "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+ NULL
+ };
+ char *argv[8];
+ int ret;
+
+ if (unlikely(!osd_login_prog[0])) {
+ dprintk("%s: osd_login_prog is disabled\n", __func__);
+ return -EACCES;
+ }
+
+ dprintk("%s uri: %s\n", __func__, login->uri);
+ dprintk("%s osdname %s\n", __func__, login->osdname);
+ dprintk("%s systemid_hex %s\n", __func__, login->systemid_hex);
+
+ argv[0] = (char *)osd_login_prog;
+ argv[1] = "-u";
+ argv[2] = login->uri;
+ argv[3] = "-o";
+ argv[4] = login->osdname;
+ argv[5] = "-s";
+ argv[6] = login->systemid_hex;
+ argv[7] = NULL;
+
+ ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ /*
+ * Disable the upcall mechanism if we're getting an ENOENT or
+ * EACCES error. The admin can re-enable it on the fly by using
+ * sysfs to set the objlayoutdriver.osd_login_prog module parameter once
+ * the problem has been fixed.
+ */
+ if (ret == -ENOENT || ret == -EACCES) {
+ printk(KERN_ERR "PNFS-OBJ: %s was not found please set "
+ "objlayoutdriver.osd_login_prog kernel parameter!\n",
+ osd_login_prog);
+ osd_login_prog[0] = '\0';
+ }
+ dprintk("%s %s return value: %d\n", __func__, osd_login_prog, ret);
+
+ return ret;
+}
+
+/* Assume dest is all zeros */
+static void __copy_nfsS_and_zero_terminate(struct nfs4_string s,
+ char *dest, int max_len,
+ const char *var_name)
+{
+ if (!s.len)
+ return;
+
+ if (s.len >= max_len) {
+ pr_warn_ratelimited(
+ "objlayout_autologin: %s: s.len(%d) >= max_len(%d)",
+ var_name, s.len, max_len);
+ s.len = max_len - 1; /* space for null terminator */
+ }
+
+ memcpy(dest, s.data, s.len);
+}
+
+/* Assume sysid is all zeros */
+static void _sysid_2_hex(struct nfs4_string s,
+ char sysid[OBJLAYOUT_MAX_SYSID_HEX_LEN])
+{
+ int i;
+ char *cur;
+
+ if (!s.len)
+ return;
+
+ if (s.len != OSD_SYSTEMID_LEN) {
+ pr_warn_ratelimited(
+ "objlayout_autologin: systemid_len(%d) != OSD_SYSTEMID_LEN",
+ s.len);
+ if (s.len > OSD_SYSTEMID_LEN)
+ s.len = OSD_SYSTEMID_LEN;
+ }
+
+ cur = sysid;
+ for (i = 0; i < s.len; i++)
+ cur = hex_byte_pack(cur, s.data[i]);
+}
+
+int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr)
+{
+ int rc;
+ struct __auto_login login;
+
+ if (!deviceaddr->oda_targetaddr.ota_netaddr.r_addr.len)
+ return -ENODEV;
+
+ memset(&login, 0, sizeof(login));
+ __copy_nfsS_and_zero_terminate(
+ deviceaddr->oda_targetaddr.ota_netaddr.r_addr,
+ login.uri, sizeof(login.uri), "URI");
+
+ __copy_nfsS_and_zero_terminate(
+ deviceaddr->oda_osdname,
+ login.osdname, sizeof(login.osdname), "OSDNAME");
+
+ _sysid_2_hex(deviceaddr->oda_systemid, login.systemid_hex);
+
+ rc = __objlayout_upcall(&login);
+ if (rc > 0) /* script returns positive values */
+ rc = -ENODEV;
+
+ return rc;
+}
diff --git a/fs/nfs/objlayout/objlayout.h b/fs/nfs/objlayout/objlayout.h
index 8ec3472..880ba08 100644
--- a/fs/nfs/objlayout/objlayout.h
+++ b/fs/nfs/objlayout/objlayout.h
@@ -184,4 +184,6 @@ extern void objlayout_encode_layoutreturn(
struct xdr_stream *,
const struct nfs4_layoutreturn_args *);
+extern int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr);
+
#endif /* _OBJLAYOUT_H */
--
1.7.6.5
--
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