linux/fs/nfs/objlayout/objlayout.h
Sachin Bhamare 18d98f6c04 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>
2012-03-21 09:31:47 -04:00

190 lines
6.0 KiB
C

/*
* Data types and function declerations for interfacing with the
* pNFS standard object layout driver.
*
* Copyright (C) 2007 Panasas Inc. [year of first publication]
* All rights reserved.
*
* Benny Halevy <bhalevy@panasas.com>
* Boaz Harrosh <bharrosh@panasas.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* See the file COPYING included with this distribution for more details.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Panasas company nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _OBJLAYOUT_H
#define _OBJLAYOUT_H
#include <linux/nfs_fs.h>
#include <linux/pnfs_osd_xdr.h>
#include "../pnfs.h"
/*
* per-inode layout
*/
struct objlayout {
struct pnfs_layout_hdr pnfs_layout;
/* for layout_commit */
enum osd_delta_space_valid_enum {
OBJ_DSU_INIT = 0,
OBJ_DSU_VALID,
OBJ_DSU_INVALID,
} delta_space_valid;
s64 delta_space_used; /* consumed by write ops */
/* for layout_return */
spinlock_t lock;
struct list_head err_list;
};
static inline struct objlayout *
OBJLAYOUT(struct pnfs_layout_hdr *lo)
{
return container_of(lo, struct objlayout, pnfs_layout);
}
/*
* per-I/O operation state
* embedded in objects provider io_state data structure
*/
struct objlayout_io_res {
struct objlayout *objlay;
void *rpcdata;
int status; /* res */
int committed; /* res */
/* Error reporting (layout_return) */
struct list_head err_list;
unsigned num_comps;
/* Pointer to array of error descriptors of size num_comps.
* It should contain as many entries as devices in the osd_layout
* that participate in the I/O. It is up to the io_engine to allocate
* needed space and set num_comps.
*/
struct pnfs_osd_ioerr *ioerrs;
};
static inline
void objlayout_init_ioerrs(struct objlayout_io_res *oir, unsigned num_comps,
struct pnfs_osd_ioerr *ioerrs, void *rpcdata,
struct pnfs_layout_hdr *pnfs_layout_type)
{
oir->objlay = OBJLAYOUT(pnfs_layout_type);
oir->rpcdata = rpcdata;
INIT_LIST_HEAD(&oir->err_list);
oir->num_comps = num_comps;
oir->ioerrs = ioerrs;
}
/*
* Raid engine I/O API
*/
extern int objio_alloc_lseg(struct pnfs_layout_segment **outp,
struct pnfs_layout_hdr *pnfslay,
struct pnfs_layout_range *range,
struct xdr_stream *xdr,
gfp_t gfp_flags);
extern void objio_free_lseg(struct pnfs_layout_segment *lseg);
/* objio_free_result will free these @oir structs recieved from
* objlayout_{read,write}_done
*/
extern void objio_free_result(struct objlayout_io_res *oir);
extern int objio_read_pagelist(struct nfs_read_data *rdata);
extern int objio_write_pagelist(struct nfs_write_data *wdata, int how);
/*
* callback API
*/
extern void objlayout_io_set_result(struct objlayout_io_res *oir,
unsigned index, struct pnfs_osd_objid *pooid,
int osd_error, u64 offset, u64 length, bool is_write);
static inline void
objlayout_add_delta_space_used(struct objlayout *objlay, s64 space_used)
{
/* If one of the I/Os errored out and the delta_space_used was
* invalid we render the complete report as invalid. Protocol mandate
* the DSU be accurate or not reported.
*/
spin_lock(&objlay->lock);
if (objlay->delta_space_valid != OBJ_DSU_INVALID) {
objlay->delta_space_valid = OBJ_DSU_VALID;
objlay->delta_space_used += space_used;
}
spin_unlock(&objlay->lock);
}
extern void objlayout_read_done(struct objlayout_io_res *oir,
ssize_t status, bool sync);
extern void objlayout_write_done(struct objlayout_io_res *oir,
ssize_t status, bool sync);
extern int objlayout_get_deviceinfo(struct pnfs_layout_hdr *pnfslay,
struct nfs4_deviceid *d_id, struct pnfs_osd_deviceaddr **deviceaddr,
gfp_t gfp_flags);
extern void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr);
/*
* exported generic objects function vectors
*/
extern struct pnfs_layout_hdr *objlayout_alloc_layout_hdr(struct inode *, gfp_t gfp_flags);
extern void objlayout_free_layout_hdr(struct pnfs_layout_hdr *);
extern struct pnfs_layout_segment *objlayout_alloc_lseg(
struct pnfs_layout_hdr *,
struct nfs4_layoutget_res *,
gfp_t gfp_flags);
extern void objlayout_free_lseg(struct pnfs_layout_segment *);
extern enum pnfs_try_status objlayout_read_pagelist(
struct nfs_read_data *);
extern enum pnfs_try_status objlayout_write_pagelist(
struct nfs_write_data *,
int how);
extern void objlayout_encode_layoutcommit(
struct pnfs_layout_hdr *,
struct xdr_stream *,
const struct nfs4_layoutcommit_args *);
extern void objlayout_encode_layoutreturn(
struct pnfs_layout_hdr *,
struct xdr_stream *,
const struct nfs4_layoutreturn_args *);
extern int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr);
#endif /* _OBJLAYOUT_H */