linux/fs/nfs/objlayout/objlayout.h
Boaz Harrosh b6c05f1693 pnfs-obj: objio_osd device information retrieval and caching
When a new layout is received in objio_alloc_lseg all device_ids
referenced are retrieved. The device information is queried for from MDS
and then the osd_device is looked-up from the osd-initiator library. The
devices are cached in a per-mount-point list, for later use. At unmount
all devices are "put" back to the library.

objlayout_get_deviceinfo(), objlayout_put_deviceinfo() middleware
API for retrieving device information given a device_id.

TODO: The device cache can get big. Cap its size. Keep an LRU and start
      to return devices which were not used, when list gets to big, or
      when new entries allocation fail.

[pnfs-obj: Bugs in new global-device-cache code]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
[gfp_flags]
[use global device cache]
[use layout driver in global device cache]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29 20:53:33 +03:00

76 lines
2.9 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"
/*
* 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);
/*
* callback API
*/
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_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 *);
#endif /* _OBJLAYOUT_H */