[pnfs] [PATCH 03/28] pnfsblock: blocklayout stub

[Fredric Isaman]

On Wed, 12 Mar 2008, Benny Halevy wrote:

> On Mar. 11, 2008, 21:31 +0200, Fred Isaman <iisaman at citi.umich.edu> wrote:
>> Adds the minimal structure for a pnfs block layout driver,
>> with all function pointers aimed at stubs.
>>
>> Signed-off-by: Fred Isaman <iisaman at citi.umich.edu>
>> ---
>>  fs/nfs/blocklayout/Makefile      |    2 +-
>>  fs/nfs/blocklayout/blocklayout.c |  223 ++++++++++++++++++++++++++++++++++++++
>>  include/linux/nfs_fs.h           |    1 +
>>  3 files changed, 225 insertions(+), 1 deletions(-)
>>  create mode 100644 fs/nfs/blocklayout/blocklayout.c
>>
>> diff --git a/fs/nfs/blocklayout/Makefile b/fs/nfs/blocklayout/Makefile
>> index 82275cd..6bf49cd 100644
>> --- a/fs/nfs/blocklayout/Makefile
>> +++ b/fs/nfs/blocklayout/Makefile
>> @@ -2,4 +2,4 @@
>>  # Makefile for the pNFS block layout driver kernel module
>>  #
>>  obj-$(CONFIG_PNFS_BLOCK) += blocklayoutdriver.o
>> -blocklayoutdriver-objs :=
>> +blocklayoutdriver-objs := blocklayout.o
>> diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
>> new file mode 100644
>> index 0000000..e4e64fc
>> --- /dev/null
>> +++ b/fs/nfs/blocklayout/blocklayout.c
>> @@ -0,0 +1,223 @@
>> +/*
>> + *  linux/fs/nfs/blocklayout/blocklayout.c
>> + *
>> + *  Module for the NFSv4.1 pNFS block layout driver.
>> + *
>> + *  Copyright (c) 2006 The Regents of the University of Michigan.
>> + *  All rights reserved.
>> + *
>> + *  Andy Adamson <andros at citi.umich.edu>
>> + *  Fred Isaman <iisaman at umich.edu>
>> + *
>> + * permission is granted to use, copy, create derivative works and
>> + * redistribute this software and such derivative works for any purpose,
>> + * so long as the name of the university of michigan is not used in
>> + * any advertising or publicity pertaining to the use or distribution
>> + * of this software without specific, written prior authorization.  if
>> + * the above copyright notice or any other identification of the
>> + * university of michigan is included in any copy of any portion of
>> + * this software, then the disclaimer below must also be included.
>> + *
>> + * this software is provided as is, without representation from the
>> + * university of michigan as to its fitness for any purpose, and without
>> + * warranty by the university of michigan of any kind, either express
>> + * or implied, including without limitation the implied warranties of
>> + * merchantability and fitness for a particular purpose.  the regents
>> + * of the university of michigan shall not be liable for any damages,
>> + * including special, indirect, incidental, or consequential damages,
>> + * with respect to any claim arising out or in connection with the use
>> + * of the software, even if it has been or is hereafter advised of the
>> + * possibility of such damages.
>> + */
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +
>> +#include <linux/nfs_fs.h>
>> +#include <linux/pnfs_xdr.h> /* Needed by nfs4_pnfs.h */
>> +#include <linux/nfs4_pnfs.h>
>> +
>> +#define NFSDBG_FACILITY         NFSDBG_BLOCKLAYOUT
>> +
>> +MODULE_LICENSE("GPL");
>> +MODULE_AUTHOR("Andy Adamson <andros at citi.umich.edu>");
>> +MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
>> +
>> +/* Callback operations to the pNFS client */
>> +struct pnfs_client_operations *pnfs_callback_ops;
>> +
>> +static int
>> +bl_commit(struct pnfs_layout_type *layoutid,
>> +		int sync,
>> +		struct nfs_write_data *nfs_data)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	/* Curently, this is only allowed to return:
>> +	 *   0 - success
>> +	 *   1 - fall back to non-pnfs commit
>> +	 */
>> +	return 1;
>> +}
>> +
>> +static int
>> +bl_read_pagelist(struct pnfs_layout_type *layoutid,
>> +		struct page **pages,
>> +		unsigned int pgbase,
>> +		unsigned nr_pages,
>> +		loff_t offset,
>> +		size_t count,
>> +		struct nfs_read_data *nfs_data)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return 1;
>> +}
>> +
>> +/* FRED - this should return just 0 (to indicate done for now)
>> + * or 1 (to indicate try normal nfs).  It can indicate bytes
>> + * written in wdata->res.count.  It can indicate error status in
>> + * wdata->task.tk_status.
>> + */
>> +static int
>> +bl_write_pagelist(struct pnfs_layout_type *layoutid,
>> +		struct page **pages,
>> +		unsigned int pgbase,
>> +		unsigned nr_pages,
>> +		loff_t offset,
>> +		size_t count,
>> +		int sync,
>> +		struct nfs_write_data *wdata)
>> +{
>> +	dprintk("%s enter - just using nfs\n", __func__);
>> +	return 1;
>> +}
>> +
>> +static void
>> +bl_free_layout(struct pnfs_layout_type *layoutid)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return;
>> +}
>> +
>> +static struct pnfs_layout_type *
>> +bl_alloc_layout(struct pnfs_mount_type *mtype, struct inode *inode)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return NULL;
>> +}
>> +
>> +static void
>> +bl_free_lseg(struct pnfs_layout_segment *lseg)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return;
>> +}
>> +
>> +static struct pnfs_layout_segment *
>> +bl_alloc_lseg(struct pnfs_layout_type *layoutid,
>> +	      struct nfs4_pnfs_layoutget_res *lgr)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return NULL;
>> +}
>> +
>> +static int
>> +bl_setup_layoutcommit(struct pnfs_layout_type *layoutid,
>> +		struct pnfs_layoutcommit_arg *arg)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return 0;
>> +}
>> +
>> +static void
>> +bl_cleanup_layoutcommit(struct pnfs_layout_type *layoutid,
>> +		struct pnfs_layoutcommit_arg *arg,
>> +		struct pnfs_layoutcommit_res *res)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +}
>> +
>> +static struct pnfs_mount_type *
>> +bl_initialize_mountpoint(struct super_block *sb, struct nfs_fh *fh)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return NULL;
>> +}
>> +
>> +static int
>> +bl_uninitialize_mountpoint(struct pnfs_mount_type *mtype)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return 0;
>> +}
>> +
>> +static ssize_t
>> +bl_get_stripesize(struct pnfs_layout_type *layoutid)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return 0;
>> +}
>> +
>> +static ssize_t
>> +bl_get_io_threshold(struct pnfs_layout_type *layoutid, struct inode *inode)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return 0;
>> +}
>> +
>> +/* This is called by nfs_can_coalesce_requests via nfs_pageio_do_add_request.
>> + * Should return False if there is a reason requests can not be coalesced,
>> + * otherwise, should default to returning True.
>> + */
>> +static int
>> +bl_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
>> +	   struct nfs_page *req)
>> +{
>> +	dprintk("%s enter\n", __func__);
>> +	return 1;
>> +}
>> +
>> +static struct layoutdriver_io_operations blocklayout_io_operations = {
>> +	.commit				= bl_commit,
>> +	.read_pagelist			= bl_read_pagelist,
>> +	.write_pagelist			= bl_write_pagelist,
>> +	.alloc_layout			= bl_alloc_layout,
>> +	.free_layout			= bl_free_layout,
>> +	.alloc_lseg			= bl_alloc_lseg,
>> +	.free_lseg			= bl_free_lseg,
>> +	.setup_layoutcommit		= bl_setup_layoutcommit,
>> +	.cleanup_layoutcommit		= bl_cleanup_layoutcommit,
>> +	.initialize_mountpoint		= bl_initialize_mountpoint,
>> +	.uninitialize_mountpoint	= bl_uninitialize_mountpoint,
>> +};
>> +
>> +static struct layoutdriver_policy_operations blocklayout_policy_operations = {
>> +	.get_stripesize			= bl_get_stripesize,
>> +	.get_read_threshold		= bl_get_io_threshold,
>> +	.get_write_threshold		= bl_get_io_threshold,
>> +	.pg_test			= bl_pg_test,
>> +};
>> +
>> +static struct pnfs_layoutdriver_type blocklayout_type = {
>> +	.id = LAYOUT_BLOCK_VOLUME,
>> +	.name = "LAYOUT_BLOCK_VOLUME",
>> +	.ld_io_ops = &blocklayout_io_operations,
>> +	.ld_policy_ops = &blocklayout_policy_operations,
>> +};
>> +
>> +static int __init nfs4blocklayout_init(void)
>> +{
>> +	dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
>> +
>> +	pnfs_callback_ops = pnfs_register_layoutdriver(&blocklayout_type);
>> +	return 0;
>> +}
>> +
>> +static void __exit nfs4blocklayout_exit(void)
>> +{
>> +	dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
>> +	       __func__);
>> +
>> +	pnfs_unregister_layoutdriver(&blocklayout_type);
>> +}
>> +
>> +module_init(nfs4blocklayout_init);
>> +module_exit(nfs4blocklayout_exit);
>> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
>> index 2b6c651..a15219d 100644
>> --- a/include/linux/nfs_fs.h
>> +++ b/include/linux/nfs_fs.h
>> @@ -611,6 +611,7 @@ extern void * nfs_root_data(void);
>>  #define NFSDBG_PNFS		0x0800
>>  #define NFSDBG_FILELAYOUT	0x1000
>>  #define NFSDBG_IO		0x2000
>> +#define NFSDBG_BLOCKLAYOUT	0x4000
>
> I'd really prefer all layout drivers to use a single NFSDBG flag.
> How about s/NFSDBG_FILELAYOUT/NFSDBG_PNFS_LD/?
>
> Benny
>

That's fine with me.

 	Fred

>>  #define NFSDBG_ALL		0xFFFF
>>
>>  #ifdef __KERNEL__
>
>