linux/fs/nfs/blocklayout/rpc_pipefs.c
Christoph Hellwig d9186c0397 nfs/blocklayout: add SCSI layout support
This is a trivial extension to the block layout driver to support the
new SCSI layouts draft.  There are three changes:

 - device identifcation through the SCSI VPD page.  This allows us to
   directly use the udev generated persistent device names instead of
   requiring an expensive lookup by crawling every block device node
   in /dev and reading a signature for it.
 - use of SCSI persistent reservations to protect device access and
   allow for robust fencing.  On the client sides this just means
   registering and unregistering a server supplied key.
 - an optimized LAYOUTCOMMIT payload that doesn't send unessecary
   fields to the server.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-18 11:38:17 -04:00

289 lines
7.3 KiB
C

/*
* Copyright (c) 2006,2007 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@citi.umich.edu>
* Fred Isaman <iisaman@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/genhd.h>
#include <linux/blkdev.h>
#include "blocklayout.h"
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
static void
nfs4_encode_simple(__be32 *p, struct pnfs_block_volume *b)
{
int i;
*p++ = cpu_to_be32(1);
*p++ = cpu_to_be32(b->type);
*p++ = cpu_to_be32(b->simple.nr_sigs);
for (i = 0; i < b->simple.nr_sigs; i++) {
p = xdr_encode_hyper(p, b->simple.sigs[i].offset);
p = xdr_encode_opaque(p, b->simple.sigs[i].sig,
b->simple.sigs[i].sig_len);
}
}
dev_t
bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b,
gfp_t gfp_mask)
{
struct net *net = server->nfs_client->cl_net;
struct nfs_net *nn = net_generic(net, nfs_net_id);
struct bl_dev_msg *reply = &nn->bl_mount_reply;
struct bl_pipe_msg bl_pipe_msg;
struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
struct bl_msg_hdr *bl_msg;
DECLARE_WAITQUEUE(wq, current);
dev_t dev = 0;
int rc;
dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
mutex_lock(&nn->bl_mutex);
bl_pipe_msg.bl_wq = &nn->bl_wq;
b->simple.len += 4; /* single volume */
if (b->simple.len > PAGE_SIZE)
goto out_unlock;
memset(msg, 0, sizeof(*msg));
msg->len = sizeof(*bl_msg) + b->simple.len;
msg->data = kzalloc(msg->len, gfp_mask);
if (!msg->data)
goto out_free_data;
bl_msg = msg->data;
bl_msg->type = BL_DEVICE_MOUNT,
bl_msg->totallen = b->simple.len;
nfs4_encode_simple(msg->data + sizeof(*bl_msg), b);
dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
add_wait_queue(&nn->bl_wq, &wq);
rc = rpc_queue_upcall(nn->bl_device_pipe, msg);
if (rc < 0) {
remove_wait_queue(&nn->bl_wq, &wq);
goto out_free_data;
}
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
remove_wait_queue(&nn->bl_wq, &wq);
if (reply->status != BL_DEVICE_REQUEST_PROC) {
printk(KERN_WARNING "%s failed to decode device: %d\n",
__func__, reply->status);
goto out_free_data;
}
dev = MKDEV(reply->major, reply->minor);
out_free_data:
kfree(msg->data);
out_unlock:
mutex_unlock(&nn->bl_mutex);
return dev;
}
static ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,
size_t mlen)
{
struct nfs_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
nfs_net_id);
if (mlen != sizeof (struct bl_dev_msg))
return -EINVAL;
if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0)
return -EFAULT;
wake_up(&nn->bl_wq);
return mlen;
}
static void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
struct bl_pipe_msg *bl_pipe_msg =
container_of(msg, struct bl_pipe_msg, msg);
if (msg->errno >= 0)
return;
wake_up(bl_pipe_msg->bl_wq);
}
static const struct rpc_pipe_ops bl_upcall_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = bl_pipe_downcall,
.destroy_msg = bl_pipe_destroy_msg,
};
static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
struct rpc_pipe *pipe)
{
struct dentry *dir, *dentry;
dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
if (dir == NULL)
return ERR_PTR(-ENOENT);
dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
dput(dir);
return dentry;
}
static void nfs4blocklayout_unregister_sb(struct super_block *sb,
struct rpc_pipe *pipe)
{
if (pipe->dentry)
rpc_unlink(pipe->dentry);
}
static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
void *ptr)
{
struct super_block *sb = ptr;
struct net *net = sb->s_fs_info;
struct nfs_net *nn = net_generic(net, nfs_net_id);
struct dentry *dentry;
int ret = 0;
if (!try_module_get(THIS_MODULE))
return 0;
if (nn->bl_device_pipe == NULL) {
module_put(THIS_MODULE);
return 0;
}
switch (event) {
case RPC_PIPEFS_MOUNT:
dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
break;
}
nn->bl_device_pipe->dentry = dentry;
break;
case RPC_PIPEFS_UMOUNT:
if (nn->bl_device_pipe->dentry)
nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
break;
default:
ret = -ENOTSUPP;
break;
}
module_put(THIS_MODULE);
return ret;
}
static struct notifier_block nfs4blocklayout_block = {
.notifier_call = rpc_pipefs_event,
};
static struct dentry *nfs4blocklayout_register_net(struct net *net,
struct rpc_pipe *pipe)
{
struct super_block *pipefs_sb;
struct dentry *dentry;
pipefs_sb = rpc_get_sb_net(net);
if (!pipefs_sb)
return NULL;
dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
rpc_put_sb_net(net);
return dentry;
}
static void nfs4blocklayout_unregister_net(struct net *net,
struct rpc_pipe *pipe)
{
struct super_block *pipefs_sb;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
rpc_put_sb_net(net);
}
}
static int nfs4blocklayout_net_init(struct net *net)
{
struct nfs_net *nn = net_generic(net, nfs_net_id);
struct dentry *dentry;
mutex_init(&nn->bl_mutex);
init_waitqueue_head(&nn->bl_wq);
nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
if (IS_ERR(nn->bl_device_pipe))
return PTR_ERR(nn->bl_device_pipe);
dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
if (IS_ERR(dentry)) {
rpc_destroy_pipe_data(nn->bl_device_pipe);
return PTR_ERR(dentry);
}
nn->bl_device_pipe->dentry = dentry;
return 0;
}
static void nfs4blocklayout_net_exit(struct net *net)
{
struct nfs_net *nn = net_generic(net, nfs_net_id);
nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
rpc_destroy_pipe_data(nn->bl_device_pipe);
nn->bl_device_pipe = NULL;
}
static struct pernet_operations nfs4blocklayout_net_ops = {
.init = nfs4blocklayout_net_init,
.exit = nfs4blocklayout_net_exit,
};
int __init bl_init_pipefs(void)
{
int ret;
ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
if (ret)
goto out;
ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
if (ret)
goto out_unregister_notifier;
return 0;
out_unregister_notifier:
rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
out:
return ret;
}
void bl_cleanup_pipefs(void)
{
rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
unregister_pernet_subsys(&nfs4blocklayout_net_ops);
}