linux/fs/nfsd/nfs4recover.c
Jeff Layton 65decb650a nfsd: skip subsequent UMH "create" operations after the first one for v4.0 clients
In the case of v4.0 clients, we may call into the "create" client
tracking operation multiple times (once for each openowner). Upcalling
for each one of those is wasteful and slow however. We can skip doing
further "create" operations after the first one if we know that one has
already been done.

v4.1+ clients generally only call into this function once (on
RECLAIM_COMPLETE), and we can't skip upcalling on the create even if the
STABLE bit is set. Doing so would make it impossible for nfsdcltrack to
lift the grace period early since the timestamp has a different meaning
in the case where the client is expected to issue a RECLAIM_COMPLETE.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-17 16:33:17 -04:00

1552 lines
35 KiB
C

/*
* Copyright (c) 2004 The Regents of the University of Michigan.
* Copyright (c) 2012 Jeff Layton <jlayton@redhat.com>
* All rights reserved.
*
* Andy Adamson <andros@citi.umich.edu>
*
* 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 University 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.
*
*/
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/crypto.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/cld.h>
#include "nfsd.h"
#include "state.h"
#include "vfs.h"
#include "netns.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
/* Declarations */
struct nfsd4_client_tracking_ops {
int (*init)(struct net *);
void (*exit)(struct net *);
void (*create)(struct nfs4_client *);
void (*remove)(struct nfs4_client *);
int (*check)(struct nfs4_client *);
void (*grace_done)(struct nfsd_net *);
};
/* Globals */
static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
static int
nfs4_save_creds(const struct cred **original_creds)
{
struct cred *new;
new = prepare_creds();
if (!new)
return -ENOMEM;
new->fsuid = GLOBAL_ROOT_UID;
new->fsgid = GLOBAL_ROOT_GID;
*original_creds = override_creds(new);
put_cred(new);
return 0;
}
static void
nfs4_reset_creds(const struct cred *original)
{
revert_creds(original);
}
static void
md5_to_hex(char *out, char *md5)
{
int i;
for (i=0; i<16; i++) {
unsigned char c = md5[i];
*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
}
*out = '\0';
}
static int
nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
{
struct xdr_netobj cksum;
struct hash_desc desc;
struct scatterlist sg;
int status;
dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
clname->len, clname->data);
desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(desc.tfm)) {
status = PTR_ERR(desc.tfm);
goto out_no_tfm;
}
cksum.len = crypto_hash_digestsize(desc.tfm);
cksum.data = kmalloc(cksum.len, GFP_KERNEL);
if (cksum.data == NULL) {
status = -ENOMEM;
goto out;
}
sg_init_one(&sg, clname->data, clname->len);
status = crypto_hash_digest(&desc, &sg, sg.length, cksum.data);
if (status)
goto out;
md5_to_hex(dname, cksum.data);
status = 0;
out:
kfree(cksum.data);
crypto_free_hash(desc.tfm);
out_no_tfm:
return status;
}
/*
* If we had an error generating the recdir name for the legacy tracker
* then warn the admin. If the error doesn't appear to be transient,
* then disable recovery tracking.
*/
static void
legacy_recdir_name_error(struct nfs4_client *clp, int error)
{
printk(KERN_ERR "NFSD: unable to generate recoverydir "
"name (%d).\n", error);
/*
* if the algorithm just doesn't exist, then disable the recovery
* tracker altogether. The crypto libs will generally return this if
* FIPS is enabled as well.
*/
if (error == -ENOENT) {
printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
"Reboot recovery will not function correctly!\n");
nfsd4_client_tracking_exit(clp->net);
}
}
static void
nfsd4_create_clid_dir(struct nfs4_client *clp)
{
const struct cred *original_cred;
char dname[HEXDIR_LEN];
struct dentry *dir, *dentry;
struct nfs4_client_reclaim *crp;
int status;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
if (!nn->rec_file)
return;
status = nfs4_make_rec_clidname(dname, &clp->cl_name);
if (status)
return legacy_recdir_name_error(clp, status);
status = nfs4_save_creds(&original_cred);
if (status < 0)
return;
status = mnt_want_write_file(nn->rec_file);
if (status)
goto out_creds;
dir = nn->rec_file->f_path.dentry;
/* lock the parent */
mutex_lock(&dir->d_inode->i_mutex);
dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
}
if (dentry->d_inode)
/*
* In the 4.1 case, where we're called from
* reclaim_complete(), records from the previous reboot
* may still be left, so this is OK.
*
* In the 4.0 case, we should never get here; but we may
* as well be forgiving and just succeed silently.
*/
goto out_put;
status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
out_put:
dput(dentry);
out_unlock:
mutex_unlock(&dir->d_inode->i_mutex);
if (status == 0) {
if (nn->in_grace) {
crp = nfs4_client_to_reclaim(dname, nn);
if (crp)
crp->cr_clp = clp;
}
vfs_fsync(nn->rec_file, 0);
} else {
printk(KERN_ERR "NFSD: failed to write recovery record"
" (err %d); please check that %s exists"
" and is writeable", status,
user_recovery_dirname);
}
mnt_drop_write_file(nn->rec_file);
out_creds:
nfs4_reset_creds(original_cred);
}
typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
struct name_list {
char name[HEXDIR_LEN];
struct list_head list;
};
struct nfs4_dir_ctx {
struct dir_context ctx;
struct list_head names;
};
static int
nfsd4_build_namelist(void *arg, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct nfs4_dir_ctx *ctx = arg;
struct name_list *entry;
if (namlen != HEXDIR_LEN - 1)
return 0;
entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
if (entry == NULL)
return -ENOMEM;
memcpy(entry->name, name, HEXDIR_LEN - 1);
entry->name[HEXDIR_LEN - 1] = '\0';
list_add(&entry->list, &ctx->names);
return 0;
}
static int
nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
{
const struct cred *original_cred;
struct dentry *dir = nn->rec_file->f_path.dentry;
struct nfs4_dir_ctx ctx = {
.ctx.actor = nfsd4_build_namelist,
.names = LIST_HEAD_INIT(ctx.names)
};
int status;
status = nfs4_save_creds(&original_cred);
if (status < 0)
return status;
status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
if (status < 0) {
nfs4_reset_creds(original_cred);
return status;
}
status = iterate_dir(nn->rec_file, &ctx.ctx);
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
while (!list_empty(&ctx.names)) {
struct name_list *entry;
entry = list_entry(ctx.names.next, struct name_list, list);
if (!status) {
struct dentry *dentry;
dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
break;
}
status = f(dir, dentry, nn);
dput(dentry);
}
list_del(&entry->list);
kfree(entry);
}
mutex_unlock(&dir->d_inode->i_mutex);
nfs4_reset_creds(original_cred);
return status;
}
static int
nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
{
struct dentry *dir, *dentry;
int status;
dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
dir = nn->rec_file->f_path.dentry;
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, dir, namlen);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
}
status = -ENOENT;
if (!dentry->d_inode)
goto out;
status = vfs_rmdir(dir->d_inode, dentry);
out:
dput(dentry);
out_unlock:
mutex_unlock(&dir->d_inode->i_mutex);
return status;
}
static void
nfsd4_remove_clid_dir(struct nfs4_client *clp)
{
const struct cred *original_cred;
struct nfs4_client_reclaim *crp;
char dname[HEXDIR_LEN];
int status;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
status = nfs4_make_rec_clidname(dname, &clp->cl_name);
if (status)
return legacy_recdir_name_error(clp, status);
status = mnt_want_write_file(nn->rec_file);
if (status)
goto out;
clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
status = nfs4_save_creds(&original_cred);
if (status < 0)
goto out_drop_write;
status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
nfs4_reset_creds(original_cred);
if (status == 0) {
vfs_fsync(nn->rec_file, 0);
if (nn->in_grace) {
/* remove reclaim record */
crp = nfsd4_find_reclaim_client(dname, nn);
if (crp)
nfs4_remove_reclaim_record(crp, nn);
}
}
out_drop_write:
mnt_drop_write_file(nn->rec_file);
out:
if (status)
printk("NFSD: Failed to remove expired client state directory"
" %.*s\n", HEXDIR_LEN, dname);
}
static int
purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
{
int status;
if (nfs4_has_reclaimed_state(child->d_name.name, nn))
return 0;
status = vfs_rmdir(parent->d_inode, child);
if (status)
printk("failed to remove client recovery directory %pd\n",
child);
/* Keep trying, success or failure: */
return 0;
}
static void
nfsd4_recdir_purge_old(struct nfsd_net *nn)
{
int status;
nn->in_grace = false;
if (!nn->rec_file)
return;
status = mnt_want_write_file(nn->rec_file);
if (status)
goto out;
status = nfsd4_list_rec_dir(purge_old, nn);
if (status == 0)
vfs_fsync(nn->rec_file, 0);
mnt_drop_write_file(nn->rec_file);
out:
nfs4_release_reclaim(nn);
if (status)
printk("nfsd4: failed to purge old clients from recovery"
" directory %pD\n", nn->rec_file);
}
static int
load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
{
if (child->d_name.len != HEXDIR_LEN - 1) {
printk("nfsd4: illegal name %pd in recovery directory\n",
child);
/* Keep trying; maybe the others are OK: */
return 0;
}
nfs4_client_to_reclaim(child->d_name.name, nn);
return 0;
}
static int
nfsd4_recdir_load(struct net *net) {
int status;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (!nn->rec_file)
return 0;
status = nfsd4_list_rec_dir(load_recdir, nn);
if (status)
printk("nfsd4: failed loading clients from recovery"
" directory %pD\n", nn->rec_file);
return status;
}
/*
* Hold reference to the recovery directory.
*/
static int
nfsd4_init_recdir(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
const struct cred *original_cred;
int status;
printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
user_recovery_dirname);
BUG_ON(nn->rec_file);
status = nfs4_save_creds(&original_cred);
if (status < 0) {
printk("NFSD: Unable to change credentials to find recovery"
" directory: error %d\n",
status);
return status;
}
nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
if (IS_ERR(nn->rec_file)) {
printk("NFSD: unable to find recovery directory %s\n",
user_recovery_dirname);
status = PTR_ERR(nn->rec_file);
nn->rec_file = NULL;
}
nfs4_reset_creds(original_cred);
if (!status)
nn->in_grace = true;
return status;
}
static void
nfsd4_shutdown_recdir(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (!nn->rec_file)
return;
fput(nn->rec_file);
nn->rec_file = NULL;
}
static int
nfs4_legacy_state_init(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
int i;
nn->reclaim_str_hashtbl = kmalloc(sizeof(struct list_head) *
CLIENT_HASH_SIZE, GFP_KERNEL);
if (!nn->reclaim_str_hashtbl)
return -ENOMEM;
for (i = 0; i < CLIENT_HASH_SIZE; i++)
INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
nn->reclaim_str_hashtbl_size = 0;
return 0;
}
static void
nfs4_legacy_state_shutdown(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
kfree(nn->reclaim_str_hashtbl);
}
static int
nfsd4_load_reboot_recovery_data(struct net *net)
{
int status;
status = nfsd4_init_recdir(net);
if (status)
return status;
status = nfsd4_recdir_load(net);
if (status)
nfsd4_shutdown_recdir(net);
return status;
}
static int
nfsd4_legacy_tracking_init(struct net *net)
{
int status;
/* XXX: The legacy code won't work in a container */
if (net != &init_net) {
WARN(1, KERN_ERR "NFSD: attempt to initialize legacy client "
"tracking in a container!\n");
return -EINVAL;
}
status = nfs4_legacy_state_init(net);
if (status)
return status;
status = nfsd4_load_reboot_recovery_data(net);
if (status)
goto err;
return 0;
err:
nfs4_legacy_state_shutdown(net);
return status;
}
static void
nfsd4_legacy_tracking_exit(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
nfs4_release_reclaim(nn);
nfsd4_shutdown_recdir(net);
nfs4_legacy_state_shutdown(net);
}
/*
* Change the NFSv4 recovery directory to recdir.
*/
int
nfs4_reset_recoverydir(char *recdir)
{
int status;
struct path path;
status = kern_path(recdir, LOOKUP_FOLLOW, &path);
if (status)
return status;
status = -ENOTDIR;
if (S_ISDIR(path.dentry->d_inode->i_mode)) {
strcpy(user_recovery_dirname, recdir);
status = 0;
}
path_put(&path);
return status;
}
char *
nfs4_recoverydir(void)
{
return user_recovery_dirname;
}
static int
nfsd4_check_legacy_client(struct nfs4_client *clp)
{
int status;
char dname[HEXDIR_LEN];
struct nfs4_client_reclaim *crp;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
/* did we already find that this client is stable? */
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return 0;
status = nfs4_make_rec_clidname(dname, &clp->cl_name);
if (status) {
legacy_recdir_name_error(clp, status);
return status;
}
/* look for it in the reclaim hashtable otherwise */
crp = nfsd4_find_reclaim_client(dname, nn);
if (crp) {
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
crp->cr_clp = clp;
return 0;
}
return -ENOENT;
}
static struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
.init = nfsd4_legacy_tracking_init,
.exit = nfsd4_legacy_tracking_exit,
.create = nfsd4_create_clid_dir,
.remove = nfsd4_remove_clid_dir,
.check = nfsd4_check_legacy_client,
.grace_done = nfsd4_recdir_purge_old,
};
/* Globals */
#define NFSD_PIPE_DIR "nfsd"
#define NFSD_CLD_PIPE "cld"
/* per-net-ns structure for holding cld upcall info */
struct cld_net {
struct rpc_pipe *cn_pipe;
spinlock_t cn_lock;
struct list_head cn_list;
unsigned int cn_xid;
};
struct cld_upcall {
struct list_head cu_list;
struct cld_net *cu_net;
struct task_struct *cu_task;
struct cld_msg cu_msg;
};
static int
__cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
{
int ret;
struct rpc_pipe_msg msg;
memset(&msg, 0, sizeof(msg));
msg.data = cmsg;
msg.len = sizeof(*cmsg);
/*
* Set task state before we queue the upcall. That prevents
* wake_up_process in the downcall from racing with schedule.
*/
set_current_state(TASK_UNINTERRUPTIBLE);
ret = rpc_queue_upcall(pipe, &msg);
if (ret < 0) {
set_current_state(TASK_RUNNING);
goto out;
}
schedule();
set_current_state(TASK_RUNNING);
if (msg.errno < 0)
ret = msg.errno;
out:
return ret;
}
static int
cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
{
int ret;
/*
* -EAGAIN occurs when pipe is closed and reopened while there are
* upcalls queued.
*/
do {
ret = __cld_pipe_upcall(pipe, cmsg);
} while (ret == -EAGAIN);
return ret;
}
static ssize_t
cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
{
struct cld_upcall *tmp, *cup;
struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
uint32_t xid;
struct nfsd_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,
nfsd_net_id);
struct cld_net *cn = nn->cld_net;
if (mlen != sizeof(*cmsg)) {
dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
sizeof(*cmsg));
return -EINVAL;
}
/* copy just the xid so we can try to find that */
if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
dprintk("%s: error when copying xid from userspace", __func__);
return -EFAULT;
}
/* walk the list and find corresponding xid */
cup = NULL;
spin_lock(&cn->cn_lock);
list_for_each_entry(tmp, &cn->cn_list, cu_list) {
if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
cup = tmp;
list_del_init(&cup->cu_list);
break;
}
}
spin_unlock(&cn->cn_lock);
/* couldn't find upcall? */
if (!cup) {
dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
return -EINVAL;
}
if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
return -EFAULT;
wake_up_process(cup->cu_task);
return mlen;
}
static void
cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
struct cld_msg *cmsg = msg->data;
struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
cu_msg);
/* errno >= 0 means we got a downcall */
if (msg->errno >= 0)
return;
wake_up_process(cup->cu_task);
}
static const struct rpc_pipe_ops cld_upcall_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = cld_pipe_downcall,
.destroy_msg = cld_pipe_destroy_msg,
};
static struct dentry *
nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
{
struct dentry *dir, *dentry;
dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
if (dir == NULL)
return ERR_PTR(-ENOENT);
dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
dput(dir);
return dentry;
}
static void
nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
{
if (pipe->dentry)
rpc_unlink(pipe->dentry);
}
static struct dentry *
nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
{
struct super_block *sb;
struct dentry *dentry;
sb = rpc_get_sb_net(net);
if (!sb)
return NULL;
dentry = nfsd4_cld_register_sb(sb, pipe);
rpc_put_sb_net(net);
return dentry;
}
static void
nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
{
struct super_block *sb;
sb = rpc_get_sb_net(net);
if (sb) {
nfsd4_cld_unregister_sb(pipe);
rpc_put_sb_net(net);
}
}
/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
static int
nfsd4_init_cld_pipe(struct net *net)
{
int ret;
struct dentry *dentry;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct cld_net *cn;
if (nn->cld_net)
return 0;
cn = kzalloc(sizeof(*cn), GFP_KERNEL);
if (!cn) {
ret = -ENOMEM;
goto err;
}
cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
if (IS_ERR(cn->cn_pipe)) {
ret = PTR_ERR(cn->cn_pipe);
goto err;
}
spin_lock_init(&cn->cn_lock);
INIT_LIST_HEAD(&cn->cn_list);
dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
goto err_destroy_data;
}
cn->cn_pipe->dentry = dentry;
nn->cld_net = cn;
return 0;
err_destroy_data:
rpc_destroy_pipe_data(cn->cn_pipe);
err:
kfree(cn);
printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
ret);
return ret;
}
static void
nfsd4_remove_cld_pipe(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct cld_net *cn = nn->cld_net;
nfsd4_cld_unregister_net(net, cn->cn_pipe);
rpc_destroy_pipe_data(cn->cn_pipe);
kfree(nn->cld_net);
nn->cld_net = NULL;
}
static struct cld_upcall *
alloc_cld_upcall(struct cld_net *cn)
{
struct cld_upcall *new, *tmp;
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return new;
/* FIXME: hard cap on number in flight? */
restart_search:
spin_lock(&cn->cn_lock);
list_for_each_entry(tmp, &cn->cn_list, cu_list) {
if (tmp->cu_msg.cm_xid == cn->cn_xid) {
cn->cn_xid++;
spin_unlock(&cn->cn_lock);
goto restart_search;
}
}
new->cu_task = current;
new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
new->cu_net = cn;
list_add(&new->cu_list, &cn->cn_list);
spin_unlock(&cn->cn_lock);
dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
return new;
}
static void
free_cld_upcall(struct cld_upcall *victim)
{
struct cld_net *cn = victim->cu_net;
spin_lock(&cn->cn_lock);
list_del(&victim->cu_list);
spin_unlock(&cn->cn_lock);
kfree(victim);
}
/* Ask daemon to create a new record */
static void
nfsd4_cld_create(struct nfs4_client *clp)
{
int ret;
struct cld_upcall *cup;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
struct cld_net *cn = nn->cld_net;
/* Don't upcall if it's already stored */
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
cup = alloc_cld_upcall(cn);
if (!cup) {
ret = -ENOMEM;
goto out_err;
}
cup->cu_msg.cm_cmd = Cld_Create;
cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
clp->cl_name.len);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
if (!ret) {
ret = cup->cu_msg.cm_status;
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
}
free_cld_upcall(cup);
out_err:
if (ret)
printk(KERN_ERR "NFSD: Unable to create client "
"record on stable storage: %d\n", ret);
}
/* Ask daemon to create a new record */
static void
nfsd4_cld_remove(struct nfs4_client *clp)
{
int ret;
struct cld_upcall *cup;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
struct cld_net *cn = nn->cld_net;
/* Don't upcall if it's already removed */
if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
cup = alloc_cld_upcall(cn);
if (!cup) {
ret = -ENOMEM;
goto out_err;
}
cup->cu_msg.cm_cmd = Cld_Remove;
cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
clp->cl_name.len);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
if (!ret) {
ret = cup->cu_msg.cm_status;
clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
}
free_cld_upcall(cup);
out_err:
if (ret)
printk(KERN_ERR "NFSD: Unable to remove client "
"record from stable storage: %d\n", ret);
}
/* Check for presence of a record, and update its timestamp */
static int
nfsd4_cld_check(struct nfs4_client *clp)
{
int ret;
struct cld_upcall *cup;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
struct cld_net *cn = nn->cld_net;
/* Don't upcall if one was already stored during this grace pd */
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return 0;
cup = alloc_cld_upcall(cn);
if (!cup) {
printk(KERN_ERR "NFSD: Unable to check client record on "
"stable storage: %d\n", -ENOMEM);
return -ENOMEM;
}
cup->cu_msg.cm_cmd = Cld_Check;
cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
clp->cl_name.len);
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
if (!ret) {
ret = cup->cu_msg.cm_status;
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
}
free_cld_upcall(cup);
return ret;
}
static void
nfsd4_cld_grace_done(struct nfsd_net *nn)
{
int ret;
struct cld_upcall *cup;
struct cld_net *cn = nn->cld_net;
cup = alloc_cld_upcall(cn);
if (!cup) {
ret = -ENOMEM;
goto out_err;
}
cup->cu_msg.cm_cmd = Cld_GraceDone;
cup->cu_msg.cm_u.cm_gracetime = (int64_t)nn->boot_time;
ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
if (!ret)
ret = cup->cu_msg.cm_status;
free_cld_upcall(cup);
out_err:
if (ret)
printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
}
static struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
.init = nfsd4_init_cld_pipe,
.exit = nfsd4_remove_cld_pipe,
.create = nfsd4_cld_create,
.remove = nfsd4_cld_remove,
.check = nfsd4_cld_check,
.grace_done = nfsd4_cld_grace_done,
};
/* upcall via usermodehelper */
static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
static bool cltrack_legacy_disable;
module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(cltrack_legacy_disable,
"Disable legacy recoverydir conversion. Default: false");
#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
static char *
nfsd4_cltrack_legacy_topdir(void)
{
int copied;
size_t len;
char *result;
if (cltrack_legacy_disable)
return NULL;
len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
strlen(nfs4_recoverydir()) + 1;
result = kmalloc(len, GFP_KERNEL);
if (!result)
return result;
copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
nfs4_recoverydir());
if (copied >= len) {
/* just return nothing if output was truncated */
kfree(result);
return NULL;
}
return result;
}
static char *
nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
{
int copied;
size_t len;
char *result;
if (cltrack_legacy_disable)
return NULL;
/* +1 is for '/' between "topdir" and "recdir" */
len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
result = kmalloc(len, GFP_KERNEL);
if (!result)
return result;
copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
nfs4_recoverydir());
if (copied > (len - HEXDIR_LEN)) {
/* just return nothing if output will be truncated */
kfree(result);
return NULL;
}
copied = nfs4_make_rec_clidname(result + copied, name);
if (copied) {
kfree(result);
return NULL;
}
return result;
}
static char *
nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
{
int copied;
size_t len;
char *result;
/* prefix + Y/N character + terminating NULL */
len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
result = kmalloc(len, GFP_KERNEL);
if (!result)
return result;
copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
clp->cl_minorversion ? 'Y' : 'N');
if (copied >= len) {
/* just return nothing if output was truncated */
kfree(result);
return NULL;
}
return result;
}
static char *
nfsd4_cltrack_grace_start(time_t grace_start)
{
int copied;
size_t len;
char *result;
/* prefix + max width of int64_t string + terminating NULL */
len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
result = kmalloc(len, GFP_KERNEL);
if (!result)
return result;
copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%ld",
grace_start);
if (copied >= len) {
/* just return nothing if output was truncated */
kfree(result);
return NULL;
}
return result;
}
static int
nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
{
char *envp[3];
char *argv[4];
int ret;
if (unlikely(!cltrack_prog[0])) {
dprintk("%s: cltrack_prog is disabled\n", __func__);
return -EACCES;
}
dprintk("%s: cmd: %s\n", __func__, cmd);
dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
envp[0] = env0;
envp[1] = env1;
envp[2] = NULL;
argv[0] = (char *)cltrack_prog;
argv[1] = cmd;
argv[2] = arg;
argv[3] = 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
* once the problem has been fixed.
*/
if (ret == -ENOENT || ret == -EACCES) {
dprintk("NFSD: %s was not found or isn't executable (%d). "
"Setting cltrack_prog to blank string!",
cltrack_prog, ret);
cltrack_prog[0] = '\0';
}
dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
return ret;
}
static char *
bin_to_hex_dup(const unsigned char *src, int srclen)
{
int i;
char *buf, *hex;
/* +1 for terminating NULL */
buf = kmalloc((srclen * 2) + 1, GFP_KERNEL);
if (!buf)
return buf;
hex = buf;
for (i = 0; i < srclen; i++) {
sprintf(hex, "%2.2x", *src++);
hex += 2;
}
return buf;
}
static int
nfsd4_umh_cltrack_init(struct net *net)
{
int ret;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
/* XXX: The usermode helper s not working in container yet. */
if (net != &init_net) {
WARN(1, KERN_ERR "NFSD: attempt to initialize umh client "
"tracking in a container!\n");
return -EINVAL;
}
ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
kfree(grace_start);
return ret;
}
static void
nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
{
wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
TASK_UNINTERRUPTIBLE);
}
static void
nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
{
smp_mb__before_atomic();
clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
smp_mb__after_atomic();
wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
}
static void
nfsd4_umh_cltrack_create(struct nfs4_client *clp)
{
char *hexid, *has_session, *grace_start;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
/*
* With v4.0 clients, there's little difference in outcome between a
* create and check operation, and we can end up calling into this
* function multiple times per client (once for each openowner). So,
* for v4.0 clients skip upcalling once the client has been recorded
* on stable storage.
*
* For v4.1+ clients, the outcome of the two operations is different,
* so we must ensure that we upcall for the create operation. v4.1+
* clients call this on RECLAIM_COMPLETE though, so we should only end
* up doing a single create upcall per client.
*/
if (clp->cl_minorversion == 0 &&
test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
if (!hexid) {
dprintk("%s: can't allocate memory for upcall!\n", __func__);
return;
}
has_session = nfsd4_cltrack_client_has_session(clp);
grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
nfsd4_cltrack_upcall_lock(clp);
if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
nfsd4_cltrack_upcall_unlock(clp);
kfree(has_session);
kfree(grace_start);
kfree(hexid);
}
static void
nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
{
char *hexid;
if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
if (!hexid) {
dprintk("%s: can't allocate memory for upcall!\n", __func__);
return;
}
nfsd4_cltrack_upcall_lock(clp);
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
nfsd4_cltrack_upcall_unlock(clp);
kfree(hexid);
}
static int
nfsd4_umh_cltrack_check(struct nfs4_client *clp)
{
int ret;
char *hexid, *has_session, *legacy;
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return 0;
hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
if (!hexid) {
dprintk("%s: can't allocate memory for upcall!\n", __func__);
return -ENOMEM;
}
has_session = nfsd4_cltrack_client_has_session(clp);
legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
nfsd4_cltrack_upcall_lock(clp);
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
ret = 0;
} else {
ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
if (ret == 0)
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
}
nfsd4_cltrack_upcall_unlock(clp);
kfree(has_session);
kfree(legacy);
kfree(hexid);
return ret;
}
static void
nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
{
char *legacy;
char timestr[22]; /* FIXME: better way to determine max size? */
sprintf(timestr, "%ld", nn->boot_time);
legacy = nfsd4_cltrack_legacy_topdir();
nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
kfree(legacy);
}
static struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
.init = nfsd4_umh_cltrack_init,
.exit = NULL,
.create = nfsd4_umh_cltrack_create,
.remove = nfsd4_umh_cltrack_remove,
.check = nfsd4_umh_cltrack_check,
.grace_done = nfsd4_umh_cltrack_grace_done,
};
int
nfsd4_client_tracking_init(struct net *net)
{
int status;
struct path path;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
/* just run the init if it the method is already decided */
if (nn->client_tracking_ops)
goto do_init;
/*
* First, try a UMH upcall. It should succeed or fail quickly, so
* there's little harm in trying that first.
*/
nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
status = nn->client_tracking_ops->init(net);
if (!status)
return status;
/*
* See if the recoverydir exists and is a directory. If it is,
* then use the legacy ops.
*/
nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
if (!status) {
status = S_ISDIR(path.dentry->d_inode->i_mode);
path_put(&path);
if (status)
goto do_init;
}
/* Finally, try to use nfsdcld */
nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
printk(KERN_WARNING "NFSD: the nfsdcld client tracking upcall will be "
"removed in 3.10. Please transition to using "
"nfsdcltrack.\n");
do_init:
status = nn->client_tracking_ops->init(net);
if (status) {
printk(KERN_WARNING "NFSD: Unable to initialize client "
"recovery tracking! (%d)\n", status);
nn->client_tracking_ops = NULL;
}
return status;
}
void
nfsd4_client_tracking_exit(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (nn->client_tracking_ops) {
if (nn->client_tracking_ops->exit)
nn->client_tracking_ops->exit(net);
nn->client_tracking_ops = NULL;
}
}
void
nfsd4_client_record_create(struct nfs4_client *clp)
{
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
if (nn->client_tracking_ops)
nn->client_tracking_ops->create(clp);
}
void
nfsd4_client_record_remove(struct nfs4_client *clp)
{
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
if (nn->client_tracking_ops)
nn->client_tracking_ops->remove(clp);
}
int
nfsd4_client_record_check(struct nfs4_client *clp)
{
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
if (nn->client_tracking_ops)
return nn->client_tracking_ops->check(clp);
return -EOPNOTSUPP;
}
void
nfsd4_record_grace_done(struct nfsd_net *nn)
{
if (nn->client_tracking_ops)
nn->client_tracking_ops->grace_done(nn);
}
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 nfsd_net *nn = net_generic(net, nfsd_net_id);
struct cld_net *cn = nn->cld_net;
struct dentry *dentry;
int ret = 0;
if (!try_module_get(THIS_MODULE))
return 0;
if (!cn) {
module_put(THIS_MODULE);
return 0;
}
switch (event) {
case RPC_PIPEFS_MOUNT:
dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
break;
}
cn->cn_pipe->dentry = dentry;
break;
case RPC_PIPEFS_UMOUNT:
if (cn->cn_pipe->dentry)
nfsd4_cld_unregister_sb(cn->cn_pipe);
break;
default:
ret = -ENOTSUPP;
break;
}
module_put(THIS_MODULE);
return ret;
}
static struct notifier_block nfsd4_cld_block = {
.notifier_call = rpc_pipefs_event,
};
int
register_cld_notifier(void)
{
return rpc_pipefs_notifier_register(&nfsd4_cld_block);
}
void
unregister_cld_notifier(void)
{
rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
}