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android_kernel_samsung_hero.../fs/nfsd/nfs4recover.c

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init: OSRC G9300ZCU2APF7
2016-08-17 10:41:52 +02:00
/*
* 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();
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);
}
Reference in a new issue Copy permalink