linux/fs/nfsd/nfs4recover.c
J. Bruce Fields c2642ab05b [PATCH] nfsd4: recovery lookup dir check
Make sure we get a directory when we look up the recovery directory.

Thanks to Christoph Hellwig for the bug report.

Based on feedback from Christoph and others, we may remove the need for this
lookup and just pass in a file descriptor from userspace instead, and/or
completely move the directory handling to userspace.  For now we're just
fixing the obvious bugs.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:26 -08:00

421 lines
9.8 KiB
C

/*
* linux/fs/nfsd/nfs4recover.c
*
* Copyright (c) 2004 The Regents of the University of Michigan.
* 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/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfs4.h>
#include <linux/nfsd/state.h>
#include <linux/nfsd/xdr4.h>
#include <linux/param.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <asm/uaccess.h>
#include <asm/scatterlist.h>
#include <linux/crypto.h>
#define NFSDDBG_FACILITY NFSDDBG_PROC
/* Globals */
static struct nameidata rec_dir;
static int rec_dir_init = 0;
static void
nfs4_save_user(uid_t *saveuid, gid_t *savegid)
{
*saveuid = current->fsuid;
*savegid = current->fsgid;
current->fsuid = 0;
current->fsgid = 0;
}
static void
nfs4_reset_user(uid_t saveuid, gid_t savegid)
{
current->fsuid = saveuid;
current->fsgid = savegid;
}
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';
}
int
nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
{
struct xdr_netobj cksum;
struct crypto_tfm *tfm;
struct scatterlist sg[1];
int status = nfserr_resource;
dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
clname->len, clname->data);
tfm = crypto_alloc_tfm("md5", CRYPTO_TFM_REQ_MAY_SLEEP);
if (tfm == NULL)
goto out;
cksum.len = crypto_tfm_alg_digestsize(tfm);
cksum.data = kmalloc(cksum.len, GFP_KERNEL);
if (cksum.data == NULL)
goto out;
crypto_digest_init(tfm);
sg[0].page = virt_to_page(clname->data);
sg[0].offset = offset_in_page(clname->data);
sg[0].length = clname->len;
crypto_digest_update(tfm, sg, 1);
crypto_digest_final(tfm, cksum.data);
md5_to_hex(dname, cksum.data);
kfree(cksum.data);
status = nfs_ok;
out:
crypto_free_tfm(tfm);
return status;
}
static void
nfsd4_sync_rec_dir(void)
{
mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
nfsd_sync_dir(rec_dir.dentry);
mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
}
int
nfsd4_create_clid_dir(struct nfs4_client *clp)
{
char *dname = clp->cl_recdir;
struct dentry *dentry;
uid_t uid;
gid_t gid;
int status;
dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
if (!rec_dir_init || clp->cl_firststate)
return 0;
nfs4_save_user(&uid, &gid);
/* lock the parent */
mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
goto out_unlock;
}
status = -EEXIST;
if (dentry->d_inode) {
dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
goto out_put;
}
status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
out_put:
dput(dentry);
out_unlock:
mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
if (status == 0) {
clp->cl_firststate = 1;
nfsd4_sync_rec_dir();
}
nfs4_reset_user(uid, gid);
dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
return status;
}
typedef int (recdir_func)(struct dentry *, struct dentry *);
struct dentry_list {
struct dentry *dentry;
struct list_head list;
};
struct dentry_list_arg {
struct list_head dentries;
struct dentry *parent;
};
static int
nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
loff_t offset, ino_t ino, unsigned int d_type)
{
struct dentry_list_arg *dla = arg;
struct list_head *dentries = &dla->dentries;
struct dentry *parent = dla->parent;
struct dentry *dentry;
struct dentry_list *child;
if (name && isdotent(name, namlen))
return nfs_ok;
dentry = lookup_one_len(name, parent, namlen);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
child = kmalloc(sizeof(*child), GFP_KERNEL);
if (child == NULL)
return -ENOMEM;
child->dentry = dentry;
list_add(&child->list, dentries);
return 0;
}
static int
nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
{
struct file *filp;
struct dentry_list_arg dla = {
.parent = dir,
};
struct list_head *dentries = &dla.dentries;
struct dentry_list *child;
uid_t uid;
gid_t gid;
int status;
if (!rec_dir_init)
return 0;
nfs4_save_user(&uid, &gid);
filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY);
status = PTR_ERR(filp);
if (IS_ERR(filp))
goto out;
INIT_LIST_HEAD(dentries);
status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
fput(filp);
while (!list_empty(dentries)) {
child = list_entry(dentries->next, struct dentry_list, list);
status = f(dir, child->dentry);
if (status)
goto out;
list_del(&child->list);
dput(child->dentry);
kfree(child);
}
out:
while (!list_empty(dentries)) {
child = list_entry(dentries->next, struct dentry_list, list);
list_del(&child->list);
dput(child->dentry);
kfree(child);
}
nfs4_reset_user(uid, gid);
return status;
}
static int
nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
{
int status;
if (!S_ISREG(dir->d_inode->i_mode)) {
printk("nfsd4: non-file found in client recovery directory\n");
return -EINVAL;
}
mutex_lock(&dir->d_inode->i_mutex);
status = vfs_unlink(dir->d_inode, dentry);
mutex_unlock(&dir->d_inode->i_mutex);
return status;
}
static int
nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
{
int status;
/* For now this directory should already be empty, but we empty it of
* any regular files anyway, just in case the directory was created by
* a kernel from the future.... */
nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
mutex_lock(&dir->d_inode->i_mutex);
status = vfs_rmdir(dir->d_inode, dentry);
mutex_unlock(&dir->d_inode->i_mutex);
return status;
}
static int
nfsd4_unlink_clid_dir(char *name, int namlen)
{
struct dentry *dentry;
int status;
dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
dentry = lookup_one_len(name, rec_dir.dentry, namlen);
mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
if (IS_ERR(dentry)) {
status = PTR_ERR(dentry);
return status;
}
status = -ENOENT;
if (!dentry->d_inode)
goto out;
status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
out:
dput(dentry);
return status;
}
void
nfsd4_remove_clid_dir(struct nfs4_client *clp)
{
uid_t uid;
gid_t gid;
int status;
if (!rec_dir_init || !clp->cl_firststate)
return;
clp->cl_firststate = 0;
nfs4_save_user(&uid, &gid);
status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
nfs4_reset_user(uid, gid);
if (status == 0)
nfsd4_sync_rec_dir();
if (status)
printk("NFSD: Failed to remove expired client state directory"
" %.*s\n", HEXDIR_LEN, clp->cl_recdir);
return;
}
static int
purge_old(struct dentry *parent, struct dentry *child)
{
int status;
if (nfs4_has_reclaimed_state(child->d_name.name))
return nfs_ok;
status = nfsd4_clear_clid_dir(parent, child);
if (status)
printk("failed to remove client recovery directory %s\n",
child->d_name.name);
/* Keep trying, success or failure: */
return nfs_ok;
}
void
nfsd4_recdir_purge_old(void) {
int status;
if (!rec_dir_init)
return;
status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
if (status == 0)
nfsd4_sync_rec_dir();
if (status)
printk("nfsd4: failed to purge old clients from recovery"
" directory %s\n", rec_dir.dentry->d_name.name);
return;
}
static int
load_recdir(struct dentry *parent, struct dentry *child)
{
if (child->d_name.len != HEXDIR_LEN - 1) {
printk("nfsd4: illegal name %s in recovery directory\n",
child->d_name.name);
/* Keep trying; maybe the others are OK: */
return nfs_ok;
}
nfs4_client_to_reclaim(child->d_name.name);
return nfs_ok;
}
int
nfsd4_recdir_load(void) {
int status;
status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
if (status)
printk("nfsd4: failed loading clients from recovery"
" directory %s\n", rec_dir.dentry->d_name.name);
return status;
}
/*
* Hold reference to the recovery directory.
*/
void
nfsd4_init_recdir(char *rec_dirname)
{
uid_t uid = 0;
gid_t gid = 0;
int status;
printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
rec_dirname);
BUG_ON(rec_dir_init);
nfs4_save_user(&uid, &gid);
status = path_lookup(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
&rec_dir);
if (status)
printk("NFSD: unable to find recovery directory %s\n",
rec_dirname);
if (!status)
rec_dir_init = 1;
nfs4_reset_user(uid, gid);
}
void
nfsd4_shutdown_recdir(void)
{
if (!rec_dir_init)
return;
rec_dir_init = 0;
path_release(&rec_dir);
}