[mirror_ubuntu-zesty-kernel.git] / fs / nfsd / nfs4recover.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/err.h>
#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 <linux/scatterlist.h>
#include <linux/crypto.h>
#include <linux/sched.h>
#include <linux/mount.h>

#define NFSDDBG_FACILITY                NFSDDBG_PROC

/* Globals */
static struct path rec_dir;
static int rec_dir_init = 0;

static int
nfs4_save_creds(const struct cred **original_creds)
{
	struct cred *new;

	new = prepare_creds();
	if (!new)
		return -ENOMEM;

	new->fsuid = 0;
	new->fsgid = 0;
	*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';
}

__be32
nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
{
	struct xdr_netobj cksum;
	struct hash_desc desc;
	struct scatterlist sg;
	__be32 status = nfserr_resource;

	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))
		goto out_no_tfm;
	cksum.len = crypto_hash_digestsize(desc.tfm);
	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
	if (cksum.data == NULL)
 		goto out;

	sg_init_one(&sg, clname->data, clname->len);

	if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
		goto out;

	md5_to_hex(dname, cksum.data);

	kfree(cksum.data);
	status = nfs_ok;
out:
	crypto_free_hash(desc.tfm);
out_no_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)
{
	const struct cred *original_cred;
	char *dname = clp->cl_recdir;
	struct dentry *dentry;
	int status;

	dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);

	if (!rec_dir_init || clp->cl_firststate)
		return 0;

	status = nfs4_save_creds(&original_cred);
	if (status < 0)
		return status;

	/* 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 = mnt_want_write(rec_dir.mnt);
	if (status)
		goto out_put;
	status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
	mnt_drop_write(rec_dir.mnt);
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_creds(original_cred);
	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, u64 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 0;
	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)
{
	const struct cred *original_cred;
	struct file *filp;
	struct dentry_list_arg dla = {
		.parent = dir,
	};
	struct list_head *dentries = &dla.dentries;
	struct dentry_list *child;
	int status;

	if (!rec_dir_init)
		return 0;

	status = nfs4_save_creds(&original_cred);
	if (status < 0)
		return status;
	INIT_LIST_HEAD(dentries);

	filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
			   current_cred());
	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_creds(original_cred);
	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_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
	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_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
	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)
{
	const struct cred *original_cred;
	int status;

	if (!rec_dir_init || !clp->cl_firststate)
		return;

	status = mnt_want_write(rec_dir.mnt);
	if (status)
		goto out;
	clp->cl_firststate = 0;

	status = nfs4_save_creds(&original_cred);
	if (status < 0)
		goto out;

	status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
	nfs4_reset_creds(original_cred);
	if (status == 0)
		nfsd4_sync_rec_dir();
	mnt_drop_write(rec_dir.mnt);
out:
	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 0;

	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 0;
}

void
nfsd4_recdir_purge_old(void) {
	int status;

	if (!rec_dir_init)
		return;
	status = mnt_want_write(rec_dir.mnt);
	if (status)
		goto out;
	status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
	if (status == 0)
		nfsd4_sync_rec_dir();
	mnt_drop_write(rec_dir.mnt);
out:
	if (status)
		printk("nfsd4: failed to purge old clients from recovery"
			" directory %s\n", rec_dir.dentry->d_name.name);
}

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 0;
	}
	nfs4_client_to_reclaim(child->d_name.name);
	return 0;
}

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)
{
	const struct cred *original_cred;
	int status;

	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
			rec_dirname);

	BUG_ON(rec_dir_init);

	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 = kern_path(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_creds(original_cred);
}

void
nfsd4_shutdown_recdir(void)
{
	if (!rec_dir_init)
		return;
	rec_dir_init = 0;
	path_put(&rec_dir);
}
Commit	Line	Data
a55370a3 N	1	/*
	2	* linux/fs/nfsd/nfs4recover.c
	3	*
	4	* Copyright (c) 2004 The Regents of the University of Michigan.
	5	* All rights reserved.
	6	*
	7	* Andy Adamson <andros@citi.umich.edu>
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	*
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. Neither the name of the University nor the names of its
	19	* contributors may be used to endorse or promote products derived
	20	* from this software without specific prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
	23	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	24	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	25	* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	27	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	28	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	29	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	30	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	31	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	32	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	33	*
	34	*/
	35
35058687	36	#include <linux/err.h>
a55370a3 N	37	#include <linux/sunrpc/svc.h>
	38	#include <linux/nfsd/nfsd.h>
	39	#include <linux/nfs4.h>
	40	#include <linux/nfsd/state.h>
	41	#include <linux/nfsd/xdr4.h>
190e4fbf N	42	#include <linux/param.h>
	43	#include <linux/file.h>
	44	#include <linux/namei.h>
a55370a3	45	#include <asm/uaccess.h>
87ae9afd	46	#include <linux/scatterlist.h>
a55370a3	47	#include <linux/crypto.h>
e8edc6e0	48	#include <linux/sched.h>
0622753b	49	#include <linux/mount.h>
a55370a3 N	50
	51	#define NFSDDBG_FACILITY NFSDDBG_PROC
	52
190e4fbf	53	/* Globals */
a63bb996	54	static struct path rec_dir;
190e4fbf N	55	static int rec_dir_init = 0;
190e4fbf N	56
d84f4f99 DH	57	static int
d84f4f99 DH	58	nfs4_save_creds(const struct cred **original_creds)
190e4fbf	59	{
d84f4f99 DH	60	struct cred *new;
	61
	62	new = prepare_creds();
	63	if (!new)
	64	return -ENOMEM;
	65
	66	new->fsuid = 0;
	67	new->fsgid = 0;
	68	*original_creds = override_creds(new);
	69	put_cred(new);
	70	return 0;
190e4fbf N	71	}
	72
	73	static void
d84f4f99	74	nfs4_reset_creds(const struct cred *original)
190e4fbf	75	{
d84f4f99	76	revert_creds(original);
190e4fbf N	77	}
190e4fbf N	78
a55370a3 N	79	static void
	80	md5_to_hex(char out, char md5)
	81	{
	82	int i;
	83
	84	for (i=0; i<16; i++) {
	85	unsigned char c = md5[i];
	86
	87	out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)('a'-'9'-1);
	88	out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)('a'-'9'-1);
	89	}
	90	*out = '\0';
	91	}
	92
b37ad28b	93	__be32
a55370a3 N	94	nfs4_make_rec_clidname(char dname, struct xdr_netobj clname)
	95	{
	96	struct xdr_netobj cksum;
35058687	97	struct hash_desc desc;
60c74f81	98	struct scatterlist sg;
b37ad28b	99	__be32 status = nfserr_resource;
a55370a3 N	100
	101	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
	102	clname->len, clname->data);
35058687 HX	103	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
	104	desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
	105	if (IS_ERR(desc.tfm))
	106	goto out_no_tfm;
	107	cksum.len = crypto_hash_digestsize(desc.tfm);
a55370a3 N	108	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
	109	if (cksum.data == NULL)
	110	goto out;
a55370a3	111
60c74f81	112	sg_init_one(&sg, clname->data, clname->len);
a55370a3	113
60c74f81	114	if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
35058687	115	goto out;
a55370a3 N	116
	117	md5_to_hex(dname, cksum.data);
	118
	119	kfree(cksum.data);
	120	status = nfs_ok;
	121	out:
35058687 HX	122	crypto_free_hash(desc.tfm);
35058687 HX	123	out_no_tfm:
a55370a3 N	124	return status;
a55370a3 N	125	}
190e4fbf	126
a6ccbbb8 N	127	static void
a6ccbbb8 N	128	nfsd4_sync_rec_dir(void)
c7b9a459	129	{
a63bb996 AV	130	mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
	131	nfsd_sync_dir(rec_dir.dentry);
	132	mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459 N	133	}
	134
	135	int
	136	nfsd4_create_clid_dir(struct nfs4_client *clp)
	137	{
d84f4f99	138	const struct cred *original_cred;
c7b9a459 N	139	char *dname = clp->cl_recdir;
c7b9a459 N	140	struct dentry *dentry;
c7b9a459 N	141	int status;
	142
	143	dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
	144
	145	if (!rec_dir_init \|\| clp->cl_firststate)
	146	return 0;
	147
d84f4f99 DH	148	status = nfs4_save_creds(&original_cred);
	149	if (status < 0)
	150	return status;
c7b9a459 N	151
c7b9a459 N	152	/* lock the parent */
a63bb996	153	mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459	154
a63bb996	155	dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
c7b9a459 N	156	if (IS_ERR(dentry)) {
	157	status = PTR_ERR(dentry);
	158	goto out_unlock;
	159	}
	160	status = -EEXIST;
	161	if (dentry->d_inode) {
	162	dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
	163	goto out_put;
	164	}
a63bb996	165	status = mnt_want_write(rec_dir.mnt);
463c3197 DH	166	if (status)
463c3197 DH	167	goto out_put;
a63bb996 AV	168	status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
a63bb996 AV	169	mnt_drop_write(rec_dir.mnt);
c7b9a459 N	170	out_put:
	171	dput(dentry);
	172	out_unlock:
a63bb996	173	mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459 N	174	if (status == 0) {
c7b9a459 N	175	clp->cl_firststate = 1;
a6ccbbb8	176	nfsd4_sync_rec_dir();
c7b9a459	177	}
d84f4f99	178	nfs4_reset_creds(original_cred);
c7b9a459 N	179	dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
	180	return status;
	181	}
	182
190e4fbf N	183	typedef int (recdir_func)(struct dentry , struct dentry );
	184
	185	struct dentry_list {
	186	struct dentry *dentry;
	187	struct list_head list;
	188	};
	189
	190	struct dentry_list_arg {
	191	struct list_head dentries;
	192	struct dentry *parent;
	193	};
	194
	195	static int
	196	nfsd4_build_dentrylist(void arg, const char name, int namlen,
afefdbb2	197	loff_t offset, u64 ino, unsigned int d_type)
190e4fbf N	198	{
	199	struct dentry_list_arg *dla = arg;
	200	struct list_head *dentries = &dla->dentries;
	201	struct dentry *parent = dla->parent;
	202	struct dentry *dentry;
	203	struct dentry_list *child;
	204
	205	if (name && isdotent(name, namlen))
b37ad28b	206	return 0;
190e4fbf N	207	dentry = lookup_one_len(name, parent, namlen);
	208	if (IS_ERR(dentry))
	209	return PTR_ERR(dentry);
	210	child = kmalloc(sizeof(*child), GFP_KERNEL);
	211	if (child == NULL)
	212	return -ENOMEM;
	213	child->dentry = dentry;
	214	list_add(&child->list, dentries);
	215	return 0;
	216	}
	217
	218	static int
	219	nfsd4_list_rec_dir(struct dentry dir, recdir_func f)
	220	{
d84f4f99	221	const struct cred *original_cred;
190e4fbf N	222	struct file *filp;
	223	struct dentry_list_arg dla = {
	224	.parent = dir,
	225	};
	226	struct list_head *dentries = &dla.dentries;
	227	struct dentry_list *child;
190e4fbf N	228	int status;
	229
	230	if (!rec_dir_init)
	231	return 0;
	232
d84f4f99 DH	233	status = nfs4_save_creds(&original_cred);
	234	if (status < 0)
	235	return status;
e4625eb8	236	INIT_LIST_HEAD(dentries);
190e4fbf	237
745ca247 DH	238	filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
745ca247 DH	239	current_cred());
190e4fbf N	240	status = PTR_ERR(filp);
	241	if (IS_ERR(filp))
	242	goto out;
	243	INIT_LIST_HEAD(dentries);
	244	status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
	245	fput(filp);
	246	while (!list_empty(dentries)) {
	247	child = list_entry(dentries->next, struct dentry_list, list);
	248	status = f(dir, child->dentry);
	249	if (status)
	250	goto out;
	251	list_del(&child->list);
	252	dput(child->dentry);
	253	kfree(child);
	254	}
	255	out:
	256	while (!list_empty(dentries)) {
	257	child = list_entry(dentries->next, struct dentry_list, list);
	258	list_del(&child->list);
	259	dput(child->dentry);
	260	kfree(child);
	261	}
d84f4f99	262	nfs4_reset_creds(original_cred);
190e4fbf N	263	return status;
	264	}
	265
c7b9a459 N	266	static int
	267	nfsd4_remove_clid_file(struct dentry dir, struct dentry dentry)
	268	{
	269	int status;
	270
	271	if (!S_ISREG(dir->d_inode->i_mode)) {
	272	printk("nfsd4: non-file found in client recovery directory\n");
	273	return -EINVAL;
	274	}
4b75f78e	275	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
c7b9a459	276	status = vfs_unlink(dir->d_inode, dentry);
1b1dcc1b	277	mutex_unlock(&dir->d_inode->i_mutex);
c7b9a459 N	278	return status;
	279	}
	280
	281	static int
	282	nfsd4_clear_clid_dir(struct dentry dir, struct dentry dentry)
	283	{
	284	int status;
	285
	286	/* For now this directory should already be empty, but we empty it of
	287	* any regular files anyway, just in case the directory was created by
	288	* a kernel from the future.... */
	289	nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
7ef55b8a	290	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
c7b9a459	291	status = vfs_rmdir(dir->d_inode, dentry);
1b1dcc1b	292	mutex_unlock(&dir->d_inode->i_mutex);
c7b9a459 N	293	return status;
	294	}
	295
	296	static int
	297	nfsd4_unlink_clid_dir(char *name, int namlen)
	298	{
	299	struct dentry *dentry;
	300	int status;
	301
	302	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
	303
a63bb996 AV	304	mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
	305	dentry = lookup_one_len(name, rec_dir.dentry, namlen);
	306	mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459 N	307	if (IS_ERR(dentry)) {
	308	status = PTR_ERR(dentry);
	309	return status;
	310	}
	311	status = -ENOENT;
	312	if (!dentry->d_inode)
	313	goto out;
	314
a63bb996	315	status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
c7b9a459 N	316	out:
	317	dput(dentry);
	318	return status;
	319	}
	320
	321	void
	322	nfsd4_remove_clid_dir(struct nfs4_client *clp)
	323	{
d84f4f99	324	const struct cred *original_cred;
c7b9a459 N	325	int status;
	326
	327	if (!rec_dir_init \|\| !clp->cl_firststate)
	328	return;
	329
a63bb996	330	status = mnt_want_write(rec_dir.mnt);
0622753b DH	331	if (status)
0622753b DH	332	goto out;
67be4313	333	clp->cl_firststate = 0;
d84f4f99 DH	334
	335	status = nfs4_save_creds(&original_cred);
	336	if (status < 0)
	337	goto out;
	338
c7b9a459	339	status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
d84f4f99	340	nfs4_reset_creds(original_cred);
c7b9a459	341	if (status == 0)
a6ccbbb8	342	nfsd4_sync_rec_dir();
a63bb996	343	mnt_drop_write(rec_dir.mnt);
0622753b	344	out:
c7b9a459 N	345	if (status)
	346	printk("NFSD: Failed to remove expired client state directory"
	347	" %.*s\n", HEXDIR_LEN, clp->cl_recdir);
	348	return;
	349	}
	350
	351	static int
	352	purge_old(struct dentry parent, struct dentry child)
	353	{
	354	int status;
	355
	356	if (nfs4_has_reclaimed_state(child->d_name.name))
b37ad28b	357	return 0;
c7b9a459 N	358
	359	status = nfsd4_clear_clid_dir(parent, child);
	360	if (status)
	361	printk("failed to remove client recovery directory %s\n",
	362	child->d_name.name);
	363	/* Keep trying, success or failure: */
b37ad28b	364	return 0;
c7b9a459 N	365	}
	366
	367	void
	368	nfsd4_recdir_purge_old(void) {
	369	int status;
	370
	371	if (!rec_dir_init)
	372	return;
a63bb996	373	status = mnt_want_write(rec_dir.mnt);
0622753b DH	374	if (status)
0622753b DH	375	goto out;
a63bb996	376	status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
c7b9a459	377	if (status == 0)
a6ccbbb8	378	nfsd4_sync_rec_dir();
a63bb996	379	mnt_drop_write(rec_dir.mnt);
0622753b	380	out:
c7b9a459 N	381	if (status)
c7b9a459 N	382	printk("nfsd4: failed to purge old clients from recovery"
a63bb996	383	" directory %s\n", rec_dir.dentry->d_name.name);
c7b9a459 N	384	}
c7b9a459 N	385
190e4fbf N	386	static int
	387	load_recdir(struct dentry parent, struct dentry child)
	388	{
	389	if (child->d_name.len != HEXDIR_LEN - 1) {
	390	printk("nfsd4: illegal name %s in recovery directory\n",
	391	child->d_name.name);
	392	/* Keep trying; maybe the others are OK: */
b37ad28b	393	return 0;
190e4fbf N	394	}
190e4fbf N	395	nfs4_client_to_reclaim(child->d_name.name);
b37ad28b	396	return 0;
190e4fbf N	397	}
	398
	399	int
	400	nfsd4_recdir_load(void) {
	401	int status;
	402
a63bb996	403	status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
190e4fbf N	404	if (status)
190e4fbf N	405	printk("nfsd4: failed loading clients from recovery"
a63bb996	406	" directory %s\n", rec_dir.dentry->d_name.name);
190e4fbf N	407	return status;
	408	}
	409
	410	/*
	411	* Hold reference to the recovery directory.
	412	*/
	413
	414	void
	415	nfsd4_init_recdir(char *rec_dirname)
	416	{
d84f4f99 DH	417	const struct cred *original_cred;
d84f4f99 DH	418	int status;
190e4fbf N	419
	420	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
	421	rec_dirname);
	422
	423	BUG_ON(rec_dir_init);
	424
d84f4f99 DH	425	status = nfs4_save_creds(&original_cred);
	426	if (status < 0) {
	427	printk("NFSD: Unable to change credentials to find recovery"
	428	" directory: error %d\n",
	429	status);
	430	return;
	431	}
190e4fbf	432
a63bb996	433	status = kern_path(rec_dirname, LOOKUP_FOLLOW \| LOOKUP_DIRECTORY,
c2642ab0 BF	434	&rec_dir);
	435	if (status)
	436	printk("NFSD: unable to find recovery directory %s\n",
190e4fbf N	437	rec_dirname);
	438
	439	if (!status)
	440	rec_dir_init = 1;
d84f4f99	441	nfs4_reset_creds(original_cred);
190e4fbf N	442	}
	443
	444	void
	445	nfsd4_shutdown_recdir(void)
	446	{
	447	if (!rec_dir_init)
	448	return;
	449	rec_dir_init = 0;
a63bb996	450	path_put(&rec_dir);
190e4fbf	451	}