[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 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';
}

__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.path.dentry->d_inode->i_mutex);
	nfsd_sync_dir(rec_dir.path.dentry);
	mutex_unlock(&rec_dir.path.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.path.dentry->d_inode->i_mutex);

	dentry = lookup_one_len(dname, rec_dir.path.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.path.dentry->d_inode, dentry, S_IRWXU);
out_put:
	dput(dentry);
out_unlock:
	mutex_unlock(&rec_dir.path.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, 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)
{
	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.path.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_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.path.dentry->d_inode->i_mutex);
	dentry = lookup_one_len(name, rec_dir.path.dentry, namlen);
	mutex_unlock(&rec_dir.path.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.path.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;

	status = mnt_want_write(rec_dir.path.mnt);
	if (status)
		goto out;
	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();
	mnt_drop_write(rec_dir.path.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.path.mnt);
	if (status)
		goto out;
	status = nfsd4_list_rec_dir(rec_dir.path.dentry, purge_old);
	if (status == 0)
		nfsd4_sync_rec_dir();
	mnt_drop_write(rec_dir.path.mnt);
out:
	if (status)
		printk("nfsd4: failed to purge old clients from recovery"
			" directory %s\n", rec_dir.path.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.path.dentry, load_recdir);
	if (status)
		printk("nfsd4: failed loading clients from recovery"
			" directory %s\n", rec_dir.path.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_put(&rec_dir.path);
}
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 */
190e4fbf N	54	static struct nameidata rec_dir;
	55	static int rec_dir_init = 0;
	56
	57	static void
	58	nfs4_save_user(uid_t saveuid, gid_t savegid)
	59	{
	60	*saveuid = current->fsuid;
	61	*savegid = current->fsgid;
	62	current->fsuid = 0;
	63	current->fsgid = 0;
	64	}
	65
	66	static void
	67	nfs4_reset_user(uid_t saveuid, gid_t savegid)
	68	{
	69	current->fsuid = saveuid;
	70	current->fsgid = savegid;
	71	}
	72
a55370a3 N	73	static void
	74	md5_to_hex(char out, char md5)
	75	{
	76	int i;
	77
	78	for (i=0; i<16; i++) {
	79	unsigned char c = md5[i];
	80
	81	out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)('a'-'9'-1);
	82	out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)('a'-'9'-1);
	83	}
	84	*out = '\0';
	85	}
	86
b37ad28b	87	__be32
a55370a3 N	88	nfs4_make_rec_clidname(char dname, struct xdr_netobj clname)
	89	{
	90	struct xdr_netobj cksum;
35058687	91	struct hash_desc desc;
60c74f81	92	struct scatterlist sg;
b37ad28b	93	__be32 status = nfserr_resource;
a55370a3 N	94
	95	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
	96	clname->len, clname->data);
35058687 HX	97	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
	98	desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
	99	if (IS_ERR(desc.tfm))
	100	goto out_no_tfm;
	101	cksum.len = crypto_hash_digestsize(desc.tfm);
a55370a3 N	102	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
	103	if (cksum.data == NULL)
	104	goto out;
a55370a3	105
60c74f81	106	sg_init_one(&sg, clname->data, clname->len);
a55370a3	107
60c74f81	108	if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
35058687	109	goto out;
a55370a3 N	110
	111	md5_to_hex(dname, cksum.data);
	112
	113	kfree(cksum.data);
	114	status = nfs_ok;
	115	out:
35058687 HX	116	crypto_free_hash(desc.tfm);
35058687 HX	117	out_no_tfm:
a55370a3 N	118	return status;
a55370a3 N	119	}
190e4fbf	120
a6ccbbb8 N	121	static void
a6ccbbb8 N	122	nfsd4_sync_rec_dir(void)
c7b9a459	123	{
4ac91378 JB	124	mutex_lock(&rec_dir.path.dentry->d_inode->i_mutex);
	125	nfsd_sync_dir(rec_dir.path.dentry);
	126	mutex_unlock(&rec_dir.path.dentry->d_inode->i_mutex);
c7b9a459 N	127	}
	128
	129	int
	130	nfsd4_create_clid_dir(struct nfs4_client *clp)
	131	{
	132	char *dname = clp->cl_recdir;
	133	struct dentry *dentry;
	134	uid_t uid;
	135	gid_t gid;
	136	int status;
	137
	138	dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
	139
	140	if (!rec_dir_init \|\| clp->cl_firststate)
	141	return 0;
	142
	143	nfs4_save_user(&uid, &gid);
	144
	145	/* lock the parent */
4ac91378	146	mutex_lock(&rec_dir.path.dentry->d_inode->i_mutex);
c7b9a459	147
4ac91378	148	dentry = lookup_one_len(dname, rec_dir.path.dentry, HEXDIR_LEN-1);
c7b9a459 N	149	if (IS_ERR(dentry)) {
	150	status = PTR_ERR(dentry);
	151	goto out_unlock;
	152	}
	153	status = -EEXIST;
	154	if (dentry->d_inode) {
	155	dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
	156	goto out_put;
	157	}
4ac91378	158	status = vfs_mkdir(rec_dir.path.dentry->d_inode, dentry, S_IRWXU);
c7b9a459 N	159	out_put:
	160	dput(dentry);
	161	out_unlock:
4ac91378	162	mutex_unlock(&rec_dir.path.dentry->d_inode->i_mutex);
c7b9a459 N	163	if (status == 0) {
c7b9a459 N	164	clp->cl_firststate = 1;
a6ccbbb8	165	nfsd4_sync_rec_dir();
c7b9a459 N	166	}
	167	nfs4_reset_user(uid, gid);
	168	dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
	169	return status;
	170	}
	171
190e4fbf N	172	typedef int (recdir_func)(struct dentry , struct dentry );
	173
	174	struct dentry_list {
	175	struct dentry *dentry;
	176	struct list_head list;
	177	};
	178
	179	struct dentry_list_arg {
	180	struct list_head dentries;
	181	struct dentry *parent;
	182	};
	183
	184	static int
	185	nfsd4_build_dentrylist(void arg, const char name, int namlen,
afefdbb2	186	loff_t offset, u64 ino, unsigned int d_type)
190e4fbf N	187	{
	188	struct dentry_list_arg *dla = arg;
	189	struct list_head *dentries = &dla->dentries;
	190	struct dentry *parent = dla->parent;
	191	struct dentry *dentry;
	192	struct dentry_list *child;
	193
	194	if (name && isdotent(name, namlen))
b37ad28b	195	return 0;
190e4fbf N	196	dentry = lookup_one_len(name, parent, namlen);
	197	if (IS_ERR(dentry))
	198	return PTR_ERR(dentry);
	199	child = kmalloc(sizeof(*child), GFP_KERNEL);
	200	if (child == NULL)
	201	return -ENOMEM;
	202	child->dentry = dentry;
	203	list_add(&child->list, dentries);
	204	return 0;
	205	}
	206
	207	static int
	208	nfsd4_list_rec_dir(struct dentry dir, recdir_func f)
	209	{
	210	struct file *filp;
	211	struct dentry_list_arg dla = {
	212	.parent = dir,
	213	};
	214	struct list_head *dentries = &dla.dentries;
	215	struct dentry_list *child;
	216	uid_t uid;
	217	gid_t gid;
	218	int status;
	219
	220	if (!rec_dir_init)
	221	return 0;
	222
	223	nfs4_save_user(&uid, &gid);
	224
4ac91378	225	filp = dentry_open(dget(dir), mntget(rec_dir.path.mnt), O_RDONLY);
190e4fbf N	226	status = PTR_ERR(filp);
	227	if (IS_ERR(filp))
	228	goto out;
	229	INIT_LIST_HEAD(dentries);
	230	status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
	231	fput(filp);
	232	while (!list_empty(dentries)) {
	233	child = list_entry(dentries->next, struct dentry_list, list);
	234	status = f(dir, child->dentry);
	235	if (status)
	236	goto out;
	237	list_del(&child->list);
	238	dput(child->dentry);
	239	kfree(child);
	240	}
	241	out:
	242	while (!list_empty(dentries)) {
	243	child = list_entry(dentries->next, struct dentry_list, list);
	244	list_del(&child->list);
	245	dput(child->dentry);
	246	kfree(child);
	247	}
	248	nfs4_reset_user(uid, gid);
	249	return status;
	250	}
	251
c7b9a459 N	252	static int
	253	nfsd4_remove_clid_file(struct dentry dir, struct dentry dentry)
	254	{
	255	int status;
	256
	257	if (!S_ISREG(dir->d_inode->i_mode)) {
	258	printk("nfsd4: non-file found in client recovery directory\n");
	259	return -EINVAL;
	260	}
4b75f78e	261	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
c7b9a459	262	status = vfs_unlink(dir->d_inode, dentry);
1b1dcc1b	263	mutex_unlock(&dir->d_inode->i_mutex);
c7b9a459 N	264	return status;
	265	}
	266
	267	static int
	268	nfsd4_clear_clid_dir(struct dentry dir, struct dentry dentry)
	269	{
	270	int status;
	271
	272	/* For now this directory should already be empty, but we empty it of
	273	* any regular files anyway, just in case the directory was created by
	274	* a kernel from the future.... */
	275	nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
7ef55b8a	276	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
c7b9a459	277	status = vfs_rmdir(dir->d_inode, dentry);
1b1dcc1b	278	mutex_unlock(&dir->d_inode->i_mutex);
c7b9a459 N	279	return status;
	280	}
	281
	282	static int
	283	nfsd4_unlink_clid_dir(char *name, int namlen)
	284	{
	285	struct dentry *dentry;
	286	int status;
	287
	288	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
	289
4ac91378 JB	290	mutex_lock(&rec_dir.path.dentry->d_inode->i_mutex);
	291	dentry = lookup_one_len(name, rec_dir.path.dentry, namlen);
	292	mutex_unlock(&rec_dir.path.dentry->d_inode->i_mutex);
c7b9a459 N	293	if (IS_ERR(dentry)) {
	294	status = PTR_ERR(dentry);
	295	return status;
	296	}
	297	status = -ENOENT;
	298	if (!dentry->d_inode)
	299	goto out;
	300
4ac91378	301	status = nfsd4_clear_clid_dir(rec_dir.path.dentry, dentry);
c7b9a459 N	302	out:
	303	dput(dentry);
	304	return status;
	305	}
	306
	307	void
	308	nfsd4_remove_clid_dir(struct nfs4_client *clp)
	309	{
	310	uid_t uid;
	311	gid_t gid;
	312	int status;
	313
	314	if (!rec_dir_init \|\| !clp->cl_firststate)
	315	return;
	316
0622753b DH	317	status = mnt_want_write(rec_dir.path.mnt);
	318	if (status)
	319	goto out;
67be4313	320	clp->cl_firststate = 0;
c7b9a459 N	321	nfs4_save_user(&uid, &gid);
	322	status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
	323	nfs4_reset_user(uid, gid);
	324	if (status == 0)
a6ccbbb8	325	nfsd4_sync_rec_dir();
0622753b DH	326	mnt_drop_write(rec_dir.path.mnt);
0622753b DH	327	out:
c7b9a459 N	328	if (status)
	329	printk("NFSD: Failed to remove expired client state directory"
	330	" %.*s\n", HEXDIR_LEN, clp->cl_recdir);
	331	return;
	332	}
	333
	334	static int
	335	purge_old(struct dentry parent, struct dentry child)
	336	{
	337	int status;
	338
	339	if (nfs4_has_reclaimed_state(child->d_name.name))
b37ad28b	340	return 0;
c7b9a459 N	341
	342	status = nfsd4_clear_clid_dir(parent, child);
	343	if (status)
	344	printk("failed to remove client recovery directory %s\n",
	345	child->d_name.name);
	346	/* Keep trying, success or failure: */
b37ad28b	347	return 0;
c7b9a459 N	348	}
	349
	350	void
	351	nfsd4_recdir_purge_old(void) {
	352	int status;
	353
	354	if (!rec_dir_init)
	355	return;
0622753b DH	356	status = mnt_want_write(rec_dir.path.mnt);
	357	if (status)
	358	goto out;
4ac91378	359	status = nfsd4_list_rec_dir(rec_dir.path.dentry, purge_old);
c7b9a459	360	if (status == 0)
a6ccbbb8	361	nfsd4_sync_rec_dir();
0622753b DH	362	mnt_drop_write(rec_dir.path.mnt);
0622753b DH	363	out:
c7b9a459 N	364	if (status)
c7b9a459 N	365	printk("nfsd4: failed to purge old clients from recovery"
4ac91378	366	" directory %s\n", rec_dir.path.dentry->d_name.name);
c7b9a459 N	367	}
c7b9a459 N	368
190e4fbf N	369	static int
	370	load_recdir(struct dentry parent, struct dentry child)
	371	{
	372	if (child->d_name.len != HEXDIR_LEN - 1) {
	373	printk("nfsd4: illegal name %s in recovery directory\n",
	374	child->d_name.name);
	375	/* Keep trying; maybe the others are OK: */
b37ad28b	376	return 0;
190e4fbf N	377	}
190e4fbf N	378	nfs4_client_to_reclaim(child->d_name.name);
b37ad28b	379	return 0;
190e4fbf N	380	}
	381
	382	int
	383	nfsd4_recdir_load(void) {
	384	int status;
	385
4ac91378	386	status = nfsd4_list_rec_dir(rec_dir.path.dentry, load_recdir);
190e4fbf N	387	if (status)
190e4fbf N	388	printk("nfsd4: failed loading clients from recovery"
4ac91378	389	" directory %s\n", rec_dir.path.dentry->d_name.name);
190e4fbf N	390	return status;
	391	}
	392
	393	/*
	394	* Hold reference to the recovery directory.
	395	*/
	396
	397	void
	398	nfsd4_init_recdir(char *rec_dirname)
	399	{
	400	uid_t uid = 0;
	401	gid_t gid = 0;
	402	int status;
	403
	404	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
	405	rec_dirname);
	406
	407	BUG_ON(rec_dir_init);
	408
	409	nfs4_save_user(&uid, &gid);
	410
c2642ab0 BF	411	status = path_lookup(rec_dirname, LOOKUP_FOLLOW \| LOOKUP_DIRECTORY,
	412	&rec_dir);
	413	if (status)
	414	printk("NFSD: unable to find recovery directory %s\n",
190e4fbf N	415	rec_dirname);
	416
	417	if (!status)
	418	rec_dir_init = 1;
	419	nfs4_reset_user(uid, gid);
	420	}
	421
	422	void
	423	nfsd4_shutdown_recdir(void)
	424	{
	425	if (!rec_dir_init)
	426	return;
	427	rec_dir_init = 0;
1d957f9b	428	path_put(&rec_dir.path);
190e4fbf	429	}