1 files changed, 431 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
new file mode 100644
index 000000000000..095f1740f3ae
--- /dev/null
+++ b/fs/nfsd/nfs4recover.c
@@ -0,0 +1,431 @@
+/*
+*  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", 0);
+	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:
+	if (tfm)
+		crypto_free_tfm(tfm);
+	return status;
+}
+
+static int
+nfsd4_rec_fsync(struct dentry *dentry)
+{
+	struct file *filp;
+	int status = nfs_ok;
+
+	dprintk("NFSD: nfs4_fsync_rec_dir\n");
+	filp = dentry_open(dget(dentry), mntget(rec_dir.mnt), O_RDWR);
+	if (IS_ERR(filp)) {
+		status = PTR_ERR(filp);
+		goto out;
+	}
+	if (filp->f_op && filp->f_op->fsync)
+		status = filp->f_op->fsync(filp, filp->f_dentry, 0);
+	fput(filp);
+out:
+	if (status)
+		printk("nfsd4: unable to sync recovery directory\n");
+	return status;
+}
+
+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 */
+	down(&rec_dir.dentry->d_inode->i_sem);
+
+	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:
+	up(&rec_dir.dentry->d_inode->i_sem);
+	if (status == 0) {
+		clp->cl_firststate = 1;
+		status = nfsd4_rec_fsync(rec_dir.dentry);
+	}
+	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_RDWR);
+	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;
+	}
+	down(&dir->d_inode->i_sem);
+	status = vfs_unlink(dir->d_inode, dentry);
+	up(&dir->d_inode->i_sem);
+	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);
+	down(&dir->d_inode->i_sem);
+	status = vfs_rmdir(dir->d_inode, dentry);
+	up(&dir->d_inode->i_sem);
+	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);
+
+	dentry = lookup_one_len(name, rec_dir.dentry, namlen);
+	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;
+
+	nfs4_save_user(&uid, &gid);
+	status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
+	nfs4_reset_user(uid, gid);
+	if (status == 0)
+		status = nfsd4_rec_fsync(rec_dir.dentry);
+	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)
+		status = nfsd4_rec_fsync(rec_dir.dentry);
+	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, &rec_dir);
+	if (status == -ENOENT)
+		printk("NFSD: recovery directory %s doesn't exist\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);
+}