initial_commit

1 files changed, 402 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
new file mode 100644
index 00000000..be268148
--- /dev/null
+++ b/fs/nfsd/nfs4recover.c
@@ -0,0 +1,402 @@
+/*
+*  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/file.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/crypto.h>
+#include <linux/sched.h>
+
+#include "nfsd.h"
+#include "state.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+/* Globals */
+static struct file *rec_file;
+
+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_jukebox;
+
+	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);
+
+	status = nfs_ok;
+out:
+	kfree(cksum.data);
+	crypto_free_hash(desc.tfm);
+out_no_tfm:
+	return status;
+}
+
+int
+nfsd4_create_clid_dir(struct nfs4_client *clp)
+{
+	const struct cred *original_cred;
+	char *dname = clp->cl_recdir;
+	struct dentry *dir, *dentry;
+	int status;
+
+	dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
+
+	if (!rec_file || clp->cl_firststate)
+		return 0;
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		return status;
+
+	dir = 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;
+	}
+	status = -EEXIST;
+	if (dentry->d_inode) {
+		dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
+		goto out_put;
+	}
+	status = mnt_want_write(rec_file->f_path.mnt);
+	if (status)
+		goto out_put;
+	status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
+	mnt_drop_write(rec_file->f_path.mnt);
+out_put:
+	dput(dentry);
+out_unlock:
+	mutex_unlock(&dir->d_inode->i_mutex);
+	if (status == 0) {
+		clp->cl_firststate = 1;
+		vfs_fsync(rec_file, 0);
+	}
+	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 name_list {
+	char name[HEXDIR_LEN];
+	struct list_head list;
+};
+
+static int
+nfsd4_build_namelist(void *arg, const char *name, int namlen,
+		loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct list_head *names = 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, names);
+	return 0;
+}
+
+static int
+nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
+{
+	const struct cred *original_cred;
+	struct file *filp;
+	LIST_HEAD(names);
+	struct name_list *entry;
+	struct dentry *dentry;
+	int status;
+
+	if (!rec_file)
+		return 0;
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		return status;
+
+	filp = dentry_open(dget(dir), mntget(rec_file->f_path.mnt), O_RDONLY,
+			   current_cred());
+	status = PTR_ERR(filp);
+	if (IS_ERR(filp))
+		goto out;
+	status = vfs_readdir(filp, nfsd4_build_namelist, &names);
+	fput(filp);
+	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
+	while (!list_empty(&names)) {
+		entry = list_entry(names.next, struct name_list, list);
+
+		dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
+		if (IS_ERR(dentry)) {
+			status = PTR_ERR(dentry);
+			break;
+		}
+		status = f(dir, dentry);
+		dput(dentry);
+		if (status)
+			break;
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	mutex_unlock(&dir->d_inode->i_mutex);
+out:
+	while (!list_empty(&names)) {
+		entry = list_entry(names.next, struct name_list, list);
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	nfs4_reset_creds(original_cred);
+	return status;
+}
+
+static int
+nfsd4_unlink_clid_dir(char *name, int namlen)
+{
+	struct dentry *dir, *dentry;
+	int status;
+
+	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
+
+	dir = 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;
+}
+
+void
+nfsd4_remove_clid_dir(struct nfs4_client *clp)
+{
+	const struct cred *original_cred;
+	int status;
+
+	if (!rec_file || !clp->cl_firststate)
+		return;
+
+	status = mnt_want_write(rec_file->f_path.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)
+		vfs_fsync(rec_file, 0);
+	mnt_drop_write(rec_file->f_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, false))
+		return 0;
+
+	status = vfs_rmdir(parent->d_inode, 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_file)
+		return;
+	status = mnt_want_write(rec_file->f_path.mnt);
+	if (status)
+		goto out;
+	status = nfsd4_list_rec_dir(rec_file->f_path.dentry, purge_old);
+	if (status == 0)
+		vfs_fsync(rec_file, 0);
+	mnt_drop_write(rec_file->f_path.mnt);
+out:
+	if (status)
+		printk("nfsd4: failed to purge old clients from recovery"
+			" directory %s\n", rec_file->f_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;
+
+	if (!rec_file)
+		return 0;
+
+	status = nfsd4_list_rec_dir(rec_file->f_path.dentry, load_recdir);
+	if (status)
+		printk("nfsd4: failed loading clients from recovery"
+			" directory %s\n", rec_file->f_path.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_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;
+	}
+
+	rec_file = filp_open(rec_dirname, O_RDONLY | O_DIRECTORY, 0);
+	if (IS_ERR(rec_file)) {
+		printk("NFSD: unable to find recovery directory %s\n",
+				rec_dirname);
+		rec_file = NULL;
+	}
+
+	nfs4_reset_creds(original_cred);
+}
+
+void
+nfsd4_shutdown_recdir(void)
+{
+	if (!rec_file)
+		return;
+	fput(rec_file);
+	rec_file = NULL;
+}