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);
+}