/* * 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> #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.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) { 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.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 = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU); 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_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.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.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) { uid_t uid; gid_t gid; int status; if (!rec_dir_init || !clp->cl_firststate) return; 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(); 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 = nfsd4_list_rec_dir(rec_dir.dentry, purge_old); if (status == 0) nfsd4_sync_rec_dir(); 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 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) { 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_release(&rec_dir); }