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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [fs/] [nfsd/] [export.c] - Blame information for rev 1765

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#define MSNFS   /* HACK HACK */
/*
 * linux/fs/nfsd/export.c
 *
 * NFS exporting and validation.
 *
 * We maintain a list of clients, each of which has a list of
 * exports. To export an fs to a given client, you first have
 * to create the client entry with NFSCTL_ADDCLIENT, which
 * creates a client control block and adds it to the hash
 * table. Then, you call NFSCTL_EXPORT for each fs.
 *
 *
 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
 */
 
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/in.h>
#include <linux/seq_file.h>
#include <linux/smp_lock.h>
 
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/nfsfh.h>
#include <linux/nfsd/syscall.h>
#include <linux/lockd/bind.h>
 
#define NFSDDBG_FACILITY        NFSDDBG_EXPORT
#define NFSD_PARANOIA 1
 
typedef struct svc_client       svc_client;
typedef struct svc_export       svc_export;
 
static svc_export *     exp_parent(svc_client *clp, kdev_t dev,
                                        struct dentry *dentry);
static svc_export *     exp_child(svc_client *clp, kdev_t dev,
                                        struct dentry *dentry);
static void             exp_unexport_all(svc_client *clp);
static void             exp_do_unexport(svc_export *unexp);
static svc_client *     exp_getclientbyname(char *name);
static void             exp_freeclient(svc_client *clp);
static void             exp_unhashclient(svc_client *clp);
static int              exp_verify_string(char *cp, int max);
 
#define CLIENT_HASHBITS         6
#define CLIENT_HASHMAX          (1 << CLIENT_HASHBITS)
#define CLIENT_HASHMASK         (CLIENT_HASHMAX - 1)
#define CLIENT_HASH(a) \
                ((((a)>>24) ^ ((a)>>16) ^ ((a)>>8) ^(a)) & CLIENT_HASHMASK)
/* XXX: is this adequate for 32bit kdev_t ? */
#define EXPORT_HASH(dev)        ((dev) & (NFSCLNT_EXPMAX - 1))
#define EXPORT_FSID_HASH(fsid)  ((fsid) & (NFSCLNT_EXPMAX - 1))
 
struct svc_clnthash {
        struct svc_clnthash *   h_next;
        struct in_addr          h_addr;
        struct svc_client *     h_client;
};
static struct svc_clnthash *    clnt_hash[CLIENT_HASHMAX];
static svc_client *             clients;
 
static int                      hash_lock;
static int                      want_lock;
static int                      hash_count;
static DECLARE_WAIT_QUEUE_HEAD( hash_wait );
 
/*
 * Find the client's export entry matching xdev/xino.
 */
svc_export *
exp_get(svc_client *clp, kdev_t dev, ino_t ino)
{
        struct list_head *head, *p;
 
        if (!clp)
                return NULL;
 
        head = &clp->cl_export[EXPORT_HASH(dev)];
        list_for_each(p, head) {
                svc_export *exp = list_entry(p, svc_export, ex_hash);
                if (exp->ex_ino == ino && exp->ex_dev == dev)
                        return exp;
        }
 
        return NULL;
}
 
/*
 * Find the client's export entry matching fsid
 */
svc_export *
exp_get_fsid(svc_client *clp, int fsid)
{
        struct list_head *head, *p;
 
        if (!clp)
                return NULL;
 
        head = &clp->cl_expfsid[EXPORT_FSID_HASH(fsid)];
        list_for_each(p, head) {
                svc_export *exp = list_entry(p, svc_export, ex_fsid_hash);
                if (exp->ex_fsid == fsid)
                        return exp;
        }
        return NULL;
}
 
/*
 * Find the export entry for a given dentry.  <gam3@acm.org>
 */
static svc_export *
exp_parent(svc_client *clp, kdev_t dev, struct dentry *dentry)
{
        struct list_head *head = &clp->cl_export[EXPORT_HASH(dev)];
        struct list_head *p;
 
        list_for_each(p,head) {
                svc_export *exp = list_entry(p, svc_export, ex_hash);
                if (is_subdir(dentry, exp->ex_dentry))
                        return exp;
        }
        return NULL;
}
 
/*
 * Find the child export entry for a given fs. This function is used
 * only by the export syscall to keep the export tree consistent.
 * <gam3@acm.org>
 */
static svc_export *
exp_child(svc_client *clp, kdev_t dev, struct dentry *dentry)
{
        struct list_head *head = &clp->cl_export[EXPORT_HASH(dev)];
        struct list_head *p;
 
 
        list_for_each(p, head) {
                svc_export *exp = list_entry(p, svc_export, ex_hash);
                struct dentry *ndentry = exp->ex_dentry;
 
                if (ndentry && is_subdir(ndentry->d_parent, dentry))
                        return exp;
        }
        return NULL;
}
 
/* Update parent pointers of all exports */
static void exp_change_parents(svc_client *clp, svc_export *old, svc_export *new)
{
        struct list_head *head = &clp->cl_list;
        struct list_head *p;
 
        list_for_each(p, head) {
                svc_export *exp = list_entry(p, svc_export, ex_list);
                if (exp->ex_parent == old)
                        exp->ex_parent = new;
        }
}
 
static void exp_fsid_unhash(struct svc_export *exp)
{
 
        if ((exp->ex_flags & NFSEXP_FSID) == 0)
                return;
 
        list_del_init(&exp->ex_fsid_hash);
}
 
static void exp_fsid_hash(struct svc_client *clp, struct svc_export *exp)
{
        struct list_head *head;
 
        if ((exp->ex_flags & NFSEXP_FSID) == 0)
                return;
        head = clp->cl_expfsid + EXPORT_FSID_HASH(exp->ex_fsid);
        list_add(&exp->ex_fsid_hash, head);
}
 
/*
 * Export a file system.
 */
int
exp_export(struct nfsctl_export *nxp)
{
        svc_client      *clp;
        svc_export      *exp = NULL, *parent;
        svc_export      *fsid_exp;
        struct nameidata nd;
        struct inode    *inode = NULL;
        int             err;
        kdev_t          dev;
        ino_t           ino;
 
        /* Consistency check */
        err = -EINVAL;
        if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
            !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
                goto out;
 
        dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
                        nxp->ex_client, nxp->ex_path,
                        nxp->ex_dev, (long) nxp->ex_ino, nxp->ex_flags);
 
        /* Try to lock the export table for update */
        if ((err = exp_writelock()) < 0)
                goto out;
 
        /* Look up client info */
        err = -EINVAL;
        if (!(clp = exp_getclientbyname(nxp->ex_client)))
                goto out_unlock;
 
 
        /* Look up the dentry */
        err = 0;
        if (path_init(nxp->ex_path, LOOKUP_POSITIVE, &nd))
                err = path_walk(nxp->ex_path, &nd);
        if (err)
                goto out_unlock;
 
        inode = nd.dentry->d_inode;
        dev = inode->i_dev;
        ino = inode->i_ino;
        err = -EINVAL;
 
        exp = exp_get(clp, dev, ino);
 
        /* must make sure there wont be an ex_fsid clash */
        if ((nxp->ex_flags & NFSEXP_FSID) &&
            (fsid_exp = exp_get_fsid(clp, nxp->ex_dev)) &&
            fsid_exp != exp)
                goto finish;
 
        if (exp != NULL) {
                /* just a flags/id/fsid update */
 
                exp_fsid_unhash(exp);
                exp->ex_flags    = nxp->ex_flags;
                exp->ex_anon_uid = nxp->ex_anon_uid;
                exp->ex_anon_gid = nxp->ex_anon_gid;
                exp->ex_fsid     = nxp->ex_dev;
                exp_fsid_hash(clp, exp);
                err = 0;
                goto finish;
        }
 
        /* We currently export only dirs and regular files.
         * This is what umountd does.
         */
        err = -ENOTDIR;
        if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode))
                goto finish;
 
        err = -EINVAL;
        /* There are two requirements on a filesystem to be exportable.
         * 1:  We must be able to identify the filesystem from a number.
         *       either a device number (so FS_REQUIRES_DEV needed)
         *       or an FSID number (so NFSEXP_FSID needed).
         * 2:  We must be able to find an inode from a filehandle.
         *       either using fh_to_dentry (prefered)
         *       or using read_inode (the hack).
         */
        if (!((inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV)
              || (nxp->ex_flags & NFSEXP_FSID))
            ||
            (inode->i_sb->s_op->read_inode == NULL
             && inode->i_sb->s_op->fh_to_dentry == NULL)) {
                dprintk("exp_export: export of invalid fs type.\n");
                goto finish;
        }
 
        if ((parent = exp_child(clp, dev, nd.dentry)) != NULL) {
                dprintk("exp_export: export not valid (Rule 3).\n");
                goto finish;
        }
        /* Is this is a sub-export, must be a proper subset of FS */
        if ((parent = exp_parent(clp, dev, nd.dentry)) != NULL) {
                dprintk("exp_export: sub-export not valid (Rule 2).\n");
                goto finish;
        }
 
        err = -ENOMEM;
        if (!(exp = kmalloc(sizeof(*exp), GFP_USER)))
                goto finish;
        dprintk("nfsd: created export entry %p for client %p\n", exp, clp);
 
        strcpy(exp->ex_path, nxp->ex_path);
        exp->ex_client = clp;
        exp->ex_parent = parent;
        exp->ex_dentry = dget(nd.dentry);
        exp->ex_mnt = mntget(nd.mnt);
        exp->ex_flags = nxp->ex_flags;
        exp->ex_dev = dev;
        exp->ex_ino = ino;
        exp->ex_anon_uid = nxp->ex_anon_uid;
        exp->ex_anon_gid = nxp->ex_anon_gid;
        exp->ex_fsid = nxp->ex_dev;
 
 
        /* Update parent pointers of all exports */
        if (parent)
                exp_change_parents(clp, parent, exp);
 
        list_add(&exp->ex_hash, clp->cl_export + EXPORT_HASH(dev));
        list_add_tail(&exp->ex_list, &clp->cl_list);
 
        exp_fsid_hash(clp, exp);
 
        err = 0;
 
finish:
        path_release(&nd);
out_unlock:
        exp_unlock();
out:
        return err;
}
 
/*
 * Unexport a file system. The export entry has already
 * been removed from the client's list of exported fs's.
 */
static void
exp_do_unexport(svc_export *unexp)
{
        struct dentry   *dentry;
        struct vfsmount *mnt;
        struct inode    *inode;
 
        list_del(&unexp->ex_hash);
        list_del(&unexp->ex_list);
        exp_fsid_unhash(unexp);
 
        exp_change_parents(unexp->ex_client, unexp, unexp->ex_parent);
 
        dentry = unexp->ex_dentry;
        mnt = unexp->ex_mnt;
        inode = dentry->d_inode;
        if (unexp->ex_dev != inode->i_dev || unexp->ex_ino != inode->i_ino)
                printk(KERN_WARNING "nfsd: bad dentry in unexport!\n");
        dput(dentry);
        mntput(mnt);
 
        kfree(unexp);
}
 
/*
 * Revoke all exports for a given client.
 * This may look very awkward, but we have to do it this way in order
 * to avoid race conditions (aka mind the parent pointer).
 */
static void
exp_unexport_all(svc_client *clp)
{
        struct list_head *p = &clp->cl_list;
 
        dprintk("unexporting all fs's for clnt %p\n", clp);
 
        while (!list_empty(p)) {
                svc_export *exp = list_entry(p->next, svc_export, ex_list);
                exp_do_unexport(exp);
        }
}
 
/*
 * unexport syscall.
 */
int
exp_unexport(struct nfsctl_export *nxp)
{
        svc_client      *clp;
        int             err;
 
        /* Consistency check */
        if (!exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
                return -EINVAL;
 
        if ((err = exp_writelock()) < 0)
                goto out;
 
        err = -EINVAL;
        clp = exp_getclientbyname(nxp->ex_client);
        if (clp) {
                svc_export *exp = exp_get(clp, nxp->ex_dev, nxp->ex_ino);
                if (exp) {
                        exp_do_unexport(exp);
                        err = 0;
                }
        }
 
        exp_unlock();
out:
        return err;
}
 
/*
 * Obtain the root fh on behalf of a client.
 * This could be done in user space, but I feel that it adds some safety
 * since its harder to fool a kernel module than a user space program.
 */
int
exp_rootfh(struct svc_client *clp, kdev_t dev, ino_t ino,
           char *path, struct knfsd_fh *f, int maxsize)
{
        struct svc_export       *exp;
        struct nameidata        nd;
        struct inode            *inode;
        struct svc_fh           fh;
        int                     err;
 
        err = -EPERM;
        if (path) {
                if (path_init(path, LOOKUP_POSITIVE, &nd) &&
                    path_walk(path, &nd)) {
                        printk("nfsd: exp_rootfh path not found %s", path);
                        return err;
                }
                dev = nd.dentry->d_inode->i_dev;
                ino = nd.dentry->d_inode->i_ino;
 
                dprintk("nfsd: exp_rootfh(%s [%p] %s:%x/%ld)\n",
                         path, nd.dentry, clp->cl_ident, dev, (long) ino);
                exp = exp_parent(clp, dev, nd.dentry);
        } else {
                dprintk("nfsd: exp_rootfh(%s:%x/%ld)\n",
                         clp->cl_ident, dev, (long) ino);
                if ((exp = exp_get(clp, dev, ino))) {
                        nd.mnt = mntget(exp->ex_mnt);
                        nd.dentry = dget(exp->ex_dentry);
                }
        }
        if (!exp) {
                dprintk("nfsd: exp_rootfh export not found.\n");
                goto out;
        }
 
        inode = nd.dentry->d_inode;
        if (!inode) {
                printk("exp_rootfh: Aieee, NULL d_inode\n");
                goto out;
        }
        if (inode->i_dev != dev || inode->i_ino != ino) {
                printk("exp_rootfh: Aieee, ino/dev mismatch\n");
                printk("exp_rootfh: arg[dev(%x):ino(%ld)]"
                       " inode[dev(%x):ino(%ld)]\n",
                       dev, (long) ino, inode->i_dev, (long) inode->i_ino);
        }
 
        /*
         * fh must be initialized before calling fh_compose
         */
        fh_init(&fh, maxsize);
        if (fh_compose(&fh, exp, dget(nd.dentry), NULL))
                err = -EINVAL;
        else
                err = 0;
        memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
        fh_put(&fh);
 
out:
        if (path)
                path_release(&nd);
        return err;
}
 
/*
 * Hashtable locking. Write locks are placed only by user processes
 * wanting to modify export information.
 */
void
exp_readlock(void)
{
        while (hash_lock || want_lock)
                sleep_on(&hash_wait);
        hash_count++;
}
 
int
exp_writelock(void)
{
        /* fast track */
        if (!hash_count && !hash_lock) {
        lock_it:
                hash_lock = 1;
                return 0;
        }
 
        current->sigpending = 0;
        want_lock++;
        while (hash_count || hash_lock) {
                interruptible_sleep_on(&hash_wait);
                if (signal_pending(current))
                        break;
        }
        want_lock--;
 
        /* restore the task's signals */
        spin_lock_irq(&current->sigmask_lock);
        recalc_sigpending(current);
        spin_unlock_irq(&current->sigmask_lock);
 
        if (!hash_count && !hash_lock)
                goto lock_it;
        return -EINTR;
}
 
void
exp_unlock(void)
{
        if (!hash_count && !hash_lock)
                printk(KERN_WARNING "exp_unlock: not locked!\n");
        if (hash_count)
                hash_count--;
        else
                hash_lock = 0;
        wake_up(&hash_wait);
}
 
/*
 * Find a valid client given an inet address. We always move the most
 * recently used client to the front of the hash chain to speed up
 * future lookups.
 * Locking against other processes is the responsibility of the caller.
 */
struct svc_client *
exp_getclient(struct sockaddr_in *sin)
{
        struct svc_clnthash     **hp, **head, *tmp;
        unsigned long           addr = sin->sin_addr.s_addr;
 
        head = &clnt_hash[CLIENT_HASH(addr)];
 
        for (hp = head; (tmp = *hp) != NULL; hp = &(tmp->h_next)) {
                if (tmp->h_addr.s_addr == addr) {
                        /* Move client to the front */
                        if (head != hp) {
                                *hp = tmp->h_next;
                                tmp->h_next = *head;
                                *head = tmp;
                        }
 
                        return tmp->h_client;
                }
        }
 
        return NULL;
}
 
/*
 * Find a client given its identifier.
 */
static svc_client *
exp_getclientbyname(char *ident)
{
        svc_client *    clp;
 
        for (clp = clients; clp; clp = clp->cl_next) {
                if (!strcmp(clp->cl_ident, ident))
                        return clp;
        }
        return NULL;
}
 
/* Iterator */
 
static void *e_start(struct seq_file *m, loff_t *pos)
{
        loff_t n = *pos;
        unsigned client, export;
        svc_client *clp;
        struct list_head *p;
 
        lock_kernel();
        exp_readlock();
        if (!n--)
                return (void *)1;
        client = n >> 32;
        export = n & ((1LL<<32) - 1);
        for (clp = clients; client && clp; clp = clp->cl_next, client--)
                ;
        if (!clp)
                return NULL;
        list_for_each(p, &clp->cl_list)
                if (!export--)
                        return list_entry(p, svc_export, ex_list);
        n &= ~((1LL<<32) - 1);
        do {
                clp = clp->cl_next;
                n += 1LL<<32;
        } while(clp && list_empty(&clp->cl_list));
        if (!clp)
                return NULL;
        *pos = n+1;
        return list_entry(clp->cl_list.next, svc_export, ex_list);
}
 
static void *e_next(struct seq_file *m, void *p, loff_t *pos)
{
        svc_export *exp = p;
        svc_client *clp;
 
        if (p == (void *)1)
                clp = clients;
        else if (exp->ex_list.next == &exp->ex_client->cl_list) {
                clp = exp->ex_client->cl_next;
                *pos += 1LL<<32;
        } else {
                ++*pos;
                return list_entry(exp->ex_list.next, svc_export, ex_list);
        }
        *pos &= ~((1LL<<32) - 1);
        while (clp && list_empty(&clp->cl_list)) {
                clp = clp->cl_next;
                *pos += 1LL<<32;
        }
        if (!clp)
                return NULL;
        ++*pos;
        return list_entry(clp->cl_list.next, svc_export, ex_list);
}
 
static void e_stop(struct seq_file *m, void *p)
{
        exp_unlock();
        unlock_kernel();
}
 
struct flags {
        int flag;
        char *name[2];
} expflags[] = {
        { NFSEXP_READONLY, {"ro", "rw"}},
        { NFSEXP_INSECURE_PORT, {"insecure", ""}},
        { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
        { NFSEXP_ALLSQUASH, {"all_squash", ""}},
        { NFSEXP_ASYNC, {"async", "sync"}},
        { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
        { NFSEXP_UIDMAP, {"uidmap", ""}},
        { NFSEXP_KERBEROS, { "kerberos", ""}},
        { NFSEXP_SUNSECURE, { "sunsecure", ""}},
        { NFSEXP_NOHIDE, {"nohide", ""}},
        { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
        { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
#ifdef MSNFS
        { NFSEXP_MSNFS, {"msnfs", ""}},
#endif
        { 0, {"", ""}}
};
 
static void exp_flags(struct seq_file *m, int flag, int fsid)
{
        int first = 0;
        struct flags *flg;
 
        for (flg = expflags; flg->flag; flg++) {
                int state = (flg->flag & flag)?0:1;
                if (*flg->name[state])
                        seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
        }
        if (flag & NFSEXP_FSID)
                seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
}
 
static inline void mangle(struct seq_file *m, const char *s)
{
        seq_escape(m, s, " \t\n\\");
}
 
static int e_show(struct seq_file *m, void *p)
{
        struct svc_export *exp = p;
        struct svc_client *clp;
        int j, first = 0;
 
        if (p == (void *)1) {
                seq_puts(m, "# Version 1.1\n");
                seq_puts(m, "# Path Client(Flags) # IPs\n");
                return 0;
        }
 
        clp = exp->ex_client;
 
        mangle(m, exp->ex_path);
        seq_putc(m, '\t');
        mangle(m, clp->cl_ident);
        seq_putc(m, '(');
        exp_flags(m, exp->ex_flags, exp->ex_fsid);
        seq_puts(m, ") # ");
        for (j = 0; j < clp->cl_naddr; j++) {
                struct svc_clnthash **hp, **head, *tmp;
                struct in_addr addr = clp->cl_addr[j];
 
                head = &clnt_hash[CLIENT_HASH(addr.s_addr)];
                for (hp = head; (tmp = *hp) != NULL; hp = &(tmp->h_next)) {
                        if (tmp->h_addr.s_addr == addr.s_addr)
                                break;
                }
                if (tmp) {
                        if (first++)
                                seq_putc(m, ' ');
                        if (tmp->h_client != clp)
                                seq_putc(m, '(');
                        seq_printf(m, "%d.%d.%d.%d",
                                htonl(addr.s_addr) >> 24 & 0xff,
                                htonl(addr.s_addr) >> 16 & 0xff,
                                htonl(addr.s_addr) >>  8 & 0xff,
                                htonl(addr.s_addr) >>  0 & 0xff);
                        if (tmp->h_client != clp)
                                seq_putc(m, ')');
                }
        }
        seq_putc(m, '\n');
        return 0;
}
 
struct seq_operations nfs_exports_op = {
        start:  e_start,
        next:   e_next,
        stop:   e_stop,
        show:   e_show,
};
 
/*
 * Add or modify a client.
 * Change requests may involve the list of host addresses. The list of
 * exports and possibly existing uid maps are left untouched.
 */
int
exp_addclient(struct nfsctl_client *ncp)
{
        struct svc_clnthash *   ch[NFSCLNT_ADDRMAX];
        svc_client *            clp;
        int                     i, err, change = 0, ilen;
 
        /* First, consistency check. */
        err = -EINVAL;
        if (!(ilen = exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX)))
                goto out;
        if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
                goto out;
 
        /* Lock the hashtable */
        if ((err = exp_writelock()) < 0)
                goto out;
 
        /* First check if this is a change request for a client. */
        for (clp = clients; clp; clp = clp->cl_next)
                if (!strcmp(clp->cl_ident, ncp->cl_ident))
                        break;
 
        err = -ENOMEM;
        if (clp) {
                change = 1;
        } else {
                if (!(clp = kmalloc(sizeof(*clp), GFP_KERNEL)))
                        goto out_unlock;
                memset(clp, 0, sizeof(*clp));
                for (i = 0; i < NFSCLNT_EXPMAX; i++) {
                        INIT_LIST_HEAD(&clp->cl_export[i]);
                        INIT_LIST_HEAD(&clp->cl_expfsid[i]);
                }
                INIT_LIST_HEAD(&clp->cl_list);
 
                dprintk("created client %s (%p)\n", ncp->cl_ident, clp);
 
                strcpy(clp->cl_ident, ncp->cl_ident);
                clp->cl_idlen = ilen;
        }
 
        /* Allocate hash buckets */
        for (i = 0; i < ncp->cl_naddr; i++) {
                ch[i] = kmalloc(sizeof(struct svc_clnthash), GFP_KERNEL);
                if (!ch[i]) {
                        while (i--)
                                kfree(ch[i]);
                        if (!change)
                                kfree(clp);
                        goto out_unlock;
                }
        }
 
        /* Copy addresses. */
        for (i = 0; i < ncp->cl_naddr; i++) {
                clp->cl_addr[i] = ncp->cl_addrlist[i];
        }
        clp->cl_naddr = ncp->cl_naddr;
 
        /* Remove old client hash entries. */
        if (change)
                exp_unhashclient(clp);
 
        /* Insert client into hashtable. */
        for (i = 0; i < ncp->cl_naddr; i++) {
                struct in_addr  addr = clp->cl_addr[i];
                int             hash;
 
                hash = CLIENT_HASH(addr.s_addr);
                ch[i]->h_client = clp;
                ch[i]->h_addr = addr;
                ch[i]->h_next = clnt_hash[hash];
                clnt_hash[hash] = ch[i];
        }
 
        if (!change) {
                clp->cl_next = clients;
                clients = clp;
        }
        err = 0;
 
out_unlock:
        exp_unlock();
out:
        return err;
}
 
/*
 * Delete a client given an identifier.
 */
int
exp_delclient(struct nfsctl_client *ncp)
{
        svc_client      **clpp, *clp;
        int             err;
 
        err = -EINVAL;
        if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
                goto out;
 
        /* Lock the hashtable */
        if ((err = exp_writelock()) < 0)
                goto out;
 
        err = -EINVAL;
        for (clpp = &clients; (clp = *clpp); clpp = &(clp->cl_next))
                if (!strcmp(ncp->cl_ident, clp->cl_ident))
                        break;
 
        if (clp) {
                *clpp = clp->cl_next;
                exp_freeclient(clp);
                err = 0;
        }
 
        exp_unlock();
out:
        return err;
}
 
/*
 * Free a client. The caller has already removed it from the client list.
 */
static void
exp_freeclient(svc_client *clp)
{
        exp_unhashclient(clp);
 
        /* umap_free(&(clp->cl_umap)); */
        exp_unexport_all(clp);
        nfsd_lockd_unexport(clp);
        kfree (clp);
}
 
/*
 * Remove client from hashtable. We first collect all hashtable
 * entries and free them in one go.
 * The hash table must be writelocked by the caller.
 */
static void
exp_unhashclient(svc_client *clp)
{
        struct svc_clnthash     **hpp, *hp, *ch[NFSCLNT_ADDRMAX];
        int                     i, count, err;
 
again:
        err = 0;
        for (i = 0, count = 0; i < CLIENT_HASHMAX && !err; i++) {
                hpp = clnt_hash + i;
                while ((hp = *hpp) && !err) {
                        if (hp->h_client == clp) {
                                *hpp = hp->h_next;
                                ch[count++] = hp;
                                err = (count >= NFSCLNT_ADDRMAX);
                        } else {
                                hpp = &(hp->h_next);
                        }
                }
        }
        if (count != clp->cl_naddr)
                printk(KERN_WARNING "nfsd: bad address count in freeclient!\n");
        if (err)
                goto again;
        for (i = 0; i < count; i++)
                kfree (ch[i]);
}
 
/*
 * Lockd is shutting down and tells us to unregister all clients
 */
void
exp_nlmdetach(void)
{
        struct svc_client       *clp;
 
        exp_readlock();
        for (clp = clients; clp; clp = clp->cl_next)
                nfsd_lockd_unexport(clp);
        exp_unlock();
}
 
/*
 * Verify that string is non-empty and does not exceed max length.
 */
static int
exp_verify_string(char *cp, int max)
{
        int     i;
 
        for (i = 0; i < max; i++)
                if (!cp[i])
                        return i;
        cp[i] = 0;
        printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
        return 0;
}
 
/*
 * Initialize the exports module.
 */
void
nfsd_export_init(void)
{
        int             i;
 
        dprintk("nfsd: initializing export module.\n");
 
        for (i = 0; i < CLIENT_HASHMAX; i++)
                clnt_hash[i] = NULL;
        clients = NULL;
 
}
 
/*
 * Shutdown the exports module.
 */
void
nfsd_export_shutdown(void)
{
        int     i;
 
        dprintk("nfsd: shutting down export module.\n");
 
        if (exp_writelock() < 0) {
                printk(KERN_WARNING "Weird: hashtable locked in exp_shutdown");
                return;
        }
        for (i = 0; i < CLIENT_HASHMAX; i++) {
                while (clnt_hash[i])
                        exp_freeclient(clnt_hash[i]->h_client);
        }
        clients = NULL; /* we may be restarted before the module unloads */
 
        exp_unlock();
        dprintk("nfsd: export shutdown complete.\n");
}
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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [fs/] [nfsd/] [export.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix	`#define MSNFS /* HACK HACK */`
2			`/*`
3			`* linux/fs/nfsd/export.c`
4			`*`
5			`* NFS exporting and validation.`
6			`*`
7			`* We maintain a list of clients, each of which has a list of`
8			`* exports. To export an fs to a given client, you first have`
9			`* to create the client entry with NFSCTL_ADDCLIENT, which`
10			`* creates a client control block and adds it to the hash`
11			`* table. Then, you call NFSCTL_EXPORT for each fs.`
12			`*`
13			`*`
14			`* Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>`
15			`*/`
16
17			`#include <linux/unistd.h>`
18			`#include <linux/slab.h>`
19			`#include <linux/stat.h>`
20			`#include <linux/in.h>`
21			`#include <linux/seq_file.h>`
22			`#include <linux/smp_lock.h>`
23
24			`#include <linux/sunrpc/svc.h>`
25			`#include <linux/nfsd/nfsd.h>`
26			`#include <linux/nfsd/nfsfh.h>`
27			`#include <linux/nfsd/syscall.h>`
28			`#include <linux/lockd/bind.h>`
29
30			`#define NFSDDBG_FACILITY NFSDDBG_EXPORT`
31			`#define NFSD_PARANOIA 1`
32
33			`typedef struct svc_client svc_client;`
34			`typedef struct svc_export svc_export;`
35
36			`static svc_export * exp_parent(svc_client *clp, kdev_t dev,`
37			`struct dentry *dentry);`
38			`static svc_export * exp_child(svc_client *clp, kdev_t dev,`
39			`struct dentry *dentry);`
40			`static void exp_unexport_all(svc_client *clp);`