/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* 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 BY THE REGENTS AND CONTRIBUTORS ``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.
*
* @(#)nfs_syscalls.c 8.5 (Berkeley) 3/30/95
*/
/*
* locking order:
* nfs_iodlist_lock -> nid_lock -> nm_lock
*/
kmutex_t nfs_iodlist_lock;
struct nfs_iodlist nfs_iodlist_idle;
struct nfs_iodlist nfs_iodlist_all;
int nfs_niothreads = -1; /* == "0, and has never been set" */
int nfs_defect = 0;
/*
* Asynchronous I/O threads for client nfs.
* They do read-ahead and write-behind operations on the block I/O cache.
* Never returns unless it fails or gets killed.
*/
for (;;) {
mutex_enter(&nfs_iodlist_lock);
LIST_INSERT_HEAD(&nfs_iodlist_idle, myiod, nid_idle);
mutex_exit(&nfs_iodlist_lock);
mutex_enter(&myiod->nid_lock);
while (/*CONSTCOND*/ true) {
nmp = myiod->nid_mount;
if (nmp) {
myiod->nid_mount = NULL;
break;
}
if (__predict_false(myiod->nid_exiting)) {
/*
* drop nid_lock to preserve locking order.
*/
mutex_exit(&myiod->nid_lock);
mutex_enter(&nfs_iodlist_lock);
mutex_enter(&myiod->nid_lock);
/*
* recheck nid_mount because nfs_asyncio can
* pick us in the meantime as we are still on
* nfs_iodlist_lock.
*/
if (myiod->nid_mount != NULL) {
mutex_exit(&nfs_iodlist_lock);
continue;
}
LIST_REMOVE(myiod, nid_idle);
mutex_exit(&nfs_iodlist_lock);
goto quit;
}
cv_wait(&myiod->nid_cv, &myiod->nid_lock);
}
mutex_exit(&myiod->nid_lock);
mutex_enter(&nmp->nm_lock);
while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) {
/* Take one off the front of the list */
TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist);
nmp->nm_bufqlen--;
if (nmp->nm_bufqlen < 2 * nmp->nm_bufqiods) {
cv_broadcast(&nmp->nm_aiocv);
}
mutex_exit(&nmp->nm_lock);
KERNEL_LOCK(1, curlwp);
(void)nfs_doio(bp);
KERNEL_UNLOCK_LAST(curlwp);
mutex_enter(&nmp->nm_lock);
/*
* If there are more than one iod on this mount,
* then defect so that the iods can be shared out
* fairly between the mounts
*/
if (nfs_defect && nmp->nm_bufqiods > 1) {
break;
}
}
KASSERT(nmp->nm_bufqiods > 0);
nmp->nm_bufqiods--;
mutex_exit(&nmp->nm_lock);
}
quit:
KASSERT(myiod->nid_mount == NULL);
mutex_exit(&myiod->nid_lock);
int
nfs_set_niothreads(int newval)
{
struct nfs_iod *nid;
int error = 0;
int hold_count;
KERNEL_UNLOCK_ALL(curlwp, &hold_count);
mutex_enter(&nfs_iodlist_lock);
/* clamp to sane range */
nfs_niothreads = uimax(0, uimin(newval, NFS_MAXASYNCDAEMON));
while (nfs_numasync != nfs_niothreads && error == 0) {
while (nfs_numasync < nfs_niothreads) {
/*
* kthread_create can wait for pagedaemon and
* pagedaemon can wait for nfsiod which needs to acquire
* nfs_iodlist_lock.
*/
mutex_exit(&nfs_iodlist_lock);
error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
nfssvc_iod, NULL, NULL, "nfsio");
mutex_enter(&nfs_iodlist_lock);
if (error) {
/* give up */
nfs_niothreads = nfs_numasync;
break;
}
nfs_numasync++;
}
while (nfs_numasync > nfs_niothreads) {
nid = LIST_FIRST(&nfs_iodlist_all);
if (nid == NULL) {
/* iod has not started yet. */
kpause("nfsiorm", false, hz, &nfs_iodlist_lock);
continue;
}
LIST_REMOVE(nid, nid_all);
mutex_enter(&nid->nid_lock);
KASSERT(!nid->nid_exiting);
nid->nid_exiting = true;
cv_signal(&nid->nid_cv);
mutex_exit(&nid->nid_lock);
nfs_numasync--;
}
}
mutex_exit(&nfs_iodlist_lock);
KERNEL_LOCK(hold_count, curlwp);
return error;
}
/*
* Get an authorization string for the uid by having the mount_nfs sitting
* on this mount point porpous out of the kernel and do it.
*/
int
nfs_getauth(struct nfsmount *nmp, struct nfsreq *rep, kauth_cred_t cred, char **auth_str, int *auth_len, char *verf_str, int *verf_len, NFSKERBKEY_T key)
/* key: return session key */
{
int error = 0;
/*
* And wait for mount_nfs to do its stuff.
*/
while ((nmp->nm_iflag & NFSMNT_HASAUTH) == 0 && error == 0) {
(void) tsleep((void *)&nmp->nm_authlen, PSOCK,
"nfsauth2", 2 * hz);
error = nfs_sigintr(nmp, rep, rep->r_lwp);
}
if (nmp->nm_iflag & NFSMNT_AUTHERR) {
nmp->nm_iflag &= ~NFSMNT_AUTHERR;
error = EAUTH;
}
if (error)
free((void *)*auth_str, M_TEMP);
else {
*auth_len = nmp->nm_authlen;
*verf_len = nmp->nm_verflen;
memcpy(key, nmp->nm_key, sizeof (NFSKERBKEY_T));
}
nmp->nm_iflag &= ~NFSMNT_HASAUTH;
nmp->nm_iflag |= NFSMNT_WAITAUTH;
if (nmp->nm_iflag & NFSMNT_WANTAUTH) {
nmp->nm_iflag &= ~NFSMNT_WANTAUTH;
wakeup((void *)&nmp->nm_authtype);
}
return (error);
}
/*
* Get a nickname authenticator and verifier.
*/
int
nfs_getnickauth(struct nfsmount *nmp, kauth_cred_t cred, char **auth_str,
int *auth_len, char *verf_str, int verf_len)
{
#ifdef NFSKERB
struct timeval ktvin;
#endif
struct timeval ktvout, tv;
struct nfsuid *nuidp;
u_int32_t *nickp, *verfp;
memset(&ktvout, 0, sizeof ktvout); /* XXX gcc */
#ifdef DIAGNOSTIC
if (verf_len < (4 * NFSX_UNSIGNED))
panic("nfs_getnickauth verf too small");
#endif
LIST_FOREACH(nuidp, NMUIDHASH(nmp, kauth_cred_geteuid(cred)), nu_hash) {
if (kauth_cred_geteuid(nuidp->nu_cr) == kauth_cred_geteuid(cred))
break;
}
if (!nuidp || nuidp->nu_expire < time_second)
return (EACCES);
/*
* Move to the end of the lru list (end of lru == most recently used).
*/
TAILQ_REMOVE(&nmp->nm_uidlruhead, nuidp, nu_lru);
TAILQ_INSERT_TAIL(&nmp->nm_uidlruhead, nuidp, nu_lru);
