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freebsd-nq/usr.sbin/rpc.lockd/lockd_lock.c
Mark Johnston 2bbeada0f7 rpc.lockd: Use libc strnlen() instead of reimplementing it 
No functional change intended.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2021-06-23 10:06:57 -04:00

2295 lines
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/* $NetBSD: lockd_lock.c,v 1.5 2000/11/21 03:47:41 enami Exp $ */
/*-
* SPDX-License-Identifier: BSD-4-Clause
*
* Copyright (c) 2001 Andrew P. Lentvorski, Jr.
* Copyright (c) 2000 Manuel Bouyer.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define LOCKD_DEBUG
#include <stdio.h>
#ifdef LOCKD_DEBUG
#include <stdarg.h>
#endif
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <rpc/rpc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include <rpcsvc/sm_inter.h>
#include <rpcsvc/nlm_prot.h>
#include "lockd_lock.h"
#include "lockd.h"
#define MAXOBJECTSIZE 64
#define MAXBUFFERSIZE 1024
/*
* A set of utilities for managing file locking
*
* XXX: All locks are in a linked list, a better structure should be used
* to improve search/access efficiency.
*/
/* struct describing a lock */
struct file_lock {
LIST_ENTRY(file_lock) nfslocklist;
fhandle_t filehandle; /* NFS filehandle */
struct sockaddr *addr;
struct nlm4_holder client; /* lock holder */
/* XXX: client_cookie used *only* in send_granted */
netobj client_cookie; /* cookie sent by the client */
int nsm_status; /* status from the remote lock manager */
int status; /* lock status, see below */
int flags; /* lock flags, see lockd_lock.h */
int blocking; /* blocking lock or not */
char client_name[SM_MAXSTRLEN]; /* client_name is really variable
length and must be last! */
};
LIST_HEAD(nfslocklist_head, file_lock);
struct nfslocklist_head nfslocklist_head = LIST_HEAD_INITIALIZER(nfslocklist_head);
LIST_HEAD(blockedlocklist_head, file_lock);
struct blockedlocklist_head blockedlocklist_head = LIST_HEAD_INITIALIZER(blockedlocklist_head);
/* lock status */
#define LKST_LOCKED 1 /* lock is locked */
/* XXX: Is this flag file specific or lock specific? */
#define LKST_WAITING 2 /* file is already locked by another host */
#define LKST_PROCESSING 3 /* child is trying to acquire the lock */
#define LKST_DYING 4 /* must dies when we get news from the child */
/* struct describing a monitored host */
struct host {
LIST_ENTRY(host) hostlst;
int refcnt;
char name[SM_MAXSTRLEN]; /* name is really variable length and
must be last! */
};
/* list of hosts we monitor */
LIST_HEAD(hostlst_head, host);
struct hostlst_head hostlst_head = LIST_HEAD_INITIALIZER(hostlst_head);
/*
* File monitoring handlers
* XXX: These might be able to be removed when kevent support
* is placed into the hardware lock/unlock routines. (ie.
* let the kernel do all the file monitoring)
*/
/* Struct describing a monitored file */
struct monfile {
LIST_ENTRY(monfile) monfilelist;
fhandle_t filehandle; /* Local access filehandle */
int fd; /* file descriptor: remains open until unlock! */
int refcount;
int exclusive;
};
/* List of files we monitor */
LIST_HEAD(monfilelist_head, monfile);
struct monfilelist_head monfilelist_head = LIST_HEAD_INITIALIZER(monfilelist_head);
static int debugdelay = 0;
enum nfslock_status { NFS_GRANTED = 0, NFS_GRANTED_DUPLICATE,
NFS_DENIED, NFS_DENIED_NOLOCK,
NFS_RESERR };
enum hwlock_status { HW_GRANTED = 0, HW_GRANTED_DUPLICATE,
HW_DENIED, HW_DENIED_NOLOCK,
HW_STALEFH, HW_READONLY, HW_RESERR };
enum partialfilelock_status { PFL_GRANTED=0, PFL_GRANTED_DUPLICATE, PFL_DENIED,
PFL_NFSDENIED, PFL_NFSBLOCKED, PFL_NFSDENIED_NOLOCK, PFL_NFSRESERR,
PFL_HWDENIED, PFL_HWBLOCKED, PFL_HWDENIED_NOLOCK, PFL_HWRESERR};
enum LFLAGS {LEDGE_LEFT, LEDGE_LBOUNDARY, LEDGE_INSIDE, LEDGE_RBOUNDARY, LEDGE_RIGHT};
enum RFLAGS {REDGE_LEFT, REDGE_LBOUNDARY, REDGE_INSIDE, REDGE_RBOUNDARY, REDGE_RIGHT};
/* XXX: WARNING! I HAVE OVERLOADED THIS STATUS ENUM! SPLIT IT APART INTO TWO */
enum split_status {SPL_DISJOINT=0, SPL_LOCK1=1, SPL_LOCK2=2, SPL_CONTAINED=4, SPL_RESERR=8};
enum partialfilelock_status lock_partialfilelock(struct file_lock *fl);
void send_granted(struct file_lock *fl, int opcode);
void siglock(void);
void sigunlock(void);
void monitor_lock_host(const char *hostname);
void unmonitor_lock_host(char *hostname);
void copy_nlm4_lock_to_nlm4_holder(const struct nlm4_lock *src,
const bool_t exclusive, struct nlm4_holder *dest);
struct file_lock * allocate_file_lock(const netobj *lockowner,
const netobj *matchcookie,
const struct sockaddr *addr,
const char *caller_name);
void deallocate_file_lock(struct file_lock *fl);
void fill_file_lock(struct file_lock *fl, const fhandle_t *fh,
const bool_t exclusive, const int32_t svid,
const u_int64_t offset, const u_int64_t len,
const int state, const int status, const int flags, const int blocking);
int regions_overlap(const u_int64_t start1, const u_int64_t len1,
const u_int64_t start2, const u_int64_t len2);
enum split_status region_compare(const u_int64_t starte, const u_int64_t lene,
const u_int64_t startu, const u_int64_t lenu,
u_int64_t *start1, u_int64_t *len1, u_int64_t *start2, u_int64_t *len2);
int same_netobj(const netobj *n0, const netobj *n1);
int same_filelock_identity(const struct file_lock *fl0,
const struct file_lock *fl2);
static void debuglog(char const *fmt, ...);
void dump_static_object(const unsigned char* object, const int sizeof_object,
unsigned char* hbuff, const int sizeof_hbuff,
unsigned char* cbuff, const int sizeof_cbuff);
void dump_netobj(const struct netobj *nobj);
void dump_filelock(const struct file_lock *fl);
struct file_lock * get_lock_matching_unlock(const struct file_lock *fl);
enum nfslock_status test_nfslock(const struct file_lock *fl,
struct file_lock **conflicting_fl);
enum nfslock_status lock_nfslock(struct file_lock *fl);
enum nfslock_status delete_nfslock(struct file_lock *fl);
enum nfslock_status unlock_nfslock(const struct file_lock *fl,
struct file_lock **released_lock, struct file_lock **left_lock,
struct file_lock **right_lock);
enum hwlock_status lock_hwlock(struct file_lock *fl);
enum split_status split_nfslock(const struct file_lock *exist_lock,
const struct file_lock *unlock_lock, struct file_lock **left_lock,
struct file_lock **right_lock);
int duplicate_block(struct file_lock *fl);
void add_blockingfilelock(struct file_lock *fl);
enum hwlock_status unlock_hwlock(const struct file_lock *fl);
enum hwlock_status test_hwlock(const struct file_lock *fl,
struct file_lock **conflicting_fl);
void remove_blockingfilelock(struct file_lock *fl);
void clear_blockingfilelock(const char *hostname);
void retry_blockingfilelocklist(void);
enum partialfilelock_status unlock_partialfilelock(
const struct file_lock *fl);
void clear_partialfilelock(const char *hostname);
enum partialfilelock_status test_partialfilelock(
const struct file_lock *fl, struct file_lock **conflicting_fl);
enum nlm_stats do_test(struct file_lock *fl,
struct file_lock **conflicting_fl);
enum nlm_stats do_unlock(struct file_lock *fl);
enum nlm_stats do_lock(struct file_lock *fl);
void do_clear(const char *hostname);
void
debuglog(char const *fmt, ...)
{
va_list ap;
if (debug_level < 1) {
return;
}
sleep(debugdelay);
va_start(ap, fmt);
vsyslog(LOG_DEBUG, fmt, ap);
va_end(ap);
}
void
dump_static_object(object, size_object, hbuff, size_hbuff, cbuff, size_cbuff)
const unsigned char *object;
const int size_object;
unsigned char *hbuff;
const int size_hbuff;
unsigned char *cbuff;
const int size_cbuff;
{
int i, objectsize;
if (debug_level < 2) {
return;
}
objectsize = size_object;
if (objectsize == 0) {
debuglog("object is size 0\n");
} else {
if (objectsize > MAXOBJECTSIZE) {
debuglog("Object of size %d being clamped"
"to size %d\n", objectsize, MAXOBJECTSIZE);
objectsize = MAXOBJECTSIZE;
}
if (hbuff != NULL) {
if (size_hbuff < objectsize*2+1) {
debuglog("Hbuff not large enough."
" Increase size\n");
} else {
for(i=0;i<objectsize;i++) {
sprintf(hbuff+i*2,"%02x",*(object+i));
}
*(hbuff+i*2) = '\0';
}
}
if (cbuff != NULL) {
if (size_cbuff < objectsize+1) {
debuglog("Cbuff not large enough."
" Increase Size\n");
}
for(i=0;i<objectsize;i++) {
if (*(object+i) >= 32 && *(object+i) <= 127) {
*(cbuff+i) = *(object+i);
} else {
*(cbuff+i) = '.';
}
}
*(cbuff+i) = '\0';
}
}
}
void
dump_netobj(const struct netobj *nobj)
{
char hbuff[MAXBUFFERSIZE*2];
char cbuff[MAXBUFFERSIZE];
if (debug_level < 2) {
return;
}
if (nobj == NULL) {
debuglog("Null netobj pointer\n");
}
else if (nobj->n_len == 0) {
debuglog("Size zero netobj\n");
} else {
dump_static_object(nobj->n_bytes, nobj->n_len,
hbuff, sizeof(hbuff), cbuff, sizeof(cbuff));
debuglog("netobj: len: %d data: %s ::: %s\n",
nobj->n_len, hbuff, cbuff);
}
}
/* #define DUMP_FILELOCK_VERBOSE */
void
dump_filelock(const struct file_lock *fl)
{
#ifdef DUMP_FILELOCK_VERBOSE
char hbuff[MAXBUFFERSIZE*2];
char cbuff[MAXBUFFERSIZE];
#endif
if (debug_level < 2) {
return;
}
if (fl != NULL) {
debuglog("Dumping file lock structure @ %p\n", fl);
#ifdef DUMP_FILELOCK_VERBOSE
dump_static_object((unsigned char *)&fl->filehandle,
sizeof(fl->filehandle), hbuff, sizeof(hbuff),
cbuff, sizeof(cbuff));
debuglog("Filehandle: %8s ::: %8s\n", hbuff, cbuff);
#endif
debuglog("Dumping nlm4_holder:\n"
"exc: %x svid: %x offset:len %llx:%llx\n",
fl->client.exclusive, fl->client.svid,
fl->client.l_offset, fl->client.l_len);
#ifdef DUMP_FILELOCK_VERBOSE
debuglog("Dumping client identity:\n");
dump_netobj(&fl->client.oh);
debuglog("Dumping client cookie:\n");
dump_netobj(&fl->client_cookie);
debuglog("nsm: %d status: %d flags: %d svid: %x"
" client_name: %s\n", fl->nsm_status, fl->status,
fl->flags, fl->client.svid, fl->client_name);
#endif
} else {
debuglog("NULL file lock structure\n");
}
}
void
copy_nlm4_lock_to_nlm4_holder(src, exclusive, dest)
const struct nlm4_lock *src;
const bool_t exclusive;
struct nlm4_holder *dest;
{
dest->exclusive = exclusive;
dest->oh.n_len = src->oh.n_len;
dest->oh.n_bytes = src->oh.n_bytes;
dest->svid = src->svid;
dest->l_offset = src->l_offset;
dest->l_len = src->l_len;
}
/*
* allocate_file_lock: Create a lock with the given parameters
*/
struct file_lock *
allocate_file_lock(const netobj *lockowner, const netobj *matchcookie,
const struct sockaddr *addr, const char *caller_name)
{
struct file_lock *newfl;
size_t n;
/* Beware of rubbish input! */
n = strnlen(caller_name, SM_MAXSTRLEN);
if (n == SM_MAXSTRLEN) {
return NULL;
}
newfl = malloc(sizeof(*newfl) - sizeof(newfl->client_name) + n + 1);
if (newfl == NULL) {
return NULL;
}
bzero(newfl, sizeof(*newfl) - sizeof(newfl->client_name));
memcpy(newfl->client_name, caller_name, n);
newfl->client_name[n] = 0;
newfl->client.oh.n_bytes = malloc(lockowner->n_len);
if (newfl->client.oh.n_bytes == NULL) {
free(newfl);
return NULL;
}
newfl->client.oh.n_len = lockowner->n_len;
bcopy(lockowner->n_bytes, newfl->client.oh.n_bytes, lockowner->n_len);
newfl->client_cookie.n_bytes = malloc(matchcookie->n_len);
if (newfl->client_cookie.n_bytes == NULL) {
free(newfl->client.oh.n_bytes);
free(newfl);
return NULL;
}
newfl->client_cookie.n_len = matchcookie->n_len;
bcopy(matchcookie->n_bytes, newfl->client_cookie.n_bytes, matchcookie->n_len);
newfl->addr = malloc(addr->sa_len);
if (newfl->addr == NULL) {
free(newfl->client_cookie.n_bytes);
free(newfl->client.oh.n_bytes);
free(newfl);
return NULL;
}
memcpy(newfl->addr, addr, addr->sa_len);
return newfl;
}
/*
* file_file_lock: Force creation of a valid file lock
*/
void
fill_file_lock(struct file_lock *fl, const fhandle_t *fh,
const bool_t exclusive, const int32_t svid,
const u_int64_t offset, const u_int64_t len,
const int state, const int status, const int flags, const int blocking)
{
bcopy(fh, &fl->filehandle, sizeof(fhandle_t));
fl->client.exclusive = exclusive;
fl->client.svid = svid;
fl->client.l_offset = offset;
fl->client.l_len = len;
fl->nsm_status = state;
fl->status = status;
fl->flags = flags;
fl->blocking = blocking;
}
/*
* deallocate_file_lock: Free all storage associated with a file lock
*/
void
deallocate_file_lock(struct file_lock *fl)
{
free(fl->addr);
free(fl->client.oh.n_bytes);
free(fl->client_cookie.n_bytes);
free(fl);
}
/*
* regions_overlap(): This function examines the two provided regions for
* overlap.
*/
int
regions_overlap(start1, len1, start2, len2)
const u_int64_t start1, len1, start2, len2;
{
u_int64_t d1,d2,d3,d4;
enum split_status result;
debuglog("Entering region overlap with vals: %llu:%llu--%llu:%llu\n",
start1, len1, start2, len2);
result = region_compare(start1, len1, start2, len2,
&d1, &d2, &d3, &d4);
debuglog("Exiting region overlap with val: %d\n",result);
if (result == SPL_DISJOINT) {
return 0;
} else {
return 1;
}
}
/*
* region_compare(): Examine lock regions and split appropriately
*
* XXX: Fix 64 bit overflow problems
* XXX: Check to make sure I got *ALL* the cases.
* XXX: This DESPERATELY needs a regression test.
*/
enum split_status
region_compare(starte, lene, startu, lenu,
start1, len1, start2, len2)
const u_int64_t starte, lene, startu, lenu;
u_int64_t *start1, *len1, *start2, *len2;
{
/*
* Please pay attention to the sequential exclusions
* of the if statements!!!
*/
enum LFLAGS lflags;
enum RFLAGS rflags;
enum split_status retval;
retval = SPL_DISJOINT;
if (lene == 0 && lenu == 0) {
/* Examine left edge of locker */
lflags = LEDGE_INSIDE;
if (startu < starte) {
lflags = LEDGE_LEFT;
} else if (startu == starte) {
lflags = LEDGE_LBOUNDARY;
}
rflags = REDGE_RBOUNDARY; /* Both are infiinite */
if (lflags == LEDGE_INSIDE) {
*start1 = starte;
*len1 = startu - starte;
}
if (lflags == LEDGE_LEFT || lflags == LEDGE_LBOUNDARY) {
retval = SPL_CONTAINED;
} else {
retval = SPL_LOCK1;
}
} else if (lene == 0 && lenu != 0) {
/* Established lock is infinite */
/* Examine left edge of unlocker */
lflags = LEDGE_INSIDE;
if (startu < starte) {
lflags = LEDGE_LEFT;
} else if (startu == starte) {
lflags = LEDGE_LBOUNDARY;
}
/* Examine right edge of unlocker */
if (startu + lenu < starte) {
/* Right edge of unlocker left of established lock */
rflags = REDGE_LEFT;
return SPL_DISJOINT;
} else if (startu + lenu == starte) {
/* Right edge of unlocker on start of established lock */
rflags = REDGE_LBOUNDARY;
return SPL_DISJOINT;
} else { /* Infinifty is right of finity */
/* Right edge of unlocker inside established lock */
rflags = REDGE_INSIDE;
}
if (lflags == LEDGE_INSIDE) {
*start1 = starte;
*len1 = startu - starte;
retval |= SPL_LOCK1;
}
if (rflags == REDGE_INSIDE) {
/* Create right lock */
*start2 = startu+lenu;
*len2 = 0;
retval |= SPL_LOCK2;
}
} else if (lene != 0 && lenu == 0) {
/* Unlocker is infinite */
/* Examine left edge of unlocker */
lflags = LEDGE_RIGHT;
if (startu < starte) {
lflags = LEDGE_LEFT;
retval = SPL_CONTAINED;
return retval;
} else if (startu == starte) {
lflags = LEDGE_LBOUNDARY;
retval = SPL_CONTAINED;
return retval;
} else if ((startu > starte) && (startu < starte + lene - 1)) {
lflags = LEDGE_INSIDE;
} else if (startu == starte + lene - 1) {
lflags = LEDGE_RBOUNDARY;
} else { /* startu > starte + lene -1 */
lflags = LEDGE_RIGHT;
return SPL_DISJOINT;
}
rflags = REDGE_RIGHT; /* Infinity is right of finity */
if (lflags == LEDGE_INSIDE || lflags == LEDGE_RBOUNDARY) {
*start1 = starte;
*len1 = startu - starte;
retval |= SPL_LOCK1;
return retval;
}
} else {
/* Both locks are finite */
/* Examine left edge of unlocker */
lflags = LEDGE_RIGHT;
if (startu < starte) {
lflags = LEDGE_LEFT;
} else if (startu == starte) {
lflags = LEDGE_LBOUNDARY;
} else if ((startu > starte) && (startu < starte + lene - 1)) {
lflags = LEDGE_INSIDE;
} else if (startu == starte + lene - 1) {
lflags = LEDGE_RBOUNDARY;
} else { /* startu > starte + lene -1 */
lflags = LEDGE_RIGHT;
return SPL_DISJOINT;
}
/* Examine right edge of unlocker */
if (startu + lenu < starte) {
/* Right edge of unlocker left of established lock */
rflags = REDGE_LEFT;
return SPL_DISJOINT;
} else if (startu + lenu == starte) {
/* Right edge of unlocker on start of established lock */
rflags = REDGE_LBOUNDARY;
return SPL_DISJOINT;
} else if (startu + lenu < starte + lene) {
/* Right edge of unlocker inside established lock */
rflags = REDGE_INSIDE;
} else if (startu + lenu == starte + lene) {
/* Right edge of unlocker on right edge of established lock */
rflags = REDGE_RBOUNDARY;
} else { /* startu + lenu > starte + lene */
/* Right edge of unlocker is right of established lock */
rflags = REDGE_RIGHT;
}
if (lflags == LEDGE_INSIDE || lflags == LEDGE_RBOUNDARY) {
/* Create left lock */
*start1 = starte;
*len1 = (startu - starte);
retval |= SPL_LOCK1;
}
if (rflags == REDGE_INSIDE) {
/* Create right lock */
*start2 = startu+lenu;
*len2 = starte+lene-(startu+lenu);
retval |= SPL_LOCK2;
}
if ((lflags == LEDGE_LEFT || lflags == LEDGE_LBOUNDARY) &&
(rflags == REDGE_RBOUNDARY || rflags == REDGE_RIGHT)) {
retval = SPL_CONTAINED;
}
}
return retval;
}
/*
* same_netobj: Compares the apprpriate bits of a netobj for identity
*/
int
same_netobj(const netobj *n0, const netobj *n1)
{
int retval;
retval = 0;
debuglog("Entering netobj identity check\n");
if (n0->n_len == n1->n_len) {
debuglog("Preliminary length check passed\n");
retval = !bcmp(n0->n_bytes, n1->n_bytes, n0->n_len);
debuglog("netobj %smatch\n", retval ? "" : "mis");
}
return (retval);
}
/*
* same_filelock_identity: Compares the appropriate bits of a file_lock
*/
int
same_filelock_identity(fl0, fl1)
const struct file_lock *fl0, *fl1;
{
int retval;
retval = 0;
debuglog("Checking filelock identity\n");
/*
* Check process ids and host information.
*/
retval = (fl0->client.svid == fl1->client.svid &&
same_netobj(&(fl0->client.oh), &(fl1->client.oh)));
debuglog("Exiting checking filelock identity: retval: %d\n",retval);
return (retval);
}
/*
* Below here are routines associated with manipulating the NFS
* lock list.
*/
/*
* get_lock_matching_unlock: Return a lock which matches the given unlock lock
* or NULL otehrwise
* XXX: It is a shame that this duplicates so much code from test_nfslock.
*/
struct file_lock *
get_lock_matching_unlock(const struct file_lock *fl)
{
struct file_lock *ifl; /* Iterator */
debuglog("Entering get_lock_matching_unlock\n");
debuglog("********Dump of fl*****************\n");
dump_filelock(fl);
LIST_FOREACH(ifl, &nfslocklist_head, nfslocklist) {
debuglog("Pointer to file lock: %p\n",ifl);
debuglog("****Dump of ifl****\n");
dump_filelock(ifl);
debuglog("*******************\n");
/*
* XXX: It is conceivable that someone could use the NLM RPC
* system to directly access filehandles. This may be a
* security hazard as the filehandle code may bypass normal
* file access controls
*/
if (bcmp(&fl->filehandle, &ifl->filehandle, sizeof(fhandle_t)))
continue;
debuglog("get_lock_matching_unlock: Filehandles match, "
"checking regions\n");
/* Filehandles match, check for region overlap */
if (!regions_overlap(fl->client.l_offset, fl->client.l_len,
ifl->client.l_offset, ifl->client.l_len))
continue;
debuglog("get_lock_matching_unlock: Region overlap"
" found %llu : %llu -- %llu : %llu\n",
fl->client.l_offset,fl->client.l_len,
ifl->client.l_offset,ifl->client.l_len);
/* Regions overlap, check the identity */
if (!same_filelock_identity(fl,ifl))
continue;
debuglog("get_lock_matching_unlock: Duplicate lock id. Granting\n");
return (ifl);
}
debuglog("Exiting bet_lock_matching_unlock\n");
return (NULL);
}
/*
* test_nfslock: check for NFS lock in lock list
*
* This routine makes the following assumptions:
* 1) Nothing will adjust the lock list during a lookup
*
* This routine has an intersting quirk which bit me hard.
* The conflicting_fl is the pointer to the conflicting lock.
* However, to modify the "*pointer* to the conflicting lock" rather
* that the "conflicting lock itself" one must pass in a "pointer to
* the pointer of the conflicting lock". Gross.
*/
enum nfslock_status
test_nfslock(const struct file_lock *fl, struct file_lock **conflicting_fl)
{
struct file_lock *ifl; /* Iterator */
enum nfslock_status retval;
debuglog("Entering test_nfslock\n");
retval = NFS_GRANTED;
(*conflicting_fl) = NULL;
debuglog("Entering lock search loop\n");
debuglog("***********************************\n");
debuglog("Dumping match filelock\n");
debuglog("***********************************\n");
dump_filelock(fl);
debuglog("***********************************\n");
LIST_FOREACH(ifl, &nfslocklist_head, nfslocklist) {
if (retval == NFS_DENIED)
break;
debuglog("Top of lock loop\n");
debuglog("Pointer to file lock: %p\n",ifl);
debuglog("***********************************\n");
debuglog("Dumping test filelock\n");
debuglog("***********************************\n");
dump_filelock(ifl);
debuglog("***********************************\n");
/*
* XXX: It is conceivable that someone could use the NLM RPC
* system to directly access filehandles. This may be a
* security hazard as the filehandle code may bypass normal
* file access controls
*/
if (bcmp(&fl->filehandle, &ifl->filehandle, sizeof(fhandle_t)))
continue;
debuglog("test_nfslock: filehandle match found\n");
/* Filehandles match, check for region overlap */
if (!regions_overlap(fl->client.l_offset, fl->client.l_len,
ifl->client.l_offset, ifl->client.l_len))
continue;
debuglog("test_nfslock: Region overlap found"
" %llu : %llu -- %llu : %llu\n",
fl->client.l_offset,fl->client.l_len,
ifl->client.l_offset,ifl->client.l_len);
/* Regions overlap, check the exclusivity */
if (!(fl->client.exclusive || ifl->client.exclusive))
continue;
debuglog("test_nfslock: Exclusivity failure: %d %d\n",
fl->client.exclusive,
ifl->client.exclusive);
if (same_filelock_identity(fl,ifl)) {
debuglog("test_nfslock: Duplicate id. Granting\n");
(*conflicting_fl) = ifl;
retval = NFS_GRANTED_DUPLICATE;
} else {
/* locking attempt fails */
debuglog("test_nfslock: Lock attempt failed\n");
debuglog("Desired lock\n");
dump_filelock(fl);
debuglog("Conflicting lock\n");
dump_filelock(ifl);
(*conflicting_fl) = ifl;
retval = NFS_DENIED;
}
}
debuglog("Dumping file locks\n");
debuglog("Exiting test_nfslock\n");
return (retval);
}
/*
* lock_nfslock: attempt to create a lock in the NFS lock list
*
* This routine tests whether the lock will be granted and then adds
* the entry to the lock list if so.
*
* Argument fl gets modified as its list housekeeping entries get modified
* upon insertion into the NFS lock list
*
* This routine makes several assumptions:
* 1) It is perfectly happy to grant a duplicate lock from the same pid.
* While this seems to be intuitively wrong, it is required for proper
* Posix semantics during unlock. It is absolutely imperative to not
* unlock the main lock before the two child locks are established. Thus,
* one has to be able to create duplicate locks over an existing lock
* 2) It currently accepts duplicate locks from the same id,pid
*/
enum nfslock_status
lock_nfslock(struct file_lock *fl)
{
enum nfslock_status retval;
struct file_lock *dummy_fl;
dummy_fl = NULL;
debuglog("Entering lock_nfslock...\n");
retval = test_nfslock(fl,&dummy_fl);
if (retval == NFS_GRANTED || retval == NFS_GRANTED_DUPLICATE) {
debuglog("Inserting lock...\n");
dump_filelock(fl);
LIST_INSERT_HEAD(&nfslocklist_head, fl, nfslocklist);
}
debuglog("Exiting lock_nfslock...\n");
return (retval);
}
/*
* delete_nfslock: delete an NFS lock list entry
*
* This routine is used to delete a lock out of the NFS lock list
* without regard to status, underlying locks, regions or anything else
*
* Note that this routine *does not deallocate memory* of the lock.
* It just disconnects it from the list. The lock can then be used
* by other routines without fear of trashing the list.
*/
enum nfslock_status
delete_nfslock(struct file_lock *fl)
{
LIST_REMOVE(fl, nfslocklist);
return (NFS_GRANTED);
}
enum split_status
split_nfslock(exist_lock, unlock_lock, left_lock, right_lock)
const struct file_lock *exist_lock, *unlock_lock;
struct file_lock **left_lock, **right_lock;
{
u_int64_t start1, len1, start2, len2;
enum split_status spstatus;
spstatus = region_compare(exist_lock->client.l_offset, exist_lock->client.l_len,
unlock_lock->client.l_offset, unlock_lock->client.l_len,
&start1, &len1, &start2, &len2);
if ((spstatus & SPL_LOCK1) != 0) {
*left_lock = allocate_file_lock(&exist_lock->client.oh, &exist_lock->client_cookie, exist_lock->addr, exist_lock->client_name);
if (*left_lock == NULL) {
debuglog("Unable to allocate resource for split 1\n");
return SPL_RESERR;
}
fill_file_lock(*left_lock, &exist_lock->filehandle,
exist_lock->client.exclusive, exist_lock->client.svid,
start1, len1,
exist_lock->nsm_status,
exist_lock->status, exist_lock->flags, exist_lock->blocking);
}
if ((spstatus & SPL_LOCK2) != 0) {
*right_lock = allocate_file_lock(&exist_lock->client.oh, &exist_lock->client_cookie, exist_lock->addr, exist_lock->client_name);
if (*right_lock == NULL) {
debuglog("Unable to allocate resource for split 1\n");
if (*left_lock != NULL) {
deallocate_file_lock(*left_lock);
}
return SPL_RESERR;
}
fill_file_lock(*right_lock, &exist_lock->filehandle,
exist_lock->client.exclusive, exist_lock->client.svid,
start2, len2,
exist_lock->nsm_status,
exist_lock->status, exist_lock->flags, exist_lock->blocking);
}
return spstatus;
}
enum nfslock_status
unlock_nfslock(fl, released_lock, left_lock, right_lock)
const struct file_lock *fl;
struct file_lock **released_lock;
struct file_lock **left_lock;
struct file_lock **right_lock;
{
struct file_lock *mfl; /* Matching file lock */
enum nfslock_status retval;
enum split_status spstatus;
debuglog("Entering unlock_nfslock\n");
*released_lock = NULL;
*left_lock = NULL;
*right_lock = NULL;
retval = NFS_DENIED_NOLOCK;
debuglog("Attempting to match lock...\n");
mfl = get_lock_matching_unlock(fl);
if (mfl != NULL) {
debuglog("Unlock matched. Querying for split\n");
spstatus = split_nfslock(mfl, fl, left_lock, right_lock);
debuglog("Split returned %d %p %p %p %p\n",spstatus,mfl,fl,*left_lock,*right_lock);
debuglog("********Split dumps********");
dump_filelock(mfl);
dump_filelock(fl);
dump_filelock(*left_lock);
dump_filelock(*right_lock);
debuglog("********End Split dumps********");
if (spstatus == SPL_RESERR) {
if (*left_lock != NULL) {
deallocate_file_lock(*left_lock);
*left_lock = NULL;
}
if (*right_lock != NULL) {
deallocate_file_lock(*right_lock);
*right_lock = NULL;
}
return NFS_RESERR;
}
/* Insert new locks from split if required */
if (*left_lock != NULL) {
debuglog("Split left activated\n");
LIST_INSERT_HEAD(&nfslocklist_head, *left_lock, nfslocklist);
}
if (*right_lock != NULL) {
debuglog("Split right activated\n");
LIST_INSERT_HEAD(&nfslocklist_head, *right_lock, nfslocklist);
}
/* Unlock the lock since it matches identity */
LIST_REMOVE(mfl, nfslocklist);
*released_lock = mfl;
retval = NFS_GRANTED;
}
debuglog("Exiting unlock_nfslock\n");
return retval;
}
/*
* Below here are the routines for manipulating the file lock directly
* on the disk hardware itself
*/
enum hwlock_status
lock_hwlock(struct file_lock *fl)
{
struct monfile *imf,*nmf;
int lflags, flerror;
/* Scan to see if filehandle already present */
LIST_FOREACH(imf, &monfilelist_head, monfilelist) {
if (bcmp(&fl->filehandle, &imf->filehandle,
sizeof(fl->filehandle)) == 0) {
/* imf is the correct filehandle */
break;
}
}
/*
* Filehandle already exists (we control the file)
* *AND* NFS has already cleared the lock for availability
* Grant it and bump the refcount.
*/
if (imf != NULL) {
++(imf->refcount);
return (HW_GRANTED);
}
/* No filehandle found, create and go */
nmf = malloc(sizeof(struct monfile));
if (nmf == NULL) {
debuglog("hwlock resource allocation failure\n");
return (HW_RESERR);
}
/* XXX: Is O_RDWR always the correct mode? */
nmf->fd = fhopen(&fl->filehandle, O_RDWR);
if (nmf->fd < 0) {
debuglog("fhopen failed (from %16s): %32s\n",
fl->client_name, strerror(errno));
free(nmf);
switch (errno) {
case ESTALE:
return (HW_STALEFH);
case EROFS:
return (HW_READONLY);
default:
return (HW_RESERR);
}
}
/* File opened correctly, fill the monitor struct */
bcopy(&fl->filehandle, &nmf->filehandle, sizeof(fl->filehandle));
nmf->refcount = 1;
nmf->exclusive = fl->client.exclusive;
lflags = (nmf->exclusive == 1) ?
(LOCK_EX | LOCK_NB) : (LOCK_SH | LOCK_NB);
flerror = flock(nmf->fd, lflags);
if (flerror != 0) {
debuglog("flock failed (from %16s): %32s\n",
fl->client_name, strerror(errno));
close(nmf->fd);
free(nmf);
switch (errno) {
case EAGAIN:
return (HW_DENIED);
case ESTALE:
return (HW_STALEFH);
case EROFS:
return (HW_READONLY);
default:
return (HW_RESERR);
break;
}
}
/* File opened and locked */
LIST_INSERT_HEAD(&monfilelist_head, nmf, monfilelist);
debuglog("flock succeeded (from %16s)\n", fl->client_name);
return (HW_GRANTED);
}
enum hwlock_status
unlock_hwlock(const struct file_lock *fl)
{
struct monfile *imf;
debuglog("Entering unlock_hwlock\n");
debuglog("Entering loop interation\n");
/* Scan to see if filehandle already present */
LIST_FOREACH(imf, &monfilelist_head, monfilelist) {
if (bcmp(&fl->filehandle, &imf->filehandle,
sizeof(fl->filehandle)) == 0) {
/* imf is the correct filehandle */
break;
}
}
debuglog("Completed iteration. Proceeding\n");
if (imf == NULL) {
/* No lock found */
debuglog("Exiting unlock_hwlock (HW_DENIED_NOLOCK)\n");
return (HW_DENIED_NOLOCK);
}
/* Lock found */
--imf->refcount;
if (imf->refcount < 0) {
debuglog("Negative hardware reference count\n");
}
if (imf->refcount <= 0) {
close(imf->fd);
LIST_REMOVE(imf, monfilelist);
free(imf);
}
debuglog("Exiting unlock_hwlock (HW_GRANTED)\n");
return (HW_GRANTED);
}
enum hwlock_status
test_hwlock(fl, conflicting_fl)
const struct file_lock *fl __unused;
struct file_lock **conflicting_fl __unused;
{
/*
* XXX: lock tests on hardware are not required until
* true partial file testing is done on the underlying file
*/
return (HW_RESERR);
}
/*
* Below here are routines for manipulating blocked lock requests
* They should only be called from the XXX_partialfilelock routines
* if at all possible
*/
int
duplicate_block(struct file_lock *fl)
{
struct file_lock *ifl;
int retval = 0;
debuglog("Entering duplicate_block");
/*
* Is this lock request already on the blocking list?
* Consider it a dupe if the file handles, offset, length,
* exclusivity and client match.
*/
LIST_FOREACH(ifl, &blockedlocklist_head, nfslocklist) {
if (!bcmp(&fl->filehandle, &ifl->filehandle,
sizeof(fhandle_t)) &&
fl->client.exclusive == ifl->client.exclusive &&
fl->client.l_offset == ifl->client.l_offset &&
fl->client.l_len == ifl->client.l_len &&
same_filelock_identity(fl, ifl)) {
retval = 1;
break;
}
}
debuglog("Exiting duplicate_block: %s\n", retval ? "already blocked"
: "not already blocked");
return retval;
}
void
add_blockingfilelock(struct file_lock *fl)
{
debuglog("Entering add_blockingfilelock\n");
/*
* A blocking lock request _should_ never be duplicated as a client
* that is already blocked shouldn't be able to request another
* lock. Alas, there are some buggy clients that do request the same
* lock repeatedly. Make sure only unique locks are on the blocked
* lock list.
*/
if (duplicate_block(fl)) {
debuglog("Exiting add_blockingfilelock: already blocked\n");
return;
}
/*
* Clear the blocking flag so that it can be reused without
* adding it to the blocking queue a second time
*/
fl->blocking = 0;
LIST_INSERT_HEAD(&blockedlocklist_head, fl, nfslocklist);
debuglog("Exiting add_blockingfilelock: added blocked lock\n");
}
void
remove_blockingfilelock(struct file_lock *fl)
{
debuglog("Entering remove_blockingfilelock\n");
LIST_REMOVE(fl, nfslocklist);
debuglog("Exiting remove_blockingfilelock\n");
}
void
clear_blockingfilelock(const char *hostname)
{
struct file_lock *ifl,*nfl;
/*
* Normally, LIST_FOREACH is called for, but since
* the current element *is* the iterator, deleting it
* would mess up the iteration. Thus, a next element
* must be used explicitly
*/
ifl = LIST_FIRST(&blockedlocklist_head);
while (ifl != NULL) {
nfl = LIST_NEXT(ifl, nfslocklist);
if (strncmp(hostname, ifl->client_name, SM_MAXSTRLEN) == 0) {
remove_blockingfilelock(ifl);
deallocate_file_lock(ifl);
}
ifl = nfl;
}
}
void
retry_blockingfilelocklist(void)
{
/* Retry all locks in the blocked list */
struct file_lock *ifl, *nfl; /* Iterator */
enum partialfilelock_status pflstatus;
debuglog("Entering retry_blockingfilelocklist\n");
LIST_FOREACH_SAFE(ifl, &blockedlocklist_head, nfslocklist, nfl) {
debuglog("Iterator choice %p\n",ifl);
debuglog("Next iterator choice %p\n",nfl);
/*
* SUBTLE BUG: The file_lock must be removed from the
* old list so that it's list pointers get disconnected
* before being allowed to participate in the new list
* which will automatically add it in if necessary.
*/
LIST_REMOVE(ifl, nfslocklist);
pflstatus = lock_partialfilelock(ifl);
if (pflstatus == PFL_GRANTED || pflstatus == PFL_GRANTED_DUPLICATE) {
debuglog("Granted blocked lock\n");
/* lock granted and is now being used */
send_granted(ifl,0);
} else {
/* Reinsert lock back into blocked list */
debuglog("Replacing blocked lock\n");
LIST_INSERT_HEAD(&blockedlocklist_head, ifl, nfslocklist);
}
}
debuglog("Exiting retry_blockingfilelocklist\n");
}
/*
* Below here are routines associated with manipulating all
* aspects of the partial file locking system (list, hardware, etc.)
*/
/*
* Please note that lock monitoring must be done at this level which
* keeps track of *individual* lock requests on lock and unlock
*
* XXX: Split unlocking is going to make the unlock code miserable
*/
/*
* lock_partialfilelock:
*
* Argument fl gets modified as its list housekeeping entries get modified
* upon insertion into the NFS lock list
*
* This routine makes several assumptions:
* 1) It (will) pass locks through to flock to lock the entire underlying file
* and then parcel out NFS locks if it gets control of the file.
* This matches the old rpc.lockd file semantics (except where it
* is now more correct). It is the safe solution, but will cause
* overly restrictive blocking if someone is trying to use the
* underlying files without using NFS. This appears to be an
* acceptable tradeoff since most people use standalone NFS servers.
* XXX: The right solution is probably kevent combined with fcntl
*
* 2) Nothing modifies the lock lists between testing and granting
* I have no idea whether this is a useful assumption or not
*/
enum partialfilelock_status
lock_partialfilelock(struct file_lock *fl)
{
enum partialfilelock_status retval;
enum nfslock_status lnlstatus;
enum hwlock_status hwstatus;
debuglog("Entering lock_partialfilelock\n");
retval = PFL_DENIED;
/*
* Execute the NFS lock first, if possible, as it is significantly
* easier and less expensive to undo than the filesystem lock
*/
lnlstatus = lock_nfslock(fl);
switch (lnlstatus) {
case NFS_GRANTED:
case NFS_GRANTED_DUPLICATE:
/*
* At this point, the NFS lock is allocated and active.
* Remember to clean it up if the hardware lock fails
*/
hwstatus = lock_hwlock(fl);
switch (hwstatus) {
case HW_GRANTED:
case HW_GRANTED_DUPLICATE:
debuglog("HW GRANTED\n");
/*
* XXX: Fixme: Check hwstatus for duplicate when
* true partial file locking and accounting is
* done on the hardware.
*/
if (lnlstatus == NFS_GRANTED_DUPLICATE) {
retval = PFL_GRANTED_DUPLICATE;
} else {
retval = PFL_GRANTED;
}
monitor_lock_host(fl->client_name);
break;
case HW_RESERR:
debuglog("HW RESERR\n");
retval = PFL_HWRESERR;
break;
case HW_DENIED:
debuglog("HW DENIED\n");
retval = PFL_HWDENIED;
break;
default:
debuglog("Unmatched hwstatus %d\n",hwstatus);
break;
}
if (retval != PFL_GRANTED &&
retval != PFL_GRANTED_DUPLICATE) {
/* Clean up the NFS lock */
debuglog("Deleting trial NFS lock\n");
delete_nfslock(fl);
}
break;
case NFS_DENIED:
retval = PFL_NFSDENIED;
break;
case NFS_RESERR:
retval = PFL_NFSRESERR;
break;
default:
debuglog("Unmatched lnlstatus %d\n");
retval = PFL_NFSDENIED_NOLOCK;
break;
}
/*
* By the time fl reaches here, it is completely free again on
* failure. The NFS lock done before attempting the
* hardware lock has been backed out
*/
if (retval == PFL_NFSDENIED || retval == PFL_HWDENIED) {
/* Once last chance to check the lock */
if (fl->blocking == 1) {
if (retval == PFL_NFSDENIED) {
/* Queue the lock */
debuglog("BLOCKING LOCK RECEIVED\n");
retval = PFL_NFSBLOCKED;
add_blockingfilelock(fl);
dump_filelock(fl);
} else {
/* retval is okay as PFL_HWDENIED */
debuglog("BLOCKING LOCK DENIED IN HARDWARE\n");
dump_filelock(fl);
}
} else {
/* Leave retval alone, it's already correct */
debuglog("Lock denied. Non-blocking failure\n");
dump_filelock(fl);
}
}
debuglog("Exiting lock_partialfilelock\n");
return retval;
}
/*
* unlock_partialfilelock:
*
* Given a file_lock, unlock all locks which match.
*
* Note that a given lock might have to unlock ITSELF! See
* clear_partialfilelock for example.
*/
enum partialfilelock_status
unlock_partialfilelock(const struct file_lock *fl)
{
struct file_lock *lfl,*rfl,*releasedfl,*selffl;
enum partialfilelock_status retval;
enum nfslock_status unlstatus;
enum hwlock_status unlhwstatus, lhwstatus;
debuglog("Entering unlock_partialfilelock\n");
selffl = NULL;
lfl = NULL;
rfl = NULL;
releasedfl = NULL;
retval = PFL_DENIED;
/*
* There are significant overlap and atomicity issues
* with partially releasing a lock. For example, releasing
* part of an NFS shared lock does *not* always release the
* corresponding part of the file since there is only one
* rpc.lockd UID but multiple users could be requesting it
* from NFS. Also, an unlock request should never allow
* another process to gain a lock on the remaining parts.
* ie. Always apply the new locks before releasing the
* old one
*/
/*
* Loop is required since multiple little locks
* can be allocated and then deallocated with one
* big unlock.
*
* The loop is required to be here so that the nfs &
* hw subsystems do not need to communicate with one
* one another
*/
do {
debuglog("Value of releasedfl: %p\n",releasedfl);
/* lfl&rfl are created *AND* placed into the NFS lock list if required */
unlstatus = unlock_nfslock(fl, &releasedfl, &lfl, &rfl);
debuglog("Value of releasedfl: %p\n",releasedfl);
/* XXX: This is grungy. It should be refactored to be cleaner */
if (lfl != NULL) {
lhwstatus = lock_hwlock(lfl);
if (lhwstatus != HW_GRANTED &&
lhwstatus != HW_GRANTED_DUPLICATE) {
debuglog("HW duplicate lock failure for left split\n");
}
monitor_lock_host(lfl->client_name);
}
if (rfl != NULL) {
lhwstatus = lock_hwlock(rfl);
if (lhwstatus != HW_GRANTED &&
lhwstatus != HW_GRANTED_DUPLICATE) {
debuglog("HW duplicate lock failure for right split\n");
}
monitor_lock_host(rfl->client_name);
}
switch (unlstatus) {
case NFS_GRANTED:
/* Attempt to unlock on the hardware */
debuglog("NFS unlock granted. Attempting hardware unlock\n");
/* This call *MUST NOT* unlock the two newly allocated locks */
unlhwstatus = unlock_hwlock(fl);
debuglog("HW unlock returned with code %d\n",unlhwstatus);
switch (unlhwstatus) {
case HW_GRANTED:
debuglog("HW unlock granted\n");
unmonitor_lock_host(releasedfl->client_name);
retval = PFL_GRANTED;
break;
case HW_DENIED_NOLOCK:
/* Huh?!?! This shouldn't happen */
debuglog("HW unlock denied no lock\n");
retval = PFL_HWRESERR;
/* Break out of do-while */
unlstatus = NFS_RESERR;
break;
default:
debuglog("HW unlock failed\n");
retval = PFL_HWRESERR;
/* Break out of do-while */
unlstatus = NFS_RESERR;
break;
}
debuglog("Exiting with status retval: %d\n",retval);
retry_blockingfilelocklist();
break;
case NFS_DENIED_NOLOCK:
retval = PFL_GRANTED;
debuglog("All locks cleaned out\n");
break;
default:
retval = PFL_NFSRESERR;
debuglog("NFS unlock failure\n");
dump_filelock(fl);
break;
}
if (releasedfl != NULL) {
if (fl == releasedfl) {
/*
* XXX: YECHHH!!! Attempt to unlock self succeeded
* but we can't deallocate the space yet. This is what
* happens when you don't write malloc and free together
*/
debuglog("Attempt to unlock self\n");
selffl = releasedfl;
} else {
/*
* XXX: this deallocation *still* needs to migrate closer
* to the allocation code way up in get_lock or the allocation
* code needs to migrate down (violation of "When you write
* malloc you must write free")
*/
deallocate_file_lock(releasedfl);
releasedfl = NULL;
}
}
} while (unlstatus == NFS_GRANTED);
if (selffl != NULL) {
/*
* This statement wipes out the incoming file lock (fl)
* in spite of the fact that it is declared const
*/
debuglog("WARNING! Destroying incoming lock pointer\n");
deallocate_file_lock(selffl);
}
debuglog("Exiting unlock_partialfilelock\n");
return retval;
}
/*
* clear_partialfilelock
*
* Normally called in response to statd state number change.
* Wipe out all locks held by a host. As a bonus, the act of
* doing so should automatically clear their statd entries and
* unmonitor the host.
*/
void
clear_partialfilelock(const char *hostname)
{
struct file_lock *ifl, *nfl;
/* Clear blocking file lock list */
clear_blockingfilelock(hostname);
/* do all required unlocks */
/* Note that unlock can smash the current pointer to a lock */
/*
* Normally, LIST_FOREACH is called for, but since
* the current element *is* the iterator, deleting it
* would mess up the iteration. Thus, a next element
* must be used explicitly
*/
ifl = LIST_FIRST(&nfslocklist_head);
while (ifl != NULL) {
nfl = LIST_NEXT(ifl, nfslocklist);
if (strncmp(hostname, ifl->client_name, SM_MAXSTRLEN) == 0) {
/* Unlock destroys ifl out from underneath */
unlock_partialfilelock(ifl);
/* ifl is NO LONGER VALID AT THIS POINT */
}
ifl = nfl;
}
}
/*
* test_partialfilelock:
*/
enum partialfilelock_status
test_partialfilelock(const struct file_lock *fl,
struct file_lock **conflicting_fl)
{
enum partialfilelock_status retval;
enum nfslock_status teststatus;
debuglog("Entering testpartialfilelock...\n");
retval = PFL_DENIED;
teststatus = test_nfslock(fl, conflicting_fl);
debuglog("test_partialfilelock: teststatus %d\n",teststatus);
if (teststatus == NFS_GRANTED || teststatus == NFS_GRANTED_DUPLICATE) {
/* XXX: Add the underlying filesystem locking code */
retval = (teststatus == NFS_GRANTED) ?
PFL_GRANTED : PFL_GRANTED_DUPLICATE;
debuglog("Dumping locks...\n");
dump_filelock(fl);
dump_filelock(*conflicting_fl);
debuglog("Done dumping locks...\n");
} else {
retval = PFL_NFSDENIED;
debuglog("NFS test denied.\n");
dump_filelock(fl);
debuglog("Conflicting.\n");
dump_filelock(*conflicting_fl);
}
debuglog("Exiting testpartialfilelock...\n");
return retval;
}
/*
* Below here are routines associated with translating the partial file locking
* codes into useful codes to send back to the NFS RPC messaging system
*/
/*
* These routines translate the (relatively) useful return codes back onto
* the few return codes which the nlm subsystems wishes to trasmit
*/
enum nlm_stats
do_test(struct file_lock *fl, struct file_lock **conflicting_fl)
{
enum partialfilelock_status pfsret;
enum nlm_stats retval;
debuglog("Entering do_test...\n");
pfsret = test_partialfilelock(fl,conflicting_fl);
switch (pfsret) {
case PFL_GRANTED:
debuglog("PFL test lock granted\n");
dump_filelock(fl);
dump_filelock(*conflicting_fl);
retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
break;
case PFL_GRANTED_DUPLICATE:
debuglog("PFL test lock granted--duplicate id detected\n");
dump_filelock(fl);
dump_filelock(*conflicting_fl);
debuglog("Clearing conflicting_fl for call semantics\n");
*conflicting_fl = NULL;
retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
break;
case PFL_NFSDENIED:
case PFL_HWDENIED:
debuglog("PFL test lock denied\n");
dump_filelock(fl);
dump_filelock(*conflicting_fl);
retval = (fl->flags & LOCK_V4) ? nlm4_denied : nlm_denied;
break;
case PFL_NFSRESERR:
case PFL_HWRESERR:
debuglog("PFL test lock resource fail\n");
dump_filelock(fl);
dump_filelock(*conflicting_fl);
retval = (fl->flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
break;
default:
debuglog("PFL test lock *FAILED*\n");
dump_filelock(fl);
dump_filelock(*conflicting_fl);
retval = (fl->flags & LOCK_V4) ? nlm4_failed : nlm_denied;
break;
}
debuglog("Exiting do_test...\n");
return retval;
}
/*
* do_lock: Try to acquire a lock
*
* This routine makes a distinction between NLM versions. I am pretty
* convinced that this should be abstracted out and bounced up a level
*/
enum nlm_stats
do_lock(struct file_lock *fl)
{
enum partialfilelock_status pfsret;
enum nlm_stats retval;
debuglog("Entering do_lock...\n");
pfsret = lock_partialfilelock(fl);
switch (pfsret) {
case PFL_GRANTED:
debuglog("PFL lock granted");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
break;
case PFL_GRANTED_DUPLICATE:
debuglog("PFL lock granted--duplicate id detected");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
break;
case PFL_NFSDENIED:
case PFL_HWDENIED:
debuglog("PFL_NFS lock denied");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_denied : nlm_denied;
break;
case PFL_NFSBLOCKED:
case PFL_HWBLOCKED:
debuglog("PFL_NFS blocking lock denied. Queued.\n");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_blocked : nlm_blocked;
break;
case PFL_NFSRESERR:
case PFL_HWRESERR:
debuglog("PFL lock resource alocation fail\n");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
break;
default:
debuglog("PFL lock *FAILED*");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_failed : nlm_denied;
break;
}
debuglog("Exiting do_lock...\n");
return retval;
}
enum nlm_stats
do_unlock(struct file_lock *fl)
{
enum partialfilelock_status pfsret;
enum nlm_stats retval;
debuglog("Entering do_unlock...\n");
pfsret = unlock_partialfilelock(fl);
switch (pfsret) {
case PFL_GRANTED:
debuglog("PFL unlock granted");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
break;
case PFL_NFSDENIED:
case PFL_HWDENIED:
debuglog("PFL_NFS unlock denied");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_denied : nlm_denied;
break;
case PFL_NFSDENIED_NOLOCK:
case PFL_HWDENIED_NOLOCK:
debuglog("PFL_NFS no lock found\n");
retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
break;
case PFL_NFSRESERR:
case PFL_HWRESERR:
debuglog("PFL unlock resource failure");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
break;
default:
debuglog("PFL unlock *FAILED*");
dump_filelock(fl);
retval = (fl->flags & LOCK_V4) ? nlm4_failed : nlm_denied;
break;
}
debuglog("Exiting do_unlock...\n");
return retval;
}
/*
* do_clear
*
* This routine is non-existent because it doesn't have a return code.
* It is here for completeness in case someone *does* need to do return
* codes later. A decent compiler should optimize this away.
*/
void
do_clear(const char *hostname)
{
clear_partialfilelock(hostname);
}
/*
* The following routines are all called from the code which the
* RPC layer invokes
*/
/*
* testlock(): inform the caller if the requested lock would be granted
*
* returns NULL if lock would granted
* returns pointer to a conflicting nlm4_holder if not
*/
struct nlm4_holder *
testlock(struct nlm4_lock *lock, bool_t exclusive, int flags __unused)
{
struct file_lock test_fl, *conflicting_fl;
bzero(&test_fl, sizeof(test_fl));
bcopy(lock->fh.n_bytes, &(test_fl.filehandle), sizeof(fhandle_t));
copy_nlm4_lock_to_nlm4_holder(lock, exclusive, &test_fl.client);
siglock();
do_test(&test_fl, &conflicting_fl);
if (conflicting_fl == NULL) {
debuglog("No conflicting lock found\n");
sigunlock();
return NULL;
} else {
debuglog("Found conflicting lock\n");
dump_filelock(conflicting_fl);
sigunlock();
return (&conflicting_fl->client);
}
}
/*
* getlock: try to acquire the lock.
* If file is already locked and we can sleep, put the lock in the list with
* status LKST_WAITING; it'll be processed later.
* Otherwise try to lock. If we're allowed to block, fork a child which
* will do the blocking lock.
*/
enum nlm_stats
getlock(nlm4_lockargs *lckarg, struct svc_req *rqstp, const int flags)
{
struct file_lock *newfl;
enum nlm_stats retval;
debuglog("Entering getlock...\n");
if (grace_expired == 0 && lckarg->reclaim == 0)
return (flags & LOCK_V4) ?
nlm4_denied_grace_period : nlm_denied_grace_period;
/* allocate new file_lock for this request */
newfl = allocate_file_lock(&lckarg->alock.oh, &lckarg->cookie,
(struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf, lckarg->alock.caller_name);
if (newfl == NULL) {
syslog(LOG_NOTICE, "lock allocate failed: %s", strerror(errno));
/* failed */
return (flags & LOCK_V4) ?
nlm4_denied_nolocks : nlm_denied_nolocks;
}
if (lckarg->alock.fh.n_len != sizeof(fhandle_t)) {
debuglog("received fhandle size %d, local size %d",
lckarg->alock.fh.n_len, (int)sizeof(fhandle_t));
}
fill_file_lock(newfl, (fhandle_t *)lckarg->alock.fh.n_bytes,
lckarg->exclusive, lckarg->alock.svid, lckarg->alock.l_offset,
lckarg->alock.l_len,
lckarg->state, 0, flags, lckarg->block);
/*
* newfl is now fully constructed and deallocate_file_lock
* can now be used to delete it
*/
siglock();
debuglog("Pointer to new lock is %p\n",newfl);
retval = do_lock(newfl);
debuglog("Pointer to new lock is %p\n",newfl);
sigunlock();
switch (retval)
{
case nlm4_granted:
/* case nlm_granted: is the same as nlm4_granted */
/* do_mon(lckarg->alock.caller_name); */
break;
case nlm4_blocked:
/* case nlm_blocked: is the same as nlm4_blocked */
/* do_mon(lckarg->alock.caller_name); */
break;
default:
deallocate_file_lock(newfl);
break;
}
debuglog("Exiting getlock...\n");
return retval;
}
/* unlock a filehandle */
enum nlm_stats
unlock(nlm4_lock *lock, const int flags __unused)
{
struct file_lock fl;
enum nlm_stats err;
siglock();
debuglog("Entering unlock...\n");
bzero(&fl,sizeof(struct file_lock));
bcopy(lock->fh.n_bytes, &fl.filehandle, sizeof(fhandle_t));
copy_nlm4_lock_to_nlm4_holder(lock, 0, &fl.client);
err = do_unlock(&fl);
sigunlock();
debuglog("Exiting unlock...\n");
return err;
}
/*
* XXX: The following monitor/unmonitor routines
* have not been extensively tested (ie. no regression
* script exists like for the locking sections
*/
/*
* monitor_lock_host: monitor lock hosts locally with a ref count and
* inform statd
*/
void
monitor_lock_host(const char *hostname)
{
struct host *ihp, *nhp;
struct mon smon;
struct sm_stat_res sres;
int rpcret, statflag;
size_t n;
rpcret = 0;
statflag = 0;
LIST_FOREACH(ihp, &hostlst_head, hostlst) {
if (strncmp(hostname, ihp->name, SM_MAXSTRLEN) == 0) {
/* Host is already monitored, bump refcount */
++ihp->refcnt;
/* Host should only be in the monitor list once */
return;
}
}
/* Host is not yet monitored, add it */
n = strnlen(hostname, SM_MAXSTRLEN);
if (n == SM_MAXSTRLEN) {
return;
}
nhp = malloc(sizeof(*nhp) - sizeof(nhp->name) + n + 1);
if (nhp == NULL) {
debuglog("Unable to allocate entry for statd mon\n");
return;
}
/* Allocated new host entry, now fill the fields */
memcpy(nhp->name, hostname, n);
nhp->name[n] = 0;
nhp->refcnt = 1;
debuglog("Locally Monitoring host %16s\n",hostname);
debuglog("Attempting to tell statd\n");
bzero(&smon,sizeof(smon));
smon.mon_id.mon_name = nhp->name;
smon.mon_id.my_id.my_name = "localhost";
smon.mon_id.my_id.my_prog = NLM_PROG;
smon.mon_id.my_id.my_vers = NLM_SM;
smon.mon_id.my_id.my_proc = NLM_SM_NOTIFY;
rpcret = callrpc("localhost", SM_PROG, SM_VERS, SM_MON,
(xdrproc_t)xdr_mon, &smon,
(xdrproc_t)xdr_sm_stat_res, &sres);
if (rpcret == 0) {
if (sres.res_stat == stat_fail) {
debuglog("Statd call failed\n");
statflag = 0;
} else {
statflag = 1;
}
} else {
debuglog("Rpc call to statd failed with return value: %d\n",
rpcret);
statflag = 0;
}
if (statflag == 1) {
LIST_INSERT_HEAD(&hostlst_head, nhp, hostlst);
} else {
free(nhp);
}
}
/*
* unmonitor_lock_host: clear monitor ref counts and inform statd when gone
*/
void
unmonitor_lock_host(char *hostname)
{
struct host *ihp;
struct mon_id smon_id;
struct sm_stat smstat;
int rpcret;
rpcret = 0;
for( ihp=LIST_FIRST(&hostlst_head); ihp != NULL;
ihp=LIST_NEXT(ihp, hostlst)) {
if (strncmp(hostname, ihp->name, SM_MAXSTRLEN) == 0) {
/* Host is monitored, bump refcount */
--ihp->refcnt;
/* Host should only be in the monitor list once */
break;
}
}
if (ihp == NULL) {
debuglog("Could not find host %16s in mon list\n", hostname);
return;
}
if (ihp->refcnt > 0)
return;
if (ihp->refcnt < 0) {
debuglog("Negative refcount!: %d\n",
ihp->refcnt);
}
debuglog("Attempting to unmonitor host %16s\n", hostname);
bzero(&smon_id,sizeof(smon_id));
smon_id.mon_name = hostname;
smon_id.my_id.my_name = "localhost";
smon_id.my_id.my_prog = NLM_PROG;
smon_id.my_id.my_vers = NLM_SM;
smon_id.my_id.my_proc = NLM_SM_NOTIFY;
rpcret = callrpc("localhost", SM_PROG, SM_VERS, SM_UNMON,
(xdrproc_t)xdr_mon_id, &smon_id,
(xdrproc_t)xdr_sm_stat, &smstat);
if (rpcret != 0) {
debuglog("Rpc call to unmonitor statd failed with "
" return value: %d\n", rpcret);
}
LIST_REMOVE(ihp, hostlst);
free(ihp);
}
/*
* notify: Clear all locks from a host if statd complains
*
* XXX: This routine has not been thoroughly tested. However, neither
* had the old one been. It used to compare the statd crash state counter
* to the current lock state. The upshot of this was that it basically
* cleared all locks from the specified host 99% of the time (with the
* other 1% being a bug). Consequently, the assumption is that clearing
* all locks from a host when notified by statd is acceptable.
*
* Please note that this routine skips the usual level of redirection
* through a do_* type routine. This introduces a possible level of
* error and might better be written as do_notify and take this one out.
*/
void
notify(const char *hostname, const int state)
{
debuglog("notify from %s, new state %d", hostname, state);
siglock();
do_clear(hostname);
sigunlock();
debuglog("Leaving notify\n");
}
void
send_granted(fl, opcode)
struct file_lock *fl;
int opcode __unused;
{
CLIENT *cli;
static char dummy;
struct timeval timeo;
int success;
static struct nlm_res retval;
static struct nlm4_res retval4;
debuglog("About to send granted on blocked lock\n");
cli = get_client(fl->addr,
(fl->flags & LOCK_V4) ? NLM_VERS4 : NLM_VERS);
if (cli == NULL) {
syslog(LOG_NOTICE, "failed to get CLIENT for %s",
fl->client_name);
/*
* We fail to notify remote that the lock has been granted.
* The client will timeout and retry, the lock will be
* granted at this time.
*/
return;
}
timeo.tv_sec = 0;
timeo.tv_usec = (fl->flags & LOCK_ASYNC) ? 0 : 500000; /* 0.5s */
if (fl->flags & LOCK_V4) {
static nlm4_testargs res;
res.cookie = fl->client_cookie;
res.exclusive = fl->client.exclusive;
res.alock.caller_name = fl->client_name;
res.alock.fh.n_len = sizeof(fhandle_t);
res.alock.fh.n_bytes = (char*)&fl->filehandle;
res.alock.oh = fl->client.oh;
res.alock.svid = fl->client.svid;
res.alock.l_offset = fl->client.l_offset;
res.alock.l_len = fl->client.l_len;
debuglog("sending v4 reply%s",
(fl->flags & LOCK_ASYNC) ? " (async)":"");
if (fl->flags & LOCK_ASYNC) {
success = clnt_call(cli, NLM4_GRANTED_MSG,
(xdrproc_t)xdr_nlm4_testargs, &res,
(xdrproc_t)xdr_void, &dummy, timeo);
} else {
success = clnt_call(cli, NLM4_GRANTED,
(xdrproc_t)xdr_nlm4_testargs, &res,
(xdrproc_t)xdr_nlm4_res, &retval4, timeo);
}
} else {
static nlm_testargs res;
res.cookie = fl->client_cookie;
res.exclusive = fl->client.exclusive;
res.alock.caller_name = fl->client_name;
res.alock.fh.n_len = sizeof(fhandle_t);
res.alock.fh.n_bytes = (char*)&fl->filehandle;
res.alock.oh = fl->client.oh;
res.alock.svid = fl->client.svid;
res.alock.l_offset = fl->client.l_offset;
res.alock.l_len = fl->client.l_len;
debuglog("sending v1 reply%s",
(fl->flags & LOCK_ASYNC) ? " (async)":"");
if (fl->flags & LOCK_ASYNC) {
success = clnt_call(cli, NLM_GRANTED_MSG,
(xdrproc_t)xdr_nlm_testargs, &res,
(xdrproc_t)xdr_void, &dummy, timeo);
} else {
success = clnt_call(cli, NLM_GRANTED,
(xdrproc_t)xdr_nlm_testargs, &res,
(xdrproc_t)xdr_nlm_res, &retval, timeo);
}
}
if (debug_level > 2)
debuglog("clnt_call returns %d(%s) for granted",
success, clnt_sperrno(success));
}
/*
* Routines below here have not been modified in the overhaul
*/
/*
* Are these two routines still required since lockd is not spawning off
* children to service locks anymore? Presumably they were originally
* put in place to prevent a one child from changing the lock list out
* from under another one.
*/
void
siglock(void)
{
sigset_t block;
sigemptyset(&block);
sigaddset(&block, SIGCHLD);
if (sigprocmask(SIG_BLOCK, &block, NULL) < 0) {
syslog(LOG_WARNING, "siglock failed: %s", strerror(errno));
}
}
void
sigunlock(void)
{
sigset_t block;
sigemptyset(&block);
sigaddset(&block, SIGCHLD);
if (sigprocmask(SIG_UNBLOCK, &block, NULL) < 0) {
syslog(LOG_WARNING, "sigunlock failed: %s", strerror(errno));
}
}
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