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freebsd-dev/usr.sbin/rpc.lockd/lockd_lock.c
Alfred Perlstein 4b4ec9b800 Fix boundry condition in lock management: 
Alfred, I took a look at retry_blockingfilelocklist() and the
 solution seemed  simple enough. Please correct me if I am wrong.
 It seems said routine doesn't  take into account boundary conditions
 when putting back file_lock entries into the blocked lock-list.
 Specifically, it fails when the file_lock being put back is the
 last element in the list, and when it is the only element in the
 list.  I've included a patch below.

 Basically, it introduces another variable: pfl, which keeps track
 of the list  item before ifl. That way if nfl is NULL, ifl gets
 inserted after pfl. If pfl  is also NULL, then it gets inserted
 at the head of the list (since it was the  only element in the
 list).

Submitted by: Mike Makonnen <mike_makonnen@yahoo.com>
Tested by: Thomas Quinot <thomas@cuivre.fr.eu.org>
2002-01-17 00:12:05 +00:00

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/* $NetBSD: lockd_lock.c,v 1.5 2000/11/21 03:47:41 enami Exp $ */
/* $FreeBSD$ */
/*
* 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.
*
*/
#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
/*
* SM_MAXSTRLEN is usually 1024. This means that lock requests and
* host name monitoring entries are *MUCH* larger than they should be
*/
/*
* 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 effeciency.
*/
/* 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 */
char client_name[SM_MAXSTRLEN];
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 */
pid_t locker; /* pid of the child process trying to get the lock */
int fd; /* file descriptor for this lock */
};
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 aquire 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;
char name[SM_MAXSTRLEN];
int refcnt;
};
/* 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(const 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);
void deallocate_file_lock(struct file_lock *fl);
void fill_file_lock(struct file_lock *fl, const fhandle_t *fh,
struct sockaddr *addr, const bool_t exclusive, const int32_t svid,
const u_int64_t offset, const u_int64_t len, const char *caller_name,
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);
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);
}
}
void
dump_filelock(const struct file_lock *fl)
{
char hbuff[MAXBUFFERSIZE*2];
char cbuff[MAXBUFFERSIZE];
if (debug_level < 2) {
return;
}
if (fl != NULL) {
debuglog("Dumping file lock structure @ %p\n", fl);
/*
dump_static_object((unsigned char *)&fl->filehandle,
sizeof(fl->filehandle), hbuff, sizeof(hbuff),
cbuff, sizeof(cbuff));
debuglog("Filehandle: %8s ::: %8s\n", hbuff, cbuff);
*/
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);
/*
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 locker: %d"
" fd: %d\n", fl->nsm_status, fl->status,
fl->flags, fl->locker, fl->fd);
*/
} 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)
{
struct file_lock *newfl;
newfl = malloc(sizeof(struct file_lock));
if (newfl == NULL) {
return NULL;
}
bzero(newfl, sizeof(newfl));
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);
return newfl;
}
/*
* file_file_lock: Force creation of a valid file lock
*/
void
fill_file_lock(struct file_lock *fl, const fhandle_t *fh,
struct sockaddr *addr, const bool_t exclusive, const int32_t svid,
const u_int64_t offset, const u_int64_t len, const char *caller_name,
const int state, const int status, const int flags, const int blocking)
{
bcopy(fh, &fl->filehandle, sizeof(fhandle_t));
fl->addr = addr;
fl->client.exclusive = exclusive;
fl->client.svid = svid;
fl->client.l_offset = offset;
fl->client.l_len = len;
strncpy(fl->client_name, caller_name, SM_MAXSTRLEN);
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->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;
}
return (result);
}
/*
* 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 */
if (startu < starte) {
lflags = LEDGE_LEFT;
} else if (startu == starte) {
lflags = LEDGE_LBOUNDARY;
} else {
lflags = LEDGE_INSIDE;
}
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 */
if (startu < starte) {
lflags = LEDGE_LEFT;
} else if (startu == starte) {
lflags = LEDGE_LBOUNDARY;
} else if (startu > starte) {
lflags = LEDGE_INSIDE;
}
/* 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 */
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 */
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 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("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("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("matching_unlock: Duplicate lock id. Granting\n");
return (ifl);
}
debuglog("Exiting 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 be 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);
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->addr,
exist_lock->client.exclusive, exist_lock->client.svid,
start1, len1,
exist_lock->client_name, 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);
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->addr,
exist_lock->client.exclusive, exist_lock->client.svid,
start2, len2,
exist_lock->client_name, 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;
printf("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(const struct file_lock *fl, struct file_lock **conflicting_fl)
{
/*
* 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
*/
void
add_blockingfilelock(struct file_lock *fl)
{
debuglog("Entering add_blockingfilelock\n");
/*
* 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\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, *pfl; /* Iterator */
enum partialfilelock_status pflstatus;
debuglog("Entering retry_blockingfilelocklist\n");
pfl = NULL;
ifl = LIST_FIRST(&blockedlocklist_head);
debuglog("Iterator choice %p\n",ifl);
while (ifl != NULL) {
/*
* SUBTLE BUG: The next element must be worked out before the
* current element has been moved
*/
nfl = LIST_NEXT(ifl, nfslocklist);
debuglog("Iterator choice %p\n",ifl);
debuglog("Prev iterator choice %p\n",pfl);
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 same place in blocked list */
debuglog("Replacing blocked lock\n");
if (pfl != NULL)
LIST_INSERT_AFTER(pfl, ifl, nfslocklist);
else
/* ifl is the only elem. in the list */
LIST_INSERT_HEAD(&blockedlocklist_head, ifl, nfslocklist);
}
/* Valid increment behavior regardless of state of ifl */
ifl = nfl;
/* if a lock was granted incrementing pfl would make it nfl */
if (pfl != NULL && (LIST_NEXT(pfl, nfslocklist) != nfl))
pfl = LIST_NEXT(pfl, nfslocklist);
else
pfl = LIST_FIRST(&blockedlocklist_head);
}
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;
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) {
/* Queue the lock */
debuglog("BLOCKING LOCK RECEIVED\n");
retval = (retval == PFL_NFSDENIED ?
PFL_NFSBLOCKED : PFL_HWBLOCKED);
add_blockingfilelock(fl);
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);
}
}
} 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)
{
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 aquire 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);
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("recieved 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,
(struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf,
lckarg->exclusive, lckarg->alock.svid, lckarg->alock.l_offset,
lckarg->alock.l_len,
lckarg->alock.caller_name, 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)
{
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;
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 */
nhp = malloc(sizeof(struct host));
if (nhp == NULL) {
debuglog("Unable to allocate entry for statd mon\n");
return;
}
/* Allocated new host entry, now fill the fields */
strncpy(nhp->name, hostname, SM_MAXSTRLEN);
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\0";
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, xdr_mon,
&smon, 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(const 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 = (char *)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, xdr_mon,
&smon_id, xdr_sm_stat_res, &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;
{
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");
sleep(1);
debuglog("Blowing off return send\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,
xdr_nlm4_testargs, &res, xdr_void, &dummy, timeo);
} else {
success = clnt_call(cli, NLM4_GRANTED,
xdr_nlm4_testargs, &res, 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,
xdr_nlm_testargs, &res, xdr_void, &dummy, timeo);
} else {
success = clnt_call(cli, NLM_GRANTED,
xdr_nlm_testargs, &res, 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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