/*
- * $Id: ad_lock.c,v 1.8 2003-01-16 21:18:15 didg Exp $
+ * $Id: ad_lock.c,v 1.15 2009-10-21 07:33:50 didg Exp $
*
* Copyright (c) 1998,1999 Adrian Sun (asun@zoology.washington.edu)
* All Rights Reserved. See COPYRIGHT for more information.
#include "config.h"
#endif /* HAVE_CONFIG_H */
+#include <atalk/adouble.h>
+
#include <stdio.h>
#include <stdlib.h>
-#include <string.h>
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif /* HAVE_UNISTD_H */
-#ifdef HAVE_FCNTL_H
-#include <fcntl.h>
-#endif /* HAVE_FCNTL_H */
#include <errno.h>
-#include <atalk/adouble.h>
+#include <string.h>
#include "ad_private.h"
((type) == ADLOCK_WR ? LOCK_EX : \
((type) == ADLOCK_CLR ? LOCK_UN : -1)))
+#ifdef DISABLE_LOCKING
+#define fcntl(a, b, c ) (0)
+#endif
+
/* ----------------------- */
static int XLATE_FCNTL_LOCK(int type)
{
}
/* ----------------------- */
-
static int OVERLAP(off_t a, off_t alen, off_t b, off_t blen)
{
return (!alen && a <= b) ||
( (a + alen > b) && (b + blen > a) );
}
-
/* allocation for lock regions. we allocate aggressively and shrink
* only in large chunks. */
#define ARRAY_BLOCK_SIZE 10
#define ARRAY_FREE_DELTA 100
/* remove a lock and compact space if necessary */
-static __inline__ void adf_freelock(struct ad_fd *ad, const int i)
+static void adf_freelock(struct ad_fd *ad, const int i)
{
adf_lock_t *lock = ad->adf_lock + i;
if (--(*lock->refcount) < 1) {
free(lock->refcount);
- lock->lock.l_type = F_UNLCK;
- fcntl(ad->adf_fd, F_SETLK, &lock->lock); /* unlock */
+ if (!ad->adf_excl) {
+ lock->lock.l_type = F_UNLCK;
+ fcntl(ad->adf_fd, F_SETLK, &lock->lock); /* unlock */
+ }
}
ad->adf_lockcount--;
/* this needs to deal with the following cases:
- * 1) user is the only user of the lock
- * 2) user shares a read lock with another user
+ * 1) fork is the only user of the lock
+ * 2) fork shares a read lock with another open fork
*
* i converted to using arrays of locks. everytime a lock
* gets removed, we shift all of the locks down.
*/
-static __inline__ void adf_unlock(struct ad_fd *ad, int fd, const int user)
+static void adf_unlock(struct ad_fd *ad, const int fork)
{
adf_lock_t *lock = ad->adf_lock;
int i;
for (i = 0; i < ad->adf_lockcount; i++) {
- if (lock[i].user == user) {
+ if (lock[i].user == fork) {
/* we're really going to delete this lock. note: read locks
are the only ones that allow refcounts > 1 */
adf_freelock(ad, i);
/* relock any byte lock that overlaps off/len. unlock everything
* else. */
-static __inline__ void adf_relockrange(struct ad_fd *ad, int fd,
+static void adf_relockrange(struct ad_fd *ad, int fd,
const off_t off, const off_t len)
{
adf_lock_t *lock = ad->adf_lock;
int i;
- for (i = 0; i < ad->adf_lockcount; i++) {
+ if (!ad->adf_excl) for (i = 0; i < ad->adf_lockcount; i++) {
if (OVERLAP(off, len, lock[i].lock.l_start, lock[i].lock.l_len))
fcntl(fd, F_SETLK, &lock[i].lock);
}
}
-/* find a byte lock that overlaps off/len for a particular user */
-static __inline__ int adf_findlock(struct ad_fd *ad,
- const int user, const int type,
+/* find a byte lock that overlaps off/len for a particular open fork */
+static int adf_findlock(struct ad_fd *ad,
+ const int fork, const int type,
const off_t off,
const off_t len)
{
for (i = 0; i < ad->adf_lockcount; i++) {
if ((((type & ADLOCK_RD) && (lock[i].lock.l_type == F_RDLCK)) ||
((type & ADLOCK_WR) && (lock[i].lock.l_type == F_WRLCK))) &&
- (lock[i].user == user) &&
+ (lock[i].user == fork) &&
OVERLAP(off, len, lock[i].lock.l_start, lock[i].lock.l_len)) {
return i;
}
}
-/* search other user lock lists */
-static __inline__ int adf_findxlock(struct ad_fd *ad,
- const int user, const int type,
+/* search other fork lock lists */
+static int adf_findxlock(struct ad_fd *ad,
+ const int fork, const int type,
const off_t off,
const off_t len)
{
for (i = 0; i < ad->adf_lockcount; i++) {
if ((((type & ADLOCK_RD) && (lock[i].lock.l_type == F_RDLCK)) ||
((type & ADLOCK_WR) && (lock[i].lock.l_type == F_WRLCK))) &&
- (lock[i].user != user) &&
+ (lock[i].user != fork) &&
OVERLAP(off, len, lock[i].lock.l_start, lock[i].lock.l_len))
return i;
}
translate a data fork lock to an offset
*/
-static int df2off(int off)
+static off_t df2off(int off)
{
int start = off;
if (off == AD_FILELOCK_OPEN_WR)
translate a resource fork lock to an offset
*/
-static int hf2off(int off)
+static off_t hf2off(int off)
{
int start = off;
if (off == AD_FILELOCK_OPEN_WR)
/* ------------------ */
int ad_fcntl_lock(struct adouble *ad, const u_int32_t eid, const int locktype,
- const off_t off, const off_t len, const int user)
+ const off_t off, const off_t len, const int fork)
{
struct flock lock;
struct ad_fd *adf;
- adf_lock_t *adflock, *oldlock;
+ adf_lock_t *adflock;
+ int oldlock;
int i;
int type;
lock.l_start = off;
type = locktype;
if (eid == ADEID_DFORK) {
- adf = &ad->ad_df;
+ adf = &ad->ad_data_fork;
if ((type & ADLOCK_FILELOCK)) {
- if (ad_hfileno(ad) != -1) {
+ if (ad_meta_fileno(ad) != -1) { /* META */
+ adf = ad->ad_md;
lock.l_start = df2off(off);
- adf = &ad->ad_hf;
}
}
} else { /* rfork */
- adf = &ad->ad_hf;
- if (type & ADLOCK_FILELOCK)
+ if (ad_meta_fileno(ad) == -1 || ad_reso_fileno(ad) == -1) {
+ /* there's no meta data. return a lock error
+ * otherwise if a second process is able to create it
+ * locks are a mess.
+ */
+ errno = EACCES;
+ return -1;
+ }
+ if (type & ADLOCK_FILELOCK) {
+ adf = ad->ad_md; /* either resource or meta data (set in ad_open) */
lock.l_start = hf2off(off);
- else
+ }
+ else {
+ /* we really want the resource fork it's a byte lock */
+ adf = &ad->ad_resource_fork;
lock.l_start += ad_getentryoff(ad, eid);
+ }
}
/* NOTE: we can't write lock a read-only file. on those, we just
* make sure that we have a read lock set. that way, we at least prevent
lock.l_len -= lock.l_start; /* otherwise EOVERFLOW error */
}
- /* see if it's locked by another user.
+ /* see if it's locked by another fork.
* NOTE: this guarantees that any existing locks must be at most
* read locks. we use ADLOCK_WR/RD because F_RD/WRLCK aren't
* guaranteed to be ORable. */
- if (adf_findxlock(adf, user, ADLOCK_WR |
+ if (adf_findxlock(adf, fork, ADLOCK_WR |
((type & ADLOCK_WR) ? ADLOCK_RD : 0),
lock.l_start, lock.l_len) > -1) {
errno = EACCES;
}
/* look for any existing lock that we may have */
- i = adf_findlock(adf, user, ADLOCK_RD | ADLOCK_WR, lock.l_start, lock.l_len);
+ i = adf_findlock(adf, fork, ADLOCK_RD | ADLOCK_WR, lock.l_start, lock.l_len);
adflock = (i < 0) ? NULL : adf->adf_lock + i;
/* here's what we check for:
}
/* attempt to lock the file. */
- if (fcntl(adf->adf_fd, F_SETLK, &lock) < 0)
+ if (!adf->adf_excl && fcntl(adf->adf_fd, F_SETLK, &lock) < 0)
return -1;
/* we upgraded this lock. */
}
/* it wasn't an upgrade */
- oldlock = NULL;
- if ((lock.l_type == F_RDLCK) &&
- ((i = adf_findxlock(adf, user, ADLOCK_RD, lock.l_start, lock.l_len)) > -1)) {
- oldlock = adf->adf_lock + i;
+ oldlock = -1;
+ if (lock.l_type == F_RDLCK) {
+ oldlock = adf_findxlock(adf, fork, ADLOCK_RD, lock.l_start, lock.l_len);
}
/* no more space. this will also happen if lockmax == lockcount == 0 */
/* fill in fields */
memcpy(&adflock->lock, &lock, sizeof(lock));
- adflock->user = user;
- if (oldlock)
- adflock->refcount = oldlock->refcount;
- else if ((adflock->refcount = calloc(1, sizeof(int))) == NULL) {
+ adflock->user = fork;
+ if (oldlock > -1) {
+ adflock->refcount = (adf->adf_lock + oldlock)->refcount;
+ } else if ((adflock->refcount = calloc(1, sizeof(int))) == NULL) {
goto fcntl_lock_err;
}
fcntl_lock_err:
lock.l_type = F_UNLCK;
- fcntl(adf->adf_fd, F_SETLK, &lock);
+ if (!adf->adf_excl) fcntl(adf->adf_fd, F_SETLK, &lock);
return -1;
}
lock.l_start = off;
if (eid == ADEID_DFORK) {
- adf = &ad->ad_df;
- if ((ad_hfileno(ad) != -1)) {
- adf = &ad->ad_hf;
+ adf = &ad->ad_data_fork;
+ if ((ad_meta_fileno(ad) != -1)) {
+ adf = ad->ad_md;
lock.l_start = df2off(off);
- }
- } else { /* rfork */
- adf = &ad->ad_hf;
+ }
+ }
+ else { /* rfork */
+ if ((ad_meta_fileno(ad) == -1)) {
+ /* there's no resource fork. return no lock */
+ return 0;
+ }
+ adf = ad->ad_md;
lock.l_start = hf2off(off);
}
plock = adf->adf_lock;
- /* Does we have a lock? */
+ /* Do we have a lock? */
lock.l_whence = SEEK_SET;
lock.l_len = 1;
for (i = 0; i < adf->adf_lockcount; i++) {
/* -------------------------
*/
-int ad_fcntl_tmplock(struct adouble *ad, const u_int32_t eid, const int type,
- const off_t off, const off_t len, const int user)
+int ad_fcntl_tmplock(struct adouble *ad, const u_int32_t eid, const int locktype,
+ const off_t off, const off_t len, const int fork)
{
struct flock lock;
struct ad_fd *adf;
int err;
+ int type;
lock.l_start = off;
+ type = locktype;
if (eid == ADEID_DFORK) {
- adf = &ad->ad_df;
+ adf = &ad->ad_data_fork;
} else {
- adf = &ad->ad_hf;
+ /* FIXME META */
+ adf = &ad->ad_resource_fork;
+ if (adf->adf_fd == -1) {
+ /* there's no resource fork. return success */
+ return 0;
+ }
/* if ADLOCK_FILELOCK we want a lock from offset 0
* it's used when deleting a file:
* in open we put read locks on meta datas
if (!(type & ADLOCK_FILELOCK))
lock.l_start += ad_getentryoff(ad, eid);
}
+
+ if (!(adf->adf_flags & O_RDWR) && (type & ADLOCK_WR)) {
+ type = (type & ~ADLOCK_WR) | ADLOCK_RD;
+ }
+
lock.l_type = XLATE_FCNTL_LOCK(type & ADLOCK_MASK);
lock.l_whence = SEEK_SET;
lock.l_len = len;
- /* see if it's locked by another user. */
- if (user && adf_findxlock(adf, user, ADLOCK_WR |
+ /* see if it's locked by another fork. */
+ if (fork && adf_findxlock(adf, fork, ADLOCK_WR |
((type & ADLOCK_WR) ? ADLOCK_RD : 0),
lock.l_start, lock.l_len) > -1) {
errno = EACCES;
* XXX: in the future, all the byte locks will be sorted and contiguous.
* we just want to upgrade all the locks and then downgrade them
* here. */
- err = fcntl(adf->adf_fd, F_SETLK, &lock);
+ if (!adf->adf_excl) {
+ err = fcntl(adf->adf_fd, F_SETLK, &lock);
+ }
+ else {
+ err = 0;
+ }
if (!err && (lock.l_type == F_UNLCK))
adf_relockrange(adf, adf->adf_fd, lock.l_start, len);
return err;
}
+/* -------------------------
+ the fork is opened in Read Write, Deny Read, Deny Write mode
+ lock the whole file once
+*/
+int ad_excl_lock(struct adouble *ad, const u_int32_t eid)
+{
+ struct ad_fd *adf;
+ struct flock lock;
+ int err;
+
+ lock.l_start = 0;
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+ lock.l_len = 0;
-void ad_fcntl_unlock(struct adouble *ad, const int user)
+ if (eid == ADEID_DFORK) {
+ adf = &ad->ad_data_fork;
+ } else {
+ adf = &ad->ad_resource_fork;
+ lock.l_start = ad_getentryoff(ad, eid);
+ }
+
+ err = fcntl(adf->adf_fd, F_SETLK, &lock);
+ if (!err)
+ adf->adf_excl = 1;
+ return err;
+}
+
+/* --------------------- */
+void ad_fcntl_unlock(struct adouble *ad, const int fork)
{
- if (ad->ad_df.adf_fd != -1) {
- adf_unlock(&ad->ad_df, ad->ad_df.adf_fd, user);
+ if (ad_data_fileno(ad) != -1) {
+ adf_unlock(&ad->ad_data_fork, fork);
+ }
+ if (ad_reso_fileno(ad) != -1) {
+ adf_unlock(&ad->ad_resource_fork, fork);
}
- if (ad->ad_hf.adf_fd != -1) {
- adf_unlock(&ad->ad_hf, ad->ad_hf.adf_fd, user);
+
+ if (ad->ad_flags != AD_VERSION1_SFM) {
+ return;
}
+ if (ad_meta_fileno(ad) != -1) {
+ adf_unlock(&ad->ad_metadata_fork, fork);
+ }
+
}
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