[svn] GnuPG - r4179 - branches/GNUPG-1-9-BRANCH/jnlib
svn author wk
cvs at cvs.gnupg.org
Wed Jun 28 17:14:10 CEST 2006
Author: wk
Date: 2006-06-28 17:14:09 +0200 (Wed, 28 Jun 2006)
New Revision: 4179
Modified:
branches/GNUPG-1-9-BRANCH/jnlib/ChangeLog
branches/GNUPG-1-9-BRANCH/jnlib/dotlock.c
Log:
Remove stale lockfiles if created on the same node.
Modified: branches/GNUPG-1-9-BRANCH/jnlib/ChangeLog
===================================================================
--- branches/GNUPG-1-9-BRANCH/jnlib/ChangeLog 2006-06-28 09:37:42 UTC (rev 4178)
+++ branches/GNUPG-1-9-BRANCH/jnlib/ChangeLog 2006-06-28 15:14:09 UTC (rev 4179)
@@ -1,3 +1,15 @@
+2006-06-28 Werner Koch <wk at g10code.com>
+
+ * dotlock.c (make_dotlock, release_dotlock, read_lockfile)
+ (maybe_deadlock, destroy_dotlock, create_dotlock): Re-indented.
+ (create_dotlock): Repalces some log_fatal by log_error as it was
+ not intended that they should terminate. Write the nodename to
+ the locking file. Code cleanups.
+ (read_lockfile): Reworked to read the node name.
+ (make_dotlock): Test for identical node name and delete lock stale
+ file.
+ (release_dotlock): Likewise.
+
2006-05-23 Werner Koch <wk at g10code.com>
* libjnlib-config.h (JNLIB_NEED_UTF8CONV): Fixed typo in name.
Modified: branches/GNUPG-1-9-BRANCH/jnlib/dotlock.c
===================================================================
--- branches/GNUPG-1-9-BRANCH/jnlib/dotlock.c 2006-06-28 09:37:42 UTC (rev 4178)
+++ branches/GNUPG-1-9-BRANCH/jnlib/dotlock.c 2006-06-28 15:14:09 UTC (rev 4179)
@@ -1,6 +1,6 @@
/* dotlock.c - dotfile locking
* Copyright (C) 1998, 2000, 2001, 2003, 2004,
- * 2005 Free Software Foundation, Inc.
+ * 2005, 2006 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
@@ -55,32 +55,35 @@
#endif
-struct dotlock_handle {
- struct dotlock_handle *next;
- char *tname; /* name of lockfile template */
- char *lockname; /* name of the real lockfile */
- int locked; /* lock status */
- int disable; /* locking */
+struct dotlock_handle
+{
+ struct dotlock_handle *next;
+ char *tname; /* Name of lockfile template. */
+ size_t nodename_off; /* Offset in TNAME of the nodename part. */
+ size_t nodename_len; /* Length of the nodename part. */
+ char *lockname; /* Name of the real lockfile. */
+ int locked; /* Lock status. */
+ int disable; /* When true, locking is disabled. */
};
static volatile DOTLOCK all_lockfiles;
static int never_lock;
-static int read_lockfile( const char *name );
+static int read_lockfile (DOTLOCK h, int *same_node);
void
disable_dotlock(void)
{
- never_lock = 1;
+ never_lock = 1;
}
/****************
* Create a lockfile with the given name and return an object of
* type DOTLOCK which may be used later to actually do the lock.
* A cleanup routine gets installed to cleanup left over locks
- * or other files used together with the lockmechanism.
- * Althoug the function is called dotlock, this does not necessarily
+ * or other files used together with the lock mechanism.
+ * Although the function is called dotlock, this does not necessarily
* mean that real lockfiles are used - the function may decide to
* use fcntl locking. Calling the function with NULL only install
* the atexit handler and maybe used to assure that the cleanup
@@ -94,160 +97,165 @@
DOTLOCK
create_dotlock( const char *file_to_lock )
{
- static int initialized;
- DOTLOCK h;
- int fd = -1;
- char pidstr[16];
- #ifndef HAVE_DOSISH_SYSTEM
- struct utsname utsbuf;
- #endif
- const char *nodename;
- const char *dirpart;
- int dirpartlen;
+ static int initialized;
+ DOTLOCK h;
+ int fd = -1;
+ char pidstr[16];
+ const char *nodename;
+ const char *dirpart;
+ int dirpartlen;
+#ifndef HAVE_DOSISH_SYSTEM
+ struct utsname utsbuf;
+#endif
- if( !initialized ) {
- atexit( dotlock_remove_lockfiles );
- initialized = 1;
+ if ( !initialized )
+ {
+ atexit( dotlock_remove_lockfiles );
+ initialized = 1;
}
- if( !file_to_lock )
- return NULL;
+ if ( !file_to_lock )
+ return NULL; /* Only initialization was requested. */
- h = jnlib_xcalloc( 1, sizeof *h );
- if( never_lock ) {
- h->disable = 1;
+ h = jnlib_xcalloc ( 1, sizeof *h );
+ if( never_lock )
+ {
+ h->disable = 1;
#ifdef _REENTRANT
- /* fixme: aquire mutex on all_lockfiles */
+ /* fixme: aquire mutex on all_lockfiles */
#endif
- h->next = all_lockfiles;
- all_lockfiles = h;
- return h;
+ h->next = all_lockfiles;
+ all_lockfiles = h;
+ return h;
}
#ifndef HAVE_DOSISH_SYSTEM
- sprintf( pidstr, "%10d\n", (int)getpid() );
- /* fixme: add the hostname to the second line (FQDN or IP addr?) */
+ sprintf (pidstr, "%10d\n", (int)getpid() );
+ /* fixme: add the hostname to the second line (FQDN or IP addr?) */
- /* create a temporary file */
- if( uname( &utsbuf ) )
- nodename = "unknown";
- else
- nodename = utsbuf.nodename;
-
+ /* Create a temporary file. */
+ if ( uname ( &utsbuf ) )
+ nodename = "unknown";
+ else
+ nodename = utsbuf.nodename;
+
#ifdef __riscos__
- {
- char *iter = (char *) nodename;
- for (; iter[0]; iter++)
- if (iter[0] == '.')
- iter[0] = '/';
- }
+ {
+ char *iter = (char *) nodename;
+ for (; iter[0]; iter++)
+ if (iter[0] == '.')
+ iter[0] = '/';
+ }
#endif /* __riscos__ */
- if( !(dirpart = strrchr( file_to_lock, DIRSEP_C )) ) {
- dirpart = EXTSEP_S;
- dirpartlen = 1;
+ if ( !(dirpart = strrchr ( file_to_lock, DIRSEP_C )) )
+ {
+ dirpart = EXTSEP_S;
+ dirpartlen = 1;
}
- else {
- dirpartlen = dirpart - file_to_lock;
- dirpart = file_to_lock;
+ else
+ {
+ dirpartlen = dirpart - file_to_lock;
+ dirpart = file_to_lock;
}
#ifdef _REENTRANT
/* fixme: aquire mutex on all_lockfiles */
#endif
- h->next = all_lockfiles;
- all_lockfiles = h;
+ h->next = all_lockfiles;
+ all_lockfiles = h;
- h->tname = jnlib_xmalloc( dirpartlen + 6+30+ strlen(nodename) + 11 );
+ h->tname = jnlib_xmalloc ( dirpartlen + 6+30+ strlen(nodename) + 11 );
+ h->nodename_len = strlen (nodename);
#ifndef __riscos__
- sprintf( h->tname, "%.*s/.#lk%p.%s.%d",
- dirpartlen, dirpart, h, nodename, (int)getpid() );
+ sprintf (h->tname, "%.*s/.#lk%p.", dirpartlen, dirpart, h );
+ h->nodename_off = strlen (h->tname);
+ sprintf (h->tname+h->nodename_off, "%s.%d", nodename, (int)getpid ());
#else /* __riscos__ */
- sprintf( h->tname, "%.*s.lk%p/%s/%d",
- dirpartlen, dirpart, h, nodename, (int)getpid() );
+ sprintf (h->tname, "%.*s.lk%p/", dirpartlen, dirpart, h );
+ h->nodename_off = strlen (h->tname);
+ sprintf (h->tname+h->nodename_off, "%s/%d", nodename, (int)getpid () );
#endif /* __riscos__ */
- do {
- errno = 0;
- fd = open( h->tname, O_WRONLY|O_CREAT|O_EXCL,
- S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR );
- } while( fd == -1 && errno == EINTR );
- if( fd == -1 ) {
- all_lockfiles = h->next;
- log_error( "failed to create temporary file `%s': %s\n",
- h->tname, strerror(errno));
- jnlib_free(h->tname);
- jnlib_free(h);
- return NULL;
+ do
+ {
+ errno = 0;
+ fd = open (h->tname, O_WRONLY|O_CREAT|O_EXCL,
+ S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR );
+ }
+ while (fd == -1 && errno == EINTR);
+
+ if ( fd == -1 )
+ {
+ all_lockfiles = h->next;
+ log_error ( "failed to create temporary file `%s': %s\n",
+ h->tname, strerror(errno));
+ jnlib_free(h->tname);
+ jnlib_free(h);
+ return NULL;
}
- if( write(fd, pidstr, 11 ) != 11 ) {
- all_lockfiles = h->next;
- #ifdef _REENTRANT
- /* release mutex */
- #endif
- log_fatal( "error writing to `%s': %s\n", h->tname, strerror(errno) );
- close(fd);
- unlink(h->tname);
- jnlib_free(h->tname);
- jnlib_free(h);
- return NULL;
- }
- if( close(fd) ) {
- all_lockfiles = h->next;
- #ifdef _REENTRANT
- /* release mutex */
- #endif
- log_fatal( "error writing to `%s': %s\n", h->tname, strerror(errno) );
- close(fd);
- unlink(h->tname);
- jnlib_free(h->tname);
- jnlib_free(h);
- return NULL;
- }
+ if ( write (fd, pidstr, 11 ) != 11 )
+ goto write_failed;
+ if ( write (fd, nodename, strlen (nodename) ) != strlen (nodename) )
+ goto write_failed;
+ if ( write (fd, "\n", 1 ) != 1 )
+ goto write_failed;
+ if ( close (fd) )
+ goto write_failed;
# ifdef _REENTRANT
- /* release mutex */
+ /* release mutex */
# endif
#endif /* !HAVE_DOSISH_SYSTEM */
- h->lockname = jnlib_xmalloc( strlen(file_to_lock) + 6 );
- strcpy(stpcpy(h->lockname, file_to_lock), EXTSEP_S "lock");
- return h;
+ h->lockname = jnlib_xmalloc ( strlen (file_to_lock) + 6 );
+ strcpy (stpcpy(h->lockname, file_to_lock), EXTSEP_S "lock");
+ return h;
+ write_failed:
+ all_lockfiles = h->next;
+# ifdef _REENTRANT
+ /* fixme: release mutex */
+# endif
+ log_error ( "error writing to `%s': %s\n", h->tname, strerror(errno) );
+ close(fd);
+ unlink(h->tname);
+ jnlib_free(h->tname);
+ jnlib_free(h);
+ return NULL;
}
void
destroy_dotlock ( DOTLOCK h )
{
-#if !defined (HAVE_DOSISH_SYSTEM)
- if ( h )
- {
- DOTLOCK hprev, htmp;
-
- /* First remove the handle from our global list of all locks. */
- for (hprev=NULL, htmp=all_lockfiles; htmp; hprev=htmp, htmp=htmp->next)
- if (htmp == h)
- {
- if (hprev)
- hprev->next = htmp->next;
- else
- all_lockfiles = htmp->next;
- h->next = NULL;
- break;
- }
-
- /* Second destroy the lock. */
- if (!h->disable)
+#ifndef HAVE_DOSISH_SYSTEM
+ if ( h )
+ {
+ DOTLOCK hprev, htmp;
+
+ /* First remove the handle from our global list of all locks. */
+ for (hprev=NULL, htmp=all_lockfiles; htmp; hprev=htmp, htmp=htmp->next)
+ if (htmp == h)
{
- if (h->locked && h->lockname)
- unlink (h->lockname);
- if (h->tname)
+ if (hprev)
+ hprev->next = htmp->next;
+ else
+ all_lockfiles = htmp->next;
+ h->next = NULL;
+ break;
+ }
+
+ /* Second destroy the lock. */
+ if (!h->disable)
+ {
+ if (h->locked && h->lockname)
+ unlink (h->lockname);
+ if (h->tname)
unlink (h->tname);
- jnlib_free (h->tname);
- jnlib_free (h->lockname);
- }
- jnlib_free(h);
-
- }
-#endif
+ jnlib_free (h->tname);
+ jnlib_free (h->lockname);
+ }
+ jnlib_free(h);
+ }
+#endif /*!HAVE_DOSISH_SYSTEM*/
}
@@ -255,107 +263,120 @@
static int
maybe_deadlock( DOTLOCK h )
{
- DOTLOCK r;
+ DOTLOCK r;
- for( r=all_lockfiles; r; r = r->next ) {
- if( r != h && r->locked )
- return 1;
+ for ( r=all_lockfiles; r; r = r->next )
+ {
+ if ( r != h && r->locked )
+ return 1;
}
- return 0;
+ return 0;
}
/****************
- * Do a lock on H. A TIMEOUT of 0 returns immediately,
- * -1 waits forever (hopefully not), other
- * values are timeouts in milliseconds.
- * Returns: 0 on success
+ * Do a lock on H. A TIMEOUT of 0 returns immediately, -1 waits
+ * forever (hopefully not), other values are reserved (should then be
+ * timeouts in milliseconds). Returns: 0 on success
*/
int
make_dotlock( DOTLOCK h, long timeout )
{
#ifdef HAVE_DOSISH_SYSTEM
- return 0;
+ return 0;
#else
- int pid;
- const char *maybe_dead="";
- int backoff=0;
+ int pid;
+ const char *maybe_dead="";
+ int backoff=0;
+ int same_node;
- if( h->disable ) {
- return 0;
- }
+ if ( h->disable )
+ return 0; /* Locks are completely disabled. Return success. */
- if( h->locked ) {
+ if ( h->locked )
+ {
#ifndef __riscos__
- log_debug("oops, `%s' is already locked\n", h->lockname );
+ log_debug("oops, `%s' is already locked\n", h->lockname );
#endif /* !__riscos__ */
- return 0;
+ return 0;
}
- for(;;) {
+ for(;;)
+ {
#ifndef __riscos__
- if( !link(h->tname, h->lockname) ) {
- /* fixme: better use stat to check the link count */
- h->locked = 1;
- return 0; /* okay */
+ if ( !link(h->tname, h->lockname) )
+ {
+ /* fixme: better use stat to check the link count */
+ h->locked = 1;
+ return 0; /* okay */
}
- if( errno != EEXIST ) {
- log_error( "lock not made: link() failed: %s\n", strerror(errno) );
- return -1;
+ if ( errno != EEXIST )
+ {
+ log_error( "lock not made: link() failed: %s\n", strerror(errno) );
+ return -1;
}
#else /* __riscos__ */
- if( !renamefile(h->tname, h->lockname) ) {
- h->locked = 1;
- return 0; /* okay */
+ if ( !renamefile(h->tname, h->lockname) )
+ {
+ h->locked = 1;
+ return 0; /* okay */
}
- if( errno != EEXIST ) {
- log_error( "lock not made: rename() failed: %s\n", strerror(errno) );
- return -1;
+ if ( errno != EEXIST )
+ {
+ log_error( "lock not made: rename() failed: %s\n", strerror(errno) );
+ return -1;
}
#endif /* __riscos__ */
- if( (pid = read_lockfile(h->lockname)) == -1 ) {
- if( errno != ENOENT ) {
- log_info("cannot read lockfile\n");
- return -1;
+
+ if ( (pid = read_lockfile (h, &same_node)) == -1 )
+ {
+ if ( errno != ENOENT )
+ {
+ log_info ("cannot read lockfile\n");
+ return -1;
}
- log_info( "lockfile disappeared\n");
- continue;
+ log_info( "lockfile disappeared\n");
+ continue;
}
- else if( pid == getpid() ) {
- log_info( "Oops: lock already held by us\n");
- h->locked = 1;
- return 0; /* okay */
+ else if ( pid == getpid() && same_node )
+ {
+ log_info( "Oops: lock already held by us\n");
+ h->locked = 1;
+ return 0; /* okay */
}
- else if( kill(pid, 0) && errno == ESRCH ) {
+ else if ( same_node && kill (pid, 0) && errno == ESRCH )
+ {
#ifndef __riscos__
- maybe_dead = " - probably dead";
-#if 0 /* we should not do this without checking the permissions */
- /* and the hostname */
- log_info( "removing stale lockfile (created by %d)", pid );
-#endif
+ log_info ("removing stale lockfile (created by %d)", pid );
+ unlink (h->lockname);
+ continue;
#else /* __riscos__ */
- /* we are *pretty* sure that the other task is dead and therefore
- we remove the other lock file */
- maybe_dead = " - probably dead - removing lock";
- unlink(h->lockname);
+ /* Under RISCOS we are *pretty* sure that the other task
+ is dead and therefore we remove the stale lock file. */
+ maybe_dead = " - probably dead - removing lock";
+ unlink(h->lockname);
#endif /* __riscos__ */
}
- if( timeout == -1 ) {
- struct timeval tv;
- log_info( "waiting for lock (held by %d%s) %s...\n",
- pid, maybe_dead, maybe_deadlock(h)? "(deadlock?) ":"");
+ if ( timeout == -1 )
+ {
+ /* Wait until lock has been released. */
+ struct timeval tv;
+
+ log_info ("waiting for lock (held by %d%s) %s...\n",
+ pid, maybe_dead, maybe_deadlock(h)? "(deadlock?) ":"");
- /* can't use sleep, cause signals may be blocked */
- tv.tv_sec = 1 + backoff;
- tv.tv_usec = 0;
- select(0, NULL, NULL, NULL, &tv);
- if( backoff < 10 )
- backoff++ ;
+
+ /* We can't use sleep, cause signals may be blocked. */
+ tv.tv_sec = 1 + backoff;
+ tv.tv_usec = 0;
+ select(0, NULL, NULL, NULL, &tv);
+ if ( backoff < 10 )
+ backoff++ ;
}
- else
- return -1;
+ else
+ return -1;
}
- /*not reached */
+ /*NOTREACHED*/
#endif /* !HAVE_DOSISH_SYSTEM */
}
@@ -368,92 +389,150 @@
release_dotlock( DOTLOCK h )
{
#ifdef HAVE_DOSISH_SYSTEM
- return 0;
+ return 0;
#else
- int pid;
+ int pid, same_node;
- /* To avoid atexit race conditions we first check whether there
- are any locks left. It might happen that another atexit
- handler tries to release the lock while the atexit handler of
- this module already ran and thus H is undefined. */
- if(!all_lockfiles)
- return 0;
+ /* To avoid atexit race conditions we first check whether there are
+ any locks left. It might happen that another atexit handler
+ tries to release the lock while the atexit handler of this module
+ already ran and thus H is undefined. */
+ if (!all_lockfiles)
+ return 0;
- if( h->disable ) {
- return 0;
- }
+ if ( h->disable )
+ return 0;
- if( !h->locked ) {
- log_debug("oops, `%s' is not locked\n", h->lockname );
- return 0;
+ if ( !h->locked )
+ {
+ log_debug("oops, `%s' is not locked\n", h->lockname );
+ return 0;
}
- pid = read_lockfile( h->lockname );
- if( pid == -1 ) {
- log_error( "release_dotlock: lockfile error\n");
- return -1;
+ pid = read_lockfile (h, &same_node);
+ if ( pid == -1 )
+ {
+ log_error( "release_dotlock: lockfile error\n");
+ return -1;
}
- if( pid != getpid() ) {
- log_error( "release_dotlock: not our lock (pid=%d)\n", pid);
- return -1;
+ if ( pid != getpid() || !same_node )
+ {
+ log_error( "release_dotlock: not our lock (pid=%d)\n", pid);
+ return -1;
}
#ifndef __riscos__
- if( unlink( h->lockname ) ) {
- log_error( "release_dotlock: error removing lockfile `%s'",
- h->lockname);
- return -1;
+ if ( unlink( h->lockname ) )
+ {
+ log_error( "release_dotlock: error removing lockfile `%s'",
+ h->lockname);
+ return -1;
}
#else /* __riscos__ */
- if( renamefile(h->lockname, h->tname) ) {
- log_error( "release_dotlock: error renaming lockfile `%s' to `%s'",
- h->lockname, h->tname);
- return -1;
+ if ( renamefile(h->lockname, h->tname) )
+ {
+ log_error( "release_dotlock: error renaming lockfile `%s' to `%s'",
+ h->lockname, h->tname);
+ return -1;
}
#endif /* __riscos__ */
- /* fixme: check that the link count is now 1 */
- h->locked = 0;
- return 0;
+ /* fixme: check that the link count is now 1 */
+ h->locked = 0;
+ return 0;
#endif /* !HAVE_DOSISH_SYSTEM */
}
-/****************
- * Read the lock file and return the pid, returns -1 on error.
+/*
+ Read the lock file and return the pid, returns -1 on error. True
+ will be stored at SAME_NODE if the lock file has been created on
+ the same node.
*/
static int
-read_lockfile( const char *name )
+read_lockfile (DOTLOCK h, int *same_node )
{
#ifdef HAVE_DOSISH_SYSTEM
- return 0;
+ return 0;
#else
- int fd, pid;
- char pidstr[16];
+ char buffer_space[10+1+70+1]; /* 70 is just an estimated value; node
+ name are usually shorter. */
+ int fd, pid;
+ char *buffer, *p;
+ size_t expected_len;
+ int res, nread;
+
+ *same_node = 0;
+ expected_len = 10 + 1 + h->nodename_len + 1;
+ if ( expected_len >= sizeof buffer_space)
+ buffer = jnlib_xmalloc (expected_len);
+ else
+ buffer = buffer_space;
- if( (fd = open(name, O_RDONLY)) == -1 ) {
- int e = errno;
- log_debug("error opening lockfile `%s': %s\n", name, strerror(errno) );
- errno = e;
- return -1;
+ if ( (fd = open (h->lockname, O_RDONLY)) == -1 )
+ {
+ int e = errno;
+ log_info ("error opening lockfile `%s': %s\n",
+ h->lockname, strerror(errno) );
+ if (buffer != buffer_space)
+ jnlib_free (buffer);
+ errno = e; /* Need to return ERRNO here. */
+ return -1;
}
- if( read(fd, pidstr, 10 ) != 10 ) { /* Read 10 digits w/o newline */
- log_debug("error reading lockfile `%s'", name );
- close(fd);
- errno = 0;
- return -1;
+
+ p = buffer;
+ nread = 0;
+ do
+ {
+ res = read (fd, p, expected_len - nread);
+ if (res == -1 && errno == EINTR)
+ continue;
+ if (res < 0)
+ {
+ log_info ("error reading lockfile `%s'", h->lockname );
+ close (fd);
+ if (buffer != buffer_space)
+ jnlib_free (buffer);
+ errno = 0; /* Do not return an inappropriate ERRNO. */
+ return -1;
+ }
+ p += res;
+ nread += res;
}
- pidstr[10] = 0; /* terminate pid string */
- close(fd);
- pid = atoi(pidstr);
+ while (res && nread != expected_len);
+ close(fd);
+
+ if (nread < 11)
+ {
+ log_info ("invalid size of lockfile `%s'", h->lockname );
+ if (buffer != buffer_space)
+ jnlib_free (buffer);
+ errno = 0; /* Do not return an inappropriate ERRNO. */
+ return -1;
+ }
+
+ if (buffer[10] != '\n'
+ || (buffer[10] = 0, pid = atoi (buffer)) == -1
#ifndef __riscos__
- if( !pid || pid == -1 ) {
+ || !pid
#else /* __riscos__ */
- if( (!pid && riscos_getpid()) || pid == -1 ) {
+ || (!pid && riscos_getpid())
#endif /* __riscos__ */
- log_error("invalid pid %d in lockfile `%s'", pid, name );
- errno = 0;
- return -1;
+ )
+ {
+ log_error ("invalid pid %d in lockfile `%s'", pid, h->lockname );
+ if (buffer != buffer_space)
+ jnlib_free (buffer);
+ errno = 0;
+ return -1;
}
- return pid;
+
+ if (nread == expected_len
+ && !memcmp (h->tname+h->nodename_off, buffer+11, h->nodename_len)
+ && buffer[11+h->nodename_len] == '\n')
+ *same_node = 1;
+
+ if (buffer != buffer_space)
+ jnlib_free (buffer);
+ return pid;
#endif
}
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