[lockdev-devel] [PATCH 01/10] RedHat patch 1
Ludwig Nussel
ludwig.nussel at suse.de
Wed Feb 10 11:46:35 UTC 2010
- install src/sample as sbin/lockdev helper utility
- introduce baudboy.h as wrapper to calling the helper
- new library calls dev_getpid/dev_setpid to allow locking on behalf
of another process
---
LockDev/Makefile.PL | 2 +-
Makefile | 22 +++++---
src/baudboy.h | 137 +++++++++++++++++++++++++++++++++++++++++++++++++++
src/lockdev.c | 48 +++++++++++++-----
src/lockdev.h | 4 ++
src/sample.c | 64 ++++++++++++++++--------
6 files changed, 234 insertions(+), 43 deletions(-)
create mode 100644 src/baudboy.h
diff --git a/LockDev/Makefile.PL b/LockDev/Makefile.PL
index 65478df..74444bc 100644
--- a/LockDev/Makefile.PL
+++ b/LockDev/Makefile.PL
@@ -7,7 +7,7 @@ WriteMakefile(
'LIBS' => [''],
'DEFINE' => '',
'INC' => '-I../src',
- 'MYEXTLIB' => '../src/lockdev.z',
+ 'MYEXTLIB' => '../liblockdev.a',
);
sub MY::postamble {
diff --git a/Makefile b/Makefile
index e27dcbd..b7b4d1f 100644
--- a/Makefile
+++ b/Makefile
@@ -4,8 +4,8 @@ libname = liblockdev
pkgname = lockdev
objs = src/lockdev.o
-shobjs = src/lockdev.z
+lockdev = src/sample.c
VER = $(shell expr `pwd` : '.*-\([0-9.]*\)')
MVER = ${shell expr `pwd` : '.*-\([0-9]*\).[0-9]*'}
@@ -18,27 +18,30 @@ soname = ${libname}.so.${MVER}
basedir = /usr/local
srcdir=.
+sbindir = ${basedir}/sbin
libdir = ${basedir}/lib
incdir = ${basedir}/include
mandir = ${basedir}/share/man
CC = gcc
-LCFLAGS = -g -O2 -fPIC -Wall -pipe -D_REENTRANT
-CFLAGS = -g
+CFLAGS = -g -O2 -Wall -pipe
+LCFLAGS = ${CFLAGS} -fPIC -D_REENTRANT
LDLIBS = -llockdev
.PHONY: shared static perl-lib
-ALL: shared static perl-lib
+ALL: shared static lockdev perl-lib
static ${static}: ${objs}
$(AR) $(ARFLAGS) ${static} $^
-shared ${shared}: ${shobjs}
+shared ${shared}: ${objs}
${CC} ${LCFLAGS} -shared -Wl,-soname,${soname} $^ -lc -o ${shared}
-src/lockdev.z: src/lockdev.c
- ${CC} ${CFLAGS} -c -fPIC -o $@ $?
+lockdev.o: ${lockdev}
+ ${CC} ${CFLAGS} -I./src -o $@ -c $^
+lockdev: lockdev.o ${static}
+ ${CC} -o $@ $^
perl-lib: static
cd LockDev && perl Makefile.PL INSTALLDIRS=vendor
@@ -54,6 +57,7 @@ install_dev: ${static} src/lockdev.h
install -m755 -d ${incdir}
install -m644 src/lockdev.h ${incdir}
install -m644 src/ttylock.h ${incdir}
+ install -m644 src/baudboy.h ${incdir}
install_debug: ${static} ${shared}
install -m755 -d ${libdir}/debug
@@ -71,7 +75,9 @@ install_doc: docs/lockdev.3
install_run: ${shared}
install -m755 -d ${libdir}
- install -m644 ${shared} ${libdir}
+ install -m755 ${shared} ${libdir}
+ install -m755 -d ${sbindir}
+ install -m755 lockdev ${sbindir}
.PHONY: clean distclean perl-clean mostyclean
perl-clean: clean
diff --git a/src/baudboy.h b/src/baudboy.h
new file mode 100644
index 0000000..55fcf9d
--- /dev/null
+++ b/src/baudboy.h
@@ -0,0 +1,137 @@
+/* Copyright (C) 2001 Red Hat, Inc.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License
+ as published by the Free Software Foundation; either version 2 of
+ the License, or (at your option) any later version.
+
+ It is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+ Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this software; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+
+#ifndef _BAUDBOY_H_
+#define _BAUDBOY_H_
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define LOCKDEV_PATH "/usr/sbin/lockdev"
+
+static inline int _doit(const char * argv[])
+{
+ pid_t child;
+ int status;
+ void (*osig) (int) = signal(SIGCHLD, SIG_DFL);
+ int rc;
+
+ if (!(child = fork())) {
+ int fd;
+ /* these have to be open to something */
+ if ((fd = open("/dev/null", 2)) < 0)
+ exit(-1);
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ close(fd);
+ /* Swap egid and gid for lockdev's access(2) device check. */
+ setregid(getegid(), getgid());
+ execv(argv[0], (char *const *)argv);
+ exit(-1);
+ }
+
+ rc = (int) waitpid(child, &status, 0);
+ signal(SIGCHLD, osig);
+ if (rc == child && WIFEXITED(status)) {
+ /*
+ * Exit dev_lock dev_unlock dev_testlock
+ * 0 OK OK not locked
+ * 1 locked other locked other locked
+ * 2 EACCES
+ * 3 EROFS
+ * 4 EFAULT
+ * 5 EINVAL
+ * 6 ENAMETOOLONG
+ * 7 ENOENT
+ * 8 ENOTDIR
+ * 9 ENOMEM
+ * 10 ELOOP
+ * 11 EIO
+ * 255 error error error
+ */
+ rc = WEXITSTATUS(status);
+ switch(rc) {
+ case 0: rc = 0; break;
+ default:
+ case 1: rc = -EPERM; break;
+ case 2: rc = -EACCES; break;
+ case 3: rc = -EROFS; break;
+ case 4: rc = -EFAULT; break;
+ case 5: rc = -EINVAL; break;
+ case 6: rc = -ENAMETOOLONG; break;
+ case 7: rc = -ENOENT; break;
+ case 8: rc = -ENOTDIR; break;
+ case 9: rc = -ENOMEM; break;
+ case 10: rc = -ELOOP; break;
+ case 11: rc = -EIO; break;
+ }
+ } else if (rc == -1)
+ rc = -errno;
+ else
+ rc = -ECHILD;
+
+ return rc;
+
+}
+
+static inline int ttylock(const char * devname)
+{
+ const char * argv[] = { LOCKDEV_PATH, "-l", NULL, NULL};
+ argv[2] = devname;
+ return _doit(argv);
+}
+
+static inline int ttyunlock(const char * devname)
+{
+ const char * argv[] = { LOCKDEV_PATH, "-u", NULL, NULL};
+ argv[2] = devname;
+ return _doit(argv);
+}
+
+static inline int ttylocked(const char * devname)
+{
+ const char * argv[] = { LOCKDEV_PATH, NULL, NULL};
+ argv[1] = devname;
+ return _doit(argv);
+}
+
+static inline int ttywait(const char * devname)
+{
+ int rc;
+ while((rc = ttylocked(devname)) == 0)
+ sleep(1);
+ return rc;
+}
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif /* _BAUDBOY_H_ */
diff --git a/src/lockdev.c b/src/lockdev.c
index 8f28002..bcc565f 100644
--- a/src/lockdev.c
+++ b/src/lockdev.c
@@ -177,6 +177,19 @@ liblockdev_reset_debug (void)
liblockdev_debug = 0;
}
+static pid_t dev_pid = 0;
+
+pid_t dev_getpid(void)
+{
+ return (dev_pid ? dev_pid : getpid());
+}
+
+pid_t dev_setpid(pid_t newpid)
+{
+ pid_t oldpid = dev_pid;
+ dev_pid = newpid;
+ return oldpid;
+}
/*
* for internal use *
@@ -423,7 +436,7 @@ _dl_check_lock(const char *lockname)
* maybe also this sprintf should be added to the
* conditional part, as the others
*/
- sprintf( tpname, "%s/.%d", LOCK_PATH, (int)getpid());
+ sprintf( tpname, "%s/.%d", LOCK_PATH, (int)dev_getpid());
unlink( tpname); /* in case there was */
rename( lockname, tpname);
if ( ! (fd=fopen( tpname, "r")) ) {
@@ -520,7 +533,7 @@ dev_testlock(const char *devname)
* and minor numbers
*/
if ( stat( device, &statbuf) == -1 ) {
- close_n_return( -1);
+ close_n_return(-errno);
}
/* first check for the FSSTND-1.2 lock, get the pid of the
@@ -585,7 +598,7 @@ dev_lock (const char *devname)
#endif /* DEBUG */
_debug( 3, "dev_lock(%s)\n", devname);
if (oldmask == -1 )
- oldmask = umask( 0); /* give full permissions to files created */
+ oldmask = umask( 002); /* apply o-w to files created */
if ( ! (p=_dl_check_devname( devname)) )
close_n_return( -1);
strcpy( device, DEV_PATH);
@@ -596,11 +609,14 @@ dev_lock (const char *devname)
* and minor numbers
*/
if ( stat( device, &statbuf) == -1 ) {
- close_n_return( -1);
+ close_n_return(-errno);
+ }
+ if ( access( device, W_OK ) == -1 ) {
+ close_n_return(-errno);
}
/* now get our own pid */
- our_pid = getpid();
+ our_pid = dev_getpid();
_debug( 2, "dev_lock() our own pid = %d\n", (int)our_pid);
/* We will use this algorithm:
@@ -641,8 +657,9 @@ dev_lock (const char *devname)
_dl_filename_1( lock1, &statbuf);
while ( ! (pid=_dl_check_lock( lock1)) ) {
if (( link( lock0, lock1) == -1 ) && ( errno != EEXIST )) {
+ int rc = -errno;
unlink( lock0);
- close_n_return( -1);
+ close_n_return(rc);
}
}
if ( pid != our_pid ) {
@@ -659,9 +676,10 @@ dev_lock (const char *devname)
/* lockfile of type /var/lock/LCK..ttyS2 */
while ( ! (pid=_dl_check_lock( lock2)) ) {
if (( link( lock0, lock2) == -1 ) && ( errno != EEXIST )) {
+ int rc = -errno;
unlink( lock0);
unlink( lock1);
- close_n_return( -1);
+ close_n_return(rc);
}
}
if ( pid != our_pid ) {
@@ -740,7 +758,7 @@ dev_relock (const char *devname,
#endif /* DEBUG */
_debug( 3, "dev_relock(%s, %d)\n", devname, (int)old_pid);
if (oldmask == -1 )
- oldmask = umask( 0); /* give full permissions to files created */
+ oldmask = umask( 002); /* apply o-w to files created */
if ( ! (p=_dl_check_devname( devname)) )
close_n_return( -1);
strcpy( device, DEV_PATH);
@@ -751,11 +769,14 @@ dev_relock (const char *devname,
* and minor numbers
*/
if ( stat( device, &statbuf) == -1 ) {
- close_n_return( -1);
+ close_n_return(-errno);
+ }
+ if ( access( device, W_OK ) == -1 ) {
+ close_n_return(-errno);
}
/* now get our own pid */
- our_pid = getpid();
+ our_pid = dev_getpid();
_debug( 2, "dev_relock() our own pid = %d\n", (int)our_pid);
/* first check for the FSSTND-1.2 lock, get the pid of the
@@ -825,7 +846,7 @@ dev_unlock (const char *devname,
#endif /* DEBUG */
_debug( 3, "dev_unlock(%s, %d)\n", devname, (int)pid);
if (oldmask == -1 )
- oldmask = umask( 0); /* give full permissions to files created */
+ oldmask = umask( 002); /* apply o-w to files created */
if ( ! (p=_dl_check_devname( devname)) )
close_n_return( -1);
strcpy( device, DEV_PATH);
@@ -836,7 +857,10 @@ dev_unlock (const char *devname,
* and minor numbers
*/
if ( stat( device, &statbuf) == -1 ) {
- close_n_return( -1);
+ close_n_return(-errno);
+ }
+ if ( access( device, W_OK ) == -1 ) {
+ close_n_return(-errno);
}
/* first remove the FSSTND-1.2 lock, get the pid of the
diff --git a/src/lockdev.h b/src/lockdev.h
index 8830b73..c20faad 100644
--- a/src/lockdev.h
+++ b/src/lockdev.h
@@ -43,12 +43,16 @@ extern "C" {
#endif
#include <sys/types.h>
+#include <errno.h>
/* API of the library */
void liblockdev_incr_debug (void);
void liblockdev_reset_debug (void);
+pid_t dev_getpid (void);
+pid_t dev_setpid (pid_t pid);
+
pid_t dev_testlock (const char *devname);
pid_t dev_lock (const char *devname);
diff --git a/src/sample.c b/src/sample.c
index f0708b6..a02dace 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -5,8 +5,8 @@
void
usage (void)
{
- fprintf( stderr, "Usage: sample [-lurd] <device>\n" );
- exit( -1 );
+ fprintf(stderr, "Usage: %s [-lud] <device>\n", "lockdev");
+ exit(-1);
}
@@ -15,7 +15,7 @@ main (int argc,
char *argv[])
{
int i, chld;
- char *p, *dev, ch;
+ char *p = NULL, *dev = NULL, ch;
ch = '\0';
for( i = argc - 1; i > 0; i-- ) {
@@ -23,8 +23,7 @@ main (int argc,
if( *p == '-' ) {
switch( *++p ) {
case 'l':
- case 'u':
- case 'r': ch = *p; break;
+ case 'u': ch = *p; break;
case 'd':
liblockdev_incr_debug();
break;
@@ -33,31 +32,52 @@ main (int argc,
}
else dev = p;
}
- fprintf( stderr, "option %c, device %s\n", ch, dev );
i = 0;
+ (void) dev_setpid(getppid());
switch( ch ) {
case 'l':
i = dev_lock( dev);
break;
case 'u':
- i = dev_unlock( dev, 0);
- break;
- case 'r':
- dev_lock( dev);
- if(( chld = fork()) == 0 ) {
- sleep(5);
- }
- else {
- sleep( 1);
- if (( i = dev_relock( dev, chld)) < 0 ) {
- fprintf( stderr, "Relock failed in parent.\n" );
- }
- }
+ i = dev_unlock(dev, 0);
break;
default:
- i = dev_testlock( dev);
+ if (dev)
+ i = dev_testlock(dev);
break;
}
- exit( i);
-}
+ /*
+ * Exit dev_lock dev_unlock dev_testlock
+ * 0 OK OK not locked
+ * 1 locked other locked other locked
+ * 2 EACCES
+ * 3 EROFS
+ * 4 EFAULT
+ * 5 EINVAL
+ * 6 ENAMETOOLONG
+ * 7 ENOENT
+ * 8 ENOTDIR
+ * 9 ENOMEM
+ * 10 ELOOP
+ * 11 EIO
+ * 255 error error error
+ */
+ switch (i) {
+ case -EACCES: i = 2; break;
+ case -EROFS: i = 3; break;
+ case -EFAULT: i = 4; break;
+ case -EINVAL: i = 5; break;
+ case -ENAMETOOLONG: i = 6; break;
+ case -ENOENT: i = 7; break;
+ case -ENOTDIR: i = 8; break;
+ case -ENOMEM: i = 9; break;
+ case -ELOOP: i = 10; break;
+ case -EIO: i = 11; break;
+ default:
+ if (i < 0) i = 255;
+ else if (i > 0) i = 1;
+ break;
+ }
+ exit(i);
+}
--
1.6.4.2
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