Print mount/umount errors

Because we are dependent of the system mount/umount utilities to
ensure correct mtab locking, we should not suppress their error
output.  During a successful mount/umount they will be silent,
but during a failure the error message they print is the only sure
way to know why a mount failed.  This is because the (u)mount(8)
return code does not contain the result of the system call issued.
The only way to clearly idenify why thing failed is to rely on
the error message printed by the tool.

Longer term once libmount is available we can issue the mount/umount
system calls within the tool and still be ensured correct mtab locking.

Closed #107

diff --git a/include/libzfs.h b/include/libzfs.h
index 082b690e92492639c1df3546802131f678a23faa..e0c6950432820ae11d07956d856221805fcc64f7 100644 (file)
--- a/include/libzfs.h
+++ b/include/libzfs.h
@@ -675,7 +675,10 @@ extern int zfs_nicestrtonum(libzfs_handle_t *, const char *, uint64_t *);
 /*
  * Utility functions to run an external process.
  */
-int libzfs_run_process(const char *, char **);
+#define        STDOUT_VERBOSE  0x01
+#define        STDERR_VERBOSE  0x02
+
+int libzfs_run_process(const char *, char **, int flags);
 int libzfs_load_module(const char *);
 
 /*

diff --git a/lib/libzfs/libzfs_mount.c b/lib/libzfs/libzfs_mount.c
index a1faf49d1ac75ac22c9a7510d1a1f3114713c452..1dc58f924a3eab48e9d81a249322da1f754c8a03 100644 (file)
--- a/lib/libzfs/libzfs_mount.c
+++ b/lib/libzfs/libzfs_mount.c
@@ -269,7 +269,7 @@ do_mount(const char *src, const char *mntpt, char *opts)
        int rc;
 
        /* Return only the most critical mount error */
-       rc = libzfs_run_process(argv[0], argv);
+       rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
        if (rc) {
                if (rc & MOUNT_FILEIO)
                        return EIO;
@@ -310,7 +310,7 @@ do_unmount(const char *mntpt, int flags)
        }
 
        argv[count] = (char *)mntpt;
-       rc = libzfs_run_process(argv[0], argv);
+       rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
 
        return (rc ? EINVAL : 0);
 }
@@ -414,8 +414,10 @@ zfs_mount(zfs_handle_t *zhp, const char *options, int flags)
 static int
 unmount_one(libzfs_handle_t *hdl, const char *mountpoint, int flags)
 {
-       if (do_unmount(mountpoint, flags) != 0) {
-               zfs_error_aux(hdl, strerror(errno));
+       int error;
+
+       error = do_unmount(mountpoint, flags);
+       if (error != 0) {
                return (zfs_error_fmt(hdl, EZFS_UMOUNTFAILED,
                    dgettext(TEXT_DOMAIN, "cannot unmount '%s'"),
                    mountpoint));

diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index 163cd1671fa9f0b17a528d9a29ca5b7062026b03..da1b9bcddf8214464cfe2fde76ad27da061dfe26 100644 (file)
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -632,15 +632,19 @@ libzfs_module_loaded(const char *module)
 }
 
 int
-libzfs_run_process(const char *path, char *argv[])
+libzfs_run_process(const char *path, char *argv[], int flags)
 {
        pid_t pid;
        int rc;
 
        pid = vfork();
        if (pid == 0) {
-               close(1);
-               close(2);
+               if (!(flags & STDOUT_VERBOSE))
+                       close(STDOUT_FILENO);
+
+               if (!(flags & STDERR_VERBOSE))
+                       close(STDERR_FILENO);
+
                (void) execvp(path, argv);
                _exit(-1);
        } else if (pid > 0) {
@@ -665,7 +669,7 @@ libzfs_load_module(const char *module)
        if (libzfs_module_loaded(module))
                return 0;
 
-       return libzfs_run_process("/sbin/modprobe", argv);
+       return libzfs_run_process("/sbin/modprobe", argv, 0);
 }
 
 libzfs_handle_t *