Add libzfs_error_init() function

All fprintf() error messages are moved out of the libzfs_init()
library function where they never belonged in the first place.  A
libzfs_error_init() function is added to provide useful error
messages for the most common causes of failure.

Additionally, in libzfs_run_process() the 'rc' variable was renamed
to 'error' for consistency with the rest of the code base.

Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: Chris Dunlap <[email protected]>
Signed-off-by: Richard Yao <[email protected]>

1 files changed, 30 insertions, 16 deletions

diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index 9d68756be..678eeadc0 100644
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -59,6 +59,31 @@ libzfs_errno(libzfs_handle_t *hdl)
 }
 
 const char *
+libzfs_error_init(int error)
+{
+	switch (error) {
+	case ENXIO:
+		return (dgettext(TEXT_DOMAIN, "The ZFS modules are not "
+		    "loaded.\nTry running '/sbin/modprobe zfs' as root "
+		    "to load them.\n"));
+	case ENOENT:
+		return (dgettext(TEXT_DOMAIN, "The /dev/zfs device is "
+		    "missing and must be created.\nTry running 'udevadm "
+		    "trigger' as root to create it.\n"));
+	case ENOEXEC:
+		return (dgettext(TEXT_DOMAIN, "The ZFS modules cannot be "
+		    "auto-loaded.\nTry running '/sbin/modprobe zfs' as "
+		    "root to manually load them.\n"));
+	case EACCES:
+		return (dgettext(TEXT_DOMAIN, "Permission denied the "
+		    "ZFS utilities must be run as root.\n"));
+	default:
+		return (dgettext(TEXT_DOMAIN, "Failed to initialize the "
+		    "libzfs library.\n"));
+	}
+}
+
+const char *
 libzfs_error_action(libzfs_handle_t *hdl)
 {
 	return (hdl->libzfs_action);
@@ -628,7 +653,7 @@ int
 libzfs_run_process(const char *path, char *argv[], int flags)
 {
 	pid_t pid;
-	int rc, devnull_fd;
+	int error, devnull_fd;
 
 	pid = vfork();
 	if (pid == 0) {
@@ -650,9 +675,9 @@ libzfs_run_process(const char *path, char *argv[], int flags)
 	} else if (pid > 0) {
 		int status;
 
-		while ((rc = waitpid(pid, &status, 0)) == -1 &&
+		while ((error = waitpid(pid, &status, 0)) == -1 &&
 			errno == EINTR);
-		if (rc < 0 || !WIFEXITED(status))
+		if (error < 0 || !WIFEXITED(status))
 			return (-1);
 
 		return (WEXITSTATUS(status));
@@ -670,7 +695,7 @@ libzfs_run_process(const char *path, char *argv[], int flags)
  * - ZFS_MODULE_LOADING="YES|yes|ON|on" - Attempt to load modules.
  * - ZFS_MODULE_TIMEOUT="<seconds>"     - Seconds to wait for ZFS_DEV
  */
-int
+static int
 libzfs_load_module(const char *module)
 {
 	char *argv[4] = {"/sbin/modprobe", "-q", (char *)module, (char *)0};
@@ -739,9 +764,7 @@ libzfs_init(void)
 
 	error = libzfs_load_module(ZFS_DRIVER);
 	if (error) {
-		(void) fprintf(stderr, gettext("Failed to load ZFS module "
-		    "stack.\nLoad the module manually by running "
-		    "'insmod <location>/zfs.ko' as root.\n"));
+		errno = error;
 		return (NULL);
 	}
 
@@ -750,13 +773,6 @@ libzfs_init(void)
 	}
 
 	if ((hdl->libzfs_fd = open(ZFS_DEV, O_RDWR)) < 0) {
-		(void) fprintf(stderr, gettext("Unable to open %s: %s.\n"),
-		    ZFS_DEV, strerror(errno));
-		if (errno == ENOENT)
-			(void) fprintf(stderr,
-			    gettext("Verify the ZFS module stack is "
-			    "loaded by running '/sbin/modprobe zfs'.\n"));
-
 		free(hdl);
 		return (NULL);
 	}
@@ -767,8 +783,6 @@ libzfs_init(void)
 	if ((hdl->libzfs_mnttab = fopen(MNTTAB, "r")) == NULL) {
 #endif
 		(void) close(hdl->libzfs_fd);
-		(void) fprintf(stderr,
-		    gettext("mtab is not present at %s.\n"), MNTTAB);
 		free(hdl);
 		return (NULL);
 	}