Read spl_hostid module parameter before gethostid()

If spl_hostid is set via module parameter, it's likely different from gethostid(). Therefore, the userspace tool should read it first before falling back to gethostid(). Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes openzfs#3034
ka7 · Feb 5, 2015 · 53698a4 · 53698a4
1 parent aa2ef41
commit 53698a4
Show file tree

Hide file tree

Showing 4 changed files with 28 additions and 3 deletions.
diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c
@@ -1917,7 +1917,7 @@ do_import(nvlist_t *config, const char *newname, const char *mntopts,
 	} else if (state != POOL_STATE_EXPORTED &&
 	    !(flags & ZFS_IMPORT_ANY_HOST)) {
 		uint64_t hostid = 0;
-		unsigned long system_hostid = gethostid() & 0xffffffff;
+		unsigned long system_hostid = get_system_hostid();
 
 		(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_HOSTID,
 		    &hostid);

diff --git a/include/libzfs.h b/include/libzfs.h
@@ -350,6 +350,7 @@ typedef enum {
 	ZPOOL_STATUS_OK
 } zpool_status_t;
 
+extern unsigned long get_system_hostid(void);
 extern zpool_status_t zpool_get_status(zpool_handle_t *, char **,
     zpool_errata_t *);
 extern zpool_status_t zpool_import_status(nvlist_t *, char **,

diff --git a/lib/libzfs/libzfs_status.c b/lib/libzfs/libzfs_status.c
@@ -195,7 +195,7 @@ check_status(nvlist_t *config, boolean_t isimport, zpool_errata_t *erratap)
 	uint64_t suspended;
 	uint64_t hostid = 0;
 	uint64_t errata = 0;
-	unsigned long system_hostid = gethostid() & 0xffffffff;
+	unsigned long system_hostid = get_system_hostid();
 
 	verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
 	    &version) == 0);

diff --git a/lib/libzpool/kernel.c b/lib/libzpool/kernel.c
@@ -1107,6 +1107,30 @@ umem_out_of_memory(void)
 	return (0);
 }
 
+static unsigned long
+get_spl_hostid(void)
+{
+	FILE *f;
+	unsigned long hostid;
+
+	f = fopen("/sys/module/spl/parameters/spl_hostid", "r");
+	if (!f)
+		return (0);
+	if (fscanf(f, "%lu", &hostid) != 1)
+		hostid = 0;
+	fclose(f);
+	return (hostid & 0xffffffff);
+}
+
+unsigned long
+get_system_hostid(void)
+{
+	unsigned long system_hostid = get_spl_hostid();
+	if (system_hostid == 0)
+		system_hostid = gethostid() & 0xffffffff;
+	return (system_hostid);
+}
+
 void
 kernel_init(int mode)
 {
@@ -1120,7 +1144,7 @@ kernel_init(int mode)
 	    (double)physmem * sysconf(_SC_PAGE_SIZE) / (1ULL << 30));
 
 	(void) snprintf(hw_serial, sizeof (hw_serial), "%ld",
-	    (mode & FWRITE) ? gethostid() : 0);
+	    (mode & FWRITE) ? get_system_hostid() : 0);
 
 	VERIFY((random_fd = open("/dev/random", O_RDONLY)) != -1);
 	VERIFY((urandom_fd = open("/dev/urandom", O_RDONLY)) != -1);