Give a much bigger buffer to getmntent_r.

https://bugs.alpinelinux.org/issues/7093

diff --git a/openjdk/jdk/src/solaris/native/sun/nio/fs/LinuxNativeDispatcher.c b/openjdk/jdk/src/solaris/native/sun/nio/fs/LinuxNativeDispatcher.c
index c8500db..d0b85d6 100644
--- openjdk/jdk/src/solaris/native/sun/nio/fs/LinuxNativeDispatcher.c
+++ openjdk/jdk/src/solaris/native/sun/nio/fs/LinuxNativeDispatcher.c
@@ -33,6 +33,7 @@
 #include <dlfcn.h>
 #include <errno.h>
 #include <mntent.h>
+#include <limits.h>
 
 #include "sun_nio_fs_LinuxNativeDispatcher.h"
 
@@ -173,8 +174,8 @@ Java_sun_nio_fs_LinuxNativeDispatcher_getmntent(JNIEnv* env, jclass this,
     jlong value, jobject entry)
 {
     struct mntent ent;
-    char buf[1024];
-    int buflen = sizeof(buf);
+    char *buf = NULL;
+    const size_t buflen = PATH_MAX * 4;
     struct mntent* m;
     FILE* fp = jlong_to_ptr(value);
     jsize len;
@@ -183,10 +184,17 @@ Java_sun_nio_fs_LinuxNativeDispatcher_getmntent(JNIEnv* env, jclass this,
     char* dir;
     char* fstype;
     char* options;
+    jint res = -1;
 
-    m = getmntent_r(fp, &ent, (char*)&buf, buflen);
-    if (m == NULL)
+    buf = malloc(buflen);
+    if (buf == NULL) {
+        JNU_ThrowOutOfMemoryError(env, "native heap");
         return -1;
+    }
+    m = getmntent_r(fp, &ent, buf, buflen);
+    if (m == NULL)
+        goto out;
+
     name = m->mnt_fsname;
     dir = m->mnt_dir;
     fstype = m->mnt_type;
@@ -195,32 +203,35 @@ Java_sun_nio_fs_LinuxNativeDispatcher_getmntent(JNIEnv* env, jclass this,
     len = strlen(name);
     bytes = (*env)->NewByteArray(env, len);
     if (bytes == NULL)
-        return -1;
+        goto out;
     (*env)->SetByteArrayRegion(env, bytes, 0, len, (jbyte*)name);
     (*env)->SetObjectField(env, entry, entry_name, bytes);
 
     len = strlen(dir);
     bytes = (*env)->NewByteArray(env, len);
     if (bytes == NULL)
-        return -1;
+        goto out;
     (*env)->SetByteArrayRegion(env, bytes, 0, len, (jbyte*)dir);
     (*env)->SetObjectField(env, entry, entry_dir, bytes);
 
     len = strlen(fstype);
     bytes = (*env)->NewByteArray(env, len);
     if (bytes == NULL)
-        return -1;
+        goto out;
     (*env)->SetByteArrayRegion(env, bytes, 0, len, (jbyte*)fstype);
     (*env)->SetObjectField(env, entry, entry_fstype, bytes);
 
     len = strlen(options);
     bytes = (*env)->NewByteArray(env, len);
     if (bytes == NULL)
-        return -1;
+        goto out;
     (*env)->SetByteArrayRegion(env, bytes, 0, len, (jbyte*)options);
     (*env)->SetObjectField(env, entry, entry_options, bytes);
 
-    return 0;
+    res = 0;
+out:
+    free(buf);
+    return res;
 }
 
 JNIEXPORT void JNICALL
