Fix bugs in the upgrade script and in the udev startup script

src/disk_tool.cpp

@@ -254,6 +254,15 @@ int main(int argc, char *argv[])
         }
         return self.exec_osd(cmd[1]);
     }
+    else if (!strcmp(cmd[0], "pre-exec"))
+    {
+        if (cmd.size() != 2)
+        {
+            fprintf(stderr, "Exactly 1 device path argument is required\n");
+            return 1;
+        }
+        return self.pre_exec_osd(cmd[1]);
+    }
     else
     {
         print_help(help_text, "vitastor-disk", cmd.size() > 1 ? cmd[1] : "", self.all);

src/disk_tool.h

@@ -126,7 +126,7 @@ void disk_tool_simple_offsets(json11::Json cfg, bool json_output);
 
 std::string realpath_str(std::string path, bool nofail = true);
 std::string read_all_fd(int fd);
-std::string read_file(std::string file);
+std::string read_file(std::string file, bool allow_enoent = false);
 int check_queue_cache(std::string dev, std::string parent_dev);
 std::string get_parent_device(std::string dev);
 bool json_is_true(const json11::Json & val);

src/disk_tool_udev.cpp

@@ -43,7 +43,7 @@ int disk_tool_t::udev_import(std::string device)
     uint64_t osd_num = sb["params"]["osd_num"].uint64_value();
     // Print variables for udev
     printf("VITASTOR_OSD_NUM=%lu\n", osd_num);
-    printf("VITASTOR_ALIAS=osd%lu%s\n", osd_num, sb["device_type"].string_value().c_str());
+    printf("VITASTOR_ALIAS=osd%lu-%s\n", osd_num, sb["device_type"].string_value().c_str());
     printf("VITASTOR_DATA_DEVICE=%s\n", udev_escape(sb["params"]["data_device"].string_value()).c_str());
     if (sb["real_meta_device"].string_value() != "" && sb["real_meta_device"] != sb["real_data_device"])
         printf("VITASTOR_META_DEVICE=%s\n", udev_escape(sb["params"]["meta_device"].string_value()).c_str());
@@ -201,9 +201,9 @@ json11::Json disk_tool_t::read_osd_superblock(std::string device, bool expect_ex
     }
     real_device = realpath_str(device);
     real_data = realpath_str(osd_params["data_device"].string_value());
-    real_meta = osd_params["meta_device"] != "" && osd_params["meta_device"] != osd_params["data_device"]
+    real_meta = osd_params["meta_device"].string_value() != "" && osd_params["meta_device"] != osd_params["data_device"]
         ? realpath_str(osd_params["meta_device"].string_value()) : "";
-    real_journal = osd_params["journal_device"] != "" && osd_params["journal_device"] != osd_params["meta_device"]
+    real_journal = osd_params["journal_device"].string_value() != "" && osd_params["journal_device"] != osd_params["meta_device"]
         ? realpath_str(osd_params["journal_device"].string_value()) : "";
     if (real_journal == real_meta)
     {
@@ -322,7 +322,7 @@ static int disable_cache(std::string dev)
         if (errno == ENOENT)
         {
             // Not a SCSI/SATA device, just check /sys/block/.../queue/write_cache
-            return check_queue_cache(dev, parent_dev);
+            return check_queue_cache(dev.substr(5), parent_dev);
         }
         else
         {
@@ -339,7 +339,7 @@ static int disable_cache(std::string dev)
         {
             // Not a SCSI/SATA device, just check /sys/block/.../queue/write_cache
             closedir(dir);
-            return check_queue_cache(dev, parent_dev);
+            return check_queue_cache(dev.substr(5), parent_dev);
         }
         scsi_disk += "/";
         scsi_disk += de->d_name;

src/disk_tool_utils.cpp

@@ -5,6 +5,7 @@
 
 #include "disk_tool.h"
 #include "rw_blocking.h"
+#include "str_util.h"
 
 std::string realpath_str(std::string path, bool nofail)
 {
@@ -36,15 +37,17 @@ std::string read_all_fd(int fd)
     return res;
 }
 
-std::string read_file(std::string file)
+std::string read_file(std::string file, bool allow_enoent)
 {
     std::string res;
     int fd = open(file.c_str(), O_RDONLY);
     if (fd < 0 || (res = read_all_fd(fd)) == "")
     {
+        int err = errno;
         if (fd >= 0)
             close(fd);
-        fprintf(stderr, "Can't read %s: %s\n", file.c_str(), strerror(errno));
+        if (!allow_enoent || err != ENOENT)
+            fprintf(stderr, "Can't read %s: %s\n", file.c_str(), strerror(err));
         return "";
     }
     close(fd);
@@ -53,12 +56,12 @@ std::string read_file(std::string file)
 
 int check_queue_cache(std::string dev, std::string parent_dev)
 {
-    auto r = read_file("/sys/block/"+dev+"/queue/write_cache");
+    auto r = read_file("/sys/block/"+dev+"/queue/write_cache", true);
     if (r == "")
         r = read_file("/sys/block/"+parent_dev+"/queue/write_cache");
     if (r == "")
         return 1;
-    return r == "write through" ? 0 : -1;
+    return trim(r) == "write through" ? 0 : -1;
 }
 
 std::string get_parent_device(std::string dev)