busybox 1.21.0: update mdev patch
authorGustavo Zacarias <gustavo@zacarias.com.ar>
Tue, 23 Apr 2013 04:13:18 +0000 (04:13 +0000)
committerPeter Korsgaard <jacmet@sunsite.dk>
Tue, 23 Apr 2013 18:39:23 +0000 (20:39 +0200)
Update the mdev patch so that subsystem matching is reintroduced.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
package/busybox/1.21.0/busybox-1.21.0-mdev.patch

index cb873fafc19d8f3b031b95206ba1879ed78ee1b3..8f6c8d80e23277ef89a2790ad11a7f05f50a3652 100644 (file)
 --- busybox-1.21.0/util-linux/mdev.c
 +++ busybox-1.21.0-mdev/util-linux/mdev.c
-@@ -661,6 +661,8 @@ static void make_device(char *device_nam
+@@ -80,7 +80,7 @@
+ //usage:      IF_FEATURE_MDEV_CONF(
+ //usage:       "\n"
+ //usage:       "It uses /etc/mdev.conf with lines\n"
+-//usage:       "      [-]DEVNAME UID:GID PERM"
++//usage:       "      [-][ENV=regex;]...DEVNAME UID:GID PERM"
+ //usage:                      IF_FEATURE_MDEV_RENAME(" [>|=PATH]|[!]")
+ //usage:                      IF_FEATURE_MDEV_EXEC(" [@|$|*PROG]")
+ //usage:       "\n"
+@@ -230,9 +230,34 @@
+  * SUBSYSTEM=block
+  */
+-static const char keywords[] ALIGN1 = "add\0remove\0change\0";
++#define DEBUG_LVL 2
++
++#if DEBUG_LVL >= 1
++# define dbg1(...) do { if (G.verbose) bb_error_msg(__VA_ARGS__); } while(0)
++#else
++# define dbg1(...) ((void)0)
++#endif
++#if DEBUG_LVL >= 2
++# define dbg2(...) do { if (G.verbose >= 2) bb_error_msg(__VA_ARGS__); } while(0)
++#else
++# define dbg2(...) ((void)0)
++#endif
++#if DEBUG_LVL >= 3
++# define dbg3(...) do { if (G.verbose >= 3) bb_error_msg(__VA_ARGS__); } while(0)
++#else
++# define dbg3(...) ((void)0)
++#endif
++
++
++static const char keywords[] ALIGN1 = "add\0remove\0"; // "change\0"
+ enum { OP_add, OP_remove };
++struct envmatch {
++      struct envmatch *next;
++      char *envname;
++      regex_t match;
++};
++
+ struct rule {
+       bool keep_matching;
+       bool regex_compiled;
+@@ -243,12 +268,14 @@ struct rule {
+       char *ren_mov;
+       IF_FEATURE_MDEV_EXEC(char *r_cmd;)
+       regex_t match;
++      struct envmatch *envmatch;
+ };
+ struct globals {
+       int root_major, root_minor;
+       smallint verbose;
+       char *subsystem;
++      char *subsys_env; /* for putenv("SUBSYSTEM=subsystem") */
+ #if ENABLE_FEATURE_MDEV_CONF
+       const char *filename;
+       parser_t *parser;
+@@ -256,6 +283,7 @@ struct globals {
+       unsigned rule_idx;
+ #endif
+       struct rule cur_rule;
++      char timestr[sizeof("60.123456")];
+ } FIX_ALIASING;
+ #define G (*(struct globals*)&bb_common_bufsiz1)
+ #define INIT_G() do { \
+@@ -270,13 +298,6 @@ struct globals {
+ /* We use additional 64+ bytes in make_device() */
+ #define SCRATCH_SIZE 80
+-#if 0
+-# define dbg(...) bb_error_msg(__VA_ARGS__)
+-#else
+-# define dbg(...) ((void)0)
+-#endif
+-
+-
+ #if ENABLE_FEATURE_MDEV_CONF
+ static void make_default_cur_rule(void)
+@@ -288,14 +309,65 @@ static void make_default_cur_rule(void)
+ static void clean_up_cur_rule(void)
+ {
++      struct envmatch *e;
++
+       free(G.cur_rule.envvar);
++      free(G.cur_rule.ren_mov);
+       if (G.cur_rule.regex_compiled)
+               regfree(&G.cur_rule.match);
+-      free(G.cur_rule.ren_mov);
+       IF_FEATURE_MDEV_EXEC(free(G.cur_rule.r_cmd);)
++      e = G.cur_rule.envmatch;
++      while (e) {
++              free(e->envname);
++              regfree(&e->match);
++              e = e->next;
++      }
+       make_default_cur_rule();
+ }
++/* In later versions, endofname is in libbb */
++#define endofname mdev_endofname
++static
++const char* FAST_FUNC
++endofname(const char *name)
++{
++#define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
++#define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))
++      if (!is_name(*name))
++              return name;
++      while (*++name) {
++              if (!is_in_name(*name))
++                      break;
++      }
++      return name;
++}
++
++static char *parse_envmatch_pfx(char *val)
++{
++      struct envmatch **nextp = &G.cur_rule.envmatch;
++
++      for (;;) {
++              struct envmatch *e;
++              char *semicolon;
++              char *eq = strchr(val, '=');
++              if (!eq /* || eq == val? */)
++                      return val;
++              if (endofname(val) != eq)
++                      return val;
++              semicolon = strchr(eq, ';');
++              if (!semicolon)
++                      return val;
++              /* ENVVAR=regex;... */
++              *nextp = e = xzalloc(sizeof(*e));
++              nextp = &e->next;
++              e->envname = xstrndup(val, eq - val);
++              *semicolon = '\0';
++              xregcomp(&e->match, eq + 1, REG_EXTENDED);
++              *semicolon = ';';
++              val = semicolon + 1;
++      }
++}
++
+ static void parse_next_rule(void)
+ {
+       /* Note: on entry, G.cur_rule is set to default */
+@@ -308,12 +380,13 @@ static void parse_next_rule(void)
+                       break;
+               /* Fields: [-]regex uid:gid mode [alias] [cmd] */
+-              dbg("token1:'%s'", tokens[1]);
++              dbg3("token1:'%s'", tokens[1]);
+               /* 1st field */
+               val = tokens[0];
+               G.cur_rule.keep_matching = ('-' == val[0]);
+               val += G.cur_rule.keep_matching; /* swallow leading dash */
++              val = parse_envmatch_pfx(val);
+               if (val[0] == '@') {
+                       /* @major,minor[-minor2] */
+                       /* (useful when name is ambiguous:
+@@ -328,8 +401,10 @@ static void parse_next_rule(void)
+                       if (sc == 2)
+                               G.cur_rule.min1 = G.cur_rule.min0;
+               } else {
++                      char *eq = strchr(val, '=');
+                       if (val[0] == '$') {
+-                              char *eq = strchr(++val, '=');
++                              /* $ENVVAR=regex ... */
++                              val++;
+                               if (!eq) {
+                                       bb_error_msg("bad $envvar=regex on line %d", G.parser->lineno);
+                                       goto next_rule;
+@@ -373,7 +448,7 @@ static void parse_next_rule(void)
+               clean_up_cur_rule();
+       } /* while (config_read) */
+-      dbg("config_close(G.parser)");
++      dbg3("config_close(G.parser)");
+       config_close(G.parser);
+       G.parser = NULL;
+@@ -390,7 +465,7 @@ static const struct rule *next_rule(void
+       /* Open conf file if we didn't do it yet */
+       if (!G.parser && G.filename) {
+-              dbg("config_open('%s')", G.filename);
++              dbg3("config_open('%s')", G.filename);
+               G.parser = config_open2(G.filename, fopen_for_read);
+               G.filename = NULL;
+       }
+@@ -399,7 +474,7 @@ static const struct rule *next_rule(void
+               /* mdev -s */
+               /* Do we have rule parsed already? */
+               if (G.rule_vec[G.rule_idx]) {
+-                      dbg("< G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
++                      dbg3("< G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
+                       return G.rule_vec[G.rule_idx++];
+               }
+               make_default_cur_rule();
+@@ -416,13 +491,28 @@ static const struct rule *next_rule(void
+                       rule = memcpy(xmalloc(sizeof(G.cur_rule)), &G.cur_rule, sizeof(G.cur_rule));
+                       G.rule_vec = xrealloc_vector(G.rule_vec, 4, G.rule_idx);
+                       G.rule_vec[G.rule_idx++] = rule;
+-                      dbg("> G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
++                      dbg3("> G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
+               }
+       }
+       return rule;
+ }
++static int env_matches(struct envmatch *e)
++{
++      while (e) {
++              int r;
++              char *val = getenv(e->envname);
++              if (!val)
++                      return 0;
++              r = regexec(&e->match, val, /*size*/ 0, /*range[]*/ NULL, /*eflags*/ 0);
++              if (r != 0) /* no match */
++                      return 0;
++              e = e->next;
++      }
++      return 1;
++}
++
+ #else
+ # define next_rule() (&G.cur_rule)
+@@ -479,9 +569,6 @@ static void make_device(char *device_nam
+ {
+       int major, minor, type, len;
+-      if (G.verbose)
+-              bb_error_msg("device: %s, %s", device_name, path);
+-
+       /* Try to read major/minor string.  Note that the kernel puts \n after
+        * the data, so we don't need to worry about null terminating the string
+        * because sscanf() will stop at the first nondigit, which \n is.
+@@ -500,8 +587,7 @@ static void make_device(char *device_nam
+                       /* no "dev" file, but we can still run scripts
+                        * based on device name */
+               } else if (sscanf(++dev_maj_min, "%u:%u", &major, &minor) == 2) {
+-                      if (G.verbose)
+-                              bb_error_msg("maj,min: %u,%u", major, minor);
++                      dbg1("dev %u,%u", major, minor);
+               } else {
+                       major = -1;
+               }
+@@ -511,7 +597,8 @@ static void make_device(char *device_nam
+       /* Determine device name, type, major and minor */
+       if (!device_name)
+               device_name = (char*) bb_basename(path);
+-      /* http://kernel.org/doc/pending/hotplug.txt says that only
++      /*
++       * http://kernel.org/doc/pending/hotplug.txt says that only
+        * "/sys/block/..." is for block devices. "/sys/bus" etc is not.
+        * But since 2.6.25 block devices are also in /sys/class/block.
+        * We use strstr("/block/") to forestall future surprises.
+@@ -537,6 +624,8 @@ static void make_device(char *device_nam
+               rule = next_rule();
+ #if ENABLE_FEATURE_MDEV_CONF
++              if (!env_matches(rule->envmatch))
++                      continue;
+               if (rule->maj >= 0) {  /* @maj,min rule */
+                       if (major != rule->maj)
+                               continue;
+@@ -547,7 +636,7 @@ static void make_device(char *device_nam
+               }
+               if (rule->envvar) { /* $envvar=regex rule */
+                       str_to_match = getenv(rule->envvar);
+-                      dbg("getenv('%s'):'%s'", rule->envvar, str_to_match);
++                      dbg3("getenv('%s'):'%s'", rule->envvar, str_to_match);
+                       if (!str_to_match)
+                               continue;
+               }
+@@ -555,7 +644,7 @@ static void make_device(char *device_nam
+               if (rule->regex_compiled) {
+                       int regex_match = regexec(&rule->match, str_to_match, ARRAY_SIZE(off), off, 0);
+-                      dbg("regex_match for '%s':%d", str_to_match, regex_match);
++                      dbg3("regex_match for '%s':%d", str_to_match, regex_match);
+                       //bb_error_msg("matches:");
+                       //for (int i = 0; i < ARRAY_SIZE(off); i++) {
+                       //      if (off[i].rm_so < 0) continue;
+@@ -574,9 +663,8 @@ static void make_device(char *device_nam
+               }
+               /* else: it's final implicit "match-all" rule */
+  rule_matches:
++              dbg2("rule matched, line %d", G.parser ? G.parser->lineno : -1);
+ #endif
+-              dbg("rule matched");
+-
+               /* Build alias name */
+               alias = NULL;
+               if (ENABLE_FEATURE_MDEV_RENAME && rule->ren_mov) {
+@@ -619,34 +707,30 @@ static void make_device(char *device_nam
+                               }
+                       }
+               }
+-              dbg("alias:'%s'", alias);
++              dbg3("alias:'%s'", alias);
+               command = NULL;
+               IF_FEATURE_MDEV_EXEC(command = rule->r_cmd;)
+               if (command) {
+-                      const char *s = "$@*";
+-                      const char *s2 = strchr(s, command[0]);
+-
+                       /* Are we running this command now?
+-                       * Run $cmd on delete, @cmd on create, *cmd on both
++                       * Run @cmd on create, $cmd on delete, *cmd on any
+                        */
+-                      if (s2 - s != (operation == OP_remove) || *s2 == '*') {
+-                              /* We are here if: '*',
+-                               * or: '@' and delete = 0,
+-                               * or: '$' and delete = 1
+-                               */
++                      if ((command[0] == '@' && operation == OP_add)
++                       || (command[0] == '$' && operation == OP_remove)
++                       || (command[0] == '*')
++                      ) {
+                               command++;
+                       } else {
+                               command = NULL;
+                       }
+               }
+-              dbg("command:'%s'", command);
++              dbg3("command:'%s'", command);
+               /* "Execute" the line we found */
+               node_name = device_name;
+               if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+                       node_name = alias = build_alias(alias, device_name);
+-                      dbg("alias2:'%s'", alias);
++                      dbg3("alias2:'%s'", alias);
+               }
+               if (operation == OP_add && major >= 0) {
+@@ -656,8 +740,17 @@ static void make_device(char *device_nam
+                               mkdir_recursive(node_name);
+                               *slash = '/';
+                       }
+-                      if (G.verbose)
+-                              bb_error_msg("mknod: %s (%d,%d) %o", node_name, major, minor, rule->mode | type);
++                      if (ENABLE_FEATURE_MDEV_CONF) {
++                              dbg1("mknod %s (%d,%d) %o"
++                                      " %u:%u",
++                                      node_name, major, minor, rule->mode | type,
++                                      rule->ugid.uid, rule->ugid.gid
++                              );
++                      } else {
++                              dbg1("mknod %s (%d,%d) %o",
++                                      node_name, major, minor, rule->mode | type
++                              );
++                      }
                        if (mknod(node_name, rule->mode | type, makedev(major, minor)) && errno != EEXIST)
                                bb_perror_msg("can't create '%s'", node_name);
                        if (ENABLE_FEATURE_MDEV_CONF) {
-+                              if (G.verbose)
-+                                      bb_error_msg("chmod: %o chown: %u:%u", rule->mode, rule->ugid.uid, rule->ugid.gid);
-                               chmod(node_name, rule->mode);
-                               chown(node_name, rule->ugid.uid, rule->ugid.gid);
+@@ -671,8 +764,7 @@ static void make_device(char *device_nam
+ //TODO: on devtmpfs, device_name already exists and symlink() fails.
+ //End result is that instead of symlink, we have two nodes.
+ //What should be done?
+-                                      if (G.verbose)
+-                                              bb_error_msg("symlink: %s", device_name);
++                                      dbg1("symlink: %s", device_name);
+                                       symlink(node_name, device_name);
+                               }
+                       }
+@@ -681,27 +773,21 @@ static void make_device(char *device_nam
+               if (ENABLE_FEATURE_MDEV_EXEC && command) {
+                       /* setenv will leak memory, use putenv/unsetenv/free */
+                       char *s = xasprintf("%s=%s", "MDEV", node_name);
+-                      char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
+                       putenv(s);
+-                      putenv(s1);
+-                      if (G.verbose)
+-                              bb_error_msg("running: %s", command);
++                      dbg1("running: %s", command);
+                       if (system(command) == -1)
+                               bb_perror_msg("can't run '%s'", command);
+-                      bb_unsetenv_and_free(s1);
+                       bb_unsetenv_and_free(s);
+               }
+               if (operation == OP_remove && major >= -1) {
+                       if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+                               if (aliaslink == '>') {
+-                                      if (G.verbose)
+-                                              bb_error_msg("unlink: %s", device_name);
++                                      dbg1("unlink: %s", device_name);
+                                       unlink(device_name);
+                               }
                        }
-@@ -813,6 +815,7 @@ static void load_firmware(const char *fi
+-                      if (G.verbose)
+-                              bb_error_msg("unlink: %s", node_name);
++                      dbg1("unlink: %s", node_name);
+                       unlink(node_name);
+               }
+@@ -746,9 +832,16 @@ static int FAST_FUNC dirAction(const cha
+        * under /sys/class/ */
+       if (1 == depth) {
+               free(G.subsystem);
++              if (G.subsys_env) {
++                      bb_unsetenv_and_free(G.subsys_env);
++                      G.subsys_env = NULL;
++              }
+               G.subsystem = strrchr(fileName, '/');
+-              if (G.subsystem)
++              if (G.subsystem) {
+                       G.subsystem = xstrdup(G.subsystem + 1);
++                      G.subsys_env = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
++                      putenv(G.subsys_env);
++              }
+       }
+       return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
+@@ -813,12 +906,107 @@ static void load_firmware(const char *fi
                full_write(loading_fd, "-1", 2);
  
   out:
        if (ENABLE_FEATURE_CLEAN_UP) {
                close(firmware_fd);
                close(loading_fd);
-@@ -919,11 +922,13 @@ int mdev_main(int argc UNUSED_PARAM, cha
-               }
+       }
+ }
++static char *curtime(void)
++{
++      struct timeval tv;
++      gettimeofday(&tv, NULL);
++      sprintf(G.timestr, "%u.%06u", (unsigned)tv.tv_sec % 60, (unsigned)tv.tv_usec);
++      return G.timestr;
++}
++
++static void open_mdev_log(const char *seq, unsigned my_pid)
++{
++      int logfd = open("mdev.log", O_WRONLY | O_APPEND);
++      if (logfd >= 0) {
++              xmove_fd(logfd, STDERR_FILENO);
++              G.verbose = 2;
++              applet_name = xasprintf("%s[%s]", applet_name, seq ? seq : utoa(my_pid));
++      }
++}
++
++/* If it exists, does /dev/mdev.seq match $SEQNUM?
++ * If it does not match, earlier mdev is running
++ * in parallel, and we need to wait.
++ * Active mdev pokes us with SIGCHLD to check the new file.
++ */
++static int
++wait_for_seqfile(const char *seq)
++{
++      /* We time out after 2 sec */
++      static const struct timespec ts = { 0, 32*1000*1000 };
++      int timeout = 2000 / 32;
++      int seq_fd = -1;
++      int do_once = 1;
++      sigset_t set_CHLD;
++
++      sigemptyset(&set_CHLD);
++      sigaddset(&set_CHLD, SIGCHLD);
++      sigprocmask(SIG_BLOCK, &set_CHLD, NULL);
++
++      for (;;) {
++              int seqlen;
++              char seqbuf[sizeof(int)*3 + 2];
++
++              if (seq_fd < 0) {
++                      seq_fd = open("mdev.seq", O_RDWR);
++                      if (seq_fd < 0)
++                              break;
++              }
++              seqlen = pread(seq_fd, seqbuf, sizeof(seqbuf) - 1, 0);
++              if (seqlen < 0) {
++                      close(seq_fd);
++                      seq_fd = -1;
++                      break;
++              }
++              seqbuf[seqlen] = '\0';
++              if (seqbuf[0] == '\n') {
++                      /* seed file: write out seq ASAP */
++                      xwrite_str(seq_fd, seq);
++                      xlseek(seq_fd, 0, SEEK_SET);
++                      dbg2("first seq written");
++                      break;
++              }
++              if (strcmp(seq, seqbuf) == 0) {
++                      /* correct idx */
++                      break;
++              }
++              if (do_once) {
++                      dbg2("%s waiting for '%s'", curtime(), seqbuf);
++                      do_once = 0;
++              }
++              if (sigtimedwait(&set_CHLD, NULL, &ts) >= 0) {
++                      dbg3("woken up");
++                      continue; /* don't decrement timeout! */
++              }
++              if (--timeout == 0) {
++                      dbg1("%s waiting for '%s'", "timed out", seqbuf);
++                      break;
++              }
++      }
++      sigprocmask(SIG_UNBLOCK, &set_CHLD, NULL);
++      return seq_fd;
++}
++
++static void signal_mdevs(unsigned my_pid)
++{
++      procps_status_t* p = NULL;
++      while ((p = procps_scan(p, PSSCAN_ARGV0)) != NULL) {
++              if (p->pid != my_pid
++               && p->argv0
++               && strcmp(bb_basename(p->argv0), "mdev") == 0
++              ) {
++                      kill(p->pid, SIGCHLD);
++              }
++      }
++}
++
+ int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+ int mdev_main(int argc UNUSED_PARAM, char **argv)
+ {
+@@ -840,8 +1028,8 @@ int mdev_main(int argc UNUSED_PARAM, cha
+       xchdir("/dev");
+       if (argv[1] && strcmp(argv[1], "-s") == 0) {
+-              /* Scan:
+-               * mdev -s
++              /*
++               * Scan: mdev -s
+                */
+               struct stat st;
+@@ -853,6 +1041,8 @@ int mdev_main(int argc UNUSED_PARAM, cha
+               G.root_major = major(st.st_dev);
+               G.root_minor = minor(st.st_dev);
  
-               {
++              putenv((char*)"ACTION=add");
++
+               /* ACTION_FOLLOWLINKS is needed since in newer kernels
+                * /sys/block/loop* (for example) are symlinks to dirs,
+                * not real directories.
+@@ -878,11 +1068,13 @@ int mdev_main(int argc UNUSED_PARAM, cha
+               char *action;
+               char *env_devname;
+               char *env_devpath;
++              unsigned my_pid;
++              int seq_fd;
+               smalluint op;
+               /* Hotplug:
+                * env ACTION=... DEVPATH=... SUBSYSTEM=... [SEQNUM=...] mdev
+-               * ACTION can be "add" or "remove"
++               * ACTION can be "add", "remove", "change"
+                * DEVPATH is like "/block/sda" or "/class/input/mice"
+                */
+               action = getenv("ACTION");
+@@ -893,39 +1085,20 @@ int mdev_main(int argc UNUSED_PARAM, cha
+               if (!action || !env_devpath /*|| !G.subsystem*/)
+                       bb_show_usage();
+               fw = getenv("FIRMWARE");
+-              /* If it exists, does /dev/mdev.seq match $SEQNUM?
+-               * If it does not match, earlier mdev is running
+-               * in parallel, and we need to wait */
+               seq = getenv("SEQNUM");
+-              if (seq) {
+-                      int timeout = 2000 / 32; /* 2000 msec */
+-                      do {
+-                              int seqlen;
+-                              char seqbuf[sizeof(int)*3 + 2];
+-
+-                              seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf) - 1);
+-                              if (seqlen < 0) {
+-                                      seq = NULL;
+-                                      break;
+-                              }
+-                              seqbuf[seqlen] = '\0';
+-                              if (seqbuf[0] == '\n' /* seed file? */
+-                               || strcmp(seq, seqbuf) == 0 /* correct idx? */
+-                              ) {
+-                                      break;
+-                              }
+-                              usleep(32*1000);
+-                      } while (--timeout);
+-              }
+-              {
 -                      int logfd = open("/dev/mdev.log", O_WRONLY | O_APPEND);
-+                      int logfd = open("mdev.log", O_WRONLY | O_APPEND);
-                       if (logfd >= 0) {
-                               xmove_fd(logfd, STDERR_FILENO);
-                               G.verbose = 1;
+-                      if (logfd >= 0) {
+-                              xmove_fd(logfd, STDERR_FILENO);
+-                              G.verbose = 1;
 -                              bb_error_msg("seq: %s action: %s", seq, action);
-+                              if (seq)
-+                                      applet_name = xasprintf("%s[%s]", applet_name, seq);
-+                              bb_error_msg("action: %s", action);
+-                      }
+-              }
++              my_pid = getpid();
++              open_mdev_log(seq, my_pid);
++
++              seq_fd = seq ? wait_for_seqfile(seq) : -1;
++
++              dbg1("%s "
++                      "ACTION:%s SUBSYSTEM:%s DEVNAME:%s DEVPATH:%s"
++                      "%s%s",
++                      curtime(),
++                      action, G.subsystem, env_devname, env_devpath,
++                      fw ? " FW:" : "", fw ? fw : ""
++              );
+               snprintf(temp, PATH_MAX, "/sys%s", env_devpath);
+               if (op == OP_remove) {
+@@ -935,16 +1108,18 @@ int mdev_main(int argc UNUSED_PARAM, cha
+                       if (!fw)
+                               make_device(env_devname, temp, op);
+               }
+-              else if (op == OP_add) {
++              else {
+                       make_device(env_devname, temp, op);
+                       if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
+-                              if (fw)
++                              if (op == OP_add && fw)
+                                       load_firmware(fw, temp);
                        }
                }
  
+-              if (seq) {
+-                      xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
++              dbg1("%s exiting", curtime());
++              if (seq_fd >= 0) {
++                      xwrite_str(seq_fd, utoa(xatou(seq) + 1));
++                      signal_mdevs(my_pid);
+               }
+       }