5 files changed, 341 insertions, 114 deletions

diff --git a/Makefile b/Makefile
index c31ca899b..ca0644230 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 1
 PATCHLEVEL = 21
-SUBLEVEL = 0
+SUBLEVEL = 1
 EXTRAVERSION =
 NAME = Unnamed
 
diff --git a/archival/libarchive/decompress_unxz.c b/archival/libarchive/decompress_unxz.c
index 79b48a152..986b7b191 100644
--- a/archival/libarchive/decompress_unxz.c
+++ b/archival/libarchive/decompress_unxz.c
@@ -30,8 +30,8 @@ static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 /* We use arch-optimized unaligned accessors */
 #define get_unaligned_le32(buf) ({ uint32_t v; move_from_unaligned32(v, buf); SWAP_LE32(v); })
 #define get_unaligned_be32(buf) ({ uint32_t v; move_from_unaligned32(v, buf); SWAP_BE32(v); })
-#define put_unaligned_le32(val, buf) move_to_unaligned16(buf, SWAP_LE32(val))
-#define put_unaligned_be32(val, buf) move_to_unaligned16(buf, SWAP_BE32(val))
+#define put_unaligned_le32(val, buf) move_to_unaligned32(buf, SWAP_LE32(val))
+#define put_unaligned_be32(val, buf) move_to_unaligned32(buf, SWAP_BE32(val))
 
 #include "unxz/xz_dec_bcj.c"
 #include "unxz/xz_dec_lzma2.c"
@@ -40,6 +40,7 @@ static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 IF_DESKTOP(long long) int FAST_FUNC
 unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
 {
+        enum xz_ret xz_result;
         struct xz_buf iobuf;
         struct xz_dec *state;
         unsigned char *membuf;
@@ -63,9 +64,8 @@ unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
         /* Limit memory usage to about 64 MiB. */
         state = xz_dec_init(XZ_DYNALLOC, 64*1024*1024);
 
+        xz_result = X_OK;
         while (1) {
-                enum xz_ret r;
-
                 if (iobuf.in_pos == iobuf.in_size) {
                         int rd = safe_read(src_fd, membuf, BUFSIZ);
                         if (rd < 0) {
@@ -73,28 +73,57 @@ unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
                                 total = -1;
                                 break;
                         }
+                        if (rd == 0 && xz_result == XZ_STREAM_END)
+                                break;
                         iobuf.in_size = rd;
                         iobuf.in_pos = 0;
                 }
+                if (xz_result == XZ_STREAM_END) {
+                        /*
+                         * Try to start decoding next concatenated stream.
+                         * Stream padding must always be a multiple of four
+                         * bytes to preserve four-byte alignment. To keep the
+                         * code slightly smaller, we aren't as strict here as
+                         * the .xz spec requires. We just skip all zero-bytes
+                         * without checking the alignment and thus can accept
+                         * files that aren't valid, e.g. the XZ utils test
+                         * files bad-0pad-empty.xz and bad-0catpad-empty.xz.
+                         */
+                        do {
+                                if (membuf[iobuf.in_pos] != 0) {
+                                        xz_dec_reset(state);
+                                        goto do_run;
+                                }
+                                iobuf.in_pos++;
+                        } while (iobuf.in_pos < iobuf.in_size);
+                }
+ do_run:
 //              bb_error_msg(">in pos:%d size:%d out pos:%d size:%d",
 //                              iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size);
-                r = xz_dec_run(state, &iobuf);
+                xz_result = xz_dec_run(state, &iobuf);
 //              bb_error_msg("<in pos:%d size:%d out pos:%d size:%d r:%d",
-//                              iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size, r);
+//                              iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size, xz_result);
                 if (iobuf.out_pos) {
                         xwrite(dst_fd, iobuf.out, iobuf.out_pos);
                         IF_DESKTOP(total += iobuf.out_pos;)
                         iobuf.out_pos = 0;
                 }
-                if (r == XZ_STREAM_END) {
-                        break;
+                if (xz_result == XZ_STREAM_END) {
+                        /*
+                         * Can just "break;" here, if not for concatenated
+                         * .xz streams.
+                         * Checking for padding may require buffer
+                         * replenishment. Can't do it here.
+                         */
+                        continue;
                 }
-                if (r != XZ_OK && r != XZ_UNSUPPORTED_CHECK) {
+                if (xz_result != XZ_OK && xz_result != XZ_UNSUPPORTED_CHECK) {
                         bb_error_msg("corrupted data");
                         total = -1;
                         break;
                 }
         }
+
         xz_dec_end(state);
         free(membuf);
 
diff --git a/include/platform.h b/include/platform.h
index 128230658..f4deb30c0 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -228,7 +228,7 @@ typedef uint32_t bb__aliased_uint32_t FIX_ALIASING;
 # define move_from_unaligned32(v, u32p) (memcpy(&(v), (u32p), 4))
 # define move_to_unaligned16(u16p, v) do { \
         uint16_t __t = (v); \
-        memcpy((u16p), &__t, 4); \
+        memcpy((u16p), &__t, 2); \
 } while (0)
 # define move_to_unaligned32(u32p, v) do { \
         uint32_t __t = (v); \
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 75de14ff1..3d4e135ba 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -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 { \
@@ -267,15 +295,8 @@ struct globals {
 /* Prevent infinite loops in /sys symlinks */
 #define MAX_SYSFS_DEPTH 3
 
-/* 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
-
+/* We use additional bytes in make_device() */
+#define SCRATCH_SIZE 128
 
 #if ENABLE_FEATURE_MDEV_CONF
 
@@ -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)
@@ -468,7 +558,7 @@ static char *build_alias(char *alias, const char *device_name)
 
 /* mknod in /dev based on a path like "/sys/block/hda/hda1"
  * NB1: path parameter needs to have SCRATCH_SIZE scratch bytes
- * after NUL, but we promise to not mangle (IOW: to restore if needed)
+ * after NUL, but we promise to not mangle (IOW: to restore NUL if needed)
  * path string.
  * NB2: "mdev -s" may call us many times, do not leak memory/fds!
  *
@@ -478,9 +568,7 @@ static char *build_alias(char *alias, const char *device_name)
 static void make_device(char *device_name, char *path, int operation)
 {
         int major, minor, type, len;
-
-        if (G.verbose)
-                bb_error_msg("device: %s, %s", device_name, path);
+        char *path_end = path + strlen(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
@@ -489,29 +577,51 @@ static void make_device(char *device_name, char *path, int operation)
          */
         major = -1;
         if (operation == OP_add) {
-                char *dev_maj_min = path + strlen(path);
-
-                strcpy(dev_maj_min, "/dev");
-                len = open_read_close(path, dev_maj_min + 1, 64);
-                *dev_maj_min = '\0';
+                strcpy(path_end, "/dev");
+                len = open_read_close(path, path_end + 1, SCRATCH_SIZE - 1);
+                *path_end = '\0';
                 if (len < 1) {
                         if (!ENABLE_FEATURE_MDEV_EXEC)
                                 return;
                         /* 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);
+                } else if (sscanf(path_end + 1, "%u:%u", &major, &minor) == 2) {
+                        dbg1("dev %u,%u", major, minor);
                 } else {
                         major = -1;
                 }
         }
         /* else: for delete, -1 still deletes the node, but < -1 suppresses that */
 
-        /* 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
+        /* Determine device name */
+        if (!device_name) {
+                /*
+                 * There was no $DEVNAME envvar (for example, mdev -s never has).
+                 * But it is very useful: it contains the *path*, not only basename,
+                 * Thankfully, uevent file has it.
+                 * Example of .../sound/card0/controlC0/uevent file on Linux-3.7.7:
+                 * MAJOR=116
+                 * MINOR=7
+                 * DEVNAME=snd/controlC0
+                 */
+                strcpy(path_end, "/uevent");
+                len = open_read_close(path, path_end + 1, SCRATCH_SIZE - 1);
+                if (len < 0)
+                        len = 0;
+                *path_end = '\0';
+                path_end[1 + len] = '\0';
+                device_name = strstr(path_end + 1, "\nDEVNAME=");
+                if (device_name) {
+                        device_name += sizeof("\nDEVNAME=")-1;
+                        strchrnul(device_name, '\n')[0] = '\0';
+                } else {
+                        /* Fall back to just basename */
+                        device_name = (char*) bb_basename(path);
+                }
+        }
+        /* Determine device type */
+        /*
+         * 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 +647,8 @@ static void make_device(char *device_name, char *path, int operation)
                 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 +659,7 @@ static void make_device(char *device_name, char *path, int operation)
                 }
                 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 +667,7 @@ static void make_device(char *device_name, char *path, int operation)
 
                 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 +686,8 @@ static void make_device(char *device_name, char *path, int operation)
                 }
                 /* 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 +730,30 @@ static void make_device(char *device_name, char *path, int operation)
                                 }
                         }
                 }
-                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 +763,17 @@ static void make_device(char *device_name, char *path, int operation)
                                 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) {
@@ -671,8 +787,7 @@ static void make_device(char *device_name, char *path, int operation)
 //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 +796,21 @@ static void make_device(char *device_name, char *path, int operation)
                 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);
                                 }
                         }
-                        if (G.verbose)
-                                bb_error_msg("unlink: %s", node_name);
+                        dbg1("unlink: %s", node_name);
                         unlink(node_name);
                 }
 
@@ -746,9 +855,16 @@ static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
          * 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 +929,107 @@ static void load_firmware(const char *firmware, const char *sysfs_path)
                 full_write(loading_fd, "-1", 2);
 
  out:
+        xchdir("/dev");
         if (ENABLE_FEATURE_CLEAN_UP) {
                 close(firmware_fd);
                 close(loading_fd);
         }
 }
 
+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 +1051,8 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
         xchdir("/dev");
 
         if (argv[1] && strcmp(argv[1], "-s") == 0) {
-                /* Scan:
-                 * mdev -s
+                /*
+                 * Scan: mdev -s
                  */
                 struct stat st;
 
@@ -853,6 +1064,8 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
                 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 +1091,13 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
                 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 +1108,20 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
                 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);
-                        if (logfd >= 0) {
-                                xmove_fd(logfd, STDERR_FILENO);
-                                G.verbose = 1;
-                                bb_error_msg("seq: %s action: %s", seq, 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 +1131,18 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
                         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);
                 }
         }
 
diff --git a/util-linux/volume_id/ntfs.c b/util-linux/volume_id/ntfs.c
index 7b2612f01..0444e546b 100644
--- a/util-linux/volume_id/ntfs.c
+++ b/util-linux/volume_id/ntfs.c
@@ -150,7 +150,7 @@ int FAST_FUNC volume_id_probe_ntfs(struct volume_id *id /*,uint64_t off*/)
 
                 attr = (struct file_attribute*) &buf[attr_off];
                 attr_type = le32_to_cpu(attr->type);
-                attr_len = le16_to_cpu(attr->len);
+                attr_len = le32_to_cpu(attr->len);
                 val_off = le16_to_cpu(attr->value_offset);
                 val_len = le32_to_cpu(attr->value_len);
                 attr_off += attr_len;