Initial DDF support code.
[thirdparty/mdadm.git] / util.c
diff --git a/util.c b/util.c
index 733a466..a33486f 100644 (file)
--- a/util.c
+++ b/util.c
@@ -31,6 +31,7 @@
 #include       "md_p.h"
 #include       <sys/utsname.h>
 #include       <ctype.h>
+#include       <dirent.h>
 
 /*
  * following taken from linux/blkpg.h because they aren't
@@ -759,7 +760,7 @@ int dev_open(char *dev, int flags)
        return fd;
 }
 
-struct superswitch *superlist[] = { &super0, &super1, NULL };
+struct superswitch *superlist[] = { &super0, &super1, &super_ddf, NULL };
 
 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 struct supertype *super_by_fd(int fd)
@@ -908,6 +909,55 @@ void get_one_disk(int mdfd, mdu_array_info_t *ainf, mdu_disk_info_t *disk)
                        return;
 }
 
+int open_container(int fd)
+{
+       /* 'fd' is a block device.  Find out if it is in use
+        * by a container, and return an open fd on that container.
+        */
+       char path[256];
+       char *e;
+       DIR *dir;
+       struct dirent *de;
+       int dfd, n;
+       char buf[200];
+       int major, minor;
+       struct stat st;
+
+       if (fstat(fd, &st) != 0)
+               return -1;
+       sprintf(path, "/sys/dev/block/%d:%d/holders",
+               (int)major(st.st_rdev), (int)minor(st.st_rdev));
+       e = path + strlen(path);
+
+       dir = opendir(path);
+       if (!dir)
+               return -1;
+       while ((de = readdir(dir))) {
+               if (de->d_ino == 0)
+                       continue;
+               if (de->d_name[0] == '.')
+                       continue;
+               sprintf(e, "/%s/dev", de->d_name);
+               dfd = open(path, O_RDONLY);
+               if (dfd < 0)
+                       continue;
+               n = read(dfd, buf, sizeof(buf));
+               close(dfd);
+               if (n <= 0 || n >= sizeof(buf))
+                       continue;
+               buf[n] = 0;
+               if (sscanf(buf, "%d:%d", &major, &minor) != 2)
+                       continue;
+               sprintf(buf, "%d:%d", major, minor);
+               dfd = dev_open(buf, O_RDONLY);
+               if (dfd >= 0) {
+                       closedir(dir);
+                       return dfd;
+               }
+       }
+       return -1;
+}
+
 #ifdef __TINYC__
 /* tinyc doesn't optimize this check in ioctl.h out ... */
 unsigned int __invalid_size_argument_for_IOC = 0;