Manage/external: for external metadata, add_to_super needs lock on container.

add_to_super could use information from the current superblock (ddf
does), so add_to_super for external metadata should be called with
the O_EXCL lock held on the container to ensure the update is complete
before any other process tries to make any changes (like adding
another device to array).

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/Manage.c b/Manage.c
index 7ed47310745c48fba7cb71e15b206a6a007f72e1..5932c9031b573c1531882ad925cf96be7e840fbc 100644 (file)
--- a/Manage.c
+++ b/Manage.c
@@ -774,7 +774,7 @@ int Manage_subdevs(char *devname, int fd,
                        disc.minor = minor(stb.st_rdev);
                        disc.number =j;
                        disc.state = 0;
-                       if (array.not_persistent==0 || tst->ss->external) {
+                       if (array.not_persistent==0) {
                                int dfd;
                                if (dv->writemostly == 1)
                                        disc.state |= 1 << MD_DISK_WRITEMOSTLY;
@@ -785,10 +785,7 @@ int Manage_subdevs(char *devname, int fd,
                                        return 1;
                                }
                                /* write_init_super will close 'dfd' */
-                               if (tst->ss->external)
-                                       /* mdmon will write the metadata */
-                                       close(dfd);
-                               else if (tst->ss->write_init_super(tst))
+                               if (tst->ss->write_init_super(tst))
                                        return 1;
                        } else if (dv->re_add) {
                                /*  this had better be raid1.
@@ -830,6 +827,7 @@ int Manage_subdevs(char *devname, int fd,
                                struct mdinfo *sra;
                                int container_fd;
                                int devnum = fd2devnum(fd);
+                               int dfd;
 
                                container_fd = open_dev_excl(devnum);
                                if (container_fd < 0) {
@@ -846,6 +844,15 @@ int Manage_subdevs(char *devname, int fd,
                                        return 1;
                                }
 
+                               dfd = dev_open(dv->devname, O_RDWR | O_EXCL|O_DIRECT);
+                               if (tst->ss->add_to_super(tst, &disc, dfd,
+                                                         dv->devname)) {
+                                       close(dfd);
+                                       close(container_fd);
+                                       return 1;
+                               }
+                               close(dfd);
+
                                sra = sysfs_read(container_fd, -1, 0);
                                if (!sra) {
                                        fprintf(stderr, Name ": add failed for %s: sysfs_read failed\n",