FIX: Close unused handle in child process during reshape restart

When array reshape (e.g. raid0->raid5 migration) is restarted during
array assembly, file system placed on this array cannot be mounted until
reshape is finished due to "busy" error.

This is caused when reshape is executed on array for external metadata
and array handle is cloned /forked/ to child process environment but not
closed.

Handle can't be closed before executing Grow_continue() because it is
used later in code.

Close unused handle in child process /reshape_container()/.
It is similar to close fd handle in reshape_array() before calling
manage_reshape()/child_monitor() in Grow.c:2290.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/Grow.c b/Grow.c
index 0e4dd108aa9617f35111503c68aa94641a655996..93a69fde609b9209fc45fbd6b8350c990485af6e 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -1350,6 +1350,7 @@ static int reshape_array(char *container, int fd, char *devname,
                         char *backup_file, int quiet, int forked,
                         int restart, int freeze_reshape);
 static int reshape_container(char *container, char *devname,
+                            int mdfd,
                             struct supertype *st, 
                             struct mdinfo *info,
                             int force,
@@ -1768,7 +1769,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                 * number of devices (On-Line Capacity Expansion) must be
                 * performed at the level of the container
                 */
-               rv = reshape_container(container, devname, st, &info,
+               rv = reshape_container(container, devname, -1, st, &info,
                                       force, backup_file, quiet, 0, 0);
                frozen = 0;
        } else {
@@ -2403,7 +2404,10 @@ release:
        return 1;
 }
 
+/* mdfd handle is passed to be closed in child process (after fork).
+ */
 int reshape_container(char *container, char *devname,
+                     int mdfd,
                      struct supertype *st, 
                      struct mdinfo *info,
                      int force,
@@ -2446,6 +2450,11 @@ int reshape_container(char *container, char *devname,
                break;
        }
 
+       /* close unused handle in child process
+        */
+       if (mdfd > -1)
+               close(mdfd);
+
        while(1) {
                /* For each member array with reshape_active,
                 * we need to perform the reshape.
@@ -3821,7 +3830,7 @@ int Grow_continue(int mdfd, struct supertype *st, struct mdinfo *info,
                fmt_devname(container, st->container_dev);
                st->ss->load_container(st, cfd, container);
                close(cfd);
-               ret_val = reshape_container(container, NULL,
+               ret_val = reshape_container(container, NULL, mdfd,
                                            st, info, 0, backup_file,
                                            0, 1, freeze_reshape);
        } else