When reshape with '--continue' option is executed mdadm doesn't know,
if mdmon is switched to using '--takeover' option to current file system
context. To resolve this, on reshape continuation when mdmon is run,
execute mdmon takeover.
Lack of takeovered mdmon can cause e.g.:
- multivolume reshape is broken when reshaped volume is changed
- size of reshaped volume dowsn't increase
Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
---
Grow.c | 2 ++
mdadm.h | 1 +
util.c | 53 ++++++++++++++++++++++++++++++++++++++++++++---------
3 files changed, 47 insertions(+), 9 deletions(-)
diff --git a/Grow.c b/Grow.c
index b2c1360..f0422d2 100644
--- a/Grow.c
+++ b/Grow.c
@@ -3876,6 +3876,8 @@ int Grow_continue_command(char *devname, int fd,
*/
if (!mdmon_running(container_dev))
start_mdmon(container_dev);
+ else
+ takeover_mdmon(container_dev);
ping_monitor(buf);
if (mdmon_running(container_dev))
diff --git a/mdadm.h b/mdadm.h
index 381ef86..f274ae7 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1223,6 +1223,7 @@ extern int mdmon_pid(int devnum);
extern int check_env(char *name);
extern __u32 random32(void);
extern int start_mdmon(int devnum);
+extern int takeover_mdmon(int devnum);
extern int child_monitor(int afd, struct mdinfo *sra, struct reshape *reshape,
struct supertype *st, unsigned long stripes,
diff --git a/util.c b/util.c
index 6985a70..e95a366 100644
--- a/util.c
+++ b/util.c
@@ -1581,11 +1581,13 @@ int mdmon_running(int devnum)
return 0;
}
-int start_mdmon(int devnum)
+#define MDMON_TAKEOVER_WAIT_COUNTER 15
+int execute_mdmon(int devnum, int takeover)
{
int i, skipped;
int len;
- pid_t pid;
+ pid_t pid;
+ pid_t pid_org;
int status;
char pathbuf[1024];
char *paths[4] = {
@@ -1611,6 +1613,12 @@ int start_mdmon(int devnum)
} else
pathbuf[0] = '\0';
+ if (takeover) {
+ pid_org = mdmon_pid(devnum);
+ if (pid_org < 0)
+ takeover = 0;
+ }
+
switch(fork()) {
case 0:
/* FIXME yuk. CLOSE_EXEC?? */
@@ -1620,24 +1628,51 @@ int start_mdmon(int devnum)
skipped++;
else
skipped = 0;
-
- for (i=0; paths[i]; i++)
- if (paths[i][0])
- execl(paths[i], "mdmon",
- devnum2devname(devnum),
- NULL);
+ for (i = 0; paths[i]; i++) {
+ if (paths[i][0]) {
+ if (!takeover)
+ execl(paths[i], "mdmon",
+ devnum2devname(devnum),
+ NULL);
+ else
+ execl(paths[i], "mdmon",
+ "--takeover",
+ devnum2devname(devnum),
+ NULL);
+ }
+ }
exit(1);
case -1: fprintf(stderr, Name ": cannot run mdmon. "
"Array remains readonly\n");
return -1;
default: /* parent - good */
- pid = wait(&status);
+ i = 0;
+ do {
+ if (i)
+ sleep(1);
+ pid = wait(&status);
+ if (takeover && (pid == pid_org))
+ pid = -1;
+ i++;
+ } while (takeover &&
+ (i < MDMON_TAKEOVER_WAIT_COUNTER) &&
+ (pid < 0));
if (pid < 0 || status != 0)
return -1;
}
return 0;
}
+int start_mdmon(int devnum)
+{
+ return execute_mdmon(devnum, 0);
+}
+
+int takeover_mdmon(int devnum)
+{
+ return execute_mdmon(devnum, 1);
+}
+
int check_env(char *name)
{
char *val = getenv(name);
--
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