[PATCH 1/2] imsm: use timeout when waiting for reshape progress

[PATCH 1/2] imsm: use timeout when waiting for reshape progress

[Artur Paszkiewicz]

Waiting for reshape progress is done by using select() on sync_completed
to block until an exception condition is signalled on the
filedescriptor. This happens when the attribute's value is updated by
the kernel, but if the array is stopped when mdadm is blocked on
select() this will never happen, because this attribute is then removed
and apparently the kernel doesn't do sysfs_notify() when removing a
sysfs attribute. So set a 3 second timeout for the sysfs_wait() call.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
---
 super-intel.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/super-intel.c b/super-intel.c
index 98fe835..68cc8d6 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -10297,7 +10297,8 @@ int wait_for_reshape_imsm(struct mdinfo *sra, int ndata)
 
 	do {
 		char action[20];
-		sysfs_wait(fd, NULL);
+		int timeout = 3000;
+		sysfs_wait(fd, &timeout);
 		if (sysfs_get_str(sra, NULL, "sync_action",
 				  action, 20) > 0 &&
 				strncmp(action, "reshape", 7) != 0) {
-- 
2.1.4

[PATCH 2/2] imsm: don't update migration record when reshape is interrupted

[Artur Paszkiewicz]

Abort imsm_manage_reshape() without updating the migration record if any
error occurs when checking progress. If reshape is interrupted and the
migration record is then updated, the checkpoint will be wrong and will
cause reshape to fail when the array is restarted.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
---
 super-intel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/super-intel.c b/super-intel.c
index 68cc8d6..abf48c0 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -10277,7 +10277,7 @@ int wait_for_reshape_imsm(struct mdinfo *sra, int ndata)
 	if (sysfs_fd_get_ll(fd, &completed) < 0) {
 		dprintf("cannot read reshape_position (no reshape in progres)\n");
 		close(fd);
-		return 0;
+		return 1;
 	}
 
 	if (completed > position_to_set) {
@@ -10566,7 +10566,7 @@ static int imsm_manage_reshape(
 		sra->reshape_progress = next_step;
 
 		/* wait until reshape finish */
-		if (wait_for_reshape_imsm(sra, ndata) < 0) {
+		if (wait_for_reshape_imsm(sra, ndata)) {
 			dprintf("wait_for_reshape_imsm returned error!\n");
 			goto abort;
 		}
-- 
2.1.4

Re: [PATCH 1/2] imsm: use timeout when waiting for reshape progress

[NeilBrown]

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On Wed, Jan 06 2016, Artur Paszkiewicz wrote:

> Waiting for reshape progress is done by using select() on sync_completed
> to block until an exception condition is signalled on the
> filedescriptor. This happens when the attribute's value is updated by
> the kernel, but if the array is stopped when mdadm is blocked on
> select() this will never happen, because this attribute is then removed
> and apparently the kernel doesn't do sysfs_notify() when removing a
> sysfs attribute. So set a 3 second timeout for the sysfs_wait() call.

I wonder if we should fix that in the kernel somehow...

I've applied this patch and the following one - thanks.

NeilBrown

>
> Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
> ---
>  super-intel.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/super-intel.c b/super-intel.c
> index 98fe835..68cc8d6 100644
> --- a/super-intel.c
> +++ b/super-intel.c
> @@ -10297,7 +10297,8 @@ int wait_for_reshape_imsm(struct mdinfo *sra, int ndata)
>  
>  	do {
>  		char action[20];
> -		sysfs_wait(fd, NULL);
> +		int timeout = 3000;
> +		sysfs_wait(fd, &timeout);
>  		if (sysfs_get_str(sra, NULL, "sync_action",
>  				  action, 20) > 0 &&
>  				strncmp(action, "reshape", 7) != 0) {
> -- 
> 2.1.4
>
> --
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