[PATCH v2] mdadm: set journal_clean after scanning all disks

[PATCH v2] mdadm: set journal_clean after scanning all disks

[Song Liu]

Summary:
In Incremental.c:count_active(), max_events is tracked to show to
which devices are up to date. If a device has events==max_events+1,
getinfo_super() is called to reload the superblock from this
device. getinfo_super1() blindly set journal_clean to 0, which is
wrong.

This patch fixes this by tracking max_journal_events for all the
disks. After scanning all disks, journal_clean is set if
max_journal_events >= max_events-1.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 Incremental.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Incremental.c b/Incremental.c
index 6cf2174..91301eb 100644
--- a/Incremental.c
+++ b/Incremental.c
@@ -684,6 +684,7 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
 	int cnt = 0;
 	int replcnt = 0;
 	__u64 max_events = 0;
+	__u64 max_journal_events = 0;
 	char *avail = NULL;
 	int *best = NULL;
 	char *devmap = NULL;
@@ -714,8 +715,9 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
 
 		info.array.raid_disks = raid_disks;
 		st->ss->getinfo_super(st, &info, devmap + raid_disks * devnum);
-		if (info.disk.raid_disk == MD_DISK_ROLE_JOURNAL)
-			bestinfo->journal_clean = 1;
+		if (info.disk.raid_disk == MD_DISK_ROLE_JOURNAL &&
+		    info.events > max_journal_events)
+			max_journal_events = info.events;
 		if (!avail) {
 			raid_disks = info.array.raid_disks;
 			avail = xcalloc(raid_disks, 1);
@@ -765,6 +767,8 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
 			replcnt++;
 		st->ss->free_super(st);
 	}
+	if (max_journal_events >= max_events - 1)
+		bestinfo->journal_clean = 1;
 
 	if (!avail)
 		return 0;
-- 
2.9.5

Re: [PATCH v2] mdadm: set journal_clean after scanning all disks

[NeilBrown]

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On Tue, Aug 29 2017, Song Liu wrote:

> Summary:
> In Incremental.c:count_active(), max_events is tracked to show to
> which devices are up to date. If a device has events==max_events+1,
> getinfo_super() is called to reload the superblock from this
> device. getinfo_super1() blindly set journal_clean to 0, which is
> wrong.
>
> This patch fixes this by tracking max_journal_events for all the
> disks. After scanning all disks, journal_clean is set if
> max_journal_events >= max_events-1.

Thanks.  That makes sense now.
Reviewed-by: NeilBrown <neilb@suse.com>


>
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  Incremental.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/Incremental.c b/Incremental.c
> index 6cf2174..91301eb 100644
> --- a/Incremental.c
> +++ b/Incremental.c
> @@ -684,6 +684,7 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
>  	int cnt = 0;
>  	int replcnt = 0;
>  	__u64 max_events = 0;
> +	__u64 max_journal_events = 0;
>  	char *avail = NULL;
>  	int *best = NULL;
>  	char *devmap = NULL;
> @@ -714,8 +715,9 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
>  
>  		info.array.raid_disks = raid_disks;
>  		st->ss->getinfo_super(st, &info, devmap + raid_disks * devnum);
> -		if (info.disk.raid_disk == MD_DISK_ROLE_JOURNAL)
> -			bestinfo->journal_clean = 1;
> +		if (info.disk.raid_disk == MD_DISK_ROLE_JOURNAL &&
> +		    info.events > max_journal_events)
> +			max_journal_events = info.events;
>  		if (!avail) {
>  			raid_disks = info.array.raid_disks;
>  			avail = xcalloc(raid_disks, 1);
> @@ -765,6 +767,8 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
>  			replcnt++;
>  		st->ss->free_super(st);
>  	}
> +	if (max_journal_events >= max_events - 1)
> +		bestinfo->journal_clean = 1;
>  
>  	if (!avail)
>  		return 0;
> -- 
> 2.9.5
>
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Re: [PATCH v2] mdadm: set journal_clean after scanning all disks

[Jes Sorensen]

On 08/29/2017 12:53 PM, Song Liu wrote:
> Summary:
> In Incremental.c:count_active(), max_events is tracked to show to
> which devices are up to date. If a device has events==max_events+1,
> getinfo_super() is called to reload the superblock from this
> device. getinfo_super1() blindly set journal_clean to 0, which is
> wrong.
> 
> This patch fixes this by tracking max_journal_events for all the
> disks. After scanning all disks, journal_clean is set if
> max_journal_events >= max_events-1.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>

Applied!

Thanks,
Jes