md: fix resync speed calculation for restarted resyncs

We introduced 'io_sectors' recently so we could count the sectors that causes
io during resync separate from sectors which didn't cause IO - there can be a
difference if a bitmap is being used to accelerate resync.

However when a speed is reported, we find the number of sectors processed
recently by subtracting an oldish io_sectors count from a current
'curr_resync' count.  This is wrong because curr_resync counts all sectors,
not just io sectors.

So, add a field to mddev to store the curren io_sectors separately from
curr_resync, and use that in the calculations.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index e0b81b607184ff0e8d1edf8f9b5e9debe69d0ac1..207e25667f410c0107cdfee9777a1566f32c924f 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2280,7 +2280,7 @@ static ssize_t
 sync_speed_show(mddev_t *mddev, char *page)
 {
        unsigned long resync, dt, db;
-       resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
+       resync = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active));
        dt = ((jiffies - mddev->resync_mark) / HZ);
        if (!dt) dt++;
        db = resync - (mddev->resync_mark_cnt);
@@ -4102,12 +4102,13 @@ static void status_resync(struct seq_file *seq, mddev_t * mddev)
         */
        dt = ((jiffies - mddev->resync_mark) / HZ);
        if (!dt) dt++;
-       db = resync - (mddev->resync_mark_cnt/2);
-       rt = (dt * ((max_blocks-resync) / (db/100+1)))/100;
+       db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
+               - mddev->resync_mark_cnt;
+       rt = (dt * ((max_blocks-resync) / (db/2/100+1)))/100;
 
        seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
 
-       seq_printf(seq, " speed=%ldK/sec", db/dt);
+       seq_printf(seq, " speed=%ldK/sec", db/2/dt);
 }
 
 static void *md_seq_start(struct seq_file *seq, loff_t *pos)
@@ -4604,6 +4605,7 @@ static void md_do_sync(mddev_t *mddev)
 
                j += sectors;
                if (j>1) mddev->curr_resync = j;
+               mddev->curr_mark_cnt = io_sectors;
                if (last_check == 0)
                        /* this is the earliers that rebuilt will be
                         * visible in /proc/mdstat

diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 617b9506c7609aca62e0b9401a3fa4705a8faec9..925b107dad67d6a22b8a4d76b54d5f7e7c3866fd 100644 (file)
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -134,9 +134,10 @@ struct mddev_s
 
        struct mdk_thread_s             *thread;        /* management thread */
        struct mdk_thread_s             *sync_thread;   /* doing resync or reconstruct */
-       sector_t                        curr_resync;    /* blocks scheduled */
+       sector_t                        curr_resync;    /* last block scheduled */
        unsigned long                   resync_mark;    /* a recent timestamp */
        sector_t                        resync_mark_cnt;/* blocks written at resync_mark */
+       sector_t                        curr_mark_cnt; /* blocks scheduled now */
 
        sector_t                        resync_max_sectors; /* may be set by personality */