[PATCH] md: Update status_resync to handle LARGE devices

status_resync - used by /proc/mdstat to report the status of a resync, assumes
that device sizes will always fit into an 'unsigned long' This is no longer
the case...

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 686314f070a5fc8b2da4686afa756f579bae1989..a3ecaf8ed30a5ee6207acac842148de8503a290d 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4044,7 +4044,10 @@ static void status_unused(struct seq_file *seq)
 
 static void status_resync(struct seq_file *seq, mddev_t * mddev)
 {
-       unsigned long max_blocks, resync, res, dt, db, rt;
+       sector_t max_blocks, resync, res;
+       unsigned long dt, db, rt;
+       int scale;
+       unsigned int per_milli;
 
        resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
 
@@ -4060,9 +4063,22 @@ static void status_resync(struct seq_file *seq, mddev_t * mddev)
                MD_BUG();
                return;
        }
-       res = (resync/1024)*1000/(max_blocks/1024 + 1);
+       /* Pick 'scale' such that (resync>>scale)*1000 will fit
+        * in a sector_t, and (max_blocks>>scale) will fit in a
+        * u32, as those are the requirements for sector_div.
+        * Thus 'scale' must be at least 10
+        */
+       scale = 10;
+       if (sizeof(sector_t) > sizeof(unsigned long)) {
+               while ( max_blocks/2 > (1ULL<<(scale+32)))
+                       scale++;
+       }
+       res = (resync>>scale)*1000;
+       sector_div(res, (u32)((max_blocks>>scale)+1));
+
+       per_milli = res;
        {
-               int i, x = res/50, y = 20-x;
+               int i, x = per_milli/50, y = 20-x;
                seq_printf(seq, "[");
                for (i = 0; i < x; i++)
                        seq_printf(seq, "=");
@@ -4071,10 +4087,12 @@ static void status_resync(struct seq_file *seq, mddev_t * mddev)
                        seq_printf(seq, ".");
                seq_printf(seq, "] ");
        }
-       seq_printf(seq, " %s =%3lu.%lu%% (%lu/%lu)",
+       seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
                       "resync" : "recovery"),
-                     res/10, res % 10, resync, max_blocks);
+                     per_milli/10, per_milli % 10,
+                  (unsigned long long) resync,
+                  (unsigned long long) max_blocks);
 
        /*
         * We do not want to overflow, so the order of operands and
@@ -4088,7 +4106,7 @@ 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;
+       rt = (dt * ((unsigned long)(max_blocks-resync) / (db/100+1)))/100;
 
        seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);