Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md:
  md: remove rd%d links immediately after stopping an array.
  md: remove ability to explicit set an inactive array to 'clean'.
  md: constify VFTs
  md: tidy up status_resync to handle large arrays.
  md: fix some (more) errors with bitmaps on devices larger than 2TB.
  md/raid10: don't clear bitmap during recovery if array will still be degraded.
  md: fix loading of out-of-date bitmap.

3 files changed, 60 insertions, 51 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 1fb91edc7de2..47c68bc75a17 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -986,6 +986,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                         oldindex = index;
                         oldpage = page;
 
+                        bitmap->filemap[bitmap->file_pages++] = page;
+                        bitmap->last_page_size = count;
+
                         if (outofdate) {
                                 /*
                                  * if bitmap is out of date, dirty the
@@ -998,15 +1001,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                                 write_page(bitmap, page, 1);
 
                                 ret = -EIO;
-                                if (bitmap->flags & BITMAP_WRITE_ERROR) {
-                                        /* release, page not in filemap yet */
-                                        put_page(page);
+                                if (bitmap->flags & BITMAP_WRITE_ERROR)
                                         goto err;
-                                }
                         }
-
-                        bitmap->filemap[bitmap->file_pages++] = page;
-                        bitmap->last_page_size = count;
                 }
                 paddr = kmap_atomic(page, KM_USER0);
                 if (bitmap->flags & BITMAP_HOSTENDIAN)
@@ -1016,9 +1013,11 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                 kunmap_atomic(paddr, KM_USER0);
                 if (b) {
                         /* if the disk bit is set, set the memory bit */
-                        bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap),
-                                               ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
-                                );
+                        int needed = ((sector_t)(i+1) << (CHUNK_BLOCK_SHIFT(bitmap))
+                                      >= start);
+                        bitmap_set_memory_bits(bitmap,
+                                               (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
+                                               needed);
                         bit_cnt++;
                         set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
                 }
@@ -1154,8 +1153,9 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                         spin_lock_irqsave(&bitmap->lock, flags);
                         clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
                 }
-                bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
-                                        &blocks, 0);
+                bmc = bitmap_get_counter(bitmap,
+                                         (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
+                                         &blocks, 0);
                 if (bmc) {
 /*
   if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc);
@@ -1169,7 +1169,8 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                         } else if (*bmc == 1) {
                                 /* we can clear the bit */
                                 *bmc = 0;
-                                bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap),
+                                bitmap_count_page(bitmap,
+                                                  (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
                                                   -1);
 
                                 /* clear the bit */
@@ -1514,7 +1515,7 @@ void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
         unsigned long chunk;
 
         for (chunk = s; chunk <= e; chunk++) {
-                sector_t sec = chunk << CHUNK_BLOCK_SHIFT(bitmap);
+                sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
                 bitmap_set_memory_bits(bitmap, sec, 1);
                 bitmap_file_set_bit(bitmap, sec);
         }
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 612343fdde94..fccc8343a250 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3066,11 +3066,8 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
                         } else
                                 err = -EBUSY;
                         spin_unlock_irq(&mddev->write_lock);
-                } else {
-                        mddev->ro = 0;
-                        mddev->recovery_cp = MaxSector;
-                        err = do_md_run(mddev);
-                }
+                } else
+                        err = -EINVAL;
                 break;
         case active:
                 if (mddev->pers) {
@@ -4297,6 +4294,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
 {
         int err = 0;
         struct gendisk *disk = mddev->gendisk;
+        mdk_rdev_t *rdev;
 
         if (atomic_read(&mddev->openers) > is_open) {
                 printk("md: %s still in use.\n",mdname(mddev));
@@ -4339,6 +4337,13 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                         /* tell userspace to handle 'inactive' */
                         sysfs_notify_dirent(mddev->sysfs_state);
 
+                        list_for_each_entry(rdev, &mddev->disks, same_set)
+                                if (rdev->raid_disk >= 0) {
+                                        char nm[20];
+                                        sprintf(nm, "rd%d", rdev->raid_disk);
+                                        sysfs_remove_link(&mddev->kobj, nm);
+                                }
+
                         set_capacity(disk, 0);
                         mddev->changed = 1;
 
@@ -4359,7 +4364,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
          * Free resources if final stop
          */
         if (mode == 0) {
-                mdk_rdev_t *rdev;
 
                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
@@ -4371,13 +4375,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                 }
                 mddev->bitmap_offset = 0;
 
-                list_for_each_entry(rdev, &mddev->disks, same_set)
-                        if (rdev->raid_disk >= 0) {
-                                char nm[20];
-                                sprintf(nm, "rd%d", rdev->raid_disk);
-                                sysfs_remove_link(&mddev->kobj, nm);
-                        }
-
                 /* make sure all md_delayed_delete calls have finished */
                 flush_scheduled_work();
 
@@ -5705,37 +5702,38 @@ static void status_unused(struct seq_file *seq)
 
 static void status_resync(struct seq_file *seq, mddev_t * mddev)
 {
-        sector_t max_blocks, resync, res;
-        unsigned long dt, db, rt;
+        sector_t max_sectors, resync, res;
+        unsigned long dt, db;
+        sector_t rt;
         int scale;
         unsigned int per_milli;
 
-        resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
+        resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
 
         if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
-                max_blocks = mddev->resync_max_sectors >> 1;
+                max_sectors = mddev->resync_max_sectors;
         else
-                max_blocks = mddev->dev_sectors / 2;
+                max_sectors = mddev->dev_sectors;
 
         /*
          * Should not happen.
          */
-        if (!max_blocks) {
+        if (!max_sectors) {
                 MD_BUG();
                 return;
         }
         /* Pick 'scale' such that (resync>>scale)*1000 will fit
-         * in a sector_t, and (max_blocks>>scale) will fit in a
+         * in a sector_t, and (max_sectors>>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)))
+                while ( max_sectors/2 > (1ULL<<(scale+32)))
                         scale++;
         }
         res = (resync>>scale)*1000;
-        sector_div(res, (u32)((max_blocks>>scale)+1));
+        sector_div(res, (u32)((max_sectors>>scale)+1));
 
         per_milli = res;
         {
@@ -5756,25 +5754,35 @@ static void status_resync(struct seq_file *seq, mddev_t * mddev)
                      (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
                       "resync" : "recovery"))),
                    per_milli/10, per_milli % 10,
-                   (unsigned long long) resync,
-                   (unsigned long long) max_blocks);
+                   (unsigned long long) resync/2,
+                   (unsigned long long) max_sectors/2);
 
         /*
-         * We do not want to overflow, so the order of operands and
-         * the * 100 / 100 trick are important. We do a +1 to be
-         * safe against division by zero. We only estimate anyway.
-         *
          * dt: time from mark until now
          * db: blocks written from mark until now
          * rt: remaining time
+         *
+         * rt is a sector_t, so could be 32bit or 64bit.
+         * So we divide before multiply in case it is 32bit and close
+         * to the limit.
+         * We scale the divisor (db) by 32 to avoid loosing precision
+         * near the end of resync when the number of remaining sectors
+         * is close to 'db'.
+         * We then divide rt by 32 after multiplying by db to compensate.
+         * The '+1' avoids division by zero if db is very small.
          */
         dt = ((jiffies - mddev->resync_mark) / HZ);
         if (!dt) dt++;
         db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
                 - mddev->resync_mark_cnt;
-        rt = (dt * ((unsigned long)(max_blocks-resync) / (db/2/100+1)))/100;
 
-        seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
+        rt = max_sectors - resync;    /* number of remaining sectors */
+        sector_div(rt, db/32+1);
+        rt *= dt;
+        rt >>= 5;
+
+        seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
+                   ((unsigned long)rt % 60)/6);
 
         seq_printf(seq, " speed=%ldK/sec", db/2/dt);
 }
@@ -5965,7 +5973,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
         return 0;
 }
 
-static struct seq_operations md_seq_ops = {
+static const struct seq_operations md_seq_ops = {
         .start  = md_seq_start,
         .next   = md_seq_next,
         .stop   = md_seq_stop,
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 81a54f17417e..499620afb44b 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1809,17 +1809,17 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                                 r10_bio->sector = sect;
 
                                 raid10_find_phys(conf, r10_bio);
-                                /* Need to check if this section will still be
+
+                                /* Need to check if the array will still be
                                  * degraded
                                  */
-                                for (j=0; j<conf->copies;j++) {
-                                        int d = r10_bio->devs[j].devnum;
-                                        if (conf->mirrors[d].rdev == NULL ||
-                                            test_bit(Faulty, &conf->mirrors[d].rdev->flags)) {
+                                for (j=0; j<conf->raid_disks; j++)
+                                        if (conf->mirrors[j].rdev == NULL ||
+                                            test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
                                                 still_degraded = 1;
                                                 break;
                                         }
-                                }
+
                                 must_sync = bitmap_start_sync(mddev->bitmap, sect,
                                                               &sync_blocks, still_degraded);