md/bitmap: separate out loading a bitmap from initialising the structures.

dm makes this distinction between ->ctr and ->resume, so we need to
too.

Also get the new bitmap_load to clear out the bitmap first, as this is
most consistent with the dm suspend/resume approach

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 9376526..1ba1e12 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1681,7 +1681,6 @@ int bitmap_create(mddev_t *mddev)
        unsigned long pages;
        struct file *file = mddev->bitmap_info.file;
        int err;
-       sector_t start;
        struct sysfs_dirent *bm = NULL;
 
        BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
@@ -1763,13 +1762,40 @@ int bitmap_create(mddev_t *mddev)
        if (!bitmap->bp)
                goto error;
 
-       /* now that we have some pages available, initialize the in-memory
-        * bitmap from the on-disk bitmap */
-       start = 0;
-       if (mddev->degraded == 0
-           || bitmap->events_cleared == mddev->events)
-               /* no need to keep dirty bits to optimise a re-add of a missing device */
-               start = mddev->recovery_cp;
+       printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
+               pages, bmname(bitmap));
+
+       mddev->bitmap = bitmap;
+
+
+       return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
+
+ error:
+       bitmap_free(bitmap);
+       return err;
+}
+
+int bitmap_load(mddev_t *mddev)
+{
+       int err = 0;
+       sector_t sector = 0;
+       struct bitmap *bitmap = mddev->bitmap;
+
+       if (!bitmap)
+               goto out;
+
+       /* Clear out old bitmap info first:  Either there is none, or we
+        * are resuming after someone else has possibly changed things,
+        * so we should forget old cached info.
+        * All chunks should be clean, but some might need_sync.
+        */
+       while (sector < mddev->resync_max_sectors) {
+               int blocks;
+               bitmap_start_sync(bitmap, sector, &blocks, 0);
+               sector += blocks;
+       }
+       bitmap_close_sync(bitmap);
+
        if (mddev->bitmap_info.log) {
                unsigned long i;
                struct dm_dirty_log *log = mddev->bitmap_info.log;
@@ -1778,29 +1804,30 @@ int bitmap_create(mddev_t *mddev)
                                bitmap_set_memory_bits(bitmap,
                                                       (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
                                                       1);
-               err = 0;
-       } else
-               err = bitmap_init_from_disk(bitmap, start);
+       } else {
+               sector_t start = 0;
+               if (mddev->degraded == 0
+                   || bitmap->events_cleared == mddev->events)
+                       /* no need to keep dirty bits to optimise a
+                        * re-add of a missing device */
+                       start = mddev->recovery_cp;
 
+               err = bitmap_init_from_disk(bitmap, start);
+       }
        if (err)
-               goto error;
-
-       printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
-               pages, bmname(bitmap));
-
-       mddev->bitmap = bitmap;
+               goto out;
 
        mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
        md_wakeup_thread(mddev->thread);
 
        bitmap_update_sb(bitmap);
 
-       return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
-
- error:
-       bitmap_free(bitmap);
+       if (bitmap->flags & BITMAP_WRITE_ERROR)
+               err = -EIO;
+out:
        return err;
 }
+EXPORT_SYMBOL_GPL(bitmap_load);
 
 static ssize_t
 location_show(mddev_t *mddev, char *page)

diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index a7a1113..e872a7b 100644 (file)
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -254,6 +254,7 @@ struct bitmap {
 
 /* these are used only by md/bitmap */
 int  bitmap_create(mddev_t *mddev);
+int bitmap_load(mddev_t *mddev);
 void bitmap_flush(mddev_t *mddev);
 void bitmap_destroy(mddev_t *mddev);
 

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9d4e44e..40b7ca0 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4594,7 +4594,11 @@ static int do_md_run(mddev_t *mddev)
        err = md_run(mddev);
        if (err)
                goto out;
-
+       err = bitmap_load(mddev);
+       if (err) {
+               bitmap_destroy(mddev);
+               goto out;
+       }
        set_capacity(mddev->gendisk, mddev->array_sectors);
        revalidate_disk(mddev->gendisk);
        kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
@@ -5382,8 +5386,11 @@ static int set_bitmap_file(mddev_t *mddev, int fd)
        err = 0;
        if (mddev->pers) {
                mddev->pers->quiesce(mddev, 1);
-               if (fd >= 0)
+               if (fd >= 0) {
                        err = bitmap_create(mddev);
+                       if (!err)
+                               err = bitmap_load(mddev);
+               }
                if (fd < 0 || err) {
                        bitmap_destroy(mddev);
                        fd = -1; /* make sure to put the file */
@@ -5632,6 +5639,8 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
                                mddev->bitmap_info.default_offset;
                        mddev->pers->quiesce(mddev, 1);
                        rv = bitmap_create(mddev);
+                       if (!rv)
+                               rv = bitmap_load(mddev);
                        if (rv)
                                bitmap_destroy(mddev);
                        mddev->pers->quiesce(mddev, 0);