From 33e38ac6887d975fe2635c7fcaefb6d5495cb2e1 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Wed, 1 Jul 2015 12:19:56 +1000 Subject: [PATCH] md-cluster: fix bitmap sub-offset in bitmap_read_sb bitmap_read_sb is modifying mddev->bitmap_info.offset. This works for the first bitmap read. However, when multiple bitmaps need to be opened by the same node, it ends up corrupting the offset. Fix it by using a local variable. Also, bitmap_read_sb is not required in bitmap_copy_from_slot since it is called in bitmap_create. Remove bitmap_read_sb(). Signed-off-by: Goldwyn Rodrigues Signed-off-by: NeilBrown --- drivers/md/bitmap.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index a4ab51350f40..1b9c2df718c6 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -559,6 +559,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) unsigned long sectors_reserved = 0; int err = -EINVAL; struct page *sb_page; + loff_t offset = bitmap->mddev->bitmap_info.offset; if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) { chunksize = 128 * 1024 * 1024; @@ -585,9 +586,9 @@ re_read: bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t); /* to 4k blocks */ bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096); - bitmap->mddev->bitmap_info.offset += bitmap->cluster_slot * (bm_blocks << 3); + offset = bitmap->mddev->bitmap_info.offset + (bitmap->cluster_slot * (bm_blocks << 3)); pr_info("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__, - bitmap->cluster_slot, (unsigned long long)bitmap->mddev->bitmap_info.offset); + bitmap->cluster_slot, offset); } if (bitmap->storage.file) { @@ -598,7 +599,7 @@ re_read: bitmap, bytes, sb_page); } else { err = read_sb_page(bitmap->mddev, - bitmap->mddev->bitmap_info.offset, + offset, sb_page, 0, sizeof(bitmap_super_t)); } @@ -1875,10 +1876,6 @@ int bitmap_copy_from_slot(struct mddev *mddev, int slot, if (IS_ERR(bitmap)) return PTR_ERR(bitmap); - rv = bitmap_read_sb(bitmap); - if (rv) - goto err; - rv = bitmap_init_from_disk(bitmap, 0); if (rv) goto err; -- 2.20.1