From f67055780caac6a99f43834795c43acf99eba6a6 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 27 Mar 2006 01:18:11 -0800 Subject: [PATCH] md: Checkpoint and allow restart of raid5 reshape We allow the superblock to record an 'old' and a 'new' geometry, and a position where any conversion is up to. The geometry allows for changing chunksize, layout and level as well as number of devices. When using verion-0.90 superblock, we convert the version to 0.91 while the conversion is happening so that an old kernel will refuse the assemble the array. For version-1, we use a feature bit for the same effect. When starting an array we check for an incomplete reshape and restart the reshape process if needed. If the reshape stopped at an awkward time (like when updating the first stripe) we refuse to assemble the array, and let user-space worry about it. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/raid/md_k.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/raid/md_k.h') diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 4e26ef2cacca..1a6f9f2f6282 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -132,6 +132,14 @@ struct mddev_s char uuid[16]; + /* If the array is being reshaped, we need to record the + * new shape and an indication of where we are up to. + * This is written to the superblock. + * If reshape_position is MaxSector, then no reshape is happening (yet). + */ + sector_t reshape_position; + int delta_disks, new_level, new_layout, new_chunk; + struct mdk_thread_s *thread; /* management thread */ struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */ sector_t curr_resync; /* blocks scheduled */ -- cgit v1.2.3-59-g8ed1b