[PATCH] md: allow checkpoint of recovery with version-1 superblock

For a while we have had checkpointing of resync.  The version-1 superblock
allows recovery to be checkpointed as well, and this patch implements that.

Due to early carelessness we need to add a feature flag to signal that the
recovery_offset field is in use, otherwise older kernels would assume that a
partially recovered array is in fact fully recovered.

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

2 files changed, 10 insertions, 1 deletions

diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index db2ca2d9066e..682574f3bd36 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -88,6 +88,10 @@ struct mdk_rdev_s
                                          * array and could again if we did a partial
                                          * resync from the bitmap
                                          */
+        sector_t        recovery_offset;/* If this device has been partially
+                                         * recovered, this is where we were
+                                         * up to.
+                                         */
 
         atomic_t        nr_pending;     /* number of pending requests.
                                          * only maintained for arrays that
@@ -183,6 +187,8 @@ struct mddev_s
 #define MD_RECOVERY_REQUESTED   6
 #define MD_RECOVERY_CHECK       7
 #define MD_RECOVERY_RESHAPE     8
+#define MD_RECOVERY_FROZEN      9
+
         unsigned long                   recovery;
 
         int                             in_sync;        /* know to not need resync */
diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h
index f1fbae7e390e..b6ebc69bae54 100644
--- a/include/linux/raid/md_p.h
+++ b/include/linux/raid/md_p.h
@@ -265,9 +265,12 @@ struct mdp_superblock_1 {
 
 /* feature_map bits */
 #define MD_FEATURE_BITMAP_OFFSET        1
+#define MD_FEATURE_RECOVERY_OFFSET      2 /* recovery_offset is present and
+                                           * must be honoured
+                                           */
 #define MD_FEATURE_RESHAPE_ACTIVE       4
 
-#define MD_FEATURE_ALL                  5
+#define MD_FEATURE_ALL                  (1|2|4)
 
 #endif