md: cleanup mddev flag clear for takeover

Commit 6995f0b (md: takeover should clear unrelated bits) clear
unrelated bits, but it's quite fragile. To avoid error in the future,
define a macro for unsupported mddev flags for each raid type and use it
to clear unsupported mddev flags. This should be less error-prone.

Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/md.h b/drivers/md/md.h
index e38936d..2a51403 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -212,6 +212,7 @@ extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
                                int is_new);
 struct md_cluster_info;
 
+/* change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added */
 enum mddev_flags {
        MD_ARRAY_FIRST_USE,     /* First use of array, needs initialization */
        MD_CLOSING,             /* If set, we are closing the array, do not open
@@ -702,4 +703,11 @@ static inline int mddev_is_clustered(struct mddev *mddev)
 {
        return mddev->cluster_info && mddev->bitmap_info.nodes > 1;
 }
+
+/* clear unsupported mddev_flags */
+static inline void mddev_clear_unsupported_flags(struct mddev *mddev,
+       unsigned long unsupported_flags)
+{
+       mddev->flags &= ~unsupported_flags;
+}
 #endif /* _MD_MD_H */

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index a162fed..848365d 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -26,6 +26,11 @@
 #include "raid0.h"
 #include "raid5.h"
 
+#define UNSUPPORTED_MDDEV_FLAGS                \
+       ((1L << MD_HAS_JOURNAL) |       \
+        (1L << MD_JOURNAL_CLEAN) |     \
+        (1L << MD_FAILFAST_SUPPORTED))
+
 static int raid0_congested(struct mddev *mddev, int bits)
 {
        struct r0conf *conf = mddev->private;
@@ -539,8 +544,7 @@ static void *raid0_takeover_raid45(struct mddev *mddev)
        mddev->delta_disks = -1;
        /* make sure it will be not marked as dirty */
        mddev->recovery_cp = MaxSector;
-       clear_bit(MD_HAS_JOURNAL, &mddev->flags);
-       clear_bit(MD_JOURNAL_CLEAN, &mddev->flags);
+       mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
 
        create_strip_zones(mddev, &priv_conf);
 
@@ -583,7 +587,7 @@ static void *raid0_takeover_raid10(struct mddev *mddev)
        mddev->degraded = 0;
        /* make sure it will be not marked as dirty */
        mddev->recovery_cp = MaxSector;
-       clear_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
+       mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
 
        create_strip_zones(mddev, &priv_conf);
        return priv_conf;
@@ -626,7 +630,7 @@ static void *raid0_takeover_raid1(struct mddev *mddev)
        mddev->raid_disks = 1;
        /* make sure it will be not marked as dirty */
        mddev->recovery_cp = MaxSector;
-       clear_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
+       mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
 
        create_strip_zones(mddev, &priv_conf);
        return priv_conf;

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1442240..7b0f647 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -42,6 +42,10 @@
 #include "raid1.h"
 #include "bitmap.h"
 
+#define UNSUPPORTED_MDDEV_FLAGS                \
+       ((1L << MD_HAS_JOURNAL) |       \
+        (1L << MD_JOURNAL_CLEAN))
+
 /*
  * Number of guaranteed r1bios in case of extreme VM load:
  */
@@ -3257,8 +3261,8 @@ static void *raid1_takeover(struct mddev *mddev)
                if (!IS_ERR(conf)) {
                        /* Array must appear to be quiesced */
                        conf->array_frozen = 1;
-                       clear_bit(MD_HAS_JOURNAL, &mddev->flags);
-                       clear_bit(MD_JOURNAL_CLEAN, &mddev->flags);
+                       mddev_clear_unsupported_flags(mddev,
+                               UNSUPPORTED_MDDEV_FLAGS);
                }
                return conf;
        }

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 06d7279..7b1da6e 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -62,6 +62,8 @@
 #include "raid0.h"
 #include "bitmap.h"
 
+#define UNSUPPORTED_MDDEV_FLAGS        (1L << MD_FAILFAST_SUPPORTED)
+
 #define cpu_to_group(cpu) cpu_to_node(cpu)
 #define ANY_GROUP NUMA_NO_NODE
 
@@ -7830,7 +7832,8 @@ static void *raid5_takeover_raid1(struct mddev *mddev)
 
        ret = setup_conf(mddev);
        if (!IS_ERR_VALUE(ret))
-               clear_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
+               mddev_clear_unsupported_flags(mddev,
+                       UNSUPPORTED_MDDEV_FLAGS);
        return ret;
 }