MD: add a new disk role to present write journal device
Next patches will use a disk as raid5/6 journaling. We need a new disk
role to present the journal device and add MD_FEATURE_JOURNAL to
feature_map for backward compability.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index cfe5c87..391341a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1638,6 +1638,15 @@
case MD_DISK_ROLE_FAULTY: /* faulty */
set_bit(Faulty, &rdev->flags);
break;
+ case MD_DISK_ROLE_JOURNAL: /* journal device */
+ if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
+ /* journal device without journal feature */
+ printk(KERN_WARNING
+ "md: journal device provided without journal feature, ignoring the device\n");
+ return -EINVAL;
+ }
+ set_bit(Journal, &rdev->flags);
+ break;
default:
rdev->saved_raid_disk = role;
if ((le32_to_cpu(sb->feature_map) &
@@ -1796,7 +1805,10 @@
sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
else if (test_bit(In_sync, &rdev2->flags))
sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
- else if (rdev2->raid_disk >= 0)
+ else if (test_bit(Journal, &rdev2->flags)) {
+ sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_JOURNAL);
+ sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
+ } else if (rdev2->raid_disk >= 0)
sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
else
sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
@@ -5840,7 +5852,8 @@
else if (test_bit(In_sync, &rdev->flags)) {
info.state |= (1<<MD_DISK_ACTIVE);
info.state |= (1<<MD_DISK_SYNC);
- }
+ } else if (test_bit(Journal, &rdev->flags))
+ info.state |= (1<<MD_DISK_JOURNAL);
if (test_bit(WriteMostly, &rdev->flags))
info.state |= (1<<MD_DISK_WRITEMOSTLY);
} else {
@@ -5955,6 +5968,8 @@
else
clear_bit(WriteMostly, &rdev->flags);
+ if (info->state & (1<<MD_DISK_JOURNAL))
+ set_bit(Journal, &rdev->flags);
/*
* check whether the device shows up in other nodes
*/
@@ -7330,6 +7345,10 @@
seq_printf(seq, "(F)");
continue;
}
+ if (test_bit(Journal, &rdev->flags)) {
+ seq_printf(seq, "(J)");
+ continue;
+ }
if (rdev->raid_disk < 0)
seq_printf(seq, "(S)"); /* spare */
if (test_bit(Replacement, &rdev->flags))
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 2ea0035..88dc6312 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -172,6 +172,11 @@
* This device is seen locally but not
* by the whole cluster
*/
+ Journal, /* This device is used as journal for
+ * raid-5/6.
+ * Usually, this device should be faster
+ * than other devices in the array
+ */
};
#define BB_LEN_MASK (0x00000000000001FFULL)
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index d1fc8a6..eaaab52 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -89,9 +89,11 @@
* read requests will only be sent here in
* dire need
*/
+#define MD_DISK_JOURNAL 18 /* disk is used as the write journal in RAID-5/6 */
#define MD_DISK_ROLE_SPARE 0xffff
#define MD_DISK_ROLE_FAULTY 0xfffe
+#define MD_DISK_ROLE_JOURNAL 0xfffd
#define MD_DISK_ROLE_MAX 0xff00 /* max value of regular disk role */
typedef struct mdp_device_descriptor_s {
@@ -307,6 +309,7 @@
* is guided by bitmap.
*/
#define MD_FEATURE_CLUSTERED 256 /* clustered MD */
+#define MD_FEATURE_JOURNAL 512 /* support write cache */
#define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \
|MD_FEATURE_RECOVERY_OFFSET \
|MD_FEATURE_RESHAPE_ACTIVE \