diff --git a/Documentation/md.txt b/Documentation/md.txt
index fc94770f44aba..993fba37b7d18 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -357,14 +357,14 @@ Each directory contains:
written to, that device.
state
- A file recording the current state of the device in the array
+ A file recording the current state of the device in the array
which can be a comma separated list of
faulty - device has been kicked from active use due to
- a detected fault or it has unacknowledged bad
- blocks
+ a detected fault, or it has unacknowledged bad
+ blocks
in_sync - device is a fully in-sync member of the array
writemostly - device will only be subject to read
- requests if there are no other options.
+ requests if there are no other options.
This applies only to raid1 arrays.
blocked - device has failed, and the failure hasn't been
acknowledged yet by the metadata handler.
@@ -374,6 +374,13 @@ Each directory contains:
This includes spares that are in the process
of being recovered to
write_error - device has ever seen a write error.
+ want_replacement - device is (mostly) working but probably
+ should be replaced, either due to errors or
+ due to user request.
+ replacement - device is a replacement for another active
+ device with same raid_disk.
+
+
This list may grow in future.
This can be written to.
Writing "faulty" simulates a failure on the device.
@@ -386,6 +393,13 @@ Each directory contains:
Writing "in_sync" sets the in_sync flag.
Writing "write_error" sets writeerrorseen flag.
Writing "-write_error" clears writeerrorseen flag.
+ Writing "want_replacement" is allowed at any time except to a
+ replacement device or a spare. It sets the flag.
+ Writing "-want_replacement" is allowed at any time. It clears
+ the flag.
+ Writing "replacement" or "-replacement" is only allowed before
+ starting the array. It sets or clears the flag.
+
This file responds to select/poll. Any change to 'faulty'
or 'blocked' causes an event.
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0e2288824938c..be569eb41a938 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1714,6 +1714,8 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
}
if (sb->devflags & WriteMostly1)
set_bit(WriteMostly, &rdev->flags);
+ if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
+ set_bit(Replacement, &rdev->flags);
} else /* MULTIPATH are always insync */
set_bit(In_sync, &rdev->flags);
@@ -1767,6 +1769,9 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
sb->recovery_offset =
cpu_to_le64(rdev->recovery_offset);
}
+ if (test_bit(Replacement, &rdev->flags))
+ sb->feature_map |=
+ cpu_to_le32(MD_FEATURE_REPLACEMENT);
if (mddev->reshape_position != MaxSector) {
sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
@@ -2560,6 +2565,15 @@ state_show(struct md_rdev *rdev, char *page)
len += sprintf(page+len, "%swrite_error", sep);
sep = ",";
}
+ if (test_bit(WantReplacement, &rdev->flags)) {
+ len += sprintf(page+len, "%swant_replacement", sep);
+ sep = ",";
+ }
+ if (test_bit(Replacement, &rdev->flags)) {
+ len += sprintf(page+len, "%sreplacement", sep);
+ sep = ",";
+ }
+
return len+sprintf(page+len, "\n");
}
@@ -2628,6 +2642,42 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
} else if (cmd_match(buf, "-write_error")) {
clear_bit(WriteErrorSeen, &rdev->flags);
err = 0;
+ } else if (cmd_match(buf, "want_replacement")) {
+ /* Any non-spare device that is not a replacement can
+ * become want_replacement at any time, but we then need to
+ * check if recovery is needed.
+ */
+ if (rdev->raid_disk >= 0 &&
+ !test_bit(Replacement, &rdev->flags))
+ set_bit(WantReplacement, &rdev->flags);
+ set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
+ md_wakeup_thread(rdev->mddev->thread);
+ err = 0;
+ } else if (cmd_match(buf, "-want_replacement")) {
+ /* Clearing 'want_replacement' is always allowed.
+ * Once replacements starts it is too late though.
+ */
+ err = 0;
+ clear_bit(WantReplacement, &rdev->flags);
+ } else if (cmd_match(buf, "replacement")) {
+ /* Can only set a device as a replacement when array has not
+ * yet been started. Once running, replacement is automatic
+ * from spares, or by assigning 'slot'.
+ */
+ if (rdev->mddev->pers)
+ err = -EBUSY;
+ else {
+ set_bit(Replacement, &rdev->flags);
+ err = 0;
+ }
+ } else if (cmd_match(buf, "-replacement")) {
+ /* Similarly, can only clear Replacement before start */
+ if (rdev->mddev->pers)
+ err = -EBUSY;
+ else {
+ clear_bit(Replacement, &rdev->flags);
+ err = 0;
+ }
}
if (!err)
sysfs_notify_dirent_safe(rdev->sysfs_state);
@@ -6717,8 +6767,11 @@ static int md_seq_show(struct seq_file *seq, void *v)
if (test_bit(Faulty, &rdev->flags)) {
seq_printf(seq, "(F)");
continue;
- } else if (rdev->raid_disk < 0)
+ }
+ if (rdev->raid_disk < 0)
seq_printf(seq, "(S)"); /* spare */
+ if (test_bit(Replacement, &rdev->flags))
+ seq_printf(seq, "(R)");
sectors += rdev->sectors;
}
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 670c10e6b4847..44c63dfeeb2b9 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -72,34 +72,7 @@ struct md_rdev {
* This reduces the burden of testing multiple flags in many cases
*/
- unsigned long flags;
-#define Faulty 1 /* device is known to have a fault */
-#define In_sync 2 /* device is in_sync with rest of array */
-#define WriteMostly 4 /* Avoid reading if at all possible */
-#define AutoDetected 7 /* added by auto-detect */
-#define Blocked 8 /* An error occurred but has not yet
- * been acknowledged by the metadata
- * handler, so don't allow writes
- * until it is cleared */
-#define WriteErrorSeen 9 /* A write error has been seen on this
- * device
- */
-#define FaultRecorded 10 /* Intermediate state for clearing
- * Blocked. The Fault is/will-be
- * recorded in the metadata, but that
- * metadata hasn't been stored safely
- * on disk yet.
- */
-#define BlockedBadBlocks 11 /* A writer is blocked because they
- * found an unacknowledged bad-block.
- * This can safely be cleared at any
- * time, and the writer will re-check.
- * It may be set at any time, and at
- * worst the writer will timeout and
- * re-check. So setting it as
- * accurately as possible is good, but
- * not absolutely critical.
- */
+ unsigned long flags; /* bit set of 'enum flag_bits' bits. */
wait_queue_head_t blocked_wait;
int desc_nr; /* descriptor index in the superblock */
@@ -152,6 +125,44 @@ struct md_rdev {
sector_t size; /* in sectors */
} badblocks;
};
+enum flag_bits {
+ Faulty, /* device is known to have a fault */
+ In_sync, /* device is in_sync with rest of array */
+ WriteMostly, /* Avoid reading if at all possible */
+ AutoDetected, /* added by auto-detect */
+ Blocked, /* An error occurred but has not yet
+ * been acknowledged by the metadata
+ * handler, so don't allow writes
+ * until it is cleared */
+ WriteErrorSeen, /* A write error has been seen on this
+ * device
+ */
+ FaultRecorded, /* Intermediate state for clearing
+ * Blocked. The Fault is/will-be
+ * recorded in the metadata, but that
+ * metadata hasn't been stored safely
+ * on disk yet.
+ */
+ BlockedBadBlocks, /* A writer is blocked because they
+ * found an unacknowledged bad-block.
+ * This can safely be cleared at any
+ * time, and the writer will re-check.
+ * It may be set at any time, and at
+ * worst the writer will timeout and
+ * re-check. So setting it as
+ * accurately as possible is good, but
+ * not absolutely critical.
+ */
+ WantReplacement, /* This device is a candidate to be
+ * hot-replaced, either because it has
+ * reported some faults, or because
+ * of explicit request.
+ */
+ Replacement, /* This device is a replacement for
+ * a want_replacement device with same
+ * raid_disk number.
+ */
+};
#define BB_LEN_MASK (0x00000000000001FFULL)
#define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL)
@@ -482,15 +493,20 @@ static inline char * mdname (struct mddev * mddev)
static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
{
char nm[20];
- sprintf(nm, "rd%d", rdev->raid_disk);
- return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
+ if (!test_bit(Replacement, &rdev->flags)) {
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
+ } else
+ return 0;
}
static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev)
{
char nm[20];
- sprintf(nm, "rd%d", rdev->raid_disk);
- sysfs_remove_link(&mddev->kobj, nm);
+ if (!test_bit(Replacement, &rdev->flags)) {
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ sysfs_remove_link(&mddev->kobj, nm);
+ }
}
/*
diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h
index 9e65d9e20662d..6f6df86f1ae51 100644
--- a/include/linux/raid/md_p.h
+++ b/include/linux/raid/md_p.h
@@ -277,7 +277,10 @@ struct mdp_superblock_1 {
*/
#define MD_FEATURE_RESHAPE_ACTIVE 4
#define MD_FEATURE_BAD_BLOCKS 8 /* badblock list is not empty */
-
-#define MD_FEATURE_ALL (1|2|4|8)
+#define MD_FEATURE_REPLACEMENT 16 /* This device is replacing an
+ * active device with same 'role'.
+ * 'recovery_offset' is also set.
+ */
+#define MD_FEATURE_ALL (1|2|4|8|16)
#endif