Specify the write cache device with --write-cache DEVICE
./mdadm --create -f /dev/md0 --assume-clean -c 32 --raid-devices=4 --level=5 /dev/sd[c-f] --write-cache /dev/sdb1
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
Only one cache device is allowed. If multiple --write-cache
are given, mdadm will use the first and ignore others
./mdadm --create -f /dev/md0 --assume-clean -c 32 --raid-devices=4 --level=5 /dev/sd[c-f] --write-cache /dev/sdb1 --write-cache /dev/sdx
mdadm: Please specify only one cache device for the array.
mdadm: Ignoring --write-cache /dev/sdx...
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
Signed-off-by: Song Liu <songliubraving@xxxxxx>
---
Create.c | 21 +++++++++++++++------
ReadMe.c | 1 +
mdadm.c | 19 +++++++++++++++++++
mdadm.h | 2 ++
super1.c | 8 ++++++++
5 files changed, 45 insertions(+), 6 deletions(-)
diff --git a/Create.c b/Create.c
index ef28da0..0d2a591 100644
--- a/Create.c
+++ b/Create.c
@@ -87,7 +87,7 @@ int Create(struct supertype *st, char *mddev,
unsigned long long minsize=0, maxsize=0;
char *mindisc = NULL;
char *maxdisc = NULL;
- int dnum;
+ int dnum, raid_disk_num;
struct mddev_dev *dv;
int fail=0, warn=0;
struct stat stb;
@@ -180,11 +180,11 @@ int Create(struct supertype *st, char *mddev,
pr_err("This metadata type does not support spare disks at create time\n");
return 1;
}
- if (subdevs > s->raiddisks+s->sparedisks) {
+ if (subdevs > s->raiddisks+s->sparedisks+s->cachedisks) {
pr_err("You have listed more devices (%d) than are in the array(%d)!\n", subdevs, s->raiddisks+s->sparedisks);
return 1;
}
- if (!have_container && subdevs < s->raiddisks+s->sparedisks) {
+ if (!have_container && subdevs < s->raiddisks+s->sparedisks+s->cachedisks) {
pr_err("You haven't given enough devices (real or missing) to create this array\n");
return 1;
}
@@ -397,6 +397,9 @@ int Create(struct supertype *st, char *mddev,
}
}
+ if (dv->disposition == 'c')
+ continue; /* skip write cache for size check */
+
freesize /= 2; /* convert to K */
if (s->chunk && s->chunk != UnSet) {
/* round to chunk size */
@@ -834,7 +837,7 @@ int Create(struct supertype *st, char *mddev,
for (pass=1; pass <=2 ; pass++) {
struct mddev_dev *moved_disk = NULL; /* the disk that was moved out of the insert point */
- for (dnum=0, dv = devlist ; dv ;
+ for (dnum=0, raid_disk_num=0, dv = devlist ; dv ;
dv=(dv->next)?(dv->next):moved_disk, dnum++) {
int fd;
struct stat stb;
@@ -859,8 +862,13 @@ int Create(struct supertype *st, char *mddev,
*inf = info;
inf->disk.number = dnum;
- inf->disk.raid_disk = dnum;
- if (inf->disk.raid_disk < s->raiddisks)
+ inf->disk.raid_disk = raid_disk_num++;
+
+ if (dv->disposition == 'c') {
+ inf->disk.raid_disk = 0xfffd;
+ inf->disk.state = (1<<MD_DISK_WRITECACHE);
+ raid_disk_num--;
+ } else if (inf->disk.raid_disk < s->raiddisks)
inf->disk.state = (1<<MD_DISK_ACTIVE) |
(1<<MD_DISK_SYNC);
else
@@ -909,6 +917,7 @@ int Create(struct supertype *st, char *mddev,
inf->disk.major = major(stb.st_rdev);
inf->disk.minor = minor(stb.st_rdev);
}
+
break;
case 2:
inf->errors = 0;
diff --git a/ReadMe.c b/ReadMe.c
index 87a4916..74f7162 100644
--- a/ReadMe.c
+++ b/ReadMe.c
@@ -140,6 +140,7 @@ struct option long_options[] = {
{"homehost", 1, 0, HomeHost},
{"symlinks", 1, 0, Symlinks},
{"data-offset",1, 0, DataOffset},
+ {"write-cache",1, 0, WriteCache},
/* For assemble */
{"uuid", 1, 0, 'u'},
diff --git a/mdadm.c b/mdadm.c
index 3e8c49b..9a7048b 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -74,6 +74,7 @@ int main(int argc, char *argv[])
.require_homehost = 1,
};
struct shape s = {
+ .cachedisks = 0,
.level = UnSet,
.layout = UnSet,
.bitmap_chunk = UnSet,
@@ -1137,6 +1138,24 @@ int main(int argc, char *argv[])
case O(INCREMENTAL, IncrementalPath):
remove_path = optarg;
continue;
+ case O(CREATE, WriteCache):
+ if (s.cachedisks) {
+ pr_err("Please specify only one cache device for the array.\n");
+ pr_err("Ignoring --write-cache %s...\n", optarg);
+ continue;
+ }
+ dv = xmalloc(sizeof(*dv));
+ dv->devname = optarg;
+ dv->disposition = 'c'; /* WriteCache */
+ dv->writemostly = writemostly;
+ dv->used = 0;
+ dv->next = NULL;
+ *devlistend = dv;
+ devlistend = &dv->next;
+ devs_found++;
+
+ s.cachedisks = 1;
+ continue;
}
/* We have now processed all the valid options. Anything else is
* an error
diff --git a/mdadm.h b/mdadm.h
index 141f963..d28caa0 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -344,6 +344,7 @@ enum special_options {
Dump,
Restore,
Action,
+ WriteCache,
};
enum prefix_standard {
@@ -423,6 +424,7 @@ struct context {
struct shape {
int raiddisks;
int sparedisks;
+ int cachedisks;
int level;
int layout;
char *layout_str;
diff --git a/super1.c b/super1.c
index 7af0fd5..f8a55c6 100644
--- a/super1.c
+++ b/super1.c
@@ -977,6 +977,10 @@ static void getinfo_super1(struct supertype *st, struct mdinfo *info, char *map)
case 0xFFFE:
info->disk.state = 1; /* faulty */
break;
+ case 0xFFFD:
+ info->disk.state = (1 << MD_DISK_WRITECACHE); /* faulty */
+ info->disk.raid_disk = role;
+ break;
default:
info->disk.state = 6; /* active and in sync */
info->disk.raid_disk = role;
@@ -1096,6 +1100,8 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
int want;
if (info->disk.state & (1<<MD_DISK_ACTIVE))
want = info->disk.raid_disk;
+ else if (info->disk.state & (1<<MD_DISK_WRITECACHE))
+ want = 0xFFFD;
else
want = 0xFFFF;
if (sb->dev_roles[d] != __cpu_to_le16(want)) {
@@ -1422,6 +1428,8 @@ static int add_to_super1(struct supertype *st, mdu_disk_info_t *dk,
*rp = __cpu_to_le16(dk->raid_disk);
else if ((dk->state & ~2) == 0) /* active or idle -> spare */
*rp = 0xffff;
+ else if (dk->state & (1<<MD_DISK_WRITECACHE))
+ *rp = 0xfffd;
else
*rp = 0xfffe;
--
1.8.1
--
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