Introduce md_cluster_info
md_cluster_info stores the cluster information in the MD device.
The join() is called when mddev detects it is a clustered device.
The main responsibilities are:
1. Setup a DLM lockspace
2. Setup all initial locks such as super block locks and bitmap lock (will come later)
The leave() clears up the lockspace and all the locks held.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 3a57679..e2aacca 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -433,6 +433,7 @@
/* This might have been changed by a reshape */
sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
+ sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
bitmap_info.space);
kunmap_atomic(sb);
@@ -544,6 +545,7 @@
bitmap_super_t *sb;
unsigned long chunksize, daemon_sleep, write_behind;
unsigned long long events;
+ int nodes = 0;
unsigned long sectors_reserved = 0;
int err = -EINVAL;
struct page *sb_page;
@@ -583,6 +585,7 @@
daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
write_behind = le32_to_cpu(sb->write_behind);
sectors_reserved = le32_to_cpu(sb->sectors_reserved);
+ nodes = le32_to_cpu(sb->nodes);
/* verify that the bitmap-specific fields are valid */
if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
@@ -643,6 +646,7 @@
bitmap->mddev->bitmap_info.chunksize = chunksize;
bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
bitmap->mddev->bitmap_info.max_write_behind = write_behind;
+ bitmap->mddev->bitmap_info.nodes = nodes;
if (bitmap->mddev->bitmap_info.space == 0 ||
bitmap->mddev->bitmap_info.space > sectors_reserved)
bitmap->mddev->bitmap_info.space = sectors_reserved;
@@ -2186,6 +2190,8 @@
static ssize_t metadata_show(struct mddev *mddev, char *page)
{
+ if (mddev_is_clustered(mddev))
+ return sprintf(page, "clustered\n");
return sprintf(page, "%s\n", (mddev->bitmap_info.external
? "external" : "internal"));
}
@@ -2198,7 +2204,8 @@
return -EBUSY;
if (strncmp(buf, "external", 8) == 0)
mddev->bitmap_info.external = 1;
- else if (strncmp(buf, "internal", 8) == 0)
+ else if ((strncmp(buf, "internal", 8) == 0) ||
+ (strncmp(buf, "clustered", 9) == 0))
mddev->bitmap_info.external = 0;
else
return -EINVAL;
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index e223560..d141d48 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -22,8 +22,16 @@
struct dlm_lksb lksb;
char *name; /* lock name. */
uint32_t flags; /* flags to pass to dlm_lock() */
- void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
struct completion completion; /* completion for synchronized locking */
+ void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
+ struct mddev *mddev; /* pointing back to mddev. */
+};
+
+struct md_cluster_info {
+ /* dlm lock space and resources for clustered raid. */
+ dlm_lockspace_t *lockspace;
+ struct dlm_lock_resource *sb_lock;
+ struct mutex sb_mutex;
};
static void sync_ast(void *arg)
@@ -53,16 +61,18 @@
return dlm_lock_sync(res, DLM_LOCK_NL);
}
-static struct dlm_lock_resource *lockres_init(dlm_lockspace_t *lockspace,
+static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
{
struct dlm_lock_resource *res = NULL;
int ret, namelen;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
if (!res)
return NULL;
- res->ls = lockspace;
+ res->ls = cinfo->lockspace;
+ res->mddev = mddev;
namelen = strlen(name);
res->name = kzalloc(namelen + 1, GFP_KERNEL);
if (!res->name) {
@@ -114,13 +124,62 @@
kfree(res);
}
+static char *pretty_uuid(char *dest, char *src)
+{
+ int i, len = 0;
+
+ for (i = 0; i < 16; i++) {
+ if (i == 4 || i == 6 || i == 8 || i == 10)
+ len += sprintf(dest + len, "-");
+ len += sprintf(dest + len, "%02x", (__u8)src[i]);
+ }
+ return dest;
+}
+
static int join(struct mddev *mddev, int nodes)
{
+ struct md_cluster_info *cinfo;
+ int ret;
+ char str[64];
+
+ if (!try_module_get(THIS_MODULE))
+ return -ENOENT;
+
+ cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
+ if (!cinfo)
+ return -ENOMEM;
+
+ memset(str, 0, 64);
+ pretty_uuid(str, mddev->uuid);
+ ret = dlm_new_lockspace(str, NULL, DLM_LSFL_FS, LVB_SIZE,
+ NULL, NULL, NULL, &cinfo->lockspace);
+ if (ret)
+ goto err;
+ cinfo->sb_lock = lockres_init(mddev, "cmd-super",
+ NULL, 0);
+ if (!cinfo->sb_lock) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ mutex_init(&cinfo->sb_mutex);
+ mddev->cluster_info = cinfo;
return 0;
+err:
+ if (cinfo->lockspace)
+ dlm_release_lockspace(cinfo->lockspace, 2);
+ kfree(cinfo);
+ module_put(THIS_MODULE);
+ return ret;
}
static int leave(struct mddev *mddev)
{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ if (!cinfo)
+ return 0;
+ lockres_free(cinfo->sb_lock);
+ dlm_release_lockspace(cinfo->lockspace, 2);
return 0;
}
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 57ecb51..3387f94 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7279,6 +7279,8 @@
void md_cluster_stop(struct mddev *mddev)
{
+ if (!md_cluster_ops)
+ return;
md_cluster_ops->leave(mddev);
module_put(md_cluster_mod);
}
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 0185931..80fc899 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -203,6 +203,8 @@
int is_new);
extern void md_ack_all_badblocks(struct badblocks *bb);
+struct md_cluster_info;
+
struct mddev {
void *private;
struct md_personality *pers;
@@ -431,6 +433,7 @@
unsigned long daemon_sleep; /* how many jiffies between updates? */
unsigned long max_write_behind; /* write-behind mode */
int external;
+ int nodes; /* Maximum number of nodes in the cluster */
} bitmap_info;
atomic_t max_corr_read_errors; /* max read retries */
@@ -449,6 +452,7 @@
struct work_struct flush_work;
struct work_struct event_work; /* used by dm to report failure event */
void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
+ struct md_cluster_info *cluster_info;
};
static inline int __must_check mddev_lock(struct mddev *mddev)
@@ -676,4 +680,8 @@
}
extern struct md_cluster_operations *md_cluster_ops;
+static inline int mddev_is_clustered(struct mddev *mddev)
+{
+ return mddev->cluster_info && mddev->bitmap_info.nodes > 1;
+}
#endif /* _MD_MD_H */