Commit c4ce867f authored by Goldwyn Rodrigues's avatar Goldwyn Rodrigues

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: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
parent edb39c9d
......@@ -433,6 +433,7 @@ void bitmap_update_sb(struct bitmap *bitmap)
/* 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 @@ static int bitmap_read_sb(struct bitmap *bitmap)
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 @@ static int bitmap_read_sb(struct bitmap *bitmap)
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 @@ static int bitmap_read_sb(struct bitmap *bitmap)
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 @@ __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
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 @@ static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
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;
......
......@@ -22,8 +22,16 @@ struct dlm_lock_resource {
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 @@ static int dlm_unlock_sync(struct dlm_lock_resource *res)
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 @@ static void lockres_free(struct dlm_lock_resource *res)
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;
}
......
......@@ -7279,6 +7279,8 @@ int md_setup_cluster(struct mddev *mddev, int nodes)
void md_cluster_stop(struct mddev *mddev)
{
if (!md_cluster_ops)
return;
md_cluster_ops->leave(mddev);
module_put(md_cluster_mod);
}
......
......@@ -203,6 +203,8 @@ extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
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 @@ struct mddev {
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 mddev {
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 @@ static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
}
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 */
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