Commit c4ce867f authored by Goldwyn Rodrigues's avatar Goldwyn Rodrigues
Browse files

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

drivers/md/bitmap.c

+8 −1
Original line number Diff line number Diff line
@@ -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 @@ out_no_sb: 
	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;

drivers/md/md-cluster.c

+62 −3
Original line number Diff line number Diff line
@@ -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;

}

drivers/md/md.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

}

drivers/md/md.h

+8 −0
Original line number Diff line number Diff line
@@ -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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