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-rw-r--r--Documentation/md-cluster.txt176
-rw-r--r--drivers/md/Kconfig16
-rw-r--r--drivers/md/Makefile1
-rw-r--r--drivers/md/bitmap.c189
-rw-r--r--drivers/md/bitmap.h10
-rw-r--r--drivers/md/md-cluster.c965
-rw-r--r--drivers/md/md-cluster.h29
-rw-r--r--drivers/md/md.c353
-rw-r--r--drivers/md/md.h24
-rw-r--r--drivers/md/raid1.c20
-rw-r--r--include/uapi/linux/raid/md_p.h7
-rw-r--r--include/uapi/linux/raid/md_u.h1
12 files changed, 1709 insertions, 82 deletions
diff --git a/Documentation/md-cluster.txt b/Documentation/md-cluster.txt
new file mode 100644
index 000000000000..de1af7db3355
--- /dev/null
+++ b/Documentation/md-cluster.txt
@@ -0,0 +1,176 @@
+The cluster MD is a shared-device RAID for a cluster.
+
+
+1. On-disk format
+
+Separate write-intent-bitmap are used for each cluster node.
+The bitmaps record all writes that may have been started on that node,
+and may not yet have finished. The on-disk layout is:
+
+0 4k 8k 12k
+-------------------------------------------------------------------
+| idle | md super | bm super [0] + bits |
+| bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] |
+| bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits |
+| bm bits [3, contd] | | |
+
+During "normal" functioning we assume the filesystem ensures that only one
+node writes to any given block at a time, so a write
+request will
+ - set the appropriate bit (if not already set)
+ - commit the write to all mirrors
+ - schedule the bit to be cleared after a timeout.
+
+Reads are just handled normally. It is up to the filesystem to
+ensure one node doesn't read from a location where another node (or the same
+node) is writing.
+
+
+2. DLM Locks for management
+
+There are two locks for managing the device:
+
+2.1 Bitmap lock resource (bm_lockres)
+
+ The bm_lockres protects individual node bitmaps. They are named in the
+ form bitmap001 for node 1, bitmap002 for node and so on. When a node
+ joins the cluster, it acquires the lock in PW mode and it stays so
+ during the lifetime the node is part of the cluster. The lock resource
+ number is based on the slot number returned by the DLM subsystem. Since
+ DLM starts node count from one and bitmap slots start from zero, one is
+ subtracted from the DLM slot number to arrive at the bitmap slot number.
+
+3. Communication
+
+Each node has to communicate with other nodes when starting or ending
+resync, and metadata superblock updates.
+
+3.1 Message Types
+
+ There are 3 types, of messages which are passed
+
+ 3.1.1 METADATA_UPDATED: informs other nodes that the metadata has been
+ updated, and the node must re-read the md superblock. This is performed
+ synchronously.
+
+ 3.1.2 RESYNC: informs other nodes that a resync is initiated or ended
+ so that each node may suspend or resume the region.
+
+3.2 Communication mechanism
+
+ The DLM LVB is used to communicate within nodes of the cluster. There
+ are three resources used for the purpose:
+
+ 3.2.1 Token: The resource which protects the entire communication
+ system. The node having the token resource is allowed to
+ communicate.
+
+ 3.2.2 Message: The lock resource which carries the data to
+ communicate.
+
+ 3.2.3 Ack: The resource, acquiring which means the message has been
+ acknowledged by all nodes in the cluster. The BAST of the resource
+ is used to inform the receive node that a node wants to communicate.
+
+The algorithm is:
+
+ 1. receive status
+
+ sender receiver receiver
+ ACK:CR ACK:CR ACK:CR
+
+ 2. sender get EX of TOKEN
+ sender get EX of MESSAGE
+ sender receiver receiver
+ TOKEN:EX ACK:CR ACK:CR
+ MESSAGE:EX
+ ACK:CR
+
+ Sender checks that it still needs to send a message. Messages received
+ or other events that happened while waiting for the TOKEN may have made
+ this message inappropriate or redundant.
+
+ 3. sender write LVB.
+ sender down-convert MESSAGE from EX to CR
+ sender try to get EX of ACK
+ [ wait until all receiver has *processed* the MESSAGE ]
+
+ [ triggered by bast of ACK ]
+ receiver get CR of MESSAGE
+ receiver read LVB
+ receiver processes the message
+ [ wait finish ]
+ receiver release ACK
+
+ sender receiver receiver
+ TOKEN:EX MESSAGE:CR MESSAGE:CR
+ MESSAGE:CR
+ ACK:EX
+
+ 4. triggered by grant of EX on ACK (indicating all receivers have processed
+ message)
+ sender down-convert ACK from EX to CR
+ sender release MESSAGE
+ sender release TOKEN
+ receiver upconvert to EX of MESSAGE
+ receiver get CR of ACK
+ receiver release MESSAGE
+
+ sender receiver receiver
+ ACK:CR ACK:CR ACK:CR
+
+
+4. Handling Failures
+
+4.1 Node Failure
+ When a node fails, the DLM informs the cluster with the slot. The node
+ starts a cluster recovery thread. The cluster recovery thread:
+ - acquires the bitmap<number> lock of the failed node
+ - opens the bitmap
+ - reads the bitmap of the failed node
+ - copies the set bitmap to local node
+ - cleans the bitmap of the failed node
+ - releases bitmap<number> lock of the failed node
+ - initiates resync of the bitmap on the current node
+
+ The resync process, is the regular md resync. However, in a clustered
+ environment when a resync is performed, it needs to tell other nodes
+ of the areas which are suspended. Before a resync starts, the node
+ send out RESYNC_START with the (lo,hi) range of the area which needs
+ to be suspended. Each node maintains a suspend_list, which contains
+ the list of ranges which are currently suspended. On receiving
+ RESYNC_START, the node adds the range to the suspend_list. Similarly,
+ when the node performing resync finishes, it send RESYNC_FINISHED
+ to other nodes and other nodes remove the corresponding entry from
+ the suspend_list.
+
+ A helper function, should_suspend() can be used to check if a particular
+ I/O range should be suspended or not.
+
+4.2 Device Failure
+ Device failures are handled and communicated with the metadata update
+ routine.
+
+5. Adding a new Device
+For adding a new device, it is necessary that all nodes "see" the new device
+to be added. For this, the following algorithm is used:
+
+ 1. Node 1 issues mdadm --manage /dev/mdX --add /dev/sdYY which issues
+ ioctl(ADD_NEW_DISC with disc.state set to MD_DISK_CLUSTER_ADD)
+ 2. Node 1 sends NEWDISK with uuid and slot number
+ 3. Other nodes issue kobject_uevent_env with uuid and slot number
+ (Steps 4,5 could be a udev rule)
+ 4. In userspace, the node searches for the disk, perhaps
+ using blkid -t SUB_UUID=""
+ 5. Other nodes issue either of the following depending on whether the disk
+ was found:
+ ioctl(ADD_NEW_DISK with disc.state set to MD_DISK_CANDIDATE and
+ disc.number set to slot number)
+ ioctl(CLUSTERED_DISK_NACK)
+ 6. Other nodes drop lock on no-new-devs (CR) if device is found
+ 7. Node 1 attempts EX lock on no-new-devs
+ 8. If node 1 gets the lock, it sends METADATA_UPDATED after unmarking the disk
+ as SpareLocal
+ 9. If not (get no-new-dev lock), it fails the operation and sends METADATA_UPDATED
+ 10. Other nodes get the information whether a disk is added or not
+ by the following METADATA_UPDATED.
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 63e05e32b462..eed1fec2d97b 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -175,6 +175,22 @@ config MD_FAULTY
In unsure, say N.
+
+config MD_CLUSTER
+ tristate "Cluster Support for MD (EXPERIMENTAL)"
+ depends on BLK_DEV_MD
+ depends on DLM
+ default n
+ ---help---
+ Clustering support for MD devices. This enables locking and
+ synchronization across multiple systems on the cluster, so all
+ nodes in the cluster can access the MD devices simultaneously.
+
+ This brings the redundancy (and uptime) of RAID levels across the
+ nodes of the cluster.
+
+ If unsure, say N.
+
source "drivers/md/bcache/Kconfig"
config BLK_DEV_DM_BUILTIN
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index a2da532b1c2b..7ed86876f3b7 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_MD_RAID10) += raid10.o
obj-$(CONFIG_MD_RAID456) += raid456.o
obj-$(CONFIG_MD_MULTIPATH) += multipath.o
obj-$(CONFIG_MD_FAULTY) += faulty.o
+obj-$(CONFIG_MD_CLUSTER) += md-cluster.o
obj-$(CONFIG_BCACHE) += bcache/
obj-$(CONFIG_BLK_DEV_MD) += md-mod.o
obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 3a5767968ba0..2bc56e2a3526 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -205,6 +205,10 @@ static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
struct block_device *bdev;
struct mddev *mddev = bitmap->mddev;
struct bitmap_storage *store = &bitmap->storage;
+ int node_offset = 0;
+
+ if (mddev_is_clustered(bitmap->mddev))
+ node_offset = bitmap->cluster_slot * store->file_pages;
while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
int size = PAGE_SIZE;
@@ -433,6 +437,7 @@ 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 +549,7 @@ 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;
@@ -562,6 +568,22 @@ static int bitmap_read_sb(struct bitmap *bitmap)
return -ENOMEM;
bitmap->storage.sb_page = sb_page;
+re_read:
+ /* If cluster_slot is set, the cluster is setup */
+ if (bitmap->cluster_slot >= 0) {
+ sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
+
+ sector_div(bm_blocks,
+ bitmap->mddev->bitmap_info.chunksize >> 9);
+ /* bits to bytes */
+ bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
+ /* to 4k blocks */
+ bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
+ bitmap->mddev->bitmap_info.offset += bitmap->cluster_slot * (bm_blocks << 3);
+ pr_info("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
+ bitmap->cluster_slot, (unsigned long long)bitmap->mddev->bitmap_info.offset);
+ }
+
if (bitmap->storage.file) {
loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
@@ -577,12 +599,15 @@ static int bitmap_read_sb(struct bitmap *bitmap)
if (err)
return err;
+ err = -EINVAL;
sb = kmap_atomic(sb_page);
chunksize = le32_to_cpu(sb->chunksize);
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);
+ strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
/* verify that the bitmap-specific fields are valid */
if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
@@ -619,7 +644,7 @@ static int bitmap_read_sb(struct bitmap *bitmap)
goto out;
}
events = le64_to_cpu(sb->events);
- if (events < bitmap->mddev->events) {
+ if (!nodes && (events < bitmap->mddev->events)) {
printk(KERN_INFO
"%s: bitmap file is out of date (%llu < %llu) "
"-- forcing full recovery\n",
@@ -634,20 +659,40 @@ static int bitmap_read_sb(struct bitmap *bitmap)
if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
+ strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
err = 0;
+
out:
kunmap_atomic(sb);
+ /* Assiging chunksize is required for "re_read" */
+ bitmap->mddev->bitmap_info.chunksize = chunksize;
+ if (nodes && (bitmap->cluster_slot < 0)) {
+ err = md_setup_cluster(bitmap->mddev, nodes);
+ if (err) {
+ pr_err("%s: Could not setup cluster service (%d)\n",
+ bmname(bitmap), err);
+ goto out_no_sb;
+ }
+ bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
+ goto re_read;
+ }
+
+
out_no_sb:
if (test_bit(BITMAP_STALE, &bitmap->flags))
bitmap->events_cleared = bitmap->mddev->events;
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;
- if (err)
+ if (err) {
bitmap_print_sb(bitmap);
+ if (bitmap->cluster_slot < 0)
+ md_cluster_stop(bitmap->mddev);
+ }
return err;
}
@@ -692,9 +737,10 @@ static inline struct page *filemap_get_page(struct bitmap_storage *store,
}
static int bitmap_storage_alloc(struct bitmap_storage *store,
- unsigned long chunks, int with_super)
+ unsigned long chunks, int with_super,
+ int slot_number)
{
- int pnum;
+ int pnum, offset = 0;
unsigned long num_pages;
unsigned long bytes;
@@ -703,6 +749,7 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
bytes += sizeof(bitmap_super_t);
num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
+ offset = slot_number * (num_pages - 1);
store->filemap = kmalloc(sizeof(struct page *)
* num_pages, GFP_KERNEL);
@@ -713,20 +760,22 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
if (store->sb_page == NULL)
return -ENOMEM;
- store->sb_page->index = 0;
}
+
pnum = 0;
if (store->sb_page) {
store->filemap[0] = store->sb_page;
pnum = 1;
+ store->sb_page->index = offset;
}
+
for ( ; pnum < num_pages; pnum++) {
store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
if (!store->filemap[pnum]) {
store->file_pages = pnum;
return -ENOMEM;
}
- store->filemap[pnum]->index = pnum;
+ store->filemap[pnum]->index = pnum + offset;
}
store->file_pages = pnum;
@@ -885,6 +934,28 @@ static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
}
}
+static int bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
+{
+ unsigned long bit;
+ struct page *page;
+ void *paddr;
+ unsigned long chunk = block >> bitmap->counts.chunkshift;
+ int set = 0;
+
+ page = filemap_get_page(&bitmap->storage, chunk);
+ if (!page)
+ return -EINVAL;
+ bit = file_page_offset(&bitmap->storage, chunk);
+ paddr = kmap_atomic(page);
+ if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
+ set = test_bit(bit, paddr);
+ else
+ set = test_bit_le(bit, paddr);
+ kunmap_atomic(paddr);
+ return set;
+}
+
+
/* this gets called when the md device is ready to unplug its underlying
* (slave) device queues -- before we let any writes go down, we need to
* sync the dirty pages of the bitmap file to disk */
@@ -935,7 +1006,7 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int n
*/
static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
{
- unsigned long i, chunks, index, oldindex, bit;
+ unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
struct page *page = NULL;
unsigned long bit_cnt = 0;
struct file *file;
@@ -981,6 +1052,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
if (!bitmap->mddev->bitmap_info.external)
offset = sizeof(bitmap_super_t);
+ if (mddev_is_clustered(bitmap->mddev))
+ node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
+
for (i = 0; i < chunks; i++) {
int b;
index = file_page_index(&bitmap->storage, i);
@@ -1001,7 +1075,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
bitmap->mddev,
bitmap->mddev->bitmap_info.offset,
page,
- index, count);
+ index + node_offset, count);
if (ret)
goto err;
@@ -1207,7 +1281,6 @@ void bitmap_daemon_work(struct mddev *mddev)
j < bitmap->storage.file_pages
&& !test_bit(BITMAP_STALE, &bitmap->flags);
j++) {
-
if (test_page_attr(bitmap, j,
BITMAP_PAGE_DIRTY))
/* bitmap_unplug will handle the rest */
@@ -1530,11 +1603,13 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int n
return;
}
if (!*bmc) {
- *bmc = 2 | (needed ? NEEDED_MASK : 0);
+ *bmc = 2;
bitmap_count_page(&bitmap->counts, offset, 1);
bitmap_set_pending(&bitmap->counts, offset);
bitmap->allclean = 0;
}
+ if (needed)
+ *bmc |= NEEDED_MASK;
spin_unlock_irq(&bitmap->counts.lock);
}
@@ -1591,6 +1666,10 @@ static void bitmap_free(struct bitmap *bitmap)
if (!bitmap) /* there was no bitmap */
return;
+ if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
+ bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
+ md_cluster_stop(bitmap->mddev);
+
/* Shouldn't be needed - but just in case.... */
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes) == 0);
@@ -1636,7 +1715,7 @@ void bitmap_destroy(struct mddev *mddev)
* initialize the bitmap structure
* if this returns an error, bitmap_destroy must be called to do clean up
*/
-int bitmap_create(struct mddev *mddev)
+struct bitmap *bitmap_create(struct mddev *mddev, int slot)
{
struct bitmap *bitmap;
sector_t blocks = mddev->resync_max_sectors;
@@ -1650,7 +1729,7 @@ int bitmap_create(struct mddev *mddev)
bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
if (!bitmap)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
spin_lock_init(&bitmap->counts.lock);
atomic_set(&bitmap->pending_writes, 0);
@@ -1659,6 +1738,7 @@ int bitmap_create(struct mddev *mddev)
init_waitqueue_head(&bitmap->behind_wait);
bitmap->mddev = mddev;
+ bitmap->cluster_slot = slot;
if (mddev->kobj.sd)
bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
@@ -1706,12 +1786,14 @@ int bitmap_create(struct mddev *mddev)
printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
bitmap->counts.pages, bmname(bitmap));
- mddev->bitmap = bitmap;
- return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
+ err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
+ if (err)
+ goto error;
+ return bitmap;
error:
bitmap_free(bitmap);
- return err;
+ return ERR_PTR(err);
}
int bitmap_load(struct mddev *mddev)
@@ -1765,6 +1847,60 @@ out:
}
EXPORT_SYMBOL_GPL(bitmap_load);
+/* Loads the bitmap associated with slot and copies the resync information
+ * to our bitmap
+ */
+int bitmap_copy_from_slot(struct mddev *mddev, int slot,
+ sector_t *low, sector_t *high, bool clear_bits)
+{
+ int rv = 0, i, j;
+ sector_t block, lo = 0, hi = 0;
+ struct bitmap_counts *counts;
+ struct bitmap *bitmap = bitmap_create(mddev, slot);
+
+ if (IS_ERR(bitmap))
+ return PTR_ERR(bitmap);
+
+ rv = bitmap_read_sb(bitmap);
+ if (rv)
+ goto err;
+
+ rv = bitmap_init_from_disk(bitmap, 0);
+ if (rv)
+ goto err;
+
+ counts = &bitmap->counts;
+ for (j = 0; j < counts->chunks; j++) {
+ block = (sector_t)j << counts->chunkshift;
+ if (bitmap_file_test_bit(bitmap, block)) {
+ if (!lo)
+ lo = block;
+ hi = block;
+ bitmap_file_clear_bit(bitmap, block);
+ bitmap_set_memory_bits(mddev->bitmap, block, 1);
+ bitmap_file_set_bit(mddev->bitmap, block);
+ }
+ }
+
+ if (clear_bits) {
+ bitmap_update_sb(bitmap);
+ /* Setting this for the ev_page should be enough.
+ * And we do not require both write_all and PAGE_DIRT either
+ */
+ for (i = 0; i < bitmap->storage.file_pages; i++)
+ set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
+ bitmap_write_all(bitmap);
+ bitmap_unplug(bitmap);
+ }
+ *low = lo;
+ *high = hi;
+err:
+ bitmap_free(bitmap);
+ return rv;
+}
+EXPORT_SYMBOL_GPL(bitmap_copy_from_slot);
+
+
void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
{
unsigned long chunk_kb;
@@ -1849,7 +1985,8 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
memset(&store, 0, sizeof(store));
if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
ret = bitmap_storage_alloc(&store, chunks,
- !bitmap->mddev->bitmap_info.external);
+ !bitmap->mddev->bitmap_info.external,
+ bitmap->cluster_slot);
if (ret)
goto err;
@@ -2021,13 +2158,18 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
return -EINVAL;
mddev->bitmap_info.offset = offset;
if (mddev->pers) {
+ struct bitmap *bitmap;
mddev->pers->quiesce(mddev, 1);
- rv = bitmap_create(mddev);
- if (!rv)
+ bitmap = bitmap_create(mddev, -1);
+ if (IS_ERR(bitmap))
+ rv = PTR_ERR(bitmap);
+ else {
+ mddev->bitmap = bitmap;
rv = bitmap_load(mddev);
- if (rv) {
- bitmap_destroy(mddev);
- mddev->bitmap_info.offset = 0;
+ if (rv) {
+ bitmap_destroy(mddev);
+ mddev->bitmap_info.offset = 0;
+ }
}
mddev->pers->quiesce(mddev, 0);
if (rv)
@@ -2186,6 +2328,8 @@ __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 +2342,8 @@ 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;
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index 30210b9c4ef9..f1f4dd01090d 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -130,8 +130,9 @@ typedef struct bitmap_super_s {
__le32 write_behind; /* 60 number of outstanding write-behind writes */
__le32 sectors_reserved; /* 64 number of 512-byte sectors that are
* reserved for the bitmap. */
-
- __u8 pad[256 - 68]; /* set to zero */
+ __le32 nodes; /* 68 the maximum number of nodes in cluster. */
+ __u8 cluster_name[64]; /* 72 cluster name to which this md belongs */
+ __u8 pad[256 - 136]; /* set to zero */
} bitmap_super_t;
/* notes:
@@ -226,12 +227,13 @@ struct bitmap {
wait_queue_head_t behind_wait;
struct kernfs_node *sysfs_can_clear;
+ int cluster_slot; /* Slot offset for clustered env */
};
/* the bitmap API */
/* these are used only by md/bitmap */
-int bitmap_create(struct mddev *mddev);
+struct bitmap *bitmap_create(struct mddev *mddev, int slot);
int bitmap_load(struct mddev *mddev);
void bitmap_flush(struct mddev *mddev);
void bitmap_destroy(struct mddev *mddev);
@@ -260,6 +262,8 @@ void bitmap_daemon_work(struct mddev *mddev);
int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
int chunksize, int init);
+int bitmap_copy_from_slot(struct mddev *mddev, int slot,
+ sector_t *lo, sector_t *hi, bool clear_bits);
#endif
#endif
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
new file mode 100644
index 000000000000..fcfc4b9b2672
--- /dev/null
+++ b/drivers/md/md-cluster.c
@@ -0,0 +1,965 @@
+/*
+ * Copyright (C) 2015, SUSE
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ */
+
+
+#include <linux/module.h>
+#include <linux/dlm.h>
+#include <linux/sched.h>
+#include <linux/raid/md_p.h>
+#include "md.h"
+#include "bitmap.h"
+#include "md-cluster.h"
+
+#define LVB_SIZE 64
+#define NEW_DEV_TIMEOUT 5000
+
+struct dlm_lock_resource {
+ dlm_lockspace_t *ls;
+ struct dlm_lksb lksb;
+ char *name; /* lock name. */
+ uint32_t flags; /* flags to pass to dlm_lock() */
+ 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 suspend_info {
+ int slot;
+ sector_t lo;
+ sector_t hi;
+ struct list_head list;
+};
+
+struct resync_info {
+ __le64 lo;
+ __le64 hi;
+};
+
+/* md_cluster_info flags */
+#define MD_CLUSTER_WAITING_FOR_NEWDISK 1
+
+
+struct md_cluster_info {
+ /* dlm lock space and resources for clustered raid. */
+ dlm_lockspace_t *lockspace;
+ int slot_number;
+ struct completion completion;
+ struct dlm_lock_resource *sb_lock;
+ struct mutex sb_mutex;
+ struct dlm_lock_resource *bitmap_lockres;
+ struct list_head suspend_list;
+ spinlock_t suspend_lock;
+ struct md_thread *recovery_thread;
+ unsigned long recovery_map;
+ /* communication loc resources */
+ struct dlm_lock_resource *ack_lockres;
+ struct dlm_lock_resource *message_lockres;
+ struct dlm_lock_resource *token_lockres;
+ struct dlm_lock_resource *no_new_dev_lockres;
+ struct md_thread *recv_thread;
+ struct completion newdisk_completion;
+ unsigned long state;
+};
+
+enum msg_type {
+ METADATA_UPDATED = 0,
+ RESYNCING,
+ NEWDISK,
+ REMOVE,
+ RE_ADD,
+};
+
+struct cluster_msg {
+ int type;
+ int slot;
+ /* TODO: Unionize this for smaller footprint */
+ sector_t low;
+ sector_t high;
+ char uuid[16];
+ int raid_slot;
+};
+
+static void sync_ast(void *arg)
+{
+ struct dlm_lock_resource *res;
+
+ res = (struct dlm_lock_resource *) arg;
+ complete(&res->completion);
+}
+
+static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
+{
+ int ret = 0;
+
+ init_completion(&res->completion);
+ ret = dlm_lock(res->ls, mode, &res->lksb,
+ res->flags, res->name, strlen(res->name),
+ 0, sync_ast, res, res->bast);
+ if (ret)
+ return ret;
+ wait_for_completion(&res->completion);
+ return res->lksb.sb_status;
+}
+
+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(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 = cinfo->lockspace;
+ res->mddev = mddev;
+ namelen = strlen(name);
+ res->name = kzalloc(namelen + 1, GFP_KERNEL);
+ if (!res->name) {
+ pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
+ goto out_err;
+ }
+ strlcpy(res->name, name, namelen + 1);
+ if (with_lvb) {
+ res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
+ if (!res->lksb.sb_lvbptr) {
+ pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
+ goto out_err;
+ }
+ res->flags = DLM_LKF_VALBLK;
+ }
+
+ if (bastfn)
+ res->bast = bastfn;
+
+ res->flags |= DLM_LKF_EXPEDITE;
+
+ ret = dlm_lock_sync(res, DLM_LOCK_NL);
+ if (ret) {
+ pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
+ goto out_err;
+ }
+ res->flags &= ~DLM_LKF_EXPEDITE;
+ res->flags |= DLM_LKF_CONVERT;
+
+ return res;
+out_err:
+ kfree(res->lksb.sb_lvbptr);
+ kfree(res->name);
+ kfree(res);
+ return NULL;
+}
+
+static void lockres_free(struct dlm_lock_resource *res)
+{
+ if (!res)
+ return;
+
+ init_completion(&res->completion);
+ dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res);
+ wait_for_completion(&res->completion);
+
+ kfree(res->name);
+ kfree(res->lksb.sb_lvbptr);
+ 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 void add_resync_info(struct mddev *mddev, struct dlm_lock_resource *lockres,
+ sector_t lo, sector_t hi)
+{
+ struct resync_info *ri;
+
+ ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
+ ri->lo = cpu_to_le64(lo);
+ ri->hi = cpu_to_le64(hi);
+}
+
+static struct suspend_info *read_resync_info(struct mddev *mddev, struct dlm_lock_resource *lockres)
+{
+ struct resync_info ri;
+ struct suspend_info *s = NULL;
+ sector_t hi = 0;
+
+ dlm_lock_sync(lockres, DLM_LOCK_CR);
+ memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
+ hi = le64_to_cpu(ri.hi);
+ if (ri.hi > 0) {
+ s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
+ if (!s)
+ goto out;
+ s->hi = hi;
+ s->lo = le64_to_cpu(ri.lo);
+ }
+ dlm_unlock_sync(lockres);
+out:
+ return s;
+}
+
+static void recover_bitmaps(struct md_thread *thread)
+{
+ struct mddev *mddev = thread->mddev;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ struct dlm_lock_resource *bm_lockres;
+ char str[64];
+ int slot, ret;
+ struct suspend_info *s, *tmp;
+ sector_t lo, hi;
+
+ while (cinfo->recovery_map) {
+ slot = fls64((u64)cinfo->recovery_map) - 1;
+
+ /* Clear suspend_area associated with the bitmap */
+ spin_lock_irq(&cinfo->suspend_lock);
+ list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
+ if (slot == s->slot) {
+ list_del(&s->list);
+ kfree(s);
+ }
+ spin_unlock_irq(&cinfo->suspend_lock);
+
+ snprintf(str, 64, "bitmap%04d", slot);
+ bm_lockres = lockres_init(mddev, str, NULL, 1);
+ if (!bm_lockres) {
+ pr_err("md-cluster: Cannot initialize bitmaps\n");
+ goto clear_bit;
+ }
+
+ ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
+ if (ret) {
+ pr_err("md-cluster: Could not DLM lock %s: %d\n",
+ str, ret);
+ goto clear_bit;
+ }
+ ret = bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
+ if (ret) {
+ pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
+ goto dlm_unlock;
+ }
+ if (hi > 0) {
+ /* TODO:Wait for current resync to get over */
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ if (lo < mddev->recovery_cp)
+ mddev->recovery_cp = lo;
+ md_check_recovery(mddev);
+ }
+dlm_unlock:
+ dlm_unlock_sync(bm_lockres);
+clear_bit:
+ clear_bit(slot, &cinfo->recovery_map);
+ }
+}
+
+static void recover_prep(void *arg)
+{
+}
+
+static void recover_slot(void *arg, struct dlm_slot *slot)
+{
+ struct mddev *mddev = arg;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
+ mddev->bitmap_info.cluster_name,
+ slot->nodeid, slot->slot,
+ cinfo->slot_number);
+ set_bit(slot->slot - 1, &cinfo->recovery_map);
+ if (!cinfo->recovery_thread) {
+ cinfo->recovery_thread = md_register_thread(recover_bitmaps,
+ mddev, "recover");
+ if (!cinfo->recovery_thread) {
+ pr_warn("md-cluster: Could not create recovery thread\n");
+ return;
+ }
+ }
+ md_wakeup_thread(cinfo->recovery_thread);
+}
+
+static void recover_done(void *arg, struct dlm_slot *slots,
+ int num_slots, int our_slot,
+ uint32_t generation)
+{
+ struct mddev *mddev = arg;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ cinfo->slot_number = our_slot;
+ complete(&cinfo->completion);
+}
+
+static const struct dlm_lockspace_ops md_ls_ops = {
+ .recover_prep = recover_prep,
+ .recover_slot = recover_slot,
+ .recover_done = recover_done,
+};
+
+/*
+ * The BAST function for the ack lock resource
+ * This function wakes up the receive thread in
+ * order to receive and process the message.
+ */
+static void ack_bast(void *arg, int mode)
+{
+ struct dlm_lock_resource *res = (struct dlm_lock_resource *)arg;
+ struct md_cluster_info *cinfo = res->mddev->cluster_info;
+
+ if (mode == DLM_LOCK_EX)
+ md_wakeup_thread(cinfo->recv_thread);
+}
+
+static void __remove_suspend_info(struct md_cluster_info *cinfo, int slot)
+{
+ struct suspend_info *s, *tmp;
+
+ list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
+ if (slot == s->slot) {
+ pr_info("%s:%d Deleting suspend_info: %d\n",
+ __func__, __LINE__, slot);
+ list_del(&s->list);
+ kfree(s);
+ break;
+ }
+}
+
+static void remove_suspend_info(struct md_cluster_info *cinfo, int slot)
+{
+ spin_lock_irq(&cinfo->suspend_lock);
+ __remove_suspend_info(cinfo, slot);
+ spin_unlock_irq(&cinfo->suspend_lock);
+}
+
+
+static void process_suspend_info(struct md_cluster_info *cinfo,
+ int slot, sector_t lo, sector_t hi)
+{
+ struct suspend_info *s;
+
+ if (!hi) {
+ remove_suspend_info(cinfo, slot);
+ return;
+ }
+ s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
+ if (!s)
+ return;
+ s->slot = slot;
+ s->lo = lo;
+ s->hi = hi;
+ spin_lock_irq(&cinfo->suspend_lock);
+ /* Remove existing entry (if exists) before adding */
+ __remove_suspend_info(cinfo, slot);
+ list_add(&s->list, &cinfo->suspend_list);
+ spin_unlock_irq(&cinfo->suspend_lock);
+}
+
+static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
+{
+ char disk_uuid[64];
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ char event_name[] = "EVENT=ADD_DEVICE";
+ char raid_slot[16];
+ char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
+ int len;
+
+ len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
+ pretty_uuid(disk_uuid + len, cmsg->uuid);
+ snprintf(raid_slot, 16, "RAID_DISK=%d", cmsg->raid_slot);
+ pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
+ init_completion(&cinfo->newdisk_completion);
+ set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
+ kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
+ wait_for_completion_timeout(&cinfo->newdisk_completion,
+ NEW_DEV_TIMEOUT);
+ clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
+}
+
+
+static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ md_reload_sb(mddev);
+ dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
+}
+
+static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
+{
+ struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev, msg->raid_slot);
+
+ if (rdev)
+ md_kick_rdev_from_array(rdev);
+ else
+ pr_warn("%s: %d Could not find disk(%d) to REMOVE\n", __func__, __LINE__, msg->raid_slot);
+}
+
+static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
+{
+ struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev, msg->raid_slot);
+
+ if (rdev && test_bit(Faulty, &rdev->flags))
+ clear_bit(Faulty, &rdev->flags);
+ else
+ pr_warn("%s: %d Could not find disk(%d) which is faulty", __func__, __LINE__, msg->raid_slot);
+}
+
+static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
+{
+ switch (msg->type) {
+ case METADATA_UPDATED:
+ pr_info("%s: %d Received message: METADATA_UPDATE from %d\n",
+ __func__, __LINE__, msg->slot);
+ process_metadata_update(mddev, msg);
+ break;
+ case RESYNCING:
+ pr_info("%s: %d Received message: RESYNCING from %d\n",
+ __func__, __LINE__, msg->slot);
+ process_suspend_info(mddev->cluster_info, msg->slot,
+ msg->low, msg->high);
+ break;
+ case NEWDISK:
+ pr_info("%s: %d Received message: NEWDISK from %d\n",
+ __func__, __LINE__, msg->slot);
+ process_add_new_disk(mddev, msg);
+ break;
+ case REMOVE:
+ pr_info("%s: %d Received REMOVE from %d\n",
+ __func__, __LINE__, msg->slot);
+ process_remove_disk(mddev, msg);
+ break;
+ case RE_ADD:
+ pr_info("%s: %d Received RE_ADD from %d\n",
+ __func__, __LINE__, msg->slot);
+ process_readd_disk(mddev, msg);
+ break;
+ default:
+ pr_warn("%s:%d Received unknown message from %d\n",
+ __func__, __LINE__, msg->slot);
+ }
+}
+
+/*
+ * thread for receiving message
+ */
+static void recv_daemon(struct md_thread *thread)
+{
+ struct md_cluster_info *cinfo = thread->mddev->cluster_info;
+ struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
+ struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
+ struct cluster_msg msg;
+
+ /*get CR on Message*/
+ if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
+ pr_err("md/raid1:failed to get CR on MESSAGE\n");
+ return;
+ }
+
+ /* read lvb and wake up thread to process this message_lockres */
+ memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
+ process_recvd_msg(thread->mddev, &msg);
+
+ /*release CR on ack_lockres*/
+ dlm_unlock_sync(ack_lockres);
+ /*up-convert to EX on message_lockres*/
+ dlm_lock_sync(message_lockres, DLM_LOCK_EX);
+ /*get CR on ack_lockres again*/
+ dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
+ /*release CR on message_lockres*/
+ dlm_unlock_sync(message_lockres);
+}
+
+/* lock_comm()
+ * Takes the lock on the TOKEN lock resource so no other
+ * node can communicate while the operation is underway.
+ */
+static int lock_comm(struct md_cluster_info *cinfo)
+{
+ int error;
+
+ error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
+ if (error)
+ pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
+ __func__, __LINE__, error);
+ return error;
+}
+
+static void unlock_comm(struct md_cluster_info *cinfo)
+{
+ dlm_unlock_sync(cinfo->token_lockres);
+}
+
+/* __sendmsg()
+ * This function performs the actual sending of the message. This function is
+ * usually called after performing the encompassing operation
+ * The function:
+ * 1. Grabs the message lockresource in EX mode
+ * 2. Copies the message to the message LVB
+ * 3. Downconverts message lockresource to CR
+ * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
+ * and the other nodes read the message. The thread will wait here until all other
+ * nodes have released ack lock resource.
+ * 5. Downconvert ack lockresource to CR
+ */
+static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
+{
+ int error;
+ int slot = cinfo->slot_number - 1;
+
+ cmsg->slot = cpu_to_le32(slot);
+ /*get EX on Message*/
+ error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
+ if (error) {
+ pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
+ goto failed_message;
+ }
+
+ memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
+ sizeof(struct cluster_msg));
+ /*down-convert EX to CR on Message*/
+ error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CR);
+ if (error) {
+ pr_err("md-cluster: failed to convert EX to CR on MESSAGE(%d)\n",
+ error);
+ goto failed_message;
+ }
+
+ /*up-convert CR to EX on Ack*/
+ error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
+ if (error) {
+ pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
+ error);
+ goto failed_ack;
+ }
+
+ /*down-convert EX to CR on Ack*/
+ error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
+ if (error) {
+ pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
+ error);
+ goto failed_ack;
+ }
+
+failed_ack:
+ dlm_unlock_sync(cinfo->message_lockres);
+failed_message:
+ return error;
+}
+
+static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
+{
+ int ret;
+
+ lock_comm(cinfo);
+ ret = __sendmsg(cinfo, cmsg);
+ unlock_comm(cinfo);
+ return ret;
+}
+
+static int gather_all_resync_info(struct mddev *mddev, int total_slots)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ int i, ret = 0;
+ struct dlm_lock_resource *bm_lockres;
+ struct suspend_info *s;
+ char str[64];
+
+
+ for (i = 0; i < total_slots; i++) {
+ memset(str, '\0', 64);
+ snprintf(str, 64, "bitmap%04d", i);
+ bm_lockres = lockres_init(mddev, str, NULL, 1);
+ if (!bm_lockres)
+ return -ENOMEM;
+ if (i == (cinfo->slot_number - 1))
+ continue;
+
+ bm_lockres->flags |= DLM_LKF_NOQUEUE;
+ ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
+ if (ret == -EAGAIN) {
+ memset(bm_lockres->lksb.sb_lvbptr, '\0', LVB_SIZE);
+ s = read_resync_info(mddev, bm_lockres);
+ if (s) {
+ pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
+ __func__, __LINE__,
+ (unsigned long long) s->lo,
+ (unsigned long long) s->hi, i);
+ spin_lock_irq(&cinfo->suspend_lock);
+ s->slot = i;
+ list_add(&s->list, &cinfo->suspend_list);
+ spin_unlock_irq(&cinfo->suspend_lock);
+ }
+ ret = 0;
+ lockres_free(bm_lockres);
+ continue;
+ }
+ if (ret)
+ goto out;
+ /* TODO: Read the disk bitmap sb and check if it needs recovery */
+ dlm_unlock_sync(bm_lockres);
+ lockres_free(bm_lockres);
+ }
+out:
+ return ret;
+}
+
+static int join(struct mddev *mddev, int nodes)
+{
+ struct md_cluster_info *cinfo;
+ int ret, ops_rv;
+ char str[64];
+
+ if (!try_module_get(THIS_MODULE))
+ return -ENOENT;
+
+ cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
+ if (!cinfo)
+ return -ENOMEM;
+
+ init_completion(&cinfo->completion);
+
+ mutex_init(&cinfo->sb_mutex);
+ mddev->cluster_info = cinfo;
+
+ memset(str, 0, 64);
+ pretty_uuid(str, mddev->uuid);
+ ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
+ DLM_LSFL_FS, LVB_SIZE,
+ &md_ls_ops, mddev, &ops_rv, &cinfo->lockspace);
+ if (ret)
+ goto err;
+ wait_for_completion(&cinfo->completion);
+ if (nodes < cinfo->slot_number) {
+ pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
+ cinfo->slot_number, nodes);
+ ret = -ERANGE;
+ goto err;
+ }
+ cinfo->sb_lock = lockres_init(mddev, "cmd-super",
+ NULL, 0);
+ if (!cinfo->sb_lock) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ /* Initiate the communication resources */
+ ret = -ENOMEM;
+ cinfo->recv_thread = md_register_thread(recv_daemon, mddev, "cluster_recv");
+ if (!cinfo->recv_thread) {
+ pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
+ goto err;
+ }
+ cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
+ if (!cinfo->message_lockres)
+ goto err;
+ cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
+ if (!cinfo->token_lockres)
+ goto err;
+ cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
+ if (!cinfo->ack_lockres)
+ goto err;
+ cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
+ if (!cinfo->no_new_dev_lockres)
+ goto err;
+
+ /* get sync CR lock on ACK. */
+ if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
+ pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
+ ret);
+ /* get sync CR lock on no-new-dev. */
+ if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
+ pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
+
+
+ pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
+ snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
+ cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
+ if (!cinfo->bitmap_lockres)
+ goto err;
+ if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
+ pr_err("Failed to get bitmap lock\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ INIT_LIST_HEAD(&cinfo->suspend_list);
+ spin_lock_init(&cinfo->suspend_lock);
+
+ ret = gather_all_resync_info(mddev, nodes);
+ if (ret)
+ goto err;
+
+ return 0;
+err:
+ lockres_free(cinfo->message_lockres);
+ lockres_free(cinfo->token_lockres);
+ lockres_free(cinfo->ack_lockres);
+ lockres_free(cinfo->no_new_dev_lockres);
+ lockres_free(cinfo->bitmap_lockres);
+ lockres_free(cinfo->sb_lock);
+ if (cinfo->lockspace)
+ dlm_release_lockspace(cinfo->lockspace, 2);
+ mddev->cluster_info = NULL;
+ 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;
+ md_unregister_thread(&cinfo->recovery_thread);
+ md_unregister_thread(&cinfo->recv_thread);
+ lockres_free(cinfo->message_lockres);
+ lockres_free(cinfo->token_lockres);
+ lockres_free(cinfo->ack_lockres);
+ lockres_free(cinfo->no_new_dev_lockres);
+ lockres_free(cinfo->sb_lock);
+ lockres_free(cinfo->bitmap_lockres);
+ dlm_release_lockspace(cinfo->lockspace, 2);
+ return 0;
+}
+
+/* slot_number(): Returns the MD slot number to use
+ * DLM starts the slot numbers from 1, wheras cluster-md
+ * wants the number to be from zero, so we deduct one
+ */
+static int slot_number(struct mddev *mddev)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ return cinfo->slot_number - 1;
+}
+
+static void resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ add_resync_info(mddev, cinfo->bitmap_lockres, lo, hi);
+ /* Re-acquire the lock to refresh LVB */
+ dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
+}
+
+static int metadata_update_start(struct mddev *mddev)
+{
+ return lock_comm(mddev->cluster_info);
+}
+
+static int metadata_update_finish(struct mddev *mddev)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ struct cluster_msg cmsg;
+ int ret;
+
+ memset(&cmsg, 0, sizeof(cmsg));
+ cmsg.type = cpu_to_le32(METADATA_UPDATED);
+ ret = __sendmsg(cinfo, &cmsg);
+ unlock_comm(cinfo);
+ return ret;
+}
+
+static int metadata_update_cancel(struct mddev *mddev)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ return dlm_unlock_sync(cinfo->token_lockres);
+}
+
+static int resync_send(struct mddev *mddev, enum msg_type type,
+ sector_t lo, sector_t hi)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ struct cluster_msg cmsg;
+ int slot = cinfo->slot_number - 1;
+
+ pr_info("%s:%d lo: %llu hi: %llu\n", __func__, __LINE__,
+ (unsigned long long)lo,
+ (unsigned long long)hi);
+ resync_info_update(mddev, lo, hi);
+ cmsg.type = cpu_to_le32(type);
+ cmsg.slot = cpu_to_le32(slot);
+ cmsg.low = cpu_to_le64(lo);
+ cmsg.high = cpu_to_le64(hi);
+ return sendmsg(cinfo, &cmsg);
+}
+
+static int resync_start(struct mddev *mddev, sector_t lo, sector_t hi)
+{
+ pr_info("%s:%d\n", __func__, __LINE__);
+ return resync_send(mddev, RESYNCING, lo, hi);
+}
+
+static void resync_finish(struct mddev *mddev)
+{
+ pr_info("%s:%d\n", __func__, __LINE__);
+ resync_send(mddev, RESYNCING, 0, 0);
+}
+
+static int area_resyncing(struct mddev *mddev, sector_t lo, sector_t hi)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ int ret = 0;
+ struct suspend_info *s;
+
+ spin_lock_irq(&cinfo->suspend_lock);
+ if (list_empty(&cinfo->suspend_list))
+ goto out;
+ list_for_each_entry(s, &cinfo->suspend_list, list)
+ if (hi > s->lo && lo < s->hi) {
+ ret = 1;
+ break;
+ }
+out:
+ spin_unlock_irq(&cinfo->suspend_lock);
+ return ret;
+}
+
+static int add_new_disk_start(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ struct cluster_msg cmsg;
+ int ret = 0;
+ struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
+ char *uuid = sb->device_uuid;
+
+ memset(&cmsg, 0, sizeof(cmsg));
+ cmsg.type = cpu_to_le32(NEWDISK);
+ memcpy(cmsg.uuid, uuid, 16);
+ cmsg.raid_slot = rdev->desc_nr;
+ lock_comm(cinfo);
+ ret = __sendmsg(cinfo, &cmsg);
+ if (ret)
+ return ret;
+ cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
+ ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
+ cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
+ /* Some node does not "see" the device */
+ if (ret == -EAGAIN)
+ ret = -ENOENT;
+ else
+ dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
+ return ret;
+}
+
+static int add_new_disk_finish(struct mddev *mddev)
+{
+ struct cluster_msg cmsg;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ int ret;
+ /* Write sb and inform others */
+ md_update_sb(mddev, 1);
+ cmsg.type = METADATA_UPDATED;
+ ret = __sendmsg(cinfo, &cmsg);
+ unlock_comm(cinfo);
+ return ret;
+}
+
+static int new_disk_ack(struct mddev *mddev, bool ack)
+{
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
+ pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
+ return -EINVAL;
+ }
+
+ if (ack)
+ dlm_unlock_sync(cinfo->no_new_dev_lockres);
+ complete(&cinfo->newdisk_completion);
+ return 0;
+}
+
+static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct cluster_msg cmsg;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+ cmsg.type = REMOVE;
+ cmsg.raid_slot = rdev->desc_nr;
+ return __sendmsg(cinfo, &cmsg);
+}
+
+static int gather_bitmaps(struct md_rdev *rdev)
+{
+ int sn, err;
+ sector_t lo, hi;
+ struct cluster_msg cmsg;
+ struct mddev *mddev = rdev->mddev;
+ struct md_cluster_info *cinfo = mddev->cluster_info;
+
+ cmsg.type = RE_ADD;
+ cmsg.raid_slot = rdev->desc_nr;
+ err = sendmsg(cinfo, &cmsg);
+ if (err)
+ goto out;
+
+ for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
+ if (sn == (cinfo->slot_number - 1))
+ continue;
+ err = bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
+ if (err) {
+ pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
+ goto out;
+ }
+ if ((hi > 0) && (lo < mddev->recovery_cp))
+ mddev->recovery_cp = lo;
+ }
+out:
+ return err;
+}
+
+static struct md_cluster_operations cluster_ops = {
+ .join = join,
+ .leave = leave,
+ .slot_number = slot_number,
+ .resync_info_update = resync_info_update,
+ .resync_start = resync_start,
+ .resync_finish = resync_finish,
+ .metadata_update_start = metadata_update_start,
+ .metadata_update_finish = metadata_update_finish,
+ .metadata_update_cancel = metadata_update_cancel,
+ .area_resyncing = area_resyncing,
+ .add_new_disk_start = add_new_disk_start,
+ .add_new_disk_finish = add_new_disk_finish,
+ .new_disk_ack = new_disk_ack,
+ .remove_disk = remove_disk,
+ .gather_bitmaps = gather_bitmaps,
+};
+
+static int __init cluster_init(void)
+{
+ pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n");
+ pr_info("Registering Cluster MD functions\n");
+ register_md_cluster_operations(&cluster_ops, THIS_MODULE);
+ return 0;
+}
+
+static void cluster_exit(void)
+{
+ unregister_md_cluster_operations();
+}
+
+module_init(cluster_init);
+module_exit(cluster_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Clustering support for MD");
diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
new file mode 100644
index 000000000000..6817ee00e053
--- /dev/null
+++ b/drivers/md/md-cluster.h
@@ -0,0 +1,29 @@
+
+
+#ifndef _MD_CLUSTER_H
+#define _MD_CLUSTER_H
+
+#include "md.h"
+
+struct mddev;
+struct md_rdev;
+
+struct md_cluster_operations {
+ int (*join)(struct mddev *mddev, int nodes);
+ int (*leave)(struct mddev *mddev);
+ int (*slot_number)(struct mddev *mddev);
+ void (*resync_info_update)(struct mddev *mddev, sector_t lo, sector_t hi);
+ int (*resync_start)(struct mddev *mddev, sector_t lo, sector_t hi);
+ void (*resync_finish)(struct mddev *mddev);
+ int (*metadata_update_start)(struct mddev *mddev);
+ int (*metadata_update_finish)(struct mddev *mddev);
+ int (*metadata_update_cancel)(struct mddev *mddev);
+ int (*area_resyncing)(struct mddev *mddev, sector_t lo, sector_t hi);
+ int (*add_new_disk_start)(struct mddev *mddev, struct md_rdev *rdev);
+ int (*add_new_disk_finish)(struct mddev *mddev);
+ int (*new_disk_ack)(struct mddev *mddev, bool ack);
+ int (*remove_disk)(struct mddev *mddev, struct md_rdev *rdev);
+ int (*gather_bitmaps)(struct md_rdev *rdev);
+};
+
+#endif /* _MD_CLUSTER_H */
diff --git a/drivers/md/md.c b/drivers/md/md.c
index e6178787ce3d..0d8968535976 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -53,6 +53,7 @@
#include <linux/slab.h>
#include "md.h"
#include "bitmap.h"
+#include "md-cluster.h"
#ifndef MODULE
static void autostart_arrays(int part);
@@ -66,6 +67,11 @@ static void autostart_arrays(int part);
static LIST_HEAD(pers_list);
static DEFINE_SPINLOCK(pers_lock);
+struct md_cluster_operations *md_cluster_ops;
+EXPORT_SYMBOL(md_cluster_ops);
+struct module *md_cluster_mod;
+EXPORT_SYMBOL(md_cluster_mod);
+
static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
static struct workqueue_struct *md_wq;
static struct workqueue_struct *md_misc_wq;
@@ -640,7 +646,7 @@ void mddev_unlock(struct mddev *mddev)
}
EXPORT_SYMBOL_GPL(mddev_unlock);
-static struct md_rdev *find_rdev_nr_rcu(struct mddev *mddev, int nr)
+struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
{
struct md_rdev *rdev;
@@ -650,6 +656,7 @@ static struct md_rdev *find_rdev_nr_rcu(struct mddev *mddev, int nr)
return NULL;
}
+EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
{
@@ -2047,11 +2054,11 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
int choice = 0;
if (mddev->pers)
choice = mddev->raid_disks;
- while (find_rdev_nr_rcu(mddev, choice))
+ while (md_find_rdev_nr_rcu(mddev, choice))
choice++;
rdev->desc_nr = choice;
} else {
- if (find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
+ if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
rcu_read_unlock();
return -EBUSY;
}
@@ -2166,11 +2173,12 @@ static void export_rdev(struct md_rdev *rdev)
kobject_put(&rdev->kobj);
}
-static void kick_rdev_from_array(struct md_rdev *rdev)
+void md_kick_rdev_from_array(struct md_rdev *rdev)
{
unbind_rdev_from_array(rdev);
export_rdev(rdev);
}
+EXPORT_SYMBOL_GPL(md_kick_rdev_from_array);
static void export_array(struct mddev *mddev)
{
@@ -2179,7 +2187,7 @@ static void export_array(struct mddev *mddev)
while (!list_empty(&mddev->disks)) {
rdev = list_first_entry(&mddev->disks, struct md_rdev,
same_set);
- kick_rdev_from_array(rdev);
+ md_kick_rdev_from_array(rdev);
}
mddev->raid_disks = 0;
mddev->major_version = 0;
@@ -2208,7 +2216,7 @@ static void sync_sbs(struct mddev *mddev, int nospares)
}
}
-static void md_update_sb(struct mddev *mddev, int force_change)
+void md_update_sb(struct mddev *mddev, int force_change)
{
struct md_rdev *rdev;
int sync_req;
@@ -2369,6 +2377,37 @@ repeat:
wake_up(&rdev->blocked_wait);
}
}
+EXPORT_SYMBOL(md_update_sb);
+
+static int add_bound_rdev(struct md_rdev *rdev)
+{
+ struct mddev *mddev = rdev->mddev;
+ int err = 0;
+
+ if (!mddev->pers->hot_remove_disk) {
+ /* If there is hot_add_disk but no hot_remove_disk
+ * then added disks for geometry changes,
+ * and should be added immediately.
+ */
+ super_types[mddev->major_version].
+ validate_super(mddev, rdev);
+ err = mddev->pers->hot_add_disk(mddev, rdev);
+ if (err) {
+ unbind_rdev_from_array(rdev);
+ export_rdev(rdev);
+ return err;
+ }
+ }
+ sysfs_notify_dirent_safe(rdev->sysfs_state);
+
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ if (mddev->degraded)
+ set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_new_event(mddev);
+ md_wakeup_thread(mddev->thread);
+ return 0;
+}
/* words written to sysfs files may, or may not, be \n terminated.
* We want to accept with case. For this we use cmd_match.
@@ -2471,10 +2510,16 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
err = -EBUSY;
else {
struct mddev *mddev = rdev->mddev;
- kick_rdev_from_array(rdev);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->remove_disk(mddev, rdev);
+ md_kick_rdev_from_array(rdev);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
if (mddev->pers)
md_update_sb(mddev, 1);
md_new_event(mddev);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
err = 0;
}
} else if (cmd_match(buf, "writemostly")) {
@@ -2553,6 +2598,21 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
clear_bit(Replacement, &rdev->flags);
err = 0;
}
+ } else if (cmd_match(buf, "re-add")) {
+ if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1)) {
+ /* clear_bit is performed _after_ all the devices
+ * have their local Faulty bit cleared. If any writes
+ * happen in the meantime in the local node, they
+ * will land in the local bitmap, which will be synced
+ * by this node eventually
+ */
+ if (!mddev_is_clustered(rdev->mddev) ||
+ (err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
+ clear_bit(Faulty, &rdev->flags);
+ err = add_bound_rdev(rdev);
+ }
+ } else
+ err = -EBUSY;
}
if (!err)
sysfs_notify_dirent_safe(rdev->sysfs_state);
@@ -3127,7 +3187,7 @@ static void analyze_sbs(struct mddev *mddev)
"md: fatal superblock inconsistency in %s"
" -- removing from array\n",
bdevname(rdev->bdev,b));
- kick_rdev_from_array(rdev);
+ md_kick_rdev_from_array(rdev);
}
super_types[mddev->major_version].
@@ -3142,18 +3202,27 @@ static void analyze_sbs(struct mddev *mddev)
"md: %s: %s: only %d devices permitted\n",
mdname(mddev), bdevname(rdev->bdev, b),
mddev->max_disks);
- kick_rdev_from_array(rdev);
+ md_kick_rdev_from_array(rdev);
continue;
}
- if (rdev != freshest)
+ if (rdev != freshest) {
if (super_types[mddev->major_version].
validate_super(mddev, rdev)) {
printk(KERN_WARNING "md: kicking non-fresh %s"
" from array!\n",
bdevname(rdev->bdev,b));
- kick_rdev_from_array(rdev);
+ md_kick_rdev_from_array(rdev);
continue;
}
+ /* No device should have a Candidate flag
+ * when reading devices
+ */
+ if (test_bit(Candidate, &rdev->flags)) {
+ pr_info("md: kicking Cluster Candidate %s from array!\n",
+ bdevname(rdev->bdev, b));
+ md_kick_rdev_from_array(rdev);
+ }
+ }
if (mddev->level == LEVEL_MULTIPATH) {
rdev->desc_nr = i++;
rdev->raid_disk = rdev->desc_nr;
@@ -4008,8 +4077,12 @@ size_store(struct mddev *mddev, const char *buf, size_t len)
if (err)
return err;
if (mddev->pers) {
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
err = update_size(mddev, sectors);
md_update_sb(mddev, 1);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
} else {
if (mddev->dev_sectors == 0 ||
mddev->dev_sectors > sectors)
@@ -5077,10 +5150,16 @@ int md_run(struct mddev *mddev)
}
if (err == 0 && pers->sync_request &&
(mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
- err = bitmap_create(mddev);
- if (err)
+ struct bitmap *bitmap;
+
+ bitmap = bitmap_create(mddev, -1);
+ if (IS_ERR(bitmap)) {
+ err = PTR_ERR(bitmap);
printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
mdname(mddev), err);
+ } else
+ mddev->bitmap = bitmap;
+
}
if (err) {
mddev_detach(mddev);
@@ -5232,6 +5311,8 @@ static void md_clean(struct mddev *mddev)
static void __md_stop_writes(struct mddev *mddev)
{
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
flush_workqueue(md_misc_wq);
if (mddev->sync_thread) {
@@ -5250,6 +5331,8 @@ static void __md_stop_writes(struct mddev *mddev)
mddev->in_sync = 1;
md_update_sb(mddev, 1);
}
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
}
void md_stop_writes(struct mddev *mddev)
@@ -5636,6 +5719,8 @@ static int get_array_info(struct mddev *mddev, void __user *arg)
info.state = (1<<MD_SB_CLEAN);
if (mddev->bitmap && mddev->bitmap_info.offset)
info.state |= (1<<MD_SB_BITMAP_PRESENT);
+ if (mddev_is_clustered(mddev))
+ info.state |= (1<<MD_SB_CLUSTERED);
info.active_disks = insync;
info.working_disks = working;
info.failed_disks = failed;
@@ -5691,7 +5776,7 @@ static int get_disk_info(struct mddev *mddev, void __user * arg)
return -EFAULT;
rcu_read_lock();
- rdev = find_rdev_nr_rcu(mddev, info.number);
+ rdev = md_find_rdev_nr_rcu(mddev, info.number);
if (rdev) {
info.major = MAJOR(rdev->bdev->bd_dev);
info.minor = MINOR(rdev->bdev->bd_dev);
@@ -5724,6 +5809,13 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
struct md_rdev *rdev;
dev_t dev = MKDEV(info->major,info->minor);
+ if (mddev_is_clustered(mddev) &&
+ !(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
+ pr_err("%s: Cannot add to clustered mddev.\n",
+ mdname(mddev));
+ return -EINVAL;
+ }
+
if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
return -EOVERFLOW;
@@ -5810,31 +5902,38 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
else
clear_bit(WriteMostly, &rdev->flags);
+ /*
+ * check whether the device shows up in other nodes
+ */
+ if (mddev_is_clustered(mddev)) {
+ if (info->state & (1 << MD_DISK_CANDIDATE)) {
+ /* Through --cluster-confirm */
+ set_bit(Candidate, &rdev->flags);
+ err = md_cluster_ops->new_disk_ack(mddev, true);
+ if (err) {
+ export_rdev(rdev);
+ return err;
+ }
+ } else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
+ /* --add initiated by this node */
+ err = md_cluster_ops->add_new_disk_start(mddev, rdev);
+ if (err) {
+ md_cluster_ops->add_new_disk_finish(mddev);
+ export_rdev(rdev);
+ return err;
+ }
+ }
+ }
+
rdev->raid_disk = -1;
err = bind_rdev_to_array(rdev, mddev);
- if (!err && !mddev->pers->hot_remove_disk) {
- /* If there is hot_add_disk but no hot_remove_disk
- * then added disks for geometry changes,
- * and should be added immediately.
- */
- super_types[mddev->major_version].
- validate_super(mddev, rdev);
- err = mddev->pers->hot_add_disk(mddev, rdev);
- if (err)
- unbind_rdev_from_array(rdev);
- }
if (err)
export_rdev(rdev);
else
- sysfs_notify_dirent_safe(rdev->sysfs_state);
-
- set_bit(MD_CHANGE_DEVS, &mddev->flags);
- if (mddev->degraded)
- set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
- set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
- if (!err)
- md_new_event(mddev);
- md_wakeup_thread(mddev->thread);
+ err = add_bound_rdev(rdev);
+ if (mddev_is_clustered(mddev) &&
+ (info->state & (1 << MD_DISK_CLUSTER_ADD)))
+ md_cluster_ops->add_new_disk_finish(mddev);
return err;
}
@@ -5895,18 +5994,29 @@ static int hot_remove_disk(struct mddev *mddev, dev_t dev)
if (!rdev)
return -ENXIO;
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
+
clear_bit(Blocked, &rdev->flags);
remove_and_add_spares(mddev, rdev);
if (rdev->raid_disk >= 0)
goto busy;
- kick_rdev_from_array(rdev);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->remove_disk(mddev, rdev);
+
+ md_kick_rdev_from_array(rdev);
md_update_sb(mddev, 1);
md_new_event(mddev);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
+
return 0;
busy:
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_cancel(mddev);
printk(KERN_WARNING "md: cannot remove active disk %s from %s ...\n",
bdevname(rdev->bdev,b), mdname(mddev));
return -EBUSY;
@@ -5956,12 +6066,15 @@ static int hot_add_disk(struct mddev *mddev, dev_t dev)
err = -EINVAL;
goto abort_export;
}
+
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
clear_bit(In_sync, &rdev->flags);
rdev->desc_nr = -1;
rdev->saved_raid_disk = -1;
err = bind_rdev_to_array(rdev, mddev);
if (err)
- goto abort_export;
+ goto abort_clustered;
/*
* The rest should better be atomic, we can have disk failures
@@ -5972,6 +6085,8 @@ static int hot_add_disk(struct mddev *mddev, dev_t dev)
md_update_sb(mddev, 1);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
/*
* Kick recovery, maybe this spare has to be added to the
* array immediately.
@@ -5981,6 +6096,9 @@ static int hot_add_disk(struct mddev *mddev, dev_t dev)
md_new_event(mddev);
return 0;
+abort_clustered:
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_cancel(mddev);
abort_export:
export_rdev(rdev);
return err;
@@ -6038,9 +6156,14 @@ static int set_bitmap_file(struct mddev *mddev, int fd)
if (mddev->pers) {
mddev->pers->quiesce(mddev, 1);
if (fd >= 0) {
- err = bitmap_create(mddev);
- if (!err)
+ struct bitmap *bitmap;
+
+ bitmap = bitmap_create(mddev, -1);
+ if (!IS_ERR(bitmap)) {
+ mddev->bitmap = bitmap;
err = bitmap_load(mddev);
+ } else
+ err = PTR_ERR(bitmap);
}
if (fd < 0 || err) {
bitmap_destroy(mddev);
@@ -6293,6 +6416,8 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
return rv;
}
}
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
rv = update_size(mddev, (sector_t)info->size * 2);
@@ -6300,33 +6425,49 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
rv = update_raid_disks(mddev, info->raid_disks);
if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
- if (mddev->pers->quiesce == NULL || mddev->thread == NULL)
- return -EINVAL;
- if (mddev->recovery || mddev->sync_thread)
- return -EBUSY;
+ if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {
+ rv = -EINVAL;
+ goto err;
+ }
+ if (mddev->recovery || mddev->sync_thread) {
+ rv = -EBUSY;
+ goto err;
+ }
if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
+ struct bitmap *bitmap;
/* add the bitmap */
- if (mddev->bitmap)
- return -EEXIST;
- if (mddev->bitmap_info.default_offset == 0)
- return -EINVAL;
+ if (mddev->bitmap) {
+ rv = -EEXIST;
+ goto err;
+ }
+ if (mddev->bitmap_info.default_offset == 0) {
+ rv = -EINVAL;
+ goto err;
+ }
mddev->bitmap_info.offset =
mddev->bitmap_info.default_offset;
mddev->bitmap_info.space =
mddev->bitmap_info.default_space;
mddev->pers->quiesce(mddev, 1);
- rv = bitmap_create(mddev);
- if (!rv)
+ bitmap = bitmap_create(mddev, -1);
+ if (!IS_ERR(bitmap)) {
+ mddev->bitmap = bitmap;
rv = bitmap_load(mddev);
+ } else
+ rv = PTR_ERR(bitmap);
if (rv)
bitmap_destroy(mddev);
mddev->pers->quiesce(mddev, 0);
} else {
/* remove the bitmap */
- if (!mddev->bitmap)
- return -ENOENT;
- if (mddev->bitmap->storage.file)
- return -EINVAL;
+ if (!mddev->bitmap) {
+ rv = -ENOENT;
+ goto err;
+ }
+ if (mddev->bitmap->storage.file) {
+ rv = -EINVAL;
+ goto err;
+ }
mddev->pers->quiesce(mddev, 1);
bitmap_destroy(mddev);
mddev->pers->quiesce(mddev, 0);
@@ -6334,6 +6475,12 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
}
}
md_update_sb(mddev, 1);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
+ return rv;
+err:
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_cancel(mddev);
return rv;
}
@@ -6393,6 +6540,7 @@ static inline bool md_ioctl_valid(unsigned int cmd)
case SET_DISK_FAULTY:
case STOP_ARRAY:
case STOP_ARRAY_RO:
+ case CLUSTERED_DISK_NACK:
return true;
default:
return false;
@@ -6665,6 +6813,13 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
goto unlock;
}
+ case CLUSTERED_DISK_NACK:
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->new_disk_ack(mddev, false);
+ else
+ err = -EINVAL;
+ goto unlock;
+
case HOT_ADD_DISK:
err = hot_add_disk(mddev, new_decode_dev(arg));
goto unlock;
@@ -7238,6 +7393,55 @@ int unregister_md_personality(struct md_personality *p)
}
EXPORT_SYMBOL(unregister_md_personality);
+int register_md_cluster_operations(struct md_cluster_operations *ops, struct module *module)
+{
+ if (md_cluster_ops != NULL)
+ return -EALREADY;
+ spin_lock(&pers_lock);
+ md_cluster_ops = ops;
+ md_cluster_mod = module;
+ spin_unlock(&pers_lock);
+ return 0;
+}
+EXPORT_SYMBOL(register_md_cluster_operations);
+
+int unregister_md_cluster_operations(void)
+{
+ spin_lock(&pers_lock);
+ md_cluster_ops = NULL;
+ spin_unlock(&pers_lock);
+ return 0;
+}
+EXPORT_SYMBOL(unregister_md_cluster_operations);
+
+int md_setup_cluster(struct mddev *mddev, int nodes)
+{
+ int err;
+
+ err = request_module("md-cluster");
+ if (err) {
+ pr_err("md-cluster module not found.\n");
+ return err;
+ }
+
+ spin_lock(&pers_lock);
+ if (!md_cluster_ops || !try_module_get(md_cluster_mod)) {
+ spin_unlock(&pers_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&pers_lock);
+
+ return md_cluster_ops->join(mddev, nodes);
+}
+
+void md_cluster_stop(struct mddev *mddev)
+{
+ if (!md_cluster_ops)
+ return;
+ md_cluster_ops->leave(mddev);
+ module_put(md_cluster_mod);
+}
+
static int is_mddev_idle(struct mddev *mddev, int init)
{
struct md_rdev *rdev;
@@ -7375,7 +7579,11 @@ int md_allow_write(struct mddev *mddev)
mddev->safemode == 0)
mddev->safemode = 1;
spin_unlock(&mddev->lock);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
md_update_sb(mddev, 0);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
sysfs_notify_dirent_safe(mddev->sysfs_state);
} else
spin_unlock(&mddev->lock);
@@ -7576,6 +7784,9 @@ void md_do_sync(struct md_thread *thread)
md_new_event(mddev);
update_time = jiffies;
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->resync_start(mddev, j, max_sectors);
+
blk_start_plug(&plug);
while (j < max_sectors) {
sector_t sectors;
@@ -7636,6 +7847,8 @@ void md_do_sync(struct md_thread *thread)
j += sectors;
if (j > 2)
mddev->curr_resync = j;
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->resync_info_update(mddev, j, max_sectors);
mddev->curr_mark_cnt = io_sectors;
if (last_check == 0)
/* this is the earliest that rebuild will be
@@ -7696,6 +7909,9 @@ void md_do_sync(struct md_thread *thread)
/* tell personality that we are finished */
mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->resync_finish(mddev);
+
if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
mddev->curr_resync > 2) {
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
@@ -7925,8 +8141,13 @@ void md_check_recovery(struct mddev *mddev)
sysfs_notify_dirent_safe(mddev->sysfs_state);
}
- if (mddev->flags & MD_UPDATE_SB_FLAGS)
+ if (mddev->flags & MD_UPDATE_SB_FLAGS) {
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
md_update_sb(mddev, 0);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
+ }
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
!test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
@@ -8024,6 +8245,8 @@ void md_reap_sync_thread(struct mddev *mddev)
set_bit(MD_CHANGE_DEVS, &mddev->flags);
}
}
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_start(mddev);
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
mddev->pers->finish_reshape)
mddev->pers->finish_reshape(mddev);
@@ -8036,6 +8259,8 @@ void md_reap_sync_thread(struct mddev *mddev)
rdev->saved_raid_disk = -1;
md_update_sb(mddev, 1);
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->metadata_update_finish(mddev);
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
@@ -8656,6 +8881,28 @@ err_wq:
return ret;
}
+void md_reload_sb(struct mddev *mddev)
+{
+ struct md_rdev *rdev, *tmp;
+
+ rdev_for_each_safe(rdev, tmp, mddev) {
+ rdev->sb_loaded = 0;
+ ClearPageUptodate(rdev->sb_page);
+ }
+ mddev->raid_disks = 0;
+ analyze_sbs(mddev);
+ rdev_for_each_safe(rdev, tmp, mddev) {
+ struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
+ /* since we don't write to faulty devices, we figure out if the
+ * disk is faulty by comparing events
+ */
+ if (mddev->events > sb->events)
+ set_bit(Faulty, &rdev->flags);
+ }
+
+}
+EXPORT_SYMBOL(md_reload_sb);
+
#ifndef MODULE
/*
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 318ca8fd430f..ecdce36ec6b8 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -23,6 +23,7 @@
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
+#include "md-cluster.h"
#define MaxSector (~(sector_t)0)
@@ -170,6 +171,10 @@ enum flag_bits {
* a want_replacement device with same
* raid_disk number.
*/
+ Candidate, /* For clustered environments only:
+ * This device is seen locally but not
+ * by the whole cluster
+ */
};
#define BB_LEN_MASK (0x00000000000001FFULL)
@@ -202,6 +207,8 @@ 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;
@@ -430,6 +437,8 @@ 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 */
+ char cluster_name[64]; /* Name of the cluster */
} bitmap_info;
atomic_t max_corr_read_errors; /* max read retries */
@@ -448,6 +457,7 @@ 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)
@@ -608,6 +618,11 @@ static inline void safe_put_page(struct page *p)
extern int register_md_personality(struct md_personality *p);
extern int unregister_md_personality(struct md_personality *p);
+extern int register_md_cluster_operations(struct md_cluster_operations *ops,
+ struct module *module);
+extern int unregister_md_cluster_operations(void);
+extern int md_setup_cluster(struct mddev *mddev, int nodes);
+extern void md_cluster_stop(struct mddev *mddev);
extern struct md_thread *md_register_thread(
void (*run)(struct md_thread *thread),
struct mddev *mddev,
@@ -654,6 +669,10 @@ extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
struct mddev *mddev);
extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
+extern void md_reload_sb(struct mddev *mddev);
+extern void md_update_sb(struct mddev *mddev, int force);
+extern void md_kick_rdev_from_array(struct md_rdev * rdev);
+struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
static inline int mddev_check_plugged(struct mddev *mddev)
{
return !!blk_check_plugged(md_unplug, mddev,
@@ -669,4 +688,9 @@ 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 */
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d34e238afa54..4efa50186a2a 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -539,7 +539,13 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
has_nonrot_disk = 0;
choose_next_idle = 0;
- choose_first = (conf->mddev->recovery_cp < this_sector + sectors);
+ if ((conf->mddev->recovery_cp < this_sector + sectors) ||
+ (mddev_is_clustered(conf->mddev) &&
+ md_cluster_ops->area_resyncing(conf->mddev, this_sector,
+ this_sector + sectors)))
+ choose_first = 1;
+ else
+ choose_first = 0;
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
sector_t dist;
@@ -1102,8 +1108,10 @@ static void make_request(struct mddev *mddev, struct bio * bio)
md_write_start(mddev, bio); /* wait on superblock update early */
if (bio_data_dir(bio) == WRITE &&
- bio_end_sector(bio) > mddev->suspend_lo &&
- bio->bi_iter.bi_sector < mddev->suspend_hi) {
+ ((bio_end_sector(bio) > mddev->suspend_lo &&
+ bio->bi_iter.bi_sector < mddev->suspend_hi) ||
+ (mddev_is_clustered(mddev) &&
+ md_cluster_ops->area_resyncing(mddev, bio->bi_iter.bi_sector, bio_end_sector(bio))))) {
/* As the suspend_* range is controlled by
* userspace, we want an interruptible
* wait.
@@ -1114,7 +1122,10 @@ static void make_request(struct mddev *mddev, struct bio * bio)
prepare_to_wait(&conf->wait_barrier,
&w, TASK_INTERRUPTIBLE);
if (bio_end_sector(bio) <= mddev->suspend_lo ||
- bio->bi_iter.bi_sector >= mddev->suspend_hi)
+ bio->bi_iter.bi_sector >= mddev->suspend_hi ||
+ (mddev_is_clustered(mddev) &&
+ !md_cluster_ops->area_resyncing(mddev,
+ bio->bi_iter.bi_sector, bio_end_sector(bio))))
break;
schedule();
}
@@ -1561,6 +1572,7 @@ static int raid1_spare_active(struct mddev *mddev)
struct md_rdev *rdev = conf->mirrors[i].rdev;
struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
if (repl
+ && !test_bit(Candidate, &repl->flags)
&& repl->recovery_offset == MaxSector
&& !test_bit(Faulty, &repl->flags)
&& !test_and_set_bit(In_sync, &repl->flags)) {
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index 49f4210d4394..2ae6131e69a5 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -78,6 +78,12 @@
#define MD_DISK_ACTIVE 1 /* disk is running or spare disk */
#define MD_DISK_SYNC 2 /* disk is in sync with the raid set */
#define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */
+#define MD_DISK_CLUSTER_ADD 4 /* Initiate a disk add across the cluster
+ * For clustered enviroments only.
+ */
+#define MD_DISK_CANDIDATE 5 /* disk is added as spare (local) until confirmed
+ * For clustered enviroments only.
+ */
#define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config.
* read requests will only be sent here in
@@ -101,6 +107,7 @@ typedef struct mdp_device_descriptor_s {
#define MD_SB_CLEAN 0
#define MD_SB_ERRORS 1
+#define MD_SB_CLUSTERED 5 /* MD is clustered */
#define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */
/*
diff --git a/include/uapi/linux/raid/md_u.h b/include/uapi/linux/raid/md_u.h
index 74e7c60c4716..1cb8aa6850b5 100644
--- a/include/uapi/linux/raid/md_u.h
+++ b/include/uapi/linux/raid/md_u.h
@@ -62,6 +62,7 @@
#define STOP_ARRAY _IO (MD_MAJOR, 0x32)
#define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
#define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
+#define CLUSTERED_DISK_NACK _IO (MD_MAJOR, 0x35)
/* 63 partitions with the alternate major number (mdp) */
#define MdpMinorShift 6