linux/drivers/md/bitmap.h, branch v4.1

md-cluster: re-add capabilities

2015-04-21T21:59:39Z

When "re-add" is writted to /sys/block/mdXX/md/dev-YYY/state, the clustered md: 1. Sends RE_ADD message with the desc_nr. Nodes receiving the message clear the Faulty bit in their respective rdev->flags. 2. The node initiating re-add, gathers the bitmaps of all nodes and copies them into the local bitmap. It does not clear the bitmap from which it is copying. 3. Initiating node schedules a md recovery to sync the devices. Signed-off-by: Guoqing Jiang Signed-off-by: Goldwyn Rodrigues Signed-off-by: NeilBrown

Copy set bits from another slot

2015-02-23T15:59:05Z

bitmap_copy_from_slot reads the bitmap from the slot mentioned. It then copies the set bits to the node local bitmap. This is helper function for the resync operation on node failure. bitmap_set_memory_bits() currently assumes it is only run at startup and that they bitmap is currently empty. So if it finds that a region is already marked as dirty, it won't mark it dirty again. Change bitmap_set_memory_bits() to always set the NEEDED_MASK bit if 'needed' is set. Signed-off-by: Goldwyn Rodrigues

bitmap_create returns bitmap pointer

2015-02-23T15:57:57Z

This is done to have multiple bitmaps open at the same time. Signed-off-by: Goldwyn Rodrigues

Use separate bitmaps for each nodes in the cluster

2015-02-23T13:30:11Z

On-disk format: 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] | | | Bitmap super has a field nodes, which defines the maximum number of nodes the device can use. While reading the bitmap super, if the cluster finds out that the number of nodes is > 0: 1. Requests the md-cluster module. 2. Calls md_cluster_ops->join(), which sets up clustering such as joining DLM lockspace. Since the first time, the first bitmap is read. After the call to the cluster_setup, the bitmap offset is adjusted and the superblock is re-read. This also ensures the bitmap is read the bitmap lock (when bitmap lock is introduced in later patches) Questions: 1. cluster name is repeated in all bitmap supers. Is that okay? Signed-off-by: Goldwyn Rodrigues

Add node recovery callbacks

2015-02-23T13:30:11Z

DLM offers callbacks when a node fails and the lock remastery is performed: 1. recover_prep: called when DLM discovers a node is down 2. recover_slot: called when DLM identifies the node and recovery can start 3. recover_done: called when all nodes have completed recover_slot recover_slot() and recover_done() are also called when the node joins initially in order to inform the node with its slot number. These slot numbers start from one, so we deduct one to make it start with zero which the cluster-md code uses. Signed-off-by: Goldwyn Rodrigues

Add number of nodes to bitmap structure for clustering

2015-02-23T13:28:30Z

Signed-off-by: Goldwyn Rodrigues

kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly

2013-12-11T23:28:36Z

kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo Cc: Neil Brown Cc: Linus Walleij Cc: Ashutosh Dixit Cc: kbuild test robot Signed-off-by: Greg Kroah-Hartman

md/bitmap: record the space available for the bitmap in the superblock.

2012-05-22T03:55:34Z

Now that bitmaps can grow and shrink it is best if we record how much space is available. This means that when we reduce the size of the bitmap we won't "lose" the space for late when we might want to increase the size of the bitmap again. Signed-off-by: NeilBrown

md/bitmap: add bitmap_resize function to allow bitmap resizing.

2012-05-22T03:55:25Z

This function will allocate the new data structures and copy bits across from old to new, allowing for the possibility that the chunksize has changed. Use the same function for performing the initial allocation of the structures. This improves test coverage. When bitmap_resize is used to resize an existing bitmap, it only copies '1' bits in, not '0' bits. So when allocating the bitmap, ensure everything is initialised to ZERO. Signed-off-by: NeilBrown

md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'

2012-05-22T03:55:24Z

The new "struct bitmap_counts" contains all the fields that are related to counting the number of active writes in each bitmap chunk. Having this separate will make it easier to change the chunksize or overall size of a bitmap atomically. Signed-off-by: NeilBrown