page->index already considers node offset. The node_offset calculation
in write_sb_page is useless and confusion.

Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: NeilBrown <neilb@suse.com>
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Suspending the entire device for resync could take too long. Resync
in small chunks.

cluster's resync window (32M) is maintained in r1conf as
cluster_sync_low and cluster_sync_high and processed in
raid1's sync_request(). If the current resync is outside the cluster
resync window:

1. Set the cluster_sync_low to curr_resync_completed.
2. Check if the sync will fit in the new window, if not issue a
   wait_barrier() and set cluster_sync_low to sector_nr.
3. Set cluster_sync_high to cluster_sync_low + resync_window.
4. Send a message to all nodes so they may add it in their suspension
   list.

bitmap_cond_end_sync is modified to allow to force a sync inorder
to get the curr_resync_completed uptodate with the sector passed.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>

Add BITMAP_MAJOR_CLUSTERED as 5, in order to prevent older kernels
to assemble a clustered device.

In order to maximize compatibility, the major version is set to
BITMAP_MAJOR_CLUSTERED *only* if the bitmap is clustered.

Added MD_FEATURE_CLUSTERED in order to return error for older
kernels which would assemble MD even if the bitmap is corrupted.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>

Passing -1 to bitmap_storage_alloc() causes page->index to be set to
-1, which is quite problematic.

So only pass ->cluster_slot if mddev_is_clustered().

Fixes: b97e92574c0b ("Use separate bitmaps for each nodes in the cluster")
Cc: stable@vger.kernel.org (v4.1+)
Signed-off-by: NeilBrown <neilb@suse.com>

Pull md fixes from Neil Brown:
 "Some md fixes for 4.2

  Several are tagged for -stable.
  A few aren't because they are not very, serious or because they are in
  the 'experimental' cluster code"

* tag 'md/4.2-fixes' of git://neil.brown.name/md:
  md/raid5: clear R5_NeedReplace when no longer needed.
  Fix read-balancing during node failure
  md-cluster: fix bitmap sub-offset in bitmap_read_sb
  md: Return error if request_module fails and returns positive value
  md: Skip cluster setup in case of error while reading bitmap
  md/raid1: fix test for 'was read error from last working device'.
  md: Skip cluster setup for dm-raid
  md: flush ->event_work before stopping array.
  md/raid10: always set reshape_safe when initializing reshape_position.
  md/raid5: avoid races when changing cache size.

bitmap_read_sb is modifying mddev->bitmap_info.offset. This works for
the first bitmap read. However, when multiple bitmaps need to be opened
by the same node, it ends up corrupting the offset. Fix it by using a
local variable.

Also, bitmap_read_sb is not required in bitmap_copy_from_slot since
it is called in bitmap_create. Remove bitmap_read_sb().

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>

If the bitmap read fails, the error code set is -EINVAL. However,
we don't check for errors and go ahead with cluster_setup.
Skip the cluster setup in case of error.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>

There is a bug that the bitmap superblock isn't initialised properly for
dm-raid, so a new field can have garbage in new fields.
(dm-raid does initialisation in the kernel - md initialised the
 superblock in mdadm).

This means that for dm-raid we cannot currently trust the new ->nodes
field. So:
 - use __GFP_ZERO to initialise the superblock properly for all new
    arrays
 - initialise all fields in bitmap_info in bitmap_new_disk_sb
 - ignore ->nodes for dm arrays (yes, this is a hack)

This bug exposes dm-raid to bug in the (still experimental) md-cluster
code, so it is suitable for -stable.  It does cause crashes.

References: https://bugzilla.kernel.org/show_bug.cgi?id=100491
Cc: stable@vger.kernel.org (v4.1)
Signed-off-By: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>

Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...

Turn
	seq_path(..., &file->f_path, ...);
into
	seq_file_path(..., file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>