linux.git/drivers/md/bitmap.c, branch v3.4-rc4

md/bitmap: prevent bitmap_daemon_work running while initialising bitmap

2012-04-12T06:05:06+00:00

If a bitmap is added while the array is active, it is possible
for bitmap_daemon_work to run while the bitmap is being
initialised.
This is particularly a problem if bitmap_daemon_work sees
bitmap->filemap as non-NULL before it has been filled in properly.
So hold bitmap_info.mutex while filling in ->filemap
to prevent problems.

This patch is suitable for any -stable kernel, though it might not
apply cleanly before about 3.1.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown

MD: Bitmap version cleanup.

2012-04-12T05:55:21+00:00

bitmap_new_disk_sb() would still create V3 bitmap superblock
with host-endian layout.

Perhaps I'm confused, but shouldn't bitmap_new_disk_sb() be
creating a V4 bitmap superblock instead, that is portable,
as per comment in bitmap.h?

Signed-off-by: Andrei Warkentin 
Signed-off-by: NeilBrown

Merge tag 'md-3.4' of git://neil.brown.name/md

2012-03-22T19:29:50+00:00

Pull md updates for 3.4 from Neil Brown:
 "Mostly tidying up code in preparation for some bigger changes next
  time.

  A few bug fixes tagged for -stable.

  Main functionality change is that some RAID10 arrays can now grow to
  use extra space that may have been made available on the individual
  devices."

Fixed up trivial conflicts with the k[un]map_atomic() cleanups in
drivers/md/bitmap.c.

* tag 'md-3.4' of git://neil.brown.name/md: (22 commits)
  md: Add judgement bb->unacked_exist in function md_ack_all_badblocks().
  md: fix clearing of the 'changed' flags for the bad blocks list.
  md/bitmap: discard CHUNK_BLOCK_SHIFT macro
  md/bitmap: remove unnecessary indirection when allocating.
  md/bitmap: remove some pointless locking.
  md/bitmap: change a 'goto' to a normal 'if' construct.
  md/bitmap: move printing of bitmap status to bitmap.c
  md/bitmap: remove some unused noise from bitmap.h
  md/raid10 - support resizing some RAID10 arrays.
  md/raid1: handle merge_bvec_fn in member devices.
  md/raid10: handle merge_bvec_fn in member devices.
  md: add proper merge_bvec handling to RAID0 and Linear.
  md: tidy up rdev_for_each usage.
  md/raid1,raid10: avoid deadlock during resync/recovery.
  md/bitmap: ensure to load bitmap when creating via sysfs.
  md: don't set md arrays to readonly on shutdown.
  md: allow re-add to failed arrays.
  md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read().
  md: Use existed macros instead of numbers
  md/raid5: removed unused 'added_devices' variable.
  ...

md: remove the second argument of k[un]map_atomic()

2012-03-20T13:48:18+00:00

Acked-by: NeilBrown 
Signed-off-by: Cong Wang

md/bitmap: discard CHUNK_BLOCK_SHIFT macro

2012-03-19T01:46:41+00:00

Be redefining ->chunkshift as the shift from sectors to chunks rather
than bytes to chunks, we can just use "bitmap->chunkshift" which is
shorter than the macro call, and less indirect.

Signed-off-by: NeilBrown

md/bitmap: remove unnecessary indirection when allocating.

2012-03-19T01:46:41+00:00

These funcitons don't add anything useful except possibly the trace
points, and I don't think they are worth the extra indirection.
So remove them.

Signed-off-by: NeilBrown

md/bitmap: remove some pointless locking.

2012-03-19T01:46:40+00:00

There is nothing gained by holding a lock while we check if a pointer
is NULL or not.  If there could be a race, then it could become NULL
immediately after the unlock - but there is no race here.

So just remove the locking.

Signed-off-by: NeilBrown

md/bitmap: change a 'goto' to a normal 'if' construct.

2012-03-19T01:46:40+00:00

The use of a goto makes the control flow more obscure here.

So make it a normal:
  if (x) {
     Y;
  }

No functional change.

Signed-off-by: NeilBrown

md/bitmap: move printing of bitmap status to bitmap.c

2012-03-19T01:46:40+00:00

The part of /proc/mdstat which describes the bitmap should really
be generated by code in bitmap.c.  So move it there.

Signed-off-by: NeilBrown

md: tidy up rdev_for_each usage.

2012-03-19T01:46:39+00:00

md.h has an 'rdev_for_each()' macro for iterating the rdevs in an
mddev.  However it uses the 'safe' version of list_for_each_entry,
and so requires the extra variable, but doesn't include 'safe' in the
name, which is useful documentation.

Consequently some places use this safe version without needing it, and
many use an explicity list_for_each entry.

So:
 - rename rdev_for_each to rdev_for_each_safe
 - create a new rdev_for_each which uses the plain
   list_for_each_entry,
 - use the 'safe' version only where needed, and convert all other
   list_for_each_entry calls to use rdev_for_each.

Signed-off-by: NeilBrown