Commit Graph

161 Commits

Author SHA1 Message Date
NeilBrown b16b1b6cd0 md/bitmap: fix calculation of 'chunks' - missing shift.
commit 61a0d80c "md/bitmap: discard CHUNK_BLOCK_SHIFT macro"
replaced CHUNK_BLOCK_RATIO() by the same text that was
replacing CHUNK_BLOCK_SHIFT() - which is clearly wrong.

The result is that 'chunks' is often too small by 1,
which can sometimes result in a crash (not sure how).

So use the correct replacement, and get rid of CHUNK_BLOCK_RATIO
which is no longe used.

Reported-by: Karl Newman <siliconfiend@gmail.com>
Tested-by: Karl Newman <siliconfiend@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-04 17:03:18 +10:00
NeilBrown afbaa90b80 md/bitmap: prevent bitmap_daemon_work running while initialising bitmap
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 <neilb@suse.de>
2012-04-12 16:05:06 +10:00
Andrei Warkentin 9e41dd35b3 MD: Bitmap version cleanup.
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 <andrey.warkentin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-12 15:55:21 +10:00
Linus Torvalds 267d7b23dd md updates for 3.4
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.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQIVAwUAT2bLBjnsnt1WYoG5AQKN3xAAv1UlR5Kem5WN7Ex4lmR9xj3lr9dbURYT
 TtvrUuCy3pYYWdTuijb+IBqkbODF0kPDHIhUiBx9fXUfMavkp/b9heXS/vJ3pcH4
 1j99NUbOGL/AylD1TPRV9TQxGTKhEjK3n26bY0t/amLc92bWJaytMO1B9cz38LN+
 qx6ufpIepz4DPXXtPYpnkBR4cZ6L4/ZXQvjf5BqG6WfKwc+0Nyncg8ipYEqhBWy7
 R7ztF5yPo0yl96Wopa2KG91OroWflmyZo1DNYcbUbKtbNGGtYC92GFadOH+wNupM
 FnmXv10ivfVGU5w4SpshAwOg+4OSUqmWNsBxUhpYbf8ChbN+lOl0VZdH6UBxo19D
 3SqZWT/yz4I4HYd5rtr35MXFdOeBNM++CHQs4F68BLA0B6OcHfWsA9bvly2tnBVx
 iEBFPd277qWztUr8m6yz7AFf/0dgyXuIhuB3d7IkVrG5yG3FX6hPi2T0FSA33qMx
 Lwi5w6O4DREg5tG09xEYEnXgXe+PnB8HsKb1U/m76XMQ0UScvX6dLA6934Vg+DCv
 xf+AYqob0Tc/Op5I7h2PbVXq7DciNXwlX1WvM0m+TEaV+3fl1FB0VsCcANAV6JVn
 uRLmvtePQRt0hxAog2p7OsumVnxMhbuEo5h8rJMKWM7IbhueKNoz+gBwpcFLzBmY
 ygWc4peLQpE=
 =MGuM
 -----END PGP SIGNATURE-----

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

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.
  ...
2012-03-22 12:29:50 -07:00
Cong Wang b2f46e6882 md: remove the second argument of k[un]map_atomic()
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:18 +08:00
NeilBrown 61a0d80ce4 md/bitmap: discard CHUNK_BLOCK_SHIFT macro
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 <neilb@suse.de>
2012-03-19 12:46:41 +11:00
NeilBrown 792a1d4bbf md/bitmap: remove unnecessary indirection when allocating.
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 <neilb@suse.de>
2012-03-19 12:46:41 +11:00
NeilBrown 5a6c824ebb md/bitmap: remove some pointless locking.
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 <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown 278c1ca2f2 md/bitmap: change a 'goto' to a normal 'if' construct.
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 <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown 57148964d9 md/bitmap: move printing of bitmap status to bitmap.c
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 <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown dafb20fa34 md: tidy up rdev_for_each usage.
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 <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown 4474ca42e2 md/bitmap: ensure to load bitmap when creating via sysfs.
When commit 69e51b449d (md/bitmap:  separate out loading a bitmap...)
created bitmap_load, it missed calling it after bitmap_create when a
bitmap is created through the sysfs interface.
So if a bitmap is added this way, we don't allocate memory properly
and can crash.

This is suitable for any -stable release since 2.6.35.
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:37 +11:00
NeilBrown 915c420ddf md/bitmap: be more consistent when setting new bits in memory bitmap.
For each active region corresponding to a bit in the bitmap with have
a 14bit counter (and some flags).
This counts
   number of active writes + bit in the on-disk bitmap + delay-needed.

The "delay-needed" is because we always want a delay before clearing a
bit.  So the number here is normally number of active writes plus 2.
If there have been no writes for a while, we drop to 1.
If still no writes we clear the bit and drop to 0.

So for consistency, when setting bit from the on-disk bitmap or by
request from user-space it is best to set the counter to '2' to start
with.

In particular we might also set the NEEDED_MASK flag at this time, and
in all other cases NEEDED_MASK is only set when the counter is 2 or
more.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown 2e61ebbcc4 md/bitmap: daemon_work cleanup.
We have a variable 'mddev' in this function, but repeatedly get the
same value by dereferencing bitmap->mddev.
There is room for simplification here...

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:50 +11:00
NeilBrown 961902c0f8 md/bitmap: It is OK to clear bits during recovery.
commit d0a4bb4927 introduced a
regression which is annoying but fairly harmless.

When writing to an array that is undergoing recovery (a spare
in being integrated into the array), writing to the array will
set bits in the bitmap, but they will not be cleared when the
write completes.

For bits covering areas that have not been recovered yet this is not a
problem as the recovery will clear the bits.  However bits set in
already-recovered region will stay set and never be cleared.
This doesn't risk data integrity.  The only negatives are:
 - next time there is a crash, more resyncing than necessary will
   be done.
 - the bitmap doesn't look clean, which is confusing.

While an array is recovering we don't want to update the
'events_cleared' setting in the bitmap but we do still want to clear
bits that have very recently been set - providing they were written to
the recovering device.

So split those two needs - which previously both depended on 'success'
and always clear the bit of the write went to all devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 09:57:48 +11:00
NeilBrown 7c8f424798 md/lock: ensure updates to page_attrs are properly locked.
Page attributes are set using __set_bit rather than set_bit as
it normally called under a spinlock so the extra atomicity is not
needed.

However there are two places where we might set or clear page
attributes without holding the spinlock.
So add the spinlock in those cases.

This might be the cause of occasional reports that bits a aren't
getting clear properly - theory is that BITMAP_PAGE_PENDING gets lost
when BITMAP_PAGE_NEEDWRITE is set or cleared.  This is an
inconvenience, not a threat to data safety.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-11-23 10:18:52 +11:00
NeilBrown 29d3247ea2 md/bitmap remove fault injection options.
These are too hard to use to be much more than noise.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:56 +11:00
NeilBrown fd01b88c75 md: remove typedefs: mddev_t -> struct mddev
Having mddev_t and 'struct mddev_s' is ugly and not preferred

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:47:53 +11:00
NeilBrown 3cb0300200 md: removing typedefs: mdk_rdev_t -> struct md_rdev
The typedefs are just annoying. 'mdk' probably refers to 'md_k.h'
which used to be an include file that defined this thing.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:45:26 +11:00
NeilBrown 36a4e1fe0f md: remove PRINTK and dprintk debugging and use pr_debug
Being able to dynamically enable these make them much more useful.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:17 +11:00
NeilBrown 2585f3ef8c md/bitmap: improve handling of 'allclean'.
The 'allclean' flag is used to cache the fact that there is nothing to
do, so we can avoid waking up and scanning the bitmap regularly.

The two sorts of pages that might need the attention of the bitmap
daemon are BITMAP_PAGE_PENDING and BITMAP_PAGE_NEEDWRITE pages.

So make sure allclean reflects exactly when there are none of those.
So:
  set it before scanning all pages with either bit set.
  clear it whenever these bits are set
  clear it when we desire not to clear one of these bits.
  don't clear it any other time.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-21 15:37:46 +10:00
NeilBrown 5a537df44d md/bitmap: rename and tidy up BITMAP_PAGE_CLEAN
The flag 'BITMAP_PAGE_CLEAN' has a confusing name as it doesn't mean
that the page is clean, but rather that there are counters in the page
which allow bits in the bitmap to be cleared - i.e. maybe cleaning can
happen.

So change it to BITMAP_PAGE_PENDING and fix some irregularities:
 - Don't set it in bitmap_init_from_disk as bitmap_set_memory_bits
   sets it when needed
 - in bitmap_daemon_work, if we find a counter that is '1', but
   need_sync is set, then set BITMAP_PAGE_PENDING again (it was
   recently cleared) to ensure we don't forget about this bit.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-21 15:37:46 +10:00
Jonathan Brassow 3520fa4db7 MD bitmap: Revert DM dirty log hooks
Revert most of commit e384e58549
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.

MD should not need to use DM's dirty log - we decided to use md's
bitmaps instead.

Keeping the DIV_ROUND_UP clean-ups that were part of commit
e384e58549, however.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:37 +10:00
Akinobu Mita a0a02a7ad6 md: use proper little-endian bitops
Using __test_and_{set,clear}_bit_le() with ignoring its return value
can be replaced with __{set,clear}_bit_le().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim 97b3d4aacf md/bitmap: remove unused fields from struct bitmap
Get rid of ->syncchunk and ->counter_bits since they're never used.

Also discard COUNTER_BYTE_RATIO which is unused.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:43:01 +10:00
Namhyung Kim 27d5ea04d0 md/bitmap: use proper accessor macro
Use COUNTER()/NEEDED() macro instead of open-coding them.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:57 +10:00
Jonathan Brassow d744540cd3 MD: use is_power_of_2 macro
Make use of is_power_of_2 macro.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:36 +10:00
Jonathan Brassow 9c81075f43 MD: support initial bitmap creation in-kernel
Add bitmap support to the device-mapper specific metadata area.

This patch allows the creation of the bitmap metadata area upon
initial array creation via device-mapper.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:41:36 +10:00
NeilBrown 8258c53208 md/bitmap: fix saving of events_cleared and other state.
If a bitmap is found to be 'stale' the events_cleared value
is set to match 'events'.
However if the array is degraded this does not get stored on disk.
This can subsequently lead to incorrect behaviour.

So change bitmap_update_sb to always update events_cleared in the
superblock from the known events_cleared.
For neatness also set ->state from ->flags.
This requires updating ->state whenever we update ->flags, which makes
sense anyway.

This is suitable for any active -stable release.

cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:26:30 +10:00
Linus Torvalds 6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Akinobu Mita 6b33aff368 md: use little-endian bitops
As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h.  This converts ext2 non-atomic bit operations to
little-endian bit operations.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:46:20 -07:00
Jens Axboe 721a9602e6 block: kill off REQ_UNPLUG
With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:27 +01:00
Jens Axboe 7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00
NeilBrown 75d3da43cb md: Don't let implementation detail of curr_resync leak out through sysfs.
mddev->curr_resync has artificial values of '1' and '2' which are used
by the code which ensures only one resync is happening at a time on
any given device.

These values are internal and should never be exposed to user-space
(except when translated appropriately as in the 'pending' status in
/proc/mdstat).

Unfortunately they are as ->curr_resync is assigned to
->curr_resync_completed and that value is directly visible through
sysfs.

So change the assignments to ->curr_resync_completed to get the same
valued from elsewhere in a form that doesn't have the magic '1' or '2'
values.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow a6ff7e089c md: separate meta and data devs
Allow the metadata to be on a separate device from the
data.

This doesn't mean the data and metadata will by on separate
physical devices - it simply gives device-mapper and userspace
tools more flexibility.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow ccebd4c415 md-new-param-to_sync_page_io
Add new parameter to 'sync_page_io'.

The new parameter allows us to distinguish between metadata and data
operations.  This becomes important later when we add the ability to
use separate devices for data and metadata.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown be2a2656ee md: unplug writes to external bitmaps.
When writing to an 'external' bitmap we don't currently unplug the
device before waiting, so we can get a 3msec delay each time;
So use REQ_UNPLUG to force and unplug.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29 16:40:32 +11:00
NeilBrown 2b193363ef md: change type of first arg to sync_page_io.
Currently sync_page_io takes a 'bdev'.
Every caller passes 'rdev->bdev'.
We will soon want another field out of the rdev in sync_page_io,
So just pass the rdev instead of the bdev out of it.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:11 +11:00
NeilBrown 57dab0bdf6 md: use sector_t in bitmap_get_counter
bitmap_get_counter returns the number of sectors covered
by the counter in a pass-by-reference variable.
In some cases this can be very large, so make it a sector_t
for safety.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:32:26 +11:00
Vasiliy Kulikov 5c04f5512f md: check return code of read_sb_page
Function read_sb_page may return ERR_PTR(...). Check for it.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07 12:02:50 +11:00
NeilBrown 070dc6dd71 md: resolve confusion of MD_CHANGE_CLEAN
MD_CHANGE_CLEAN is used for two different purposes and this leads to
confusion.
One of the purposes is largely mirrored by MD_CHANGE_PENDING which is
not used for anything else, so have MD_CHANGE_PENDING take over that
purpose fully.

The two purposes are:
 1/ tell md_update_sb that an update is needed and that it is just a
   clean/dirty transition.
 2/ tell user-space that an transition from clean to dirty is pending
    (something wants to write), and tell te kernel (by clearin the
    flag) that the transition is OK.

The first purpose remains wit MD_CHANGE_CLEAN, the second is moved
fully to MD_CHANGE_PENDING.

This means that various places which conditionally set or cleared
MD_CHANGE_CLEAN no longer need to be conditional.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:21 +10:00
NeilBrown 69e51b449d md/bitmap: separate out loading a bitmap from initialising the structures.
dm makes this distinction between ->ctr and ->resume, so we need to
too.

Also get the new bitmap_load to clear out the bitmap first, as this is
most consistent with the dm suspend/resume approach

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:34 +10:00
NeilBrown e384e58549 md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
This allows md/raid5 to fully work as a dm target.

Normally md uses a 'filemap' which contains a list of pages of bits
each of which may be written separately.
dm-log uses and all-or-nothing approach to writing the log, so
when using a dm-log, ->filemap is NULL and the flags normally stored
in filemap_attr are stored in ->logattrs instead.



Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:34 +10:00
NeilBrown ef42567335 md/bitmap: optimise scanning of empty bitmaps.
A bitmap is stored as one page per 2048 bits.
If none of the bits are set, the page is not allocated.

When bitmap_get_counter finds that a page isn't allocate,
it just reports that one bit work of space isn't flagged,
rather than reporting that 2048 bits worth of space are
unflagged.
This can cause searches for flagged bits (e.g. bitmap_close_sync)
to do more work than is really necessary.

So change bitmap_get_counter (when creating) to report a number of
blocks that more accurately reports the range of the device for which
no counter currently exists.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:32 +10:00
NeilBrown b63d7c2e29 md/bitmap: clean up plugging calls.
1/ use md_unplug in bitmap.c as we will soon be using bitmaps under
  arrays with no queue attached.

2/ Don't bother plugging the queue when we set a bit in the bitmap.
   The reason for this was to encourage as many bits as possible to
   get set before we unplug and write stuff out.
   However every personality already plugs the queue after
   bitmap_startwrite either directly (raid1/raid10) or be setting
   STRIPE_BIT_DELAY which causes the queue to be plugged later
   (raid5).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:32 +10:00
NeilBrown 5ff5afffe6 md/bitmap: reduce dependence on sysfs.
For dm-raid45 we will want to use bitmaps in dm-targets which don't
have entries in sysfs, so cope with the mddev not living in sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:31 +10:00
NeilBrown ac2f40be46 md/bitmap: white space clean up and similar.
Fixes some whitespace problems
Fixed some checkpatch.pl complaints.
Replaced kmalloc ... memset(0), with kzalloc
Fixed an unlikely memory leak on an error path.
Reformatted a number of 'if/else' sets, sometimes
replacing goto with an else clause.
Removed some old comments and commented-out code.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:07:22 +10:00
NeilBrown 676e42d896 md: be more careful setting MD_CHANGE_CLEAN
When MD_CHANGE_CLEAN is set we might block in md_write_start.
So we should only set it when fairly sure that something will clear
it.

There are two places where it is set so as to encourage a metadata
update to record the progress of resync/recovery.  This should only
be done if the internal metadata update mechanisms are in use, which
can be tested by by inspecting '->persistent'.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
Linus Torvalds e8bebe2f71 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits)
  fix handling of offsets in cris eeprom.c, get rid of fake on-stack files
  get rid of home-grown mutex in cris eeprom.c
  switch ecryptfs_write() to struct inode *, kill on-stack fake files
  switch ecryptfs_get_locked_page() to struct inode *
  simplify access to ecryptfs inodes in ->readpage() and friends
  AFS: Don't put struct file on the stack
  Ban ecryptfs over ecryptfs
  logfs: replace inode uid,gid,mode initialization with helper function
  ufs: replace inode uid,gid,mode initialization with helper function
  udf: replace inode uid,gid,mode init with helper
  ubifs: replace inode uid,gid,mode initialization with helper function
  sysv: replace inode uid,gid,mode initialization with helper function
  reiserfs: replace inode uid,gid,mode initialization with helper function
  ramfs: replace inode uid,gid,mode initialization with helper function
  omfs: replace inode uid,gid,mode initialization with helper function
  bfs: replace inode uid,gid,mode initialization with helper function
  ocfs2: replace inode uid,gid,mode initialization with helper function
  nilfs2: replace inode uid,gid,mode initialization with helper function
  minix: replace inode uid,gid,mode init with helper
  ext4: replace inode uid,gid,mode init with helper
  ...

Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
2010-05-21 19:37:45 -07:00
NeilBrown 19fdb9eefb Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linus
Conflicts:
	drivers/md/md.c

- Resolved conflict in md_update_sb
- Added extra 'NULL' arg to new instance of sysfs_get_dirent.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-22 08:31:36 +10:00