Commit Graph

187 Commits

Author SHA1 Message Date
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Jianpeng Ma 582e2e056a md/bitmap:Don't use IS_ERR to judge alloc_page().
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:45:36 +11:00
Michael Wang fd177481b4 raid: replace list_for_each_continue_rcu with new interface
This patch replaces list_for_each_continue_rcu() with
list_for_each_entry_continue_rcu() to save a few lines
of code and allow removing list_for_each_continue_rcu().

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:43:21 +11:00
NeilBrown f54a9d0e59 md/raid1: submit IO from originating thread instead of md thread.
queuing writes to the md thread means that all requests go through the
one processor which may not be able to keep up with very high request
rates.

So use the plugging infrastructure to submit all requests on unplug.
If a 'schedule' is needed, we fall back on the old approach of handing
the requests to the thread for it to handle.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02 08:33:20 +10:00
NeilBrown 1dff2b87a3 md/bitmap: record the space available for the bitmap in the superblock.
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 <neilb@suse.de>
2012-05-22 13:55:34 +10:00
NeilBrown b81a040481 md/bitmap: make sure reshape request are reflected in superblock.
As a reshape may change the sync_size and/or chunk_size, we need
to update these whenever we write out the bitmap superblock.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:26 +10:00
NeilBrown d60b479d17 md/bitmap: add bitmap_resize function to allow bitmap resizing.
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 <neilb@suse.de>
2012-05-22 13:55:25 +10:00
NeilBrown 15702d7fb6 md/bitmap: use DIV_ROUND_UP instead of open-code
Also take the opportunity to simplify CHUNK_BLOCK_RATIO.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:25 +10:00
NeilBrown 40cffcc0e8 md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'
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 <neilb@suse.de>
2012-05-22 13:55:24 +10:00
NeilBrown 63c68268b2 md/bitmap: make bitmap bitops atomic.
This allows us to remove spinlock protection which is
more heavy-weight than simple atomics.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:23 +10:00
NeilBrown bdfd114073 md/bitmap: make _page_attr bitops atomic.
Using e.g. set_bit instead of __set_bit and using test_and_clear_bit
allow us to remove some locking and contract other locked ranges.

It is rare that we set or clear a lot of these bits, so gain should
outweigh any cost.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:22 +10:00
NeilBrown fae7d326cd md/bitmap: merge bitmap_file_unmap and bitmap_file_put.
There functions really do one thing together: release the
'bitmap_storage'.  So make them just one function.

Since we removed the locking (previous patch), we don't need to zero
any fields before freeing them, so it all becomes a bit simpler.


Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:21 +10:00
NeilBrown 62f82faace md/bitmap: remove async freeing of bitmap file.
There is no real value in freeing things the moment there is an error.
It is just as good to free the bitmap file and pages when the bitmap
is explicitly removed (and replaced?) or at shutdown.

With this gone, the bitmap will only disappear when the array is
quiescent, so we can remove some locking.

As the 'filemap' doesn't disappear now, include extra checks before
trying to write any of it out.
Also remove the check for "has it disappeared" in
bitmap_daemon_write().


Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:21 +10:00
NeilBrown 7466712347 md/bitmap: convert some spin_lock_irqsave to spin_lock_irq
All of these sites can only be called from process context with
irqs enabled, so using irqsave/irqrestore just adds noise.
Remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:19 +10:00
NeilBrown b405fe91e5 md/bitmap: use set_bit, test_bit, etc for operation on bitmap->flags.
We currently use '&' and '|' which isn't the norm in the kernel
and doesn't allow easy atomicity.
So change to bit numbers and {set,clear,test}_bit.
This allows us to remove a spinlock/unlock (which was dubious anyway)
and some other simplifications.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:15 +10:00
NeilBrown 84e923453e md/bitmap: remove single-bit manipulation on sb->state
Just do single-bit manipulations on bitmap->flags and copy whole
value between that and sb->state.

This will allow next patch which changes how bit manipulations are
performed on bitmap->flags.

This does result in BITMAP_STALE not being set in sb by
bitmap_read_sb, however as the setting is determined by other
information in the 'sb' we do not lose information this way.
Normally, bitmap_load will be called shortly which will clear
BITMAP_STALE anyway.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:14 +10:00
NeilBrown edbb79df67 md/bitmap: remove bitmap_mask_state
This function isn't really needed.  It sets or clears a flag in both
bitmap->flags and sb->state.
However both times it is called, bitmap_update_sb is called soon
afterwards which copies bitmap->flags to sb->state.
So just make changes to bitmap->flags, and open-code those rather than
hiding in a function.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:13 +10:00
NeilBrown bc9891a885 md/bitmap: move storage allocation from bitmap_load to bitmap_create.
We should allocate memory for the storage-bitmap at create-time, not
load time.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:12 +10:00
NeilBrown d1244cb062 md/bitmap: separate bitmap file allocation to its own function.
This will allow allocation before swapping in a new bitmap.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:12 +10:00
NeilBrown 9b1215c102 md/bitmap: store bytes in file rather than just in last page.
This number is more generally useful, and bytes-in-last-page is
easily extracted from it.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:11 +10:00
NeilBrown 1ec885cdd0 md/bitmap: move some fields of 'struct bitmap' into a 'storage' substruct.
This new 'struct bitmap_storage' reflects the external storage of the
bitmap.
Having this clearly defined will make it easier to change the storage
used while the array is active.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:10 +10:00
NeilBrown d189122d4b md/bitmap: change *_page_attr() to take a page number, not a page.
Most often we have the page number, not the page.  And that is what
the  *_page_attr() functions really want.  So change the arguments to
take that number.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:09 +10:00
NeilBrown 27581e5ae0 md/bitmap: centralise allocation of bitmap file pages.
Instead of allocating pages in read_sb_page, read_page and
bitmap_read_sb, allocate them all in bitmap_init_from disk.

Also replace the hack of calling "attach_page_buffers(page, NULL)" to
ensure that free_buffer() won't complain, by putting a test for
PagePrivate in free_buffer().

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:08 +10:00
NeilBrown ef99bf480d md/bitmap: allow a bitmap with no backing storage.
An md bitmap comprises two parts
 - internal counting of active writes per 'chunk'.
 - external storage of whether there are any active writes on
   each chunk

The second requires the first, but the first doesn't require the
second.

Not having backing storage means that the bitmap cannot expedite
resync after a crash, but it still allows us to expedite the recovery
of a recently-removed device.

So: allow a bitmap to exist even if there is no backing device.
In that case we default to 128M chunks.

A particular value of this is that we can remove and re-add a bitmap
(possibly of a different granularity) on a degraded array, and not
lose the information needed to fast-recover the missing device.

We don't actually activate these bitmaps yet - that will come
in a later patch.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:08 +10:00
NeilBrown 6409bb05a9 md/bitmap: add new 'space' attribute for bitmaps.
If we are to allow bitmaps to be resized when the array is resized,
we need to know how much space there is.

So create an attribute to store this information and set appropriate
defaults.

It can be set more precisely via sysfs, or future metadata extensions
may allow it to be recorded.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:07 +10:00
NeilBrown bf07bb7d5b md/bitmap: disentangle two different 'pending' flags.
There are two different 'pending' concepts in the handling of the
write intent bitmap.

Firstly, a 'page' from the bitmap (which container PAGE_SIZE*8 bits)
may have changes (bits cleared) that should be written in due course.
There is no hurry for these and the page will transition from
PENDING to NEEDWRITE and will then be written, though if it ever
becomes DIRTY it will be written much sooner and PENDING will be
cleared.

Secondly, a page of counters - which contains PAGE_SIZE/2 counters, one
for each bit, can usefully have a 'pending' flag which indicates if
any of the counters are low (2 or 1) and ready to be processed by
bitmap_daemon_work().  If this flag is clear we can skip the whole
page.

These two concepts are currently combined in the bitmap-file flag.
This causes a tighter connection between the counters and the bitmap
file than I would like - as I want to add some flexibility to the
bitmap file.

So introduce a new flag with the page-of-counters, and rewrite
bitmap_daemon_work() so that it handles the two different 'pending'
concepts separately.

This also allows us to clear BITMAP_PAGE_PENDING when we write out
a dirty page, which may occasionally reduce the number of times we
write a page.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:06 +10:00
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.
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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