this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
raid5 overloads bi_phys_segments to count the number of blocks that the
request was broken in to so that it knows when the bio is completely handled.
Accessing this must always be done under a spinlock. In one case we also call
bi_end_io under that spinlock, which probably isn't ideal as bi_end_io could
be expensive (even though it isn't allowed to sleep).
So we reducde the range of the spinlock to just accessing bi_phys_segments.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
wait_event_lock_irq puts a ';' after its usage of the 4th arg, so we don't
need to.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This allows user-space to access data safely. This is needed for raid5
reshape as user-space needs to take a backup of the first few stripes before
allowing reshape to commence.
It will also be useful in cluster-aware raid1 configurations so that all
cluster members can leave a section of the array untouched while a
resync/recovery happens.
A 'start' and 'end' of the suspended range are written to 2 sysfs attributes.
Note that only one range can be suspended at a time.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
check_reshape checks validity and does things that can be done instantly -
like adding devices to raid1. start_reshape initiates a restriping process to
convert the whole array.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Instead of checkpointing at each stripe, only checkpoint when a new write
would overwrite uncheckpointed data. Block any write to the uncheckpointed
area. Arbitrarily checkpoint at least every 3Meg.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We allow the superblock to record an 'old' and a 'new' geometry, and a
position where any conversion is up to. The geometry allows for changing
chunksize, layout and level as well as number of devices.
When using verion-0.90 superblock, we convert the version to 0.91 while the
conversion is happening so that an old kernel will refuse the assemble the
array. For version-1, we use a feature bit for the same effect.
When starting an array we check for an incomplete reshape and restart the
reshape process if needed. If the reshape stopped at an awkward time (like
when updating the first stripe) we refuse to assemble the array, and let
user-space worry about it.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds raid5_reshape and end_reshape which will start and finish the
reshape processes.
raid5_reshape is only enabled in CONFIG_MD_RAID5_RESHAPE is set, to discourage
accidental use.
Read the 'help' for the CONFIG_MD_RAID5_RESHAPE entry.
and Make sure that you have backups, just in case.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch provides the core of the resize/expand process.
sync_request notices if a 'reshape' is happening and acts accordingly.
It allocated new stripe_heads for the next chunk-wide-stripe in the target
geometry, marking them STRIPE_EXPANDING.
Then it finds which stripe heads in the old geometry can provide data needed
by these and marks them STRIPE_EXPAND_SOURCE. This causes stripe_handle to
read all blocks on those stripes.
Once all blocks on a STRIPE_EXPAND_SOURCE stripe_head are read, any that are
needed are copied into the corresponding STRIPE_EXPANDING stripe_head. Once a
STRIPE_EXPANDING stripe_head is full, it is marks STRIPE_EXPAND_READY and then
is written out and released.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to allow that different stripes are of different effective sizes, and
use the appropriate size. Also, when a stripe is being expanded, we must
block any IO attempts until the stripe is stable again.
Key elements in this change are:
- each stripe_head gets a 'disk' field which is part of the key,
thus there can sometimes be two stripe heads of the same area of
the array, but covering different numbers of devices. One of these
will be marked STRIPE_EXPANDING and so won't accept new requests.
- conf->expand_progress tracks how the expansion is progressing and
is used to determine whether the target part of the array has been
expanded yet or not.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Before a RAID-5 can be expanded, we need to be able to expand the stripe-cache
data structure.
This requires allocating new stripes in a new kmem_cache. If this succeeds,
we copy cache pages over and release the old stripes and kmem_cache.
We then allocate new pages. If that fails, we leave the stripe cache at it's
new size. It isn't worth the effort to shrink it back again.
Unfortuanately this means we need two kmem_cache names as we, for a short
period of time, we have two kmem_caches. So they are raid5/%s and
raid5/%s-alt
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The remainder of this batch implements raid5 reshaping. Currently the only
shape change that is supported is added a device, but it is envisioned that
changing the chunksize and layout will also be supported, as well as changing
the level (e.g. 1->5, 5->6).
The reshape process naturally has to move all of the data in the array, and so
should be used with caution. It is believed to work, and some testing does
support this, but wider testing would be great for increasing my confidence.
You will need a version of mdadm newer than 2.3.1 to make use of raid5 growth.
This is because mdadm need to take a copy of a 'critical section' at the
start of the array incase there is a crash at an awkward moment. On restart,
mdadm will restore the critical section and allow reshape to continue.
I hope to release a 2.4-pre by early next week - it still needs a little more
polishing.
This patch:
Previously the array of disk information was included in the raid5 'conf'
structure which was allocated to an appropriate size. This makes it awkward
to change the size of that array. So we split it off into a separate
kmalloced array which will require a little extra indexing, but is much easier
to grow.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- version-1 superblock
+ The default_bitmap_offset is in sectors, not bytes.
+ the 'size' field in the superblock is in sectors, not KB
- raid0_run should return a negative number on error, not '1'
- raid10_read_balance should not return a valid 'disk' number if
->rdev turned out to be NULL
- kmem_cache_destroy doesn't like being passed a NULL.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the "inline" keyword from a bunch of big functions in the kernel with
the goal of shrinking it by 30kb to 40kb
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Store this total in superblock (As appropriate), and make it available to
userspace via sysfs.
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
md supports multiple different RAID level, each being implemented by a
'personality' (which is often in a separate module).
These personalities have fairly artificial 'numbers'. The numbers
are use to:
1- provide an index into an array where the various personalities
are recorded
2- identify the module (via an alias) which implements are particular
personality.
Neither of these uses really justify the existence of personality numbers.
The array can be replaced by a linked list which is searched (array lookup
only happens very rarely). Module identification can be done using an alias
based on level rather than 'personality' number.
The current 'raid5' modules support two level (4 and 5) but only one
personality. This slight awkwardness (which was handled in the mapping from
level to personality) can be better handled by allowing raid5 to register 2
personalities.
With this change in place, the core md module does not need to have an
exhaustive list of all possible personalities, so other personalities can be
added independently.
This patch also moves the check for chunksize being non-zero into the ->run
routines for the personalities that need it, rather than having it in core-md.
This has a side effect of allowing 'faulty' and 'linear' not to have a
chunk-size set.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- replace open-coded hash chain with hlist macros
- Fix hash-table size at one page - it is already quite generous, so there
will never be a need to use multiple pages, so no need for __get_free_pages
No functional change.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace multiple kmalloc/memset pairs with kzalloc calls.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Substitute:
page_cache_get -> get_page
page_cache_release -> put_page
PAGE_CACHE_SHIFT -> PAGE_SHIFT
PAGE_CACHE_SIZE -> PAGE_SIZE
PAGE_CACHE_MASK -> PAGE_MASK
__free_page -> put_page
because we aren't using the page cache, we are just using pages.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is this "FIXME" comment with a typo in it!! that been annoying me for
days, so I just had to remove it.
conf->disks[i].rdev should only be accessed if
- we know we hold a reference or
- the mddev->reconfig_sem is down or
- we have a rcu_readlock
handle_stripe was referencing rdev in three places without any of these. For
the first two, get an rcu_readlock. For the last, the same access
(md_sync_acct call) is made a little later after the rdev has been claimed
under and rcu_readlock, if R5_Syncio is set. So just use that access...
However R5_Syncio isn't really needed as the 'syncing' variable contains the
same information. So use that instead.
Issues, comment, and fix are identical in raid5 and raid6.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is important because bitmap_create uses
mddev->resync_max_sectors
and that doesn't have a valid value until after the array
has been initialised (with pers->run()).
[It doesn't make a difference for current personalities that
support bitmaps, but will make a difference for raid10]
This has the added advantage of meaning with can move the thread->timeout
manipulation inside the bitmap.c code instead of sprinkling identical code
throughout all personalities.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
See patch to md.txt for more details
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Resync code:
A test that isn't needed,
a 'compute_block' that makes more sense
elsewhere (And then doesn't need a test),
a couple of BUG_ONs to confirm the change makes sense.
Printks:
A few were missing KERN_*
Also fix a typo in a comment..
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
