Commit Graph

134 Commits

Author SHA1 Message Date
Maciej Trela 049d6c1ef9 md: enable raid4->raid0 takeover
Only level 5 with layout=PARITY_N can be taken over to raid0 now.
Lets allow level 4 either.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:34:57 +10:00
Maciej Trela 001048a318 md: clear layout after ->raid0 takeover
After takeover from raid5/10 -> raid0 mddev->layout is not cleared.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:34:45 +10:00
NeilBrown e93f68a1fc md: fix handling of array level takeover that re-arranges devices.
Most array level changes leave the list of devices largely unchanged,
possibly causing one at the end to become redundant.
However conversions between RAID0 and RAID10 need to renumber
all devices (except 0).

This renumbering is currently being done in the ->run method when the
new personality takes over.  However this is too late as the common
code in md.c might already have invalidated some of the devices if
they had a ->raid_disk number that appeared to high.

Moving it into the ->takeover method is too early as the array is
still active at that time and wrong ->raid_disk numbers could cause
confusion.

So add a ->new_raid_disk field to mdk_rdev_s and use it to communicate
the new raid_disk number.
Now the common code knows exactly which devices need to be renumbered,
and which can be invalidated, and can do it all at a convenient time
when the array is suspend.
It can also update some symlinks in sysfs which previously were not be
updated correctly.

Reported-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:33:24 +10:00
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
NeilBrown b5a20961f3 md/raid0: tidy up printk messages.
All messages now start
   md/raid0:md-device-name:

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:59 +10:00
NeilBrown 21a52c6d05 md: pass mddev to make_request functions rather than request_queue
We used to pass the personality make_request function direct
to the block layer so the first argument had to be a queue.
But now we have the intermediary md_make_request so it makes
at lot more sense to pass a struct mddev_s.
It makes it possible to have an mddev without its own queue too.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown 490773268c md: move io accounting out of personalities into md_make_request
While I generally prefer letting personalities do as much as possible,
given that we have a central md_make_request anyway we may as well use
it to simplify code.
Also this centralises knowledge of ->gendisk which will help later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
Trela, Maciej 9af204cf72 md: Add support for Raid5->Raid0 and Raid10->Raid0 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:48 +10:00
NeilBrown 84707f38e7 md: don't use mddev->raid_disks in raid0 or raid10 while array is active.
In a subsequent patch we will make it possible to change
mddev->raid_disks while a RAID0 or RAID10 array is active.  This is
part of the process of reshaping such an array.

This means that we cannot use this value while processes requests
(it is OK to use it during initialisation as we are locked against
changes then).
Both RAID0 and RAID10 have the same value stored in the private data
structure, so use that value instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:47 +10:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
NeilBrown 627a2d3c29 md: deal with merge_bvec_fn in component devices better.
If a component device has a merge_bvec_fn then as we never call it
we must ensure we never need to.  Currently this is done by setting
max_sector to 1 PAGE, however this does not stop a bio being created
with several sub-page iovecs that would violate the merge_bvec_fn.

So instead set max_segments to 1 and set the segment boundary to the
same as a page boundary to ensure there is only ever one single-page
segment of IO requested at a time.

This can particularly be an issue when 'xen' is used as it is
known to submit multiple small buffers in a single bio.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-03-16 17:04:24 +11:00
Martin K. Petersen 086fa5ff08 block: Rename blk_queue_max_sectors to blk_queue_max_hw_sectors
The block layer calling convention is blk_queue_<limit name>.
blk_queue_max_sectors predates this practice, leading to some confusion.
Rename the function to appropriately reflect that its intended use is to
set max_hw_sectors.

Also introduce a temporary wrapper for backwards compability.  This can
be removed after the merge window is closed.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-26 13:58:08 +01:00
NeilBrown 0efb9e6191 md: add MODULE_DESCRIPTION for all md related modules.
Suggested by  Oren Held <orenhe@il.ibm.com>

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown a2826aa92e md: support barrier requests on all personalities.
Previously barriers were only supported on RAID1.  This is because
other levels requires synchronisation across all devices and so needed
a different approach.
Here is that approach.

When a barrier arrives, we send a zero-length barrier to every active
device.  When that completes - and if the original request was not
empty -  we submit the barrier request itself (with the barrier flag
cleared) and then submit a fresh load of zero length barriers.

The barrier request itself is asynchronous, but any subsequent
request will block until the barrier completes.

The reason for clearing the barrier flag is that a barrier request is
allowed to fail.  If we pass a non-empty barrier through a striping
raid level it is conceivable that part of it could succeed and part
could fail.  That would be way too hard to deal with.
So if the first run of zero length barriers succeed, we assume all is
sufficiently well that we send the request and ignore errors in the
second run of barriers.

RAID5 needs extra care as write requests may not have been submitted
to the underlying devices yet.  So we flush the stripe cache before
proceeding with the barrier.

Note that the second set of zero-length barriers are submitted
immediately after the original request is submitted.  Thus when
a personality finds mddev->barrier to be set during make_request,
it should not return from make_request until the corresponding
per-device request(s) have been queued.

That will be done in later patches.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
2009-12-14 12:49:49 +11:00
NeilBrown 3fa841d7e7 md: report device as congested when suspended
This should writeback from coming when the device is temporarily
suspended.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:10:29 +10:00
NeilBrown a9f326ebf2 md: remove sparse waring "symbol xxx shadows an earlier one"
Rename some variable and remove some duplicate definitions
to avoid there warnings.  None of them are actual errors.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:06:41 +10:00
Jens Axboe 1f98a13f62 bio: first step in sanitizing the bio->bi_rw flag testing
Get rid of any functions that test for these bits and make callers
use bio_rw_flagged() directly. Then it is at least directly apparent
what variable and flag they check.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11 14:33:31 +02:00
Andre Noll ac5e7113e7 md: Push down data integrity code to personalities.
This patch replaces md_integrity_check() by two new public functions:
md_integrity_register() and md_integrity_add_rdev() which are both
personality-independent.

md_integrity_register() is called from the ->run and ->hot_remove
methods of all personalities that support data integrity.  The
function iterates over the component devices of the array and
determines if all active devices are integrity capable and if their
profiles match. If this is the case, the common profile is registered
for the mddev via blk_integrity_register().

The second new function, md_integrity_add_rdev() is called from the
->hot_add_disk methods, i.e. whenever a new device is being added
to a raid array. If the new device does not support data integrity,
or has a profile different from the one already registered, data
integrity for the mddev is disabled.

For raid0 and linear, only the call to md_integrity_register() from
the ->run method is necessary.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:47 +10:00
Martin K. Petersen 8f6c2e4b32 md: Use new topology calls to indicate alignment and I/O sizes
Switch MD over to the new disk_stack_limits() function which checks for
aligment and adjusts preferred I/O sizes when stacking.

Also indicate preferred I/O sizes where applicable.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 11:13:45 +10:00
Andre Noll 0894cc3066 md: Move check for bitmap presence to personality code.
If the superblock of a component device indicates the presence of a
bitmap but the corresponding raid personality does not support bitmaps
(raid0, linear, multipath, faulty), then something is seriously wrong
and we'd better refuse to run such an array.

Currently, this check is performed while the superblocks are examined,
i.e. before entering personality code. Therefore the generic md layer
must know which raid levels support bitmaps and which do not.

This patch avoids this layer violation without adding identical code
to various personalities. This is accomplished by introducing a new
public function to md.c, md_check_no_bitmap(), which replaces the
hard-coded checks in the superblock loading functions.

A call to md_check_no_bitmap() is added to the ->run method of each
personality which does not support bitmaps and assembly is aborted
if at least one component device contains a bitmap.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:49:23 +10:00
NeilBrown 13f2682b72 md: raid0/linear: ensure device sizes are rounded to chunk size.
This is currently ensured by common code, but it is more reliable to
ensure it where it is needed in personality code.
All the other personalities that care already round the size to
the chunk_size.  raid0 and linear are the only hold-outs.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:55 +10:00
NeilBrown d6e412eaa5 md: raid0: chunk_sectors cleanups.
following the conversion to chunk_sectors, there is room
for cleaning up a little.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:00 +10:00
Andre Noll 9d8f036362 md: Make mddev->chunk_size sector-based.
This patch renames the chunk_size field to chunk_sectors with the
implied change of semantics.  Since

	is_power_of_2(chunk_size) = is_power_of_2(chunk_sectors << 9)
				  = is_power_of_2(chunk_sectors)

these bits don't need an adjustment for the shift.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:45:01 +10:00
raz ben yehuda fbb704efb7 md: raid0 :Enables chunk size other than powers of 2.
Maintain two flows, one for pow2 chunk sizes (which uses masks and
shift), and a flow for the general case (which uses sector_div).
This is for the sake of performance.

 - introduce map_sector and is_io_in_chunk_boundary to encapsulate
   those two flows better for raid0_make_request
 - fix blk_mergeable to support the two flows.

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:02:05 +10:00
raz ben yehuda 92e59b6ba2 md: raid0: chunk size check in raid0_run
have raid0 check chunk size in run method instead of in md.
This is part of a series moving the checks from common code to
the personalities where they belong.

hardsect is short and chunksize is an int, so it is safe to use %.

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:00:57 +10:00
raz ben yehuda 46994191ae md: have raid0 report its formation
Report to the user what are the raid zones

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:00:54 +10:00
raz ben yehuda 1b9614291e md: have raid0 compile with MD_DEBUG on
Because of the removal of the device list from
the strips raid0 did not compile with MD_DEBUG flag on

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:57:40 +10:00
NeilBrown 070ec55d07 md: remove mddev_to_conf "helper" macro
Having a macro just to cast a void* isn't really helpful.
I would must rather see that we are simply de-referencing ->private,
than have to know what the macro does.

So open code the macro everywhere and remove the pointless cast.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:54:21 +10:00
NeilBrown a6b3deafe0 md: raid0: remove setting of segment boundary.
This setting doesn't seem to make sense (half the chunk size??) and
shouldn't be needed.
The segment boundary exported by raid0 should simply be the minimum
of the segment boundary of all component devices.  And we already
get that right.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:54:07 +10:00
NeilBrown b414579f45 md: raid0: remove ->dev pointer from strip_zone structure
If we treat conf->devlist more like a 2 dimensional array,
we can get the devlist for a particular zone simply by indexing
that array, so we don't need to store the pointers to subarrays
in strip_zone.  This makes strip_zone smaller and so (hopefully)
searches faster.

Signed-of-by: NeilBrown <neilb@suse.de>
2009-06-16 16:50:52 +10:00
NeilBrown 49f357a22b md: raid0: remove ->sectors from the strip_zone structure.
storing ->sectors is redundant as is can be computed from the
difference  z->zone_end - (z-1)->zone_end

The one place where it is used, it is just as efficient to use
a zone_end value instead.

And removing it makes strip_zone smaller, so they array of these that
is searched on every request has a better chance to say in cache.

So discard the field and get the value from elsewhere.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:50:35 +10:00
Andre Noll fb5ab4b5d6 md: raid0: Fix a memory leak when stopping a raid0 array.
raid0_stop() removes all references to the raid0 configuration but
misses to free the ->devlist buffer.

This patch closes this leak, removes a pointless initialization and
fixes a coding style issue in raid0_stop().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:48:19 +10:00
Andre Noll ed7b00380d md: raid0: Allocate all buffers for the raid0 configuration in one function.
Currently the raid0 configuration is allocated in raid0_run() while
the buffers for the strip_zone and the dev_list arrays are allocated
in create_strip_zones(). On errors, all three buffers are freed
in raid0_run().

It's easier and more readable to do the allocation and cleanup within
a single function. So move that code into create_strip_zones().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:47:36 +10:00
Andre Noll 5568a6035d md: raid0: Make raid0_run() return a proper error code.
Currently raid0_run() always returns -ENOMEM on errors. This is
incorrect as running the array might fail for other reasons, for
example because not all component devices were available.

This patch changes create_strip_zones() so that it returns a proper
error code (either -ENOMEM or -EINVAL) rather than 1 on errors and
makes raid0_run(), its single caller, return that value instead
of -ENOMEM.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:47:21 +10:00
Andre Noll 8f79cfcdb6 md: raid0: Remove hash spacing and sector shift.
The "sector_shift" and "spacing" fields of struct raid0_private_data
were only used for the hash table lookups. So the removal of the
hash table allows get rid of these fields as well which simplifies
create_strip_zones() and raid0_run() quite a bit.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:47:10 +10:00
Andre Noll 09770e0b6e md: raid0: Remove hash table.
The raid0 hash table has become unused due to the changes in the
previous patch. This patch removes the hash table allocation and
setup code and kills the hash_table field of struct raid0_private_data.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:46:48 +10:00
NeilBrown d27a43abd7 md/raid0: two cleanups in create_stripe_zones.
1/ remove current_start.  The same value is available in
     zone->dev_start and storing it separately doesn't gain anything.
2/ rename curr_zone_start to curr_zone_end as we are now more
     focused on the 'end' of each zone.  We end up storing the
     same number though - the old name was a little confusing
     (and what does 'current' mean in this context anyway).

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:46:46 +10:00
Andre Noll dc58266385 md: raid0: Replace hash table lookup by looping over all strip_zones.
The number of strip_zones of a raid0 array is bounded by the number of
drives in the array and is in fact much smaller for typical setups. For
example, any raid0 array containing identical disks will have only
a single strip_zone.

Therefore, the hash tables which are used for quickly finding the
strip_zone that holds a particular sector are of questionable value
and add quite a bit of unnecessary complexity.

This patch replaces the hash table lookup by equivalent code which
simply loops over all strip zones to find the zone that holds the
given sector.

In order to make this loop as fast as possible, the zone->start field
of struct strip_zone has been renamed to zone_end, and it now stores
the beginning of the next zone in sectors. This allows to save one
addition in the loop.

Subsequent cleanup patches will remove the hash table structure.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:18:43 +10:00
Martin K. Petersen ae03bf639a block: Use accessor functions for queue limits
Convert all external users of queue limits to using wrapper functions
instead of poking the request queue variables directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22 23:22:54 +02:00
Dan Williams b522adcde9 md: 'array_size' sysfs attribute
Allow userspace to set the size of the array according to the following
semantics:

1/ size must be <= to the size returned by mddev->pers->size(mddev, 0, 0)
   a) If size is set before the array is running, do_md_run will fail
      if size is greater than the default size
   b) A reshape attempt that reduces the default size to less than the set
      array size should be blocked
2/ once userspace sets the size the kernel will not change it
3/ writing 'default' to this attribute returns control of the size to the
   kernel and reverts to the size reported by the personality

Also, convert locations that need to know the default size from directly
reading ->array_sectors to <pers>_size.  Resync/reshape operations
always follow the default size.

Finally, fixup other locations that read a number of 1k-blocks from
userspace to use strict_blocks_to_sectors() which checks for unsigned
long long to sector_t overflow and blocks to sectors overflow.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31 15:00:31 +11:00
Dan Williams 1f403624bd md: centralize ->array_sectors modifications
Get personalities out of the business of directly modifying
->array_sectors.  Lays groundwork to introduce policy on when
->array_sectors can be modified.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31 14:59:03 +11:00
Dan Williams 80c3a6ce4b md: add 'size' as a personality method
In preparation for giving userspace control over ->array_sectors we need
to be able to retrieve the 'default' size, and the 'anticipated' size
when a reshape is requested.  For personalities that do not reshape emit
a warning if anything but the default size is requested.

In the raid5 case we need to update ->previous_raid_disks to make the
new 'default' size available.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31 14:57:49 +11:00
Andre Noll dd8ac336c1 md: Represent raid device size in sectors.
This patch renames the "size" field of struct mdk_rdev_s to
"sectors" and changes this field to store sectors instead of
blocks.

All users of this field, linear.c, raid0.c and md.c, are fixed up
accordingly which gets rid of many multiplications and divisions.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown 43b2e5d86d md: move md_k.h from include/linux/raid/ to drivers/md/
It really is nicer to keep related code together..

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown bff61975b3 md: move lots of #include lines out of .h files and into .c
This makes the includes more explicit, and is preparation for moving
md_k.h to drivers/md/md.h

Remove include/raid/md.h as its only remaining use was to #include
other files.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
Christoph Hellwig ef740c372d md: move headers out of include/linux/raid/
Move the headers with the local structures for the disciplines and
bitmap.h into drivers/md/ so that they are more easily grepable for
hacking and not far away.  md.h is left where it is for now as there
are some uses from the outside.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:03 +11:00
Cheng Renquan 159ec1fc06 md: use list_for_each_entry macro directly
The rdev_for_each macro defined in <linux/raid/md_k.h> is identical to
list_for_each_entry_safe, from <linux/list.h>, it should be defined to
use list_for_each_entry_safe, instead of reinventing the wheel.

But some calls to each_entry_safe don't really need a safe version,
just a direct list_for_each_entry is enough, this could save a temp
variable (tmp) in every function that used rdev_for_each.

In this patch, most rdev_for_each loops are replaced by list_for_each_entry,
totally save many tmp vars; and only in the other situations that will call
list_del to delete an entry, the safe version is used.

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:08 +11:00
Andre Noll ccacc7d2cf md: raid0: make hash_spacing and preshift sector-based.
This patch renames the hash_spacing and preshift members of struct
raid0_private_data to spacing and sector_shift respectively and
changes the semantics as follows:

We always have spacing = 2 * hash_spacing. In case
sizeof(sector_t) > sizeof(u32) we also have sector_shift = preshift + 1
while sector_shift = preshift = 0 otherwise.

Note that the values of nb_zone and zone are unaffected by these changes
because in the sector_div() preceeding the assignement of these two
variables both arguments double.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:08 +11:00
Andre Noll 83838ed878 md: raid0: Represent the size of strip zones in sectors.
This completes the block -> sector conversion of struct strip_zone.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:07 +11:00
Andre Noll 0825b87a7d md: raid0 create_strip_zones(): Add KERN_INFO/KERN_ERR to printk's.
This patch consists only of these trivial changes.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:07 +11:00
Andre Noll 6b8796cc3d md: raid0 create_strip_zones(): Make two local variables sector-based.
current_offset and curr_zone_offset stored the corresponding offsets
as 1K quantities. Rename them to current_start and curr_zone_start
to match the naming of struct strip_zone and store the offsets as
sector counts.

Also, add KERN_INFO to the printk() affected by this change to make
checkpatch happy.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:07 +11:00
Andre Noll 6199d3db0f md: raid0: Represent zone->zone_offset in sectors.
For the same reason as in the previous patch, rename it from zone_offset
to zone_start.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:07 +11:00
Andre Noll 019c4e2f3e md: raid0: Represent device offset in sectors.
Rename zone->dev_offset to zone->dev_start to make sure all users
have been converted.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:06 +11:00
Andre Noll e0f0686834 md: raid0_make_request(): Replace local variable block by sector.
This change already simplifies the code a bit.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:06 +11:00
Andre Noll a471200595 md: raid0_make_request(): Remove local variable chunk_size.
We might as well use chunk_sects instead.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:06 +11:00
Andre Noll 1b7fdf8ff7 md: raid0_make_request(): Replace chunksize_bits by chunksect_bits.
As ffz(~(2 * x)) = ffz(~x) + 1, we have

	chunksect_bits = chunksize_bits + 1.

Fixup all users accordingly.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:06 +11:00
NeilBrown fb4d8c76e5 md: Remove unnecessary #includes, #defines, and function declarations.
A lot of cruft has gathered over the years.  Time to remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13 11:55:12 +11:00
Denis ChengRq 6feef531f5 block: mark bio_split_pool static
Since all bio_split calls refer the same single bio_split_pool, the bio_split
function can use bio_split_pool directly instead of the mempool_t parameter;

then the mempool_t parameter can be removed from bio_split param list, and
bio_split_pool is only referred in fs/bio.c file, can be marked static.

Signed-off-by: Denis ChengRq <crquan@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:57:05 +02:00
Tejun Heo 074a7aca7a block: move stats from disk to part0
Move stats related fields - stamp, in_flight, dkstats - from disk to
part0 and unify stat handling such that...

* part_stat_*() now updates part0 together if the specified partition
  is not part0.  ie. part_stat_*() are now essentially all_stat_*().

* {disk|all}_stat_*() are gone.

* part_round_stats() is updated similary.  It handles part0 stats
  automatically and disk_round_stats() is killed.

* part_{inc|dec}_in_fligh() is implemented which automatically updates
  part0 stats for parts other than part0.

* disk_map_sector_rcu() is updated to return part0 if no part matches.
  Combined with the above changes, this makes NULL special case
  handling in callers unnecessary.

* Separate stats show code paths for disk are collapsed into part
  stats show code paths.

* Rename disk_stat_lock/unlock() to part_stat_lock/unlock()

While at it, reposition stat handling macros a bit and add missing
parentheses around macro parameters.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:08 +02:00
Tejun Heo c995905916 block: fix diskstats access
There are two variants of stat functions - ones prefixed with double
underbars which don't care about preemption and ones without which
disable preemption before manipulating per-cpu counters.  It's unclear
whether the underbarred ones assume that preemtion is disabled on
entry as some callers don't do that.

This patch unifies diskstats access by implementing disk_stat_lock()
and disk_stat_unlock() which take care of both RCU (for partition
access) and preemption (for per-cpu counter access).  diskstats access
should always be enclosed between the two functions.  As such, there's
no need for the versions which disables preemption.  They're removed
and double underbars ones are renamed to drop the underbars.  As an
extra argument is added, there's no danger of using the old version
unconverted.

disk_stat_lock() uses get_cpu() and returns the cpu index and all
diskstat functions which access per-cpu counters now has @cpu
argument to help RT.

This change adds RCU or preemption operations at some places but also
collapses several preemption ops into one at others.  Overall, the
performance difference should be negligible as all involved ops are
very lightweight per-cpu ones.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:06 +02:00
Linus Torvalds 8a392625b6 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (52 commits)
  md: Protect access to mddev->disks list using RCU
  md: only count actual openers as access which prevent a 'stop'
  md: linear: Make array_size sector-based and rename it to array_sectors.
  md: Make mddev->array_size sector-based.
  md: Make super_type->rdev_size_change() take sector-based sizes.
  md: Fix check for overlapping devices.
  md: Tidy up rdev_size_store a bit:
  md: Remove some unused macros.
  md: Turn rdev->sb_offset into a sector-based quantity.
  md: Make calc_dev_sboffset() return a sector count.
  md: Replace calc_dev_size() by calc_num_sectors().
  md: Make update_size() take the number of sectors.
  md: Better control of when do_md_stop is allowed to stop the array.
  md: get_disk_info(): Don't convert between signed and unsigned and back.
  md: Simplify restart_array().
  md: alloc_disk_sb(): Return proper error value.
  md: Simplify sb_equal().
  md: Simplify uuid_equal().
  md: sb_equal(): Fix misleading printk.
  md: Fix a typo in the comment to cmd_match().
  ...
2008-07-21 10:29:12 -07:00
Andre Noll f233ea5c9e md: Make mddev->array_size sector-based.
This patch renames the array_size field of struct mddev_s to array_sectors
and converts all instances to use units of 512 byte sectors instead of 1k
blocks.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21 17:05:22 +10:00
Alasdair G Kergon cc371e66e3 Add bvec_merge_data to handle stacked devices and ->merge_bvec()
When devices are stacked, one device's merge_bvec_fn may need to perform
the mapping and then call one or more functions for its underlying devices.

The following bio fields are used:
  bio->bi_sector
  bio->bi_bdev
  bio->bi_size
  bio->bi_rw  using bio_data_dir()

This patch creates a new struct bvec_merge_data holding a copy of those
fields to avoid having to change them directly in the struct bio when
going down the stack only to have to change them back again on the way
back up.  (And then when the bio gets mapped for real, the whole
exercise gets repeated, but that's a problem for another day...)

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Milan Broz <mbroz@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03 13:21:15 +02:00
Neil Brown e7e72bf641 Remove blkdev warning triggered by using md
As setting and clearing queue flags now requires that we hold a spinlock
on the queue, and as blk_queue_stack_limits is called without that lock,
get the lock inside blk_queue_stack_limits.

For blk_queue_stack_limits to be able to find the right lock, each md
personality needs to set q->queue_lock to point to the appropriate lock.
Those personalities which didn't previously use a spin_lock, us
q->__queue_lock.  So always initialise that lock when allocated.

With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no
longer cause warnings as it will be clear that the proper lock is held.

Thanks to Dan Williams for review and fixing the silly bugs.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Nick Piggin <npiggin@suse.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Jacek Luczak <difrost.kernel@gmail.com>
Cc: Prakash Punnoor <prakash@punnoor.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:15 -07:00
NeilBrown d089c6af10 md: change ITERATE_RDEV to rdev_for_each
As this is more in line with common practice in the kernel.  Also swap the
args around to be more like list_for_each.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:19 -08:00
Alan D. Brunelle 2ad8b1ef11 Add UNPLUG traces to all appropriate places
Added blk_unplug interface, allowing all invocations of unplugs to result
in a generated blktrace UNPLUG.

Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-09 13:41:32 +01:00
NeilBrown 8299d7f7c0 md: fix a bug in some never-used code.
http://bugzilla.kernel.org/show_bug.cgi?id=3277

There is a seq_printf here that isn't being passed a 'seq'.  Howeve as the
code is inside #ifdef MD_DEBUG, nobody noticed.

Also remove some extra spaces.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:03 -07:00
Jens Axboe fd5d806266 block: convert blkdev_issue_flush() to use empty barriers
Then we can get rid of ->issue_flush_fn() and all the driver private
implementations of that.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16 11:05:02 +02:00
NeilBrown 6712ecf8f6 Drop 'size' argument from bio_endio and bi_end_io
As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant.  Remove it.

Now there is no need for bio_endio to subtract the size completed
from bi_size.  So don't do that either.

While we are at it, change bi_end_io to return void.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10 09:25:57 +02:00
Jens Axboe 165125e1e4 [BLOCK] Get rid of request_queue_t typedef
Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-24 09:28:11 +02:00
NeilBrown 787f17feb2 md: avoid overflow in raid0 calculation with large components
If a raid0 has a component device larger than 4TB, and is accessed on a 32bit
machines, then as 'chunk' is unsigned long,

   chunk << chunksize_bits

can overflow (this can be as high as the size of the device in KB).  chunk
itself will not overflow (without triggering a BUG).

So change 'chunk' to be 'sector_t, and get rid of the 'BUG' as it becomes
impossible to hit.

Cc: "Jeff Zheng" <Jeff.Zheng@endace.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:14 -07:00
NeilBrown 26be34dc3a [PATCH] md: define backing_dev_info.congested_fn for raid0 and linear
Each backing_dev needs to be able to report whether it is congested, either by
modulating BDI_*_congested in ->state, or by defining a ->congested_fn.
md/raid did neither of these.  This patch add a congested_fn which simply
checks all component devices to see if they are congested.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:04:18 -07:00
NeilBrown 5c4c33318d [PATCH] md: fix possible oops when starting a raid0 array
This loop that sets up the hash_table has problems.

Careful examination will show that the last time through, everything but
the first line is pointless.  This is because all it does is change 'cur'
and 'size' and neither of these are used after the loop.  This should ring
warning bells...  That last time through the loop,

        size += conf->strip_zone[cur].size

can index off the end of the strip_zone array.  Depending on what it finds
there, it might exit the loop cleanly, or it might spin going further and
further beyond the array until it hits an unmapped address.

This patch rearranges the code so that the last, pointless, iteration of
the loop never happens.  i.e.  the one statement of the last loop that is
needed is moved the the end of the previous loop - or to before the loop
starts - and the loop counter starts from 1 instead of 0.

Cc: "Don Dupuis" <dondster@gmail.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-23 10:35:31 -07:00
NeilBrown 29fc7e3e70 [PATCH] md: Assorted little md fixes
- 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>
2006-02-03 08:32:00 -08:00
Andrew Morton a136564702 [PATCH] remove gcc-2 checks
Remove various things which were checking for gcc-1.x and gcc-2.x compilers.

From: Adrian Bunk <bunk@stusta.de>

    Some documentation updates and removes some code paths for gcc < 3.2.

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:14:02 -08:00
NeilBrown d9d166c2a9 [PATCH] md: allow array level to be set textually 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>
2006-01-06 08:34:09 -08:00
NeilBrown 2604b703b6 [PATCH] md: remove personality numbering from md
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>
2006-01-06 08:34:06 -08:00
NeilBrown 9ffae0cf3e [PATCH] md: convert md to use kzalloc throughout
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>
2006-01-06 08:34:05 -08:00
NeilBrown 2d1f3b5d1b [PATCH] md: clean up 'page' related names in md
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>
2006-01-06 08:34:05 -08:00
Jens Axboe a362357b6c [BLOCK] Unify the seperate read/write io stat fields into arrays
Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).

Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-01 09:26:16 +01:00
NeilBrown e5dcdd80a6 [PATCH] md: fail IO request to md that require a barrier.
md does not yet support BIO_RW_BARRIER, so be honest about it and fail
(-EOPNOTSUPP) any such requests.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09 16:39:09 -07:00
Neil Brown 1eb29128c6 [PATCH] Fix raid0's attempt to divide by 64bit numbers
Apparently sector_div is only guaranteed to work with a 32bit divisor, even
on 64bit architectures.  So allow for this in raid0.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-15 09:54:50 -07:00
Jesper Juhl 990a8baf56 [PATCH] md: remove unneeded NULL checks before kfree
This patch removes some unneeded checks of pointers being NULL before
calling kfree() on them.  kfree() handles NULL pointers just fine, checking
first is pointless.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21 19:07:48 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00