Commit Graph

483 Commits

Author SHA1 Message Date
Andre Noll
8c6ac868b1 md: Push down reconstruction log message to personality code.
Currently, the md layer checks in analyze_sbs() if the raid level
supports reconstruction (mddev->level >= 1) and if reconstruction is
in progress (mddev->recovery_cp != MaxSector).

Move that printk into the personality code of those raid levels that
care (levels 1, 4, 5, 6, 10).

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:06 +10:00
NeilBrown
50ac168a6e md: merge reconfig and check_reshape methods.
The difference between these two methods is artificial.
Both check that a pending reshape is valid, and perform any
aspect of it that can be done immediately.
'reconfig' handles chunk size and layout.
'check_reshape' handles raid_disks.

So make them just one method.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:55 +10:00
NeilBrown
597a711b69 md: remove unnecessary arguments from ->reconfig method.
Passing the new layout and chunksize as args is not necessary as
the mddev has fields for new_check and new_layout.

This is preparation for combining the check_reshape and reconfig
methods

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:42 +10:00
Andre Noll
664e7c413f md: Convert mddev->new_chunk to sectors.
A straight-forward conversion which gets rid of some
multiplications/divisions/shifts. The patch also introduces a couple
of new ones, most of which are due to conf->chunk_size still being
represented in bytes. This will be cleaned up in subsequent patches.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:45:27 +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
2ac06c3332 md: prepare for non-power-of-two chunk sizes
Remove chunk size check from md as this is now performed in the run
function in each personality.

Replace chunk size power 2 code calculations by a regular division.

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:01:42 +10:00
Linus Torvalds
c9059598ea Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context->refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c
2009-06-11 11:10:35 -07:00
NeilBrown
b492b852cd md: don't use locked_ioctl.
md has no need for the BKL - it does its own locking.
So md_ioctl doesn't need to be a locked_ioctl.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 12:57:36 +10:00
NeilBrown
7a91ee1f62 md: don't update curr_resync_completed without also updating reshape_position.
In order for the metadata to always be consistent, we mustn't updated
curr_resync_completed without also updating reshape_position.

The reshape code updates both at the same time.  However since
commit 97e4f42d62
the common md_do_sync will sometimes update curr_resync_completed
but is not in a position to update reshape_position.
So if MD_RECOVERY_RESHAPE is set (indicating that a reshape is
happening, so reshape_position might change), don't update
curr_resync_completed in md_do_sync, leave it to the per-personality
reshape code.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 12:57:21 +10:00
NeilBrown
b6a9ce688f md: export 'frozen' resync state through sysfs
The md resync engine has a 'frozen' state which ensures that
no resync/recovery.  This is used to avoid races.

Export this state through the 'sync_action' sysfs attribute
so that user-space can benefit and also avoid some races.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:41:17 +10:00
NeilBrown
2b69c83924 md: improve errno return when setting array_size
Instead of always returns EINVAL if anything goes wrong
when setting the array size, add the option of
  E2BIG
if the size requested is too large.  This makes it easier
for user-space to be sure what went wrong.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:41:17 +10:00
NeilBrown
62e1e389f8 md: always update level / chunk_size / layout when writing v1.x metadata.
We previously didn't update these fields when writing the metadata
because they could never change.  They can now, so we better write
them.
v0.90 metadata always updated these fields.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:40:59 +10:00
Martin K. Petersen
e1defc4ff0 block: Do away with the notion of hardsect_size
Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case.  The
sector size will be 4KB but the logical block size will remain
512-bytes.  Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.

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
NeilBrown
c4647292fd md: remove rd%d links immediately after stopping an array.
md maintains link in sys/mdXX/md/ to identify which device has
which role in the array. e.g.
   rd2 -> dev-sda

indicates that the device with role '2' in the array is sda.

These links are only present when the array is active.  They are
created immediately after ->run is called, and so should be removed
immediately after ->stop is called.
However they are currently removed a little bit later, and it is
possible for ->run to be called again, thus adding these links, before
they are removed.

So move the removal earlier so they are consistently only present when
the array is active.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:51:06 +10:00
NeilBrown
5bf2959754 md: remove ability to explicit set an inactive array to 'clean'.
Being able to write 'clean' to an 'array_state' of an inactive array
to activate it in 'clean' mode is both unnecessary and inconvenient.

It is unnecessary because the same can be achieved by writing
'active'.  This activates and array, but it still remains 'clean'
until the first write.

It is inconvenient because writing 'clean' is more often used to
cause an 'active' array to revert to 'clean' mode (thus blocking
any writes until a 'write-pending' is promoted to 'active').

Allowing 'clean' to both activate an array and mark an active array as
clean can lead to races:  One program writes 'clean' to mark the
active array as clean at the same time as another program writes
'inactive' to deactivate (stop) and active array.  Depending on which
writes first, the array could be deactivated and immediately
reactivated which isn't what was desired.

So just disable the use of 'clean' to activate an array.

This avoids a race that can be triggered with mdadm-3.0 and external
metadata, so it suitable for -stable.

Reported-by: Rafal Marszewski <rafal.marszewski@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:50:57 +10:00
Jan Engelhardt
110518bccf md: constify VFTs
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:49:37 +10:00
NeilBrown
dd71cf6b27 md: tidy up status_resync to handle large arrays.
Two problems in status_resync.
1/ It still used Kilobytes as the basic block unit, while most code
   now uses sectors uniformly.
2/ It doesn't allow for the possibility that max_sectors exceeds
   the range of "unsigned long".

So
 - change "max_blocks" to "max_sectors", and store sector numbers
   in there and in 'resync'
 - Make 'rt' a 'sector_t' so it can temporarily hold the number of
   remaining sectors.
 - use sector_div rather than normal division.
 - change the magic '100' used to preserve precision to '32'.
   + making it a power of 2 makes division easier
   + it doesn't need to be as large as it was chosen when we averaged
     speed over the entire run.  Now we average speed over the last 30
     seconds or so.

Reported-by: "Mario 'BitKoenig' Holbe" <Mario.Holbe@TU-Ilmenau.DE>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:49:35 +10:00
NeilBrown
c03f6a1969 md: update sync_completed and reshape_position even more often.
There are circumstances when a user-space process might need to
"oversee" a resync/reshape process.  For example when doing an
in-place reshape of a raid5, it is prudent to take a backup of each
section before reshaping it as this is the only way to provide
safety against an unplanned shutdown (i.e. crash/power failure).

The sync_max sysfs value can be used to stop the resync from
advancing beyond a particular point.
So user-space can:
  suspend IO to the first section and back it up
  set 'sync_max' to the end of the section
  wait for 'sync_completed' to reach that point
  resume IO on the first section and move on to the next section.

However this process requires the kernel and user-space to run in
lock-step which could introduce unnecessary delays.

It would be better if a 'double buffered' approach could be used with
userspace and kernel space working on different sections with the
'next' section always ready when the 'current' section is finished.

One problem with implementing this is that sync_completed is only
guaranteed to be updated when the sync process reaches sync_max.
(it is updated on a time basis at other times, but it is hard to rely
on that).  This defeats some of the double buffering.

With this patch, sync_completed (and reshape_position) get updated as
the current position approaches sync_max, so there is room for
userspace to advance sync_max early without losing updates.

To be precise, sync_completed is updated when the current sync
position reaches half way between the current value of sync_completed
and the value of sync_max.  This will usually be a good time for user
space to update sync_max.

If sync_max does not get updated, the updates to sync_completed
(together with associated metadata updates) will occur at an
exponentially increasing frequency which will get unreasonably fast
(one update every page) immediately before the process hits sync_max
and stops.  So the update rate will be unreasonably fast only for an
insignificant period of time.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-17 11:06:30 +10:00
NeilBrown
acb180b0e3 md: improve usefulness and accuracy of sysfs file md/sync_completed.
The sync_completed file reports how much of a resync (or recovery or
reshape) has been completed.
However due to the possibility of out-of-order completion of writes,
it is not certain to be accurate.

We have an internal value - mddev->curr_resync_completed - which is an
accurate value (though it might not always be quite so uptodate).

So:
 - make curr_resync_completed be uptodate a little more often,
   particularly when raid5 reshape updates status in the metadata
 - report curr_resync_completed in the sysfs file
 - allow poll/select to report all updates to md/sync_completed.

This makes sync_completed completed usable by any external metadata
handler that wants to record this status information in its metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14 16:28:34 +10:00
NeilBrown
6d56e27844 md: allow setting newly added device to 'in_sync' via sysfs.
When adding devices to an active array via sysfs, there is currently
no way to mark a device as 'in-sync' which is useful when
incrementally assembling an array.

So add that option.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14 12:01:57 +10:00
Linus Torvalds
223cdea4c4 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (53 commits)
  md/raid5 revise rules for when to update metadata during reshape
  md/raid5: minor code cleanups in make_request.
  md: remove CONFIG_MD_RAID_RESHAPE config option.
  md/raid5: be more careful about write ordering when reshaping.
  md: don't display meaningless values in sysfs files resync_start and sync_speed
  md/raid5: allow layout and chunksize to be changed on active array.
  md/raid5: reshape using largest of old and new chunk size
  md/raid5: prepare for allowing reshape to change layout
  md/raid5: prepare for allowing reshape to change chunksize.
  md/raid5: clearly differentiate 'before' and 'after' stripes during reshape.
  Documentation/md.txt update
  md: allow number of drives in raid5 to be reduced
  md/raid5: change reshape-progress measurement to cope with reshaping backwards.
  md: add explicit method to signal the end of a reshape.
  md/raid5: enhance raid5_size to work correctly with negative delta_disks
  md/raid5: drop qd_idx from r6_state
  md/raid6: move raid6 data processing to raid6_pq.ko
  md: raid5 run(): Fix max_degraded for raid level 4.
  md: 'array_size' sysfs attribute
  md: centralize ->array_sectors modifications
  ...
2009-04-03 09:08:19 -07:00
NeilBrown
d1a7c50369 md: don't display meaningless values in sysfs files resync_start and sync_speed
When no resync if happening, both of these files currently have
meaningless values (is slightly different ways).
Change them to "none" in that case.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 15:24:32 +11:00
NeilBrown
cea9c22800 md: add explicit method to signal the end of a reshape.
Currently raid5 (the only module that supports restriping)
notices that the reshape has finished be sync_request being
given a large value, and handles any cleanup them.

This patch changes it so md_check_recovery calls into an
explicit finish_reshape method as well.

The clean-up from sync_request can do things that need to be
done promptly, typically things local to the raid5_conf_t
structure.

The "finish_reshape" method is called under the mddev_lock
so it can do things involving reconfiguring the device.

This allows us to get rid of md_set_array_sectors_locked, which
would have caused a deadlock if you tried to stop and array
while a reshape was happening.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 15:15:05 +11:00
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
NeilBrown
b354603527 md/raid5: allow layout/chunksize to be changed on an active 2-drive raid5.
2-drive raid5's aren't very interesting.  But if you are converting
a raid1 into a raid5, you will at least temporarily have one.  And
that it a good time to set the layout/chunksize for the new RAID5
if you aren't happy with the defaults.

layout and chunksize don't actually affect the placement of data
on a 2-drive raid5, so we just do some internal book-keeping.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:56:41 +11:00
NeilBrown
245f46c2c2 md: add ->takeover method to support changing the personality managing an array
Implement this for RAID6 to be able to 'takeover' a RAID5 array.  The
new RAID6 will use a layout which places Q on the last device, and
that device will be missing.
If there are any available spares, one will immediately have Q
recovered onto it.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:39:39 +11:00
NeilBrown
409c57f380 md: enable suspend/resume of md devices.
To be able to change the 'level' of an md/raid array, we need to
suspend the device so that no requests are active - then move some
pointers around etc.

The code already keeps counts of active requests and the ->quiesce
function can be used to wait until those counts hit zero.
However the quiesce function blocks new requests once they are all
ready 'inside' the personality module, and that is too late if we want
to replace the personality modules.

So make all md requests come in through a common md_make_request
function that keeps track of how many requests have entered the
modules but may not yet be on the internal reference counts.
Allow md_make_request to be blocked when we want to suspend the
device, and make it possible to wait for all those in-transit requests
to be added to internal lists so that ->quiesce can wait for them.

There is still a problem that when a request completes, we drop the
ref count inside the personality code so there is a short time between
when the refcount hits zero, and when the personality code is no
longer being used.
The personality code never blocks (schedule or spinlock) between
dropping the refcount and exiting the routine, so this should be safe
(as put_module calls synchronize_sched() before unmapping the module
code).

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:39:39 +11:00
NeilBrown
e0cf8f045b md: md_unregister_thread should cope with being passed NULL
Mostly md_unregister_thread is only called when we know that the
thread is NULL, but sometimes we need to check first.  It is safer
to put the check inside md_unregister_thread itself.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:39:39 +11:00
NeilBrown
34817e8c39 md: make sure new_level, new_chunksize, new_layout always have sensible values.
When an md array is undergoing a change, we have new_* fields that
show the new values.
When no change is happening, it is least confusing if these have
the same value as the normal fields.
This is true in most cases, but not when the values are set via sysfs.

So fix this up.

A subsequent patch will BUG_ON if these things aren't consistent.


Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:39:38 +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
Andre Noll
58c0fed400 md: Make mddev->size sector-based.
This patch renames the "size" field of struct mddev_s to "dev_sectors"
and stores the number of 512-byte sectors instead of the number of
1K-blocks in it.

All users of that field, including raid levels 1,4-6,10, are adjusted
accordingly. This simplifies the code a bit because it allows to get
rid of a couple of divisions/multiplications by two.

In order to make checkpatch happy, some minor coding style issues
have also been addressed. In particular, size_store() now uses
strict_strtoull() instead of simple_strtoull().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown
575a80fa4f md: be more consistent about setting WriteMostly flag when adding a drive to an array
When a drive is added to an array using ADD_NEW_DISK, there are two
places we can get certain flags from:  the metadata on the disk or the
flags passed through the IOCTL.

For the WriteMostly flag (aka MD_DISK_WRITEMOSTLY) we take the value
from either of those sources depending on if it is set (i.e. we
effectively 'or' the two sources together).

This makes it awkward to clear, and is at best inconsistent.

As documented code (in mdadm) requires that setting
MD_DISK_WRITEMOSTLY in the ioctl will be effective, we resolve the
inconsistency by always using the value for this flag from the ioctl,
and ignoring the value on disk.


Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown
97e4f42d62 md: occasionally checkpoint drive recovery to reduce duplicate effort after a crash
Version 1.x metadata has the ability to record the status of a
partially completed drive recovery.
However we only update that record on a clean shutdown.
It would be nice to update it on unclean shutdowns too, particularly
when using a bitmap that removes much to the 'sync' effort after an
unclean shutdown.

One complication with checkpointing recovery is that we only know
where we are up to in terms of IO requests started, not which ones
have completed.  And we need to know what has completed to record
how much is recovered.  So occasionally pause the recovery until all
submitted requests are completed, then update the record of where
we are up to.

When we have a bitmap, we already do that pause occasionally to keep
the bitmap up-to-date.  So enhance that code to record the recovery
offset and schedule a superblock update.
And when there is no bitmap, just pause 16 times during the resync to
do a checkpoint.
'16' is a fairly arbitrary number.  But we don't really have any good
way to judge how often is acceptable, and it seems like a reasonable
number for now.


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
NeilBrown
8b2b5c217c md: move LEVEL_* definition from md_k.h to md_u.h
.. as they are part of the user-space interface.
Also move MdpMinorShift into there so we can remove duplication.

Lastly move mdp_major in.  It is less obviously part of the user-space
interface, but do_mounts_md.c uses it, and it is acting a bit like
user-space.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:03 +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
Christoph Hellwig
3dbd8c2e3f md: stop defining MAJOR_NR
MAJOR_NR was only required for magic in linux/blk.h in 2.4 or earlier
kernels, so no need to keep it around.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:02 +11:00
Martin K. Petersen
3f9d99c12a MD data integrity support
md: Add support for data integrity to MD

If all subdevices support the same protection format the MD device is
flagged as integrity capable.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:02 +11:00
NeilBrown
eea1bf384e md: Fix is_mddev_idle test (again).
There are two problems with is_mddev_idle.

1/ sync_io is 'atomic_t' and hence 'int'.  curr_events and all the
   rest are 'long'.
   So if sync_io were to wrap on a 64bit host, the value of
   curr_events would go very negative suddenly, and take a very
   long time to return to positive.

   So do all calculations as 'int'.  That gives us plenty of precision
   for what we need.

2/ To initialise rdev->last_events we simply call is_mddev_idle, on
   the assumption that it will make sure that last_events is in a
   suitable range.  It used to do this, but now it does not.
   So now we need to be more explicit about initialisation.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:02 +11:00
Dan Williams
5fd3a17ed4 md: fix deadlock when stopping arrays
Resolve a deadlock when stopping redundant arrays, i.e. ones that
require a call to sysfs_remove_group when shutdown.  The deadlock is
summarized below:

Thread1                Thread2
-------                -------
read sysfs attribute   stop array
                       take mddev lock
                       sysfs_remove_group
sysfs_get_active
wait for mddev lock
                       wait for active

Sysrq-w:
--------
mdmon         S 00000017  2212  4163      1
  f1982ea8 00000046 2dcf6b85 00000017 c0b23100 f2f83ed0 c0b23100 f2f8413c
  c0b23100 c0b23100 c0b1fb98 f2f8413c 00000000 f2f8413c c0b23100 f2291ecc
  00000002 c0b23100 00000000 00000017 f2f83ed0 f1982eac 00000046 c044d9dd
Call Trace:
  [<c044d9dd>] ? debug_mutex_add_waiter+0x1d/0x58
  [<c06ef451>] __mutex_lock_common+0x1d9/0x338
  [<c06ef451>] ? __mutex_lock_common+0x1d9/0x338
  [<c06ef5e3>] mutex_lock_interruptible_nested+0x33/0x3a
  [<c0634553>] ? mddev_lock+0x14/0x16
  [<c0634553>] mddev_lock+0x14/0x16
  [<c0634eda>] md_attr_show+0x2a/0x49
  [<c04e9997>] sysfs_read_file+0x93/0xf9
mdadm         D 00000017  2812  4177      1
  f0401d78 00000046 430456f8 00000017 f0401d58 f0401d20 c0b23100 f2da2c4c
  c0b23100 c0b23100 c0b1fb98 f2da2c4c 0a10fc36 00000000 c0b23100 f0401d70
  00000003 c0b23100 00000000 00000017 f2da29e0 00000001 00000002 00000000
Call Trace:
  [<c06eed1b>] schedule_timeout+0x1b/0x95
  [<c06eed1b>] ? schedule_timeout+0x1b/0x95
  [<c06eeb97>] ? wait_for_common+0x34/0xdc
  [<c044fa8a>] ? trace_hardirqs_on_caller+0x18/0x145
  [<c044fbc2>] ? trace_hardirqs_on+0xb/0xd
  [<c06eec03>] wait_for_common+0xa0/0xdc
  [<c0428c7c>] ? default_wake_function+0x0/0x12
  [<c06eeccc>] wait_for_completion+0x17/0x19
  [<c04ea620>] sysfs_addrm_finish+0x19f/0x1d1
  [<c04e920e>] sysfs_hash_and_remove+0x42/0x55
  [<c04eb4db>] sysfs_remove_group+0x57/0x86
  [<c0638086>] do_md_stop+0x13a/0x499

This has been there for a while, but is easier to trigger now that mdmon
is closely watching sysfs.

Cc: <stable@kernel.org>
Reported-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-04 00:57:25 -07:00
Jens Axboe
93dbb39350 block: fix bad definition of BIO_RW_SYNC
We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO
and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before
213d9417fe.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-18 10:32:00 +01:00
NeilBrown
de01dfadf2 md: Ensure an md array never has too many devices.
Each different metadata format supported by md supports a
different maximum number of devices.
We really should be enforcing this maximum in the kernel, but
we aren't quite doing that properly.

We currently only enforce it at the 'hot_add' point, which is an
older interface which is not used by current userspace.

We need to also enforce it at 'add_new_disk' time for active arrays
and at 'do_md_run' time when starting a new array.

So move the test from 'hot_add' into 'bind_rdev_to_array' which is
called from both 'hot_add' and 'add_new_disk, and add a new
test in 'analyse_sbs' which is called from 'do_md_run'.

This bug (or missing feature) has been around "forever" and so
the patch is suitable for any -stable that is currently maintained.

Cc: stable@kernel.org

Signed-off-by: NeilBrown <neilb@suse.de>
2009-02-06 18:02:46 +11:00
NeilBrown
4044ba58dd md: don't retry recovery of raid1 that fails due to error on source drive.
If a raid1 has only one working drive and it has a sector which
gives an error on read, then an attempt to recover onto a spare will
fail, but as the single remaining drive is not removed from the
array, the recovery will be immediately re-attempted, resulting
in an infinite recovery loop.

So detect this situation and don't retry recovery once an error
on the lone remaining drive is detected.

Allow recovery to be retried once every time a spare is added
in case the problem wasn't actually a media error.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:11 +11:00
NeilBrown
efeb53c0e5 md: Allow md devices to be created by name.
Using sequential numbers to identify md devices is somewhat artificial.
Using names can be a lot more user-friendly.

Also, creating md devices by opening the device special file is a bit
awkward.

So this patch provides a new option for creating and naming devices.

Writing a name such as "md_home" to
    /sys/modules/md_mod/parameters/new_array
will cause an array with that name to be created.  It will appear in
/sys/block/ /proc/partitions and /proc/mdstat as 'md_home'.
It will have an arbitrary minor number allocated.

md devices that a created by an open are destroyed on the last
close when the device is inactive.
For named md devices, they will not be destroyed until the array
is explicitly stopped, either with the STOP_ARRAY ioctl or by
writing 'clear' to /sys/block/md_XXXX/md/array_state.

The name of the array must start 'md_' to avoid conflict with
other devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
NeilBrown
d3374825ce md: make devices disappear when they are no longer needed.
Currently md devices, once created, never disappear until the module
is unloaded.  This is essentially because the gendisk holds a
reference to the mddev, and the mddev holds a reference to the
gendisk, this a circular reference.

If we drop the reference from mddev to gendisk, then we need to ensure
that the mddev is destroyed when the gendisk is destroyed.  However it
is not possible to hook into the gendisk destruction process to enable
this.

So we drop the reference from the gendisk to the mddev and destroy the
gendisk when the mddev gets destroyed.  However this has a
complication.
Between the call
   __blkdev_get->get_gendisk->kobj_lookup->md_probe
and the call
   __blkdev_get->md_open

there is no obvious way to hold a reference on the mddev any more, so
unless something is done, it will disappear and gendisk will be
destroyed prematurely.

Also, once we decide to destroy the mddev, there will be an unlockable
moment before the gendisk is unlinked (blk_unregister_region) during
which a new reference to the gendisk can be created.  We need to
ensure that this reference can not be used.  i.e. the ->open must
fail.

So:
 1/  in md_probe we set a flag in the mddev (hold_active) which
     indicates that the array should be treated as active, even
     though there are no references, and no appearance of activity.
     This is cleared by md_release when the device is closed if it
     is no longer needed.
     This ensures that the gendisk will survive between md_probe and
     md_open.

 2/  In md_open we check if the mddev we expect to open matches
     the gendisk that we did open.
     If there is a mismatch we return -ERESTARTSYS and modify
     __blkdev_get to retry from the top in that case.
     In the -ERESTARTSYS sys case we make sure to wait until
     the old gendisk (that we succeeded in opening) is really gone so
     we loop at most once.

Some udev configurations will always open an md device when it first
appears.   If we allow an md device that was just created by an open
to disappear on an immediate close, then this can race with such udev
configurations and result in an infinite loop the device being opened
and closed, then re-open due to the 'ADD' even from the first open,
and then close and so on.
So we make sure an md device, once created by an open, remains active
at least until some md 'ioctl' has been made on it.  This means that
all normal usage of md devices will allow them to disappear promptly
when not needed, but the worst that an incorrect usage will do it
cause an inactive md device to be left in existence (it can easily be
removed).

As an array can be stopped by writing to a sysfs attribute
  echo clear > /sys/block/mdXXX/md/array_state
we need to use scheduled work for deleting the gendisk and other
kobjects.  This allows us to wait for any pending gendisk deletion to
complete by simply calling flush_scheduled_work().



Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
NeilBrown
a21d15042d md: centralise all freeing of an 'mddev' in 'md_free'
md_free is the .release handler for the md kobj_type.
So it makes sense to release all the objects referenced by
the mddev in there, rather than just prior to calling kobject_put
for what we think is the last time.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:09 +11:00
NeilBrown
8b76539823 md: move allocation of ->queue from mddev_find to md_probe
It is more balanced to just do simple initialisation in mddev_find,
which allocates and links a new md device, and leave all the
more sophisticated allocation to md_probe (which calls mddev_find).
md_probe already allocated the gendisk.  It should allocate the
queue too.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:08 +11:00
Cheng Renquan
cd2ac9321c md: need another print_sb for mdp_superblock_1
md_print_devices is called in two code path: MD_BUG(...), and md_ioctl
with PRINT_RAID_DEBUG.  it will dump out all in use md devices
information;

However, it wrongly processed two types of superblock in one:

The header file <linux/raid/md_p.h> has defined two types of superblock,
struct mdp_superblock_s (typedefed with mdp_super_t) according to md with
metadata 0.90, and struct mdp_superblock_1 according to md with metadata
1.0 and later,

These two types of superblock are very different,

The md_print_devices code processed them both in mdp_super_t, that would
lead to wrong informaton dump like:

	[ 6742.345877]
	[ 6742.345887] md:	**********************************
	[ 6742.345890] md:	* <COMPLETE RAID STATE PRINTOUT> *
	[ 6742.345892] md:	**********************************
	[ 6742.345896] md1: <ram7><ram6><ram5><ram4>
	[ 6742.345907] md: rdev ram7, SZ:00065472 F:0 S:1 DN:3
	[ 6742.345909] md: rdev superblock:
	[ 6742.345914] md:  SB: (V:0.90.0) ID:<42ef13c7.598c059a.5f9f1645.801e9ee6> CT:4919856d
	[ 6742.345918] md:     L5 S00065472 ND:4 RD:4 md1 LO:2 CS:65536
	[ 6742.345922] md:     UT:4919856d ST:1 AD:4 WD:4 FD:0 SD:0 CSUM:b7992907 E:00000001
	[ 6742.345924]      D  0:  DISK<N:0,(1,8),R:0,S:6>
	[ 6742.345930]      D  1:  DISK<N:1,(1,10),R:1,S:6>
	[ 6742.345933]      D  2:  DISK<N:2,(1,12),R:2,S:6>
	[ 6742.345937]      D  3:  DISK<N:3,(1,14),R:3,S:6>
	[ 6742.345942] md:     THIS:  DISK<N:3,(1,14),R:3,S:6>
	...
	[ 6742.346058] md0: <ram3><ram2><ram1><ram0>
	[ 6742.346067] md: rdev ram3, SZ:00065472 F:0 S:1 DN:3
	[ 6742.346070] md: rdev superblock:
	[ 6742.346073] md:  SB: (V:1.0.0) ID:<369aad81.00000000.00000000.00000000> CT:9a322a9c
	[ 6742.346077] md:     L-1507699579 S976570180 ND:48 RD:0 md0 LO:65536 CS:196610
	[ 6742.346081] md:     UT:00000018 ST:0 AD:131048 WD:0 FD:8 SD:0 CSUM:00000000 E:00000000
	[ 6742.346084]      D  0:  DISK<N:-1,(-1,-1),R:-1,S:-1>
	[ 6742.346089]      D  1:  DISK<N:-1,(-1,-1),R:-1,S:-1>
	[ 6742.346092]      D  2:  DISK<N:-1,(-1,-1),R:-1,S:-1>
	[ 6742.346096]      D  3:  DISK<N:-1,(-1,-1),R:-1,S:-1>
	[ 6742.346102] md:     THIS:  DISK<N:0,(0,0),R:0,S:0>
	...
	[ 6742.346219] md:	**********************************
	[ 6742.346221]

Here md1 is metadata 0.90.0, and md0 is metadata 1.2

After some more code to distinguish these two types of superblock, in this patch,

it will generate dump information like:

	[ 7906.755790]
	[ 7906.755799] md:	**********************************
	[ 7906.755802] md:	* <COMPLETE RAID STATE PRINTOUT> *
	[ 7906.755804] md:	**********************************
	[ 7906.755808] md1: <ram7><ram6><ram5><ram4>
	[ 7906.755819] md: rdev ram7, SZ:00065472 F:0 S:1 DN:3
	[ 7906.755821] md: rdev superblock (MJ:0):
	[ 7906.755826] md:  SB: (V:0.90.0) ID:<3fca7a0d.a612bfed.5f9f1645.801e9ee6> CT:491989f3
	[ 7906.755830] md:     L5 S00065472 ND:4 RD:4 md1 LO:2 CS:65536
	[ 7906.755834] md:     UT:491989f3 ST:1 AD:4 WD:4 FD:0 SD:0 CSUM:00fb52ad E:00000001
	[ 7906.755836]      D  0:  DISK<N:0,(1,8),R:0,S:6>
	[ 7906.755842]      D  1:  DISK<N:1,(1,10),R:1,S:6>
	[ 7906.755845]      D  2:  DISK<N:2,(1,12),R:2,S:6>
	[ 7906.755849]      D  3:  DISK<N:3,(1,14),R:3,S:6>
	[ 7906.755855] md:     THIS:  DISK<N:3,(1,14),R:3,S:6>
	...
	[ 7906.755972] md0: <ram3><ram2><ram1><ram0>
	[ 7906.755981] md: rdev ram3, SZ:00065472 F:0 S:1 DN:3
	[ 7906.755984] md: rdev superblock (MJ:1):
	[ 7906.755989] md:  SB: (V:1) (F:0) Array-ID:<5fbcf158:55aa:5fbe:9a79:1e939880dcbd>
	[ 7906.755990] md:    Name: "DG5:0" CT:1226410480
	[ 7906.755998] md:       L5 SZ130944 RD:4 LO:2 CS:128 DO:24 DS:131048 SO:8 RO:0
	[ 7906.755999] md:     Dev:00000003 UUID: 9194d744:87f7:a448:85f2:7497b84ce30a
	[ 7906.756001] md:       (F:0) UT:1226410480 Events:0 ResyncOffset:-1 CSUM:0dbcd829
	[ 7906.756003] md:         (MaxDev:384)
	...
	[ 7906.756113] md:	**********************************
	[ 7906.756116]

this md0 (metadata 1.2) information dumping is exactly according to struct
mdp_superblock_1.

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:08 +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
NeilBrown
0c3573f19d md: use sysfs_notify_dirent to notify changes to md/sync_action.
There is no compelling need for this, but sysfs_notify_dirent is a
nicer interface and the change is good for consistency.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:05 +11:00
NeilBrown
cb3ac42b8a md: revert the recent addition of a call to the BLKRRPART ioctl.
It turns out that it is only safe to call blkdev_ioctl when the device
is actually open (as ->bd_disk is set to NULL on last close).  And it
is quite possible for do_md_stop to be called when the device is not
open.  So discard the call to blkdev_ioctl(BLKRRPART) which was
added in
   commit 934d9c23b4

It is just as easy to call this ioctl from userspace when needed (on
mdadm -S) so leave it out of the kernel

Signed-off-by: NeilBrown <neilb@suse.de>
2008-11-06 17:28:01 +11:00
NeilBrown
934d9c23b4 md: destroy partitions and notify udev when md array is stopped.
md arrays are not currently destroyed when they are stopped - they
remain in /sys/block.  Last time I tried this I tripped over locking
too much.

A consequence of this is that udev doesn't remove anything from /dev.
This is rather ugly.

As an interim measure until proper device removal can be achieved,
make sure all partitions are removed using the BLKRRPART ioctl, and
send a KOBJ_CHANGE when an md array is stopped.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-28 17:01:23 +11:00
Linus Torvalds
f8d56f1771 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: allow extended partitions on md devices.
  md: use sysfs_notify_dirent to notify changes to md/dev-xxx/state
  md: use sysfs_notify_dirent to notify changes to md/array_state
2008-10-26 16:42:18 -07:00
Al Viro
9a1c354276 [PATCH] pass fmode_t to blkdev_put()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21 07:48:58 -04:00
Al Viro
a39907fa2f [PATCH] switch md
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21 07:48:31 -04:00
Al Viro
d4430d62fa [PATCH] beginning of methods conversion
To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
	1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both.  That's this changeset.
	2) for each driver convert to new methods.  *ALL* drivers
are converted in this series.
	3) kill the old (renamed) methods.

Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain.  The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.

New methods:
	open(bdev, mode)
	release(disk, mode)
	ioctl(bdev, mode, cmd, arg)		/* Called without BKL */
	compat_ioctl(bdev, mode, cmd, arg)
	locked_ioctl(bdev, mode, cmd, arg)	/* Called with BKL, legacy */

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21 07:47:32 -04:00
NeilBrown
92850bbd71 md: allow extended partitions on md devices.
The new extended partition support provides a much nicer was
to have partitions on md devices that the 'mdp' alternate major.
We cannot really get rid of 'mdp' at this time, but we can
enable extended partitions as that will probably make life
easier for sysadmins.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-21 13:25:32 +11:00
NeilBrown
3c0ee63a64 md: use sysfs_notify_dirent to notify changes to md/dev-xxx/state
The 'state' file for a device reports, for example, when the device
has failed.  Changes should be reported to userspace ASAP without
the possibility of blocking on low-memory.  sysfs_notify does
have that possibility (as it takes a mutex which can be held
across a kmalloc) so use sysfs_notify_dirent instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-21 13:25:28 +11:00
NeilBrown
b62b75905d md: use sysfs_notify_dirent to notify changes to md/array_state
Now that we have sysfs_notify_dirent, use it to notify changes
to md/array_state.
As sysfs_notify_dirent can be called in atomic context, we can
remove the delayed notify and the MD_NOTIFY_ARRAY_STATE flag.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-21 13:25:21 +11:00
Dan Williams
97ce0a7f9c md: fix input truncation in safe_delay_store()
safe_delay_store() currently truncates the last character of input since
it tells strlcpy that the buffer can only hold 'len' characters, off by
one.  sysfs already null terminates the buffer, so just increase the
last argument to strlcpy.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-16 17:03:08 +11:00
Stephen Rothwell
255707274e md: build failure due to missing delay.h
Today's linux-next build (powerpc ppc64_defconfig) failed like this:

drivers/md/raid1.c: In function 'sync_request':
drivers/md/raid1.c:1759: error: implicit declaration of function 'msleep_interruptible'
make[3]: *** [drivers/md/raid1.o] Error 1
make[3]: *** Waiting for unfinished jobs....
drivers/md/raid10.c: In function 'sync_request':
drivers/md/raid10.c:1749: error: implicit declaration of function 'msleep_interruptible'
make[3]: *** [drivers/md/raid10.o] Error 1
drivers/md/md.c: In function 'md_do_sync':
drivers/md/md.c:5915: error: implicit declaration of function 'msleep'

Caused by commit 6caa3b0bbdb474647f6bdd8a958ffc46f78d8d58 ("md: Remove
unnecessary #includes, #defines, and function declarations").  I added
the following patch.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-15 21:57:05 +11:00
NeilBrown
4bbf3771ca md: Relax minimum size restrictions on chunk_size.
Currently, the 'chunk_size' of an array must be at-least PAGE_SIZE.

This makes moving an array to a machine with a larger PAGE_SIZE, or
changing the kernel to use a larger PAGE_SIZE, can stop an array from
working.

For RAID10 and RAID4/5/6, this is non-trivial to fix as the resync
process works on whole pages at a time, and assumes them to be wholly
within a stripe.  For other raid personalities, this restriction is
not needed at all and can be dropped.

So remove the test on chunk_size from common can, and add it in just
the places where it is needed: raid10 and raid4/5/6.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13 11:55:12 +11:00
NeilBrown
d710e13812 md: remove space after function name in declaration and call.
Having
   function (args)
instead of
   function(args)

make is harder to search for calls of particular functions.
So remove all those spaces.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13 11:55:12 +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
NeilBrown
80268ee927 md: Don't try to set an array to 'read-auto' if it is already in that state.
'read-auto' is a variant of 'readonly' which will switch to writable
on the first write attempt.

Calling do_md_stop to set the array readonly when it is already readonly
returns an error.  So make sure not to do that.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13 11:55:12 +11:00
NeilBrown
ea43ddd849 md: Allow metadata_version to be updated for externally managed metadata.
For externally managed metadata, the 'metadata_version' sysfs
attribute is really just a channel for user-space programs to
communicate about how the array is being managed.
It can be useful for this to be changed while the array is active.

Normally changes to metadata_version are not permitted while the array
is active.  Change that so that if the metadata is externally managed,
the metadata_version can be changed to a different flavour of external
management.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13 11:55:11 +11:00
Chris Webb
7d3c6f8717 md: Fix rdev_size_store with size == 0
Fix rdev_size_store with size == 0.
size == 0 means to use the largest size allowed by the
underlying device and is used when modifying an active array.

This fixes a regression introduced by
 commit d7027458d6

Cc: <stable@kernel.org>
Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13 11:55:11 +11:00
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
0762b8bde9 block: always set bdev->bd_part
Till now, bdev->bd_part is set only if the bdev was for parts other
than part0.  This patch makes bdev->bd_part always set so that code
paths don't have to differenciate common handling.

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
ed9e198234 block: implement and use {disk|part}_to_dev()
Implement {disk|part}_to_dev() and use them to access generic device
instead of directly dereferencing {disk|part}->dev.  To make sure no
user is left behind, rename generic devices fields to __dev.

This is in preparation of unifying partition 0 handling with other
partitions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:07 +02:00
NeilBrown
9744197c3d md: Don't wait UNINTERRUPTIBLE for other resync to finish
When two md arrays share some block device (e.g each uses different
partitions on the one device), a resync of one array will wait for
the resync on the other to finish.

This can be a long time and as it currently waits TASK_UNINTERRUPTIBLE,
the softlockup code notices and complains.

So use TASK_INTERRUPTIBLE instead and make sure to flush signals
before calling schedule.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-09-19 11:49:54 +10:00
NeilBrown
271f5a9b8f Remove invalidate_partition call from do_md_stop.
When stopping an md array, or just switching to read-only, we
currently call invalidate_partition while holding the mddev lock.
The main reason for this is probably to ensure all dirty buffers
are flushed (invalidate_partition calls fsync_bdev).

However if any dirty buffers are found, it will almost certainly cause
a deadlock as starting writeout will require an update to the
superblock, and performing that updates requires taking the mddev
lock - which is already held.

This deadlock can be demonstrated by running "reboot -f -n" with
a root filesystem on md/raid, and some dirty buffers in memory.

All other calls to stop an array should already happen after a flush.
The normal sequence is to stop using the array (e.g. umount) which
will cause __blkdev_put to call sync_blockdev.  Then open the
array and issue the STOP_ARRAY ioctl while the buffers are all still
clean.

So this invalidate_partition is normally a no-op, except for one case
where it will cause a deadlock.

So remove it.

This patch possibly addresses the regression recored in
   http://bugzilla.kernel.org/show_bug.cgi?id=11460
and
   http://bugzilla.kernel.org/show_bug.cgi?id=11452

though it isn't yet clear how it ever worked.


Signed-off-by: NeilBrown <neilb@suse.de>
2008-09-01 12:32:52 +10:00
Dan Williams
56ac36d722 md: cancel check/repair requests when recovery is needed
If a 'repair' is requested when an array is in a position to 'recover' raid1
will perform the repair while md believes a recovery is happening.  Address
this at both ends, i.e. cancel check/repair requests upon detecting a
recover condition and do not call ->spare_active after completing a
check/repair.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-08-07 10:02:47 -07:00
NeilBrown
c89a8eee61 Allow faulty devices to be removed from a readonly array.
Removing faulty devices from an array is a two stage process.
First the device is moved from being a part of the active array
to being similar to a spare device.  Then it can be removed
by a request from user space.

The first step is currently not performed for read-only arrays,
so the second step can never succeed.

So allow readonly arrays to remove failed devices (which aren't
blocked).

Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05 15:56:32 +10:00
NeilBrown
dba034eef2 Fail safely when trying to grow an array with a write-intent bitmap.
We cannot currently change the size of a write-intent bitmap.
So if we change the size of an array which has such a bitmap, it
tries to set bits beyond the end of the bitmap.

For now, simply reject any request to change the size of an array
which has a bitmap.  mdadm can remove the bitmap and add a new one
after the array has changed size.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05 15:56:32 +10:00
NeilBrown
2b25000bf5 Restore force switch of md array to readonly at reboot time.
A recent patch allowed do_md_stop to know whether it was being called
via an ioctl or not, and thus where to allow for an extra open file
descriptor when checking if it is in use.
This broke then switch to readonly performed by the shutdown notifier,
which needs to work even when the array is still (apparently) active
(as md doesn't get told when the filesystem becomes readonly).

So restore this feature by pretending that there can be lots of
file descriptors open, but we still want do_md_stop to switch to
readonly.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05 15:56:31 +10:00
NeilBrown
19052c0e85 Make writes to md/safe_mode_delay immediately effective.
If we reduce the 'safe_mode_delay', it could still wait for the old
delay to completely expire before doing anything about safe_mode.
Thus the effect if the change is delayed.

To make the effect more immediate, run the timeout function
immediately if the delay was reduced.  This may cause it to run
slightly earlier that required, but that is the safer option.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05 15:56:31 +10:00
Dan Williams
e542713529 md: do not count blocked devices as spares
remove_and_add_spares() assumes that failed devices have been hot-removed
from the array.  Removal is skipped in the 'blocked' case so do not count a
device in this state as 'spare'.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-28 17:52:44 -07:00
Dan Williams
d8e64406a0 md: delay notification of 'active_idle' to the recovery thread
sysfs_notify might sleep, so do not call it from md_safemode_timeout.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-23 13:09:48 -07:00
NeilBrown
4b80991c6c md: Protect access to mddev->disks list using RCU
All modifications and most access to the mddev->disks list are made
under the reconfig_mutex lock.  However there are three places where
the list is walked without any locking.  If a reconfig happens at this
time, havoc (and oops) can ensue.

So use RCU to protect these accesses:
  - wrap them in rcu_read_{,un}lock()
  - use list_for_each_entry_rcu
  - add to the list with list_add_rcu
  - delete from the list with list_del_rcu
  - delay the 'free' with call_rcu rather than schedule_work

Note that export_rdev did a list_del_init on this list.  In almost all
cases the entry was not in the list anymore so it was a no-op and so
safe.  It is no longer safe as after list_del_rcu we may not touch
the list_head.
An audit shows that export_rdev is called:
  - after unbind_rdev_from_array, in which case the delete has
     already been done,
  - after bind_rdev_to_array fails, in which case the delete isn't needed.
  - before the device has been put on a list at all (e.g. in
      add_new_disk where reading the superblock fails).
  - and in autorun devices after a failure when the device is on a
      different list.

So remove the list_del_init call from export_rdev, and add it back
immediately before the called to export_rdev for that last case.

Note also that ->same_set is sometimes used for lists other than
mddev->list (e.g. candidates).  In these cases rcu is not needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21 17:05:25 +10:00
NeilBrown
f2ea68cf42 md: only count actual openers as access which prevent a 'stop'
Open isn't the only thing that increments ->active.  e.g. reading
/proc/mdstat will increment it briefly.  So to avoid false positives
in testing for concurrent access, introduce a new counter that counts
just the number of times the md device it open.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21 17:05:25 +10:00
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
Andre Noll
15f4a5fdf3 md: Make super_type->rdev_size_change() take sector-based sizes.
Also, change the type of the size parameter from unsigned long long to
sector_t and rename it to num_sectors.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21 14:42:12 +10:00
Andre Noll
d07bd3bcc4 md: Fix check for overlapping devices.
The checks in overlaps() expect all parameters either in block-based
or sector-based quantities. However, its single caller passes two
rdev->data_offset arguments as well as two rdev->size arguments, the
former being sector counts while the latter are measured in 1K blocks.

This could cause rdev_size_store() to accept an invalid size from user
space. Fix it by passing only sector-based quantities to overlaps().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21 14:42:07 +10:00
Neil Brown
d7027458d6 md: Tidy up rdev_size_store a bit:
- used strict_strtoull in place of simple_strtoull
 - use my_mddev in place of rdev->mddev (they have the same value)
and more significantly,
 - don't adjust mddev->size to fit, rather reject changes which make
   rdev->size smaller than mddev->size

Adjusting mddev->size is a hangover from bind_rdev_to_array which
does a similar thing.  But it really is a better design to insist that
mddev->size is set as required, then the rdev->sizes are set to allow
for that.  The previous way invites confusion.

Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21 14:22:18 +10:00
Andre Noll
0f420358e3 md: Turn rdev->sb_offset into a sector-based quantity.
Rename it to sb_start to make sure all users have been converted.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:23 +10:00
Andre Noll
b73df2d3d6 md: Make calc_dev_sboffset() return a sector count.
As BLOCK_SIZE_BITS is 10 and

	MD_NEW_SIZE_SECTORS(2 * x) = 2 * NEW_SIZE_BLOCKS(x),

the return value of calc_dev_sboffset() doubles. Fix up all three
callers accordingly.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:23 +10:00
Andre Noll
e7debaa495 md: Replace calc_dev_size() by calc_num_sectors().
Number of sectors is the preferred unit for sizes of raid devices,
so change calc_dev_size() so that it returns this unit instead of
the number of 1K blocks.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:23 +10:00
Andre Noll
d71f9f88d7 md: Make update_size() take the number of sectors.
Changing the internal representations of sizes of raid devices
from 1K blocks to sector counts (512B units) is desirable because
it allows to get rid of many divisions/multiplications and unnecessary
casts that are present in the current code.

This patch is a first step in this direction. It replaces the old
1K-based "size" argument of update_size() by "num_sectors" and
fixes up its two callers.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:22 +10:00
Neil Brown
df5b20cf68 md: Better control of when do_md_stop is allowed to stop the array.
do_md_stop check the number of active users before allowing the array
to be stopped.
Two problems:
  1/ it assumes the request is coming through an open file descriptor
     (via ioctl) so it allows for that.  This is not always the case.
  2/ it doesn't do the check it the array hasn't been activated.
     This is not good for cases when we use an inactive array to hold
     some devices in a container.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:22 +10:00
Andre Noll
26ef379f53 md: get_disk_info(): Don't convert between signed and unsigned and back.
The current code copies a signed int from user space, converts it to
unsigned and passes the unsigned value to find_rdev_nr() which expects
a signed value. Simply pass the signed value from user space directly.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:21 +10:00
Andre Noll
80fab1d77b md: Simplify restart_array().
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:21 +10:00
Andre Noll
ebc2433728 md: alloc_disk_sb(): Return proper error value.
If alloc_page() fails, ENOMEM is a more suitable error value
than EINVAL.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:20 +10:00
Andre Noll
ce0c8e05f8 md: Simplify sb_equal().
The only caller of sb_equal() tests the return value against
zero, so it's OK to return the negated return value of memcmp().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:20 +10:00
Andre Noll
05710466c9 md: Simplify uuid_equal().
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-11 22:02:20 +10:00
Andre Noll
35020f1a06 md: sb_equal(): Fix misleading printk.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:53:20 +10:00
Andre Noll
7f6ce76928 md: Fix a typo in the comment to cmd_match().
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:53:00 +10:00
Andre Noll
910d8cb3f4 md: Fix typo in array_state comment.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:52:45 +10:00
Andre Noll
9687a60c78 md: sync_speed_show(): Trivial cleanups.
- Remove superfluous parentheses.
- Make format string match the type of the variable that is printed.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:52:26 +10:00
Andre Noll
13e53df354 md: do_md_run(): Fix misleading error message.
In case pers->run() succeeds but creating the bitmap fails, we
print an error message stating that pers->run() has failed.

Print this message only if pers->run() really failed.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:52:15 +10:00
Andre Noll
2f9618ce63 md: md_getgeo(): Move comment to proper position.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:52:00 +10:00
Andre Noll
bb57fc64b2 md: md_ioctl(): Fix misleading indentation.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-07-08 10:51:29 +10:00
Dan Williams
b5470dc5fc md: resolve external metadata handling deadlock in md_allow_write
md_allow_write() marks the metadata dirty while holding mddev->lock and then
waits for the write to complete.  For externally managed metadata this causes a
deadlock as userspace needs to take the lock to communicate that the metadata
update has completed.

Change md_allow_write() in the 'external' case to start the 'mark active'
operation and then return -EAGAIN.  The expected side effects while waiting for
userspace to write 'active' to 'array_state' are holding off reshape (code
currently handles -ENOMEM), cause some 'stripe_cache_size' change requests to
fail, cause some GET_BITMAP_FILE ioctl requests to fall back to GFP_NOIO, and
cause updates to 'raid_disks' to fail.  Except for 'stripe_cache_size' changes
these failures can be mitigated by coordinating with mdmon.

md_write_start() still prevents writes from occurring until the metadata
handler has had a chance to take action as it unconditionally waits for
MD_CHANGE_CLEAN to be cleared.

[neilb@suse.de: return -EAGAIN, try GFP_NOIO]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-06-30 17:18:19 -07:00
Chris Webb
0cd17fec98 Support changing rdev size on running arrays.
From: Chris Webb <chris@arachsys.com>

Allow /sys/block/mdX/md/rdY/size to change on running arrays, moving the
superblock if necessary for this metadata version. We prevent the available
space from shrinking to less than the used size, and allow it to be set to zero
to fill all the available space on the underlying device.

Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:46 +10:00
Neil Brown
526647320e Make sure all changes to md/dev-XX/state are notified
The important state change happens during an interrupt
in md_error.  So just set a flag there and call sysfs_notify
later in process context.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:44 +10:00
Neil Brown
a99ac97113 Make sure all changes to md/degraded are notified.
When a device fails, when a spare is activated, when
an array is reshaped, or when an array is started,
the extent to which the array is degraded can change.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:43 +10:00
Neil Brown
72a23c211e Make sure all changes to md/sync_action are notified.
When the 'resync' thread starts or stops, when we explicitly
set sync_action, or when we determine that there is definitely nothing
to do, we notify sync_action.

To stop "sync_action" from occasionally showing the wrong value,
we introduce a new flags - MD_RECOVERY_RECOVER - to say that a
recovery is probably needed or happening, and we make sure
that we set MD_RECOVERY_RUNNING before clearing MD_RECOVERY_NEEDED.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:41 +10:00
Neil Brown
0fd62b861e Make sure all changes to md/array_state are notified.
Changes in md/array_state could be of interest to a monitoring
program.  So make sure all changes trigger a notification.

Exceptions:
   changing active_idle to active is not reported because it
      is frequent and not interesting.
   changing active to active_idle is only reported on arrays
      with externally managed metadata, as it is not interesting
      otherwise.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:36 +10:00
Neil Brown
c7d0c941ae Don't reject HOT_REMOVE_DISK request for an array that is not yet started.
There is really no need for this test here, and there are valid
cases for selectively removing devices from an array that
it not actually active.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:34 +10:00
Neil Brown
199050ea1f rationalise return value for ->hot_add_disk method.
For all array types but linear, ->hot_add_disk returns 1 on
success, 0 on failure.
For linear, it returns 0 on success and -errno on failure.

This doesn't cause a functional problem because the ->hot_add_disk
function of linear is used quite differently to the others.
However it is confusing.

So convert all to return 0 for success or -errno on failure
and fix call sites to match.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:33 +10:00
Neil Brown
6c2fce2ef6 Support adding a spare to a live md array with external metadata.
i.e. extend the 'md/dev-XXX/slot' attribute so that you can
tell a device to fill an vacant slot in an and md array.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:31 +10:00
Neil Brown
8ed0a5216a Enable setting of 'offset' and 'size' of a hot-added spare.
offset_store and rdev_size_store allow control of the region of a
device which is to be using in an md/raid array.
They only allow these values to be set when an array is being assembled,
as changing them on an active array could be dangerous.
However when adding a spare device to an array, we might need to
set the offset and size before starting recovery.  So allow
these values to be set also if "->raid_disk < 0" which indicates that
the device is still a spare.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:29 +10:00
Neil Brown
1a0fd49773 Don't try to make md arrays dirty if that is not meaningful.
Arrays personalities such as 'raid0' and 'linear' have no redundancy,
and so marking them as 'clean' or 'dirty' is not meaningful.
So always allow write requests without requiring a superblock update.

Such arrays types are detected by ->sync_request being NULL.  If it is
not possible to send a sync request we don't need a 'dirty' flag because
all a dirty flag does is trigger some sync_requests.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:27 +10:00
Neil Brown
f48ed53838 Close race in md_probe
There is a possible race in md_probe.  If two threads call md_probe
for the same device, then one could exit (having checked that
->gendisk exists) before the other has called kobject_init_and_add,
thus returning an incomplete kobj which will cause problems when
we try to add children to it.

So extend the range of protection of disks_mutex slightly to
avoid this possibility.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:26 +10:00
Neil Brown
5e96ee65c8 Allow setting start point for requested check/repair
This makes it possible to just resync a small part of an array.
e.g. if a drive reports that it has questionable sectors,
a 'repair' of just the region covering those sectors will
cause them to be read and, if there is an error, re-written
with correct data.

Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:24 +10:00
Neil Brown
9bbbca3a0e Fix error paths if md_probe fails.
md_probe can fail (e.g. alloc_disk could fail) without
returning an error (as it alway returns NULL).
So when we call mddev_find immediately afterwards, we need
to check that md_probe actually succeeded.  This means checking
that mdev->gendisk is non-NULL.

cc: <stable@kernel.org>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28 08:31:17 +10:00
Dan Williams
a6d8113a98 md: fix uninitialized use of mddev->recovery_wait
If an array was created with --assume-clean we will oops when trying to
set ->resync_max.

Fix this by initializing ->recovery_wait in mddev_find.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2008-06-06 11:29:08 -07:00
NeilBrown
dfc7064500 md: restart recovery cleanly after device failure.
When we get any IO error during a recovery (rebuilding a spare), we abort
the recovery and restart it.

For RAID6 (and multi-drive RAID1) it may not be best to restart at the
beginning: when multiple failures can be tolerated, the recovery may be
able to continue and re-doing all that has already been done doesn't make
sense.

We already have the infrastructure to record where a recovery is up to
and restart from there, but it is not being used properly.
This is because:
  - We sometimes abort with MD_RECOVERY_ERR rather than just MD_RECOVERY_INTR,
    which causes the recovery not be be checkpointed.
  - We remove spares and then re-added them which loses important state
    information.

The distinction between MD_RECOVERY_ERR and MD_RECOVERY_INTR really isn't
needed.  If there is an error, the relevant drive will be marked as
Faulty, and that is enough to ensure correct handling of the error.  So we
first remove MD_RECOVERY_ERR, changing some of the uses of it to
MD_RECOVERY_INTR.

Then we cause the attempt to remove a non-faulty device from an array to
fail (unless recovery is impossible as the array is too degraded).  Then
when remove_and_add_spares attempts to remove the devices on which
recovery can continue, it will fail, they will remain in place, and
recovery will continue on them as desired.

Issue:  If we are halfway through rebuilding a spare and another drive
fails, and a new spare is immediately available,  do we want to:
 1/ complete the current rebuild, then go back and rebuild the new spare or
 2/ restart the rebuild from the start and rebuild both devices in
    parallel.

Both options can be argued for.  The code currently takes option 2 as
  a/ this requires least code change
  b/ this results in a minimally-degraded array in minimal time.

Cc: "Eivind Sarto" <ivan@kasenna.com>
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>
2008-05-24 09:56:10 -07:00
Bernd Schubert
90b08710e4 md: allow parallel resync of md-devices.
In some configurations, a raid6 resync can be limited by CPU speed
(Calculating P and Q and moving data) rather than by device speed.  In
these cases there is nothing to be gained byt serialising resync of arrays
that share a device, and doing the resync in parallel can provide benefit.
 So add a sysfs tunable to flag an array as being allowed to resync in
parallel with other arrays that use (a different part of) the same device.

Signed-off-by: Bernd Schubert <bs@q-leap.de>
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>
2008-05-24 09:56:10 -07:00
Dan Williams
4f54b0e948 md: notify userspace on 'stop' events
This additional notification to 'array_state' is needed to allow the
monitor application to learn about stop events via sysfs.  The
sysfs_notify("sync_action") call that comes at the end of do_md_stop()
(via md_new_event) is insufficient since the 'sync_action' attribute has
been removed by this point.

(Seems like a sysfs-notify-on-removal patch is a better fix.  Currently
removal updates the event count but does not wake up waiters)

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2008-05-24 09:56:10 -07:00
NeilBrown
09a44cc150 md: notify userspace on 'write-pending' changes to array_state
When an array enters write pending, 'array_state' changes, so we must be
sure to sysfs_notify.

Also, when waiting for user-space to acknowledge 'write-pending' by
marking the metadata as dirty, we don't want to wait for MD_CHANGE_DEVS to
be cleared as that might not happen.  So explicity test for the bits that
we are really interested in.

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>
2008-05-24 09:56:10 -07:00
Christoph Hellwig
6bcfd60186 md: kill file_path wrapper
Kill the trivial and rather pointless file_path wrapper around d_path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
2008-05-24 09:56:09 -07:00
Dan Williams
6bfe0b4990 md: support blocking writes to an array on device failure
Allows a userspace metadata handler to take action upon detecting a device
failure.

Based on an original patch by Neil Brown.

Changes:
-added blocked_wait waitqueue to rdev
-don't qualify Blocked with Faulty always let userspace block writes
-added md_wait_for_blocked_rdev to wait for the block device to be clear, if
 userspace misses the notification another one is sent every 5 seconds
-set MD_RECOVERY_NEEDED after clearing "blocked"
-kill DoBlock flag, just test mddev->external

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2008-04-30 08:29:33 -07:00
Dan Williams
11e2ede022 md: prevent duplicates in bind_rdev_to_array
Found when trying to reassemble an active externally managed array.  Without
this check we hit the more noisy "sysfs duplicate" warning in the later call
to kobject_add.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2008-04-30 08:29:33 -07:00
Dan Williams
242b363e22 md: remove a stray command from a copy and paste error in resync_start_store
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2008-04-30 08:29:33 -07:00
NeilBrown
648b629ed4 md: fix up switching md arrays between read-only and read-write
When setting an array to 'readonly' or to 'active' via sysfs, we must make the
appropriate set_disk_ro call too.

Also when switching to "read_auto" (which is like readonly, but blocks on the
first write so that metadata can be marked 'dirty') we need to be more careful
about what state we are changing from.

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>
2008-04-30 08:29:32 -07:00
NeilBrown
31a59e3425 md: fix 'safemode' handling for external metadata.
'safemode' relates to marking an array as 'clean' if there has been no write
traffic for a while (a couple of seconds), to reduce the chance of the array
being found dirty on reboot.

->safemode is set to '1' when there have been no write for a while, and it
gets set to '0' when the superblock is updates with the 'clean' flag set.

This requires a few fixes for 'external' metadata:
 - When an array is set to 'clean' via sysfs, 'safemode' must be cleared.
 - when we write to an array that has 'safemode' set (there must have been
        some delay in updating the metadata), we need to clear safemode.
 - Don't try to update external metadata in md_check_recovery for safemode
        transitions - it won't work.

Also, don't try to support "immediate safe mode" (safemode==2) for external
metadata, it cannot really work (the safemode timeout can be set very low if
this is really needed).

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>
2008-04-30 08:29:32 -07:00
NeilBrown
d897dbf914 md: reinitialise more mddev fields in do_md_stop.
I keep finding problems where an mddev gets reused and some fields has a value
from a previous usage that confuses the new usage.  So clear all fields that
could possible need clearing when calling do_md_stop.

Also initialise the 'level' of a new array to LEVEL_NONE (which isn't 0).

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>
2008-04-30 08:29:32 -07:00
NeilBrown
8377bc8080 md: skip all metadata update processing when using external metadata.
All the metadata update processing for external metadata is on in user-space
or through the sysfs interfaces, so make "md_update_sb" a no-op in that case.

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>
2008-04-30 08:29:32 -07:00
Dan Williams
6a51830e14 md: fix use after free when removing rdev via sysfs
rdev->mddev is no longer valid upon return from entry->store() when the
'remove' command is given.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2008-04-30 08:29:32 -07:00
Linus Torvalds
bd5d435a96 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: Skip I/O merges when disabled
  block: add large command support
  block: replace sizeof(rq->cmd) with BLK_MAX_CDB
  ide: use blk_rq_init() to initialize the request
  block: use blk_rq_init() to initialize the request
  block: rename and export rq_init()
  block: no need to initialize rq->cmd with blk_get_request
  block: no need to initialize rq->cmd in prepare_flush_fn hook
  block/blk-barrier.c:blk_ordered_cur_seq() mustn't be inline
  block/elevator.c:elv_rq_merge_ok() mustn't be inline
  block: make queue flags non-atomic
  block: add dma alignment and padding support to blk_rq_map_kern
  unexport blk_max_pfn
  ps3disk: Remove superfluous cast
  block: make rq_init() do a full memset()
  relay: fix splice problem
2008-04-29 08:18:03 -07:00
Denis V. Lunev
c7705f3449 drivers: use non-racy method for proc entries creation (2)
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Neil Brown <neilb@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:22 -07:00
Nick Piggin
75ad23bc0f block: make queue flags non-atomic
We can save some atomic ops in the IO path, if we clearly define
the rules of how to modify the queue flags.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-29 14:48:33 +02:00
Harvey Harrison
9a7b2b0f36 md: fix integer as NULL pointer warnings in md.c
drivers/md/md.c:734:16: warning: Using plain integer as NULL pointer
drivers/md/md.c:1115:16: warning: Using plain integer as NULL pointer

Add some braces to match the else-block as well.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:42 -07:00
Nick Andrew
fdefa4d87e RAID: remove trailing space from printk line
drivers/md/*.[ch] contains only one more printk line with a trailing space.
Remove it.

Signed-off-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
2008-04-21 22:42:58 +00:00
NeilBrown
0e82989d95 md: remove the 'super' sysfs attribute from devices in an 'md' array
Exposing the binary blob which is the md 'super-block' via sysfs doesn't
really fit with the whole sysfs model, and ever since commit
8118a859dc ("sysfs: fix off-by-one error
in fill_read_buffer()") it doesn't actually work at all (as the size of
the blob is often one page).

(akpm: as in, fs/sysfs/file.c:fill_read_buffer() goes BUG)

So just remove it altogether.  It isn't really useful.

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>
2008-03-19 18:53:35 -07:00
NeilBrown
52720ae77d md: fix formatting error in /proc/mdstat
If an md array is "auto-read-only", then this appears in /proc/mdstat as

   /dev/md0: active(auto-read-only)

whereas if it is truely readonly, it appears as

   /dev/md0: active (read-only)

The difference being a space.

One program known to parse this file expects the space and gets badly
confused.  It will be fixed, but it would be best if what the kernel generates
is more consistent too.

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>
2008-03-10 18:01:19 -07:00
NeilBrown
27c529bb8e md: lock access to rdev attributes properly
When we access attributes of an rdev (component device on an md array) through
sysfs, we really need to lock the array against concurrent changes.  We
currently do that when we change an attribute, but not when we read an
attribute.  We need to lock when reading as well else rdev->mddev could become
NULL while we are accessing it.

So add appropriate locking (mddev_lock) to rdev_attr_show.

rdev_size_store requires some extra care as well as it needs to unlock the
mddev while scanning other mddevs for overlapping regions.  We currently
assume that rdev->mddev will still be unchanged after the scan, but that
cannot be certain.  So take a copy of rdev->mddev for use at the end of the
function.

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>
2008-03-04 16:35:18 -08:00
NeilBrown
2515619823 md: make sure a reshape is started when device switches to read-write
A resync/reshape/recovery thread will refuse to progress when the array is
marked read-only.  So whenever it mark it not read-only, it is important to
wake up thread resync thread.  There is one place we didn't do this.

The problem manifests if the start_ro module parameters is set, and a raid5
array that is in the middle of a reshape (restripe) is started.  The array
will initially be semi-read-only (meaning it acts like it is readonly until
the first write).  So the reshape will not proceed.

On the first write, the array will become read-write, but the reshape will not
be started, and there is no event which will ever restart that thread.

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>
2008-03-04 16:35:18 -08:00
NeilBrown
d0fae18f1b md: clean up irregularity with raid autodetect
When a raid1 array is stopped, all components currently get added to the list
for auto-detection.  However we should really only add components that were
found by autodetection in the first place.  So add a flag to record that
information, and use it.

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>
2008-03-04 16:35:18 -08:00
NeilBrown
a1801f858e md: guard against possible bad array geometry in v1 metadata
Make sure the data doesn't start before the end of the superblock when the
superblock is at the start of the device.

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>
2008-03-04 16:35:17 -08:00
Jan Blunck
c32c2f63a9 d_path: Make seq_path() use a struct path argument
seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:17:08 -08:00
NeilBrown
73c34431c7 md: change ITERATE_RDEV_GENERIC to rdev_for_each_list, and remove ITERATE_RDEV_PENDING.
Finish ITERATE_ to for_each conversion.

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
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
NeilBrown
29ac4aa3fc md: change INTERATE_MDDEV to for_each_mddev
As this is more consistent with kernel style.

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
NeilBrown
20a49ff679 md: change a few 'int' to 'size_t' in md
As suggested by Andrew Morton.

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
NeilBrown
177a99b23e md: fix use-after-free bug when dropping an rdev from an md array
Due to possible deadlock issues we need to use a schedule work to kobject_del
an 'rdev' object from a different thread.

A recent change means that kobject_add no longer gets a refernce, and
kobject_del doesn't put a reference.  Consequently, we need to explicitly hold
a reference to ensure that the last reference isn't dropped before the
scheduled work get a chance to call kobject_del.

Also, rename delayed_delete to md_delayed_delete to that it is more obvious in
a stack trace which code is to blame.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
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
NeilBrown
a17184a911 md: allow an md array to appear with 0 drives if it has external metadata
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