Commit Graph

734 Commits

Author SHA1 Message Date
NeilBrown ef286f6fa6 md: fix some lockdep issues between md and sysfs.
======
This fix is related to
    http://bugzilla.kernel.org/show_bug.cgi?id=15142
but does not address that exact issue.
======

sysfs does like attributes being removed while they are being accessed
(i.e. read or written) and waits for the access to complete.

As accessing some md attributes takes the same lock that is held while
removing those attributes a deadlock can occur.

This patch addresses 3 issues in md that could lead to this deadlock.

Two relate to calling flush_scheduled_work while the lock is held.
This is probably a bad idea in general and as we use schedule_work to
delete various sysfs objects it is particularly bad.

In one case flush_scheduled_work is called from md_alloc (called by
md_probe) called from do_md_run which holds the lock.  This call is
only present to ensure that ->gendisk is set.  However we can be sure
that gendisk is always set (though possibly we couldn't when that code
was originally written.  This is because do_md_run is called in three
different contexts:
  1/ from md_ioctl.  This requires that md_open has succeeded, and it
     fails if ->gendisk is not set.
  2/ from writing a sysfs attribute.  This can only happen if the
     mddev has been registered in sysfs which happens in md_alloc
     after ->gendisk has been set.
  3/ from autorun_array which is only called by autorun_devices, which
     checks for ->gendisk to be set before calling autorun_array.
So the call to md_probe in do_md_run can be removed, and the check on
->gendisk can also go.


In the other case flush_scheduled_work is being called in do_md_stop,
purportedly to wait for all md_delayed_delete calls (which delete the
component rdevs) to complete.  However there really isn't any need to
wait for them - they have already been disconnected in all important
ways.

The third issue is that raid5->stop() removes some attribute names
while the lock is held.  There is already some infrastructure in place
to delay attribute removal until after the lock is released (using
schedule_work).  So extend that infrastructure to remove the
raid5_attrs_group.

This does not address all lockdep issues related to the sysfs
"s_active" lock.  The rest can be address by splitting that lockdep
context between symlinks and non-symlinks which hopefully will happen.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-02-10 11:26:09 +11:00
NeilBrown 404e4b43fd md: allow a resync that is waiting for other resync to complete, to be aborted.
If two arrays share a device, then they will not both resync at the
same time.  One will wait for the other to complete.
While waiting, the MD_RECOVERY_INTR flag is not checked so a device
failure, which would make the resync pointless, does not cause the
resync to abort, so the failed device cannot be removed (as it cannot
be remove while a resync is happening).

So add a test for MD_RECOVERY_INTR.

Reported-by: Brett Russ <bruss@netezza.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:25:23 +11:00
NeilBrown 7fb9dadc91 md: remove unnecessary code from do_md_run
Since commit dfc7064500,
->hot_remove_disks has not removed non-failed devices from
an array until recovery is no longer possible.
So the code in do_md_run to get around the fact that
md_check_recovery (which calls ->hot_remove_disks) would
remove partially-in-sync devices is no longer needed.

So remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:43 +11:00
Dan Williams a2d79c324a md: make recovery started by do_md_run() visible via sync_action
By default md_do_sync() will perform recovery if no other actions are
specified.  However, action_show() relies on MD_RECOVERY_RECOVER to be
set otherwise it returns 'idle'.  So, add a missing set
MD_RECOVERY_RECOVER when starting recovery.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:31 +11:00
NeilBrown 0f9552b5dc md: fix small irregularity with start_ro module parameter
The start_ro modules parameter can be used to force arrays to be
started in 'auto-readonly' in which they are read-only until the first
write.  This ensures that no resync/recovery happens until something
else writes to the device.  This is important for resume-from-disk
off an md array.

However if an array is started 'readonly' (by writing 'readonly' to
the 'array_state' sysfs attribute) we want it to be really 'readonly',
not 'auto-readonly'.

So strengthen the condition to only set auto-readonly if the
array is not already read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:12 +11:00
NeilBrown cbd1998377 md: Fix unfortunate interaction with evms
evms configures md arrays by:
  open device
  send ioctl
  close device

for each different ioctl needed.
Since 2.6.29, the device can disappear after the 'close'
unless a significant configuration has happened to the device.
The change made by "SET_ARRAY_INFO" can too minor to stop the device
from disappearing, but important enough that losing the change is bad.

So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device
active as long as ctime is non-zero (it gets zeroed with lots of other
things when the array is stopped).

This is suitable for -stable kernels since 2.6.29.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2009-12-30 12:08:49 +11:00
Joe Perches 7b75c2f8cf drivers/md/md.c: use %pU to print UUIDs
Signed-off-by: Joe Perches <joe@perches.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>
2009-12-15 08:53:33 -08:00
André Goddard Rosa e7d2860b69 tree-wide: convert open calls to remove spaces to skip_spaces() lib function
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
Dan Williams 06e3c817b7 md: add 'recovery_start' per-device sysfs attribute
Enable external metadata arrays to manage rebuild checkpointing via a
md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset

Also update resync_start_store to allow 'none' to be written, for
consistency.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:58:57 +11:00
Dan Williams 4e59ca7da0 md: rcu_read_lock() walk of mddev->disks in md_do_sync()
Other walks of this list are either under rcu_read_lock() or the list
mutation lock (mddev_lock()).  This protects against the improbable case of a
disk being removed from the array at the start of md_do_sync().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-12-14 12:57:43 +11:00
NeilBrown 93be75ffde md: integrate spares into array at earliest opportunity.
As v1.x metadata can record that a member of the array is
not completely recovered, it make sense to record that a
spare has become a regular member of the array at the earliest
opportunity.
So remove the tests on "recovery_offset > 0" in super_1_sync
as they really aren't needed, and schedule a metadata update
immediately after adding spares to a degraded array.

This means that if a crash happens immediately after a recovery
starts, the new device will be included in the array and recovery will
continue from wherever it was up to.  Previously this didn't happen
unless recovery was at least 1/16 of the way through.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
Arnd Bergmann aa98aa3198 md: move compat_ioctl handling into md.c
The RAID ioctls are only implemented in md.c, so the
handling for them should also be moved there from
fs/compat_ioctl.c.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Andre Noll <maan@systemlinux.org>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
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
Robert Becker 1e50915fe0 raid: improve MD/raid10 handling of correctable read errors.
We've noticed severe lasting performance degradation of our raid
arrays when we have drives that yield large amounts of media errors.
The raid10 module will queue each failed read for retry, and also
will attempt call fix_read_error() to perform the read recovery.
Read recovery is performed while the array is frozen, so repeated
recovery attempts can degrade the performance of the array for
extended periods of time.

With this patch I propose adding a per md device max number of
corrected read attempts.  Each rdev will maintain a count of
read correction attempts in the rdev->read_errors field (not
used currently for raid10). When we enter fix_read_error()
we'll check to see when the last read error occurred, and
divide the read error count by 2 for every hour since the
last read error. If at that point our read error count
exceeds the read error threshold, we'll fail the raid device.

In addition in this patch I add sysfs nodes (get/set) for
the per md max_read_errors attribute, the rdev->read_errors
attribute, and added some printk's to indicate when
fix_read_error fails to repair an rdev.

For testing I used debugfs->fail_make_request to inject
IO errors to the rdev while doing IO to the raid array.

Signed-off-by: Robert Becker <Rob.Becker@riverbed.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown 43a705076e md: support updating bitmap parameters via sysfs.
A new attribute directory 'bitmap' in 'md' is created which
contains files for configuring the bitmap.
'location' identifies where the bitmap is, either 'none',
or 'file' or 'sector offset from metadata'.
Writing 'location' can create or remove a bitmap.
Adding a 'file' bitmap this way is not yet supported.
'chunksize' and 'time_base' must be set before 'location'
can be set.

'chunksize' can be set before creating a bitmap, but is
currently always over-ridden by the bitmap superblock.

'time_base' and 'backlog' can be updated at any time.


Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
2009-12-14 12:51:41 +11:00
NeilBrown 72e02075a3 md: factor out parsing of fixed-point numbers
safe_delay_store can parse fixed point numbers (for fractions
of a second).  We will want to do that for another sysfs
file soon, so factor out the code.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown 42a04b5078 md: move offset, daemon_sleep and chunksize out of bitmap structure
... and into bitmap_info.  These are all configuration parameters
that need to be set before the bitmap is created.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown c3d9714e88 md: collect bitmap-specific fields into one structure.
In preparation for making bitmap fields configurable via sysfs,
start tidying up by making a single structure to contain the
configuration fields.

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 efa593390e md: don't reset curr_resync_completed after an interrupted resync
If a resync/recovery/check/repair is interrupted for some reason, it
can be useful to know exactly where it got up to.
So in that case, do not clear curr_resync_completed.
Initialise it when starting a resync/recovery/... instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:49:49 +11:00
NeilBrown c07b70ad32 md: adjust resync_min usefully when resync aborts.
When a 'check' or 'repair' finished we should clear resync_min
so that a future check/repair will cover the whole array (by default).
However if it is interrupted, we should update resync_min to
where we got up to, so that when the check/repair continues it
just does the remainder of the array.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:49:48 +11:00
NeilBrown aa5cbd1038 md/bitmap: protect against bitmap removal while being updated.
A write intent bitmap can be removed from an array while the
array is active.
When this happens, all IO is suspended and flushed before the
bitmap is removed.
However it is possible that bitmap_daemon_work is still running to
clear old bits from the bitmap.  If it is, it can dereference the
bitmap after it has been freed.

So introduce a new mutex to protect bitmap_daemon_work and get it
before destroying a bitmap.

This is suitable for any current -stable kernel.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2009-12-14 12:49:46 +11:00
Linus Torvalds 1557d33007 Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits)
  security/tomoyo: Remove now unnecessary handling of security_sysctl.
  security/tomoyo: Add a special case to handle accesses through the internal proc mount.
  sysctl: Drop & in front of every proc_handler.
  sysctl: Remove CTL_NONE and CTL_UNNUMBERED
  sysctl: kill dead ctl_handler definitions.
  sysctl: Remove the last of the generic binary sysctl support
  sysctl net: Remove unused binary sysctl code
  sysctl security/tomoyo: Don't look at ctl_name
  sysctl arm: Remove binary sysctl support
  sysctl x86: Remove dead binary sysctl support
  sysctl sh: Remove dead binary sysctl support
  sysctl powerpc: Remove dead binary sysctl support
  sysctl ia64: Remove dead binary sysctl support
  sysctl s390: Remove dead sysctl binary support
  sysctl frv: Remove dead binary sysctl support
  sysctl mips/lasat: Remove dead binary sysctl support
  sysctl drivers: Remove dead binary sysctl support
  sysctl crypto: Remove dead binary sysctl support
  sysctl security/keys: Remove dead binary sysctl support
  sysctl kernel: Remove binary sysctl logic
  ...
2009-12-08 07:38:50 -08:00
Eric W. Biederman 6d4561110a sysctl: Drop & in front of every proc_handler.
For consistency drop & in front of every proc_handler.  Explicity
taking the address is unnecessary and it prevents optimizations
like stubbing the proc_handlers to NULL.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-18 08:37:40 -08:00
Eric W. Biederman bb9074ff58 Merge commit 'v2.6.32-rc7'
Resolve the conflict between v2.6.32-rc7 where dn_def_dev_handler
gets a small bug fix and the sysctl tree where I am removing all
sysctl strategy routines.
2009-11-17 01:01:34 -08:00
NeilBrown 0261cd9f1c md: allow v0.91 metadata to record devices as being active but not in-sync.
This is a combination that didn't really make sense before.
However when a reshape is converting e.g. raid5 -> raid6, the extra
device is not fully in-sync, but is certainly active and contains
important data.
So allow that start to be meaningful and in particular get
the 'recovery_offset' value (which is needed for any non-in-sync
active device) from the reshape_position.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-13 17:40:48 +11:00
Eric W. Biederman 894d249115 sysctl drivers: Remove dead binary sysctl support
Now that sys_sysctl is a wrapper around /proc/sys all of
the binary sysctl support elsewhere in the tree is
dead code.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Neil Brown <neilb@suse.de>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de> for drivers/char/hpet.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12 02:04:58 -08:00
NeilBrown 5e8651060c md: factor out updating of 'recovery_offset'.
Each device has its own 'recovery_offset' showing how far
recovery has progressed on the device.
As the only real significance of this is that fact that it can
be stored in the metadata and recovered at restart, and as
only 1.x metadata can do this, we were only updating
'recovery_offset' to 'curr_resync_completed' when updating
v1.x metadata.
But this is wrong, and we will shortly make limited use of this
field in v0.90 metadata.

So move the update into common code.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-12 12:08:04 +11:00
NeilBrown 24395a85d8 md: don't clear endpoint for resync when resync is interrupted.
If a 'sync_max' has been set (via sysfs), it is wrong to clear it
until a resync (or reshape or recovery ...) actually reached that
point.
So if a resync is interrupted (e.g. by device failure),
leave 'resync_max' unchanged.

This is particularly important for 'reshape' operations that do not
change the size of the array.  For such operations mdadm needs to
monitor the reshape taking rolling backups of the section being
reshaped.  If resync_max gets cleared, the reshape can get ahead of
mdadm and then the backups that mdadm creates are useless.

This is suitable for 2.6.31.y stable kernels.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-06 14:59:27 +11:00
NeilBrown 5e5e3e78ed md: Fix handling of raid5 array which is being reshaped to fewer devices.
When a raid5 (or raid6) array is being reshaped to have fewer devices,
conf->raid_disks is the latter and hence smaller number of devices.
However sometimes we want to use a number which is the total number of
currently required devices - the larger of the 'old' and 'new' sizes.
Before we implemented reducing the number of devices, this was always
'new' i.e. ->raid_disks.
Now we need max(raid_disks, previous_raid_disks) in those places.

This particularly affects assembling an array that was shutdown while
in the middle of a reshape to fewer devices.

md.c needs a similar fix when interpreting the md metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:35:30 +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 0da3c6194e md: Improve name of threads created by md_register_thread
The management thread for raid4,5,6 arrays are all called
mdX_raid5, independent of the actual raid level, which is wrong and
can be confusion.

So change md_register_thread to use the name from the personality
unless no alternate name (like 'resync' or 'reshape') is given.

This is simpler and more correct.

Cc: Jinzc <zhenchengjin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:09:45 +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
Alexey Dobriyan 83d5cde47d const: make block_device_operations const
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:25 -07:00
NeilBrown 80ffb3ccea Fix new incorrect error return from do_md_stop.
Recent commit c8c00a6915
changed the exit paths in do_md_stop and was not quite
careful enough.  There is one path were 'err' now needs
to be cleared but it isn't.
So setting an array to readonly (with mdadm --readonly) will
work, but will incorrectly report and error: ENXIO.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-18 10:35:26 +10:00
NeilBrown 4d484a4a7a md: allow upper limit for resync/reshape to be set when array is read-only
Normally we only allow the upper limit for a reshape to be decreased
when the array not performing a sync/recovery/reshape, otherwise there
could be races.  But if an array is part-way through a reshape when it
is assembled the reshape is started immediately leaving no window
to set an upper bound.

If the array is started read-only, the reshape will be suspended until
the array becomes writable, so that provides a window during which it
is perfectly safe to reduce the upper limit of a reshape.

So: allow the upper limit (sync_max) to be reduced even if the reshape
thread is running, as long as the array is still read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:41:50 +10:00
NeilBrown 51d5668cb2 md: never advance 'events' counter by more than 1.
When assembling arrays, md allows two devices to have different event
counts as long as the difference is only '1'.  This is to cope with
a system failure between updating the metadata on two difference
devices.

However there are currently times when we update the event count by
2.  This was done to keep the event count even when the array is clean
and odd when it is dirty, which allows us to avoid writing common
update to spare devices and so allow those spares to go to sleep.

This is bad for the above reason.  So change it to never increase by
two.  This means that the alignment between 'odd/even' and
'clean/dirty' might take a little longer to attain, but that is only a
small cost.  The spares will get a few more updates but that will
still be spared (;-) most updates and can still go to sleep.

Prior to this patch there was a small chance that after a crash an
array would fail to assemble due to the overly large event count
mismatch.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 09:54:02 +10:00
NeilBrown c8c00a6915 Remove deadlock potential in md_open
A recent commit:
  commit 449aad3e25

introduced the possibility of an A-B/B-A deadlock between
bd_mutex and reconfig_mutex.

__blkdev_get holds bd_mutex while calling md_open which takes
   reconfig_mutex,
do_md_run is always called with reconfig_mutex held, and it now
   takes bd_mutex in the call the revalidate_disk.

This potential deadlock was not caught by lockdep due to the
use of mutex_lock_interruptible_nexted which was introduced
by
   commit d63a5a74de
do avoid a warning of an impossible deadlock.

It is quite possible to split reconfig_mutex in to two locks.
One protects the array data structures while it is being
reconfigured, the other ensures that an array is never even partially
open while it is being deactivated.
In particular, the second lock prevents an open from completing
between the time when do_md_stop checks if there are any active opens,
and the time when the array is either set read-only, or when ->pers is
set to NULL.  So we can be certain that no IO is in flight as the
array is being destroyed.

So create a new lock, open_mutex, just to ensure exclusion between
'open' and 'stop'.

This avoids the deadlock and also avoids the lockdep warning mentioned
in commit d63a5a74d

Reported-by: "Mike Snitzer" <snitzer@gmail.com>
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-10 12:50:52 +10:00
NeilBrown 449aad3e25 md: Use revalidate_disk to effect changes in size of device.
As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode.  So use that instead of mucking about with locks and
i_size_write.

Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:58 +10:00
NeilBrown 70471dafe3 md: Handle growth of v1.x metadata correctly.
The v1.x metadata does not have a fixed size and can grow
when devices are added.
If it grows enough to require an extra sector of storage,
we need to update the 'sb_size' to match.

Without this, md can write out an incomplete superblock with a
bad checksum, which will be rejected when trying to re-assemble
the array.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:57 +10:00
NeilBrown 3673f305fa md: avoid array overflow with bad v1.x metadata
We trust the 'desc_nr' field in v1.x metadata enough to use it
as an index in an array.  This isn't really safe.
So range-check the value first.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:56 +10:00
NeilBrown 3a981b03f3 md: when a level change reduces the number of devices, remove the excess.
When an array is changed from RAID6 to RAID5, fewer drives are
needed.  So any device that is made superfluous by the level
conversion must be marked as not-active.
For the RAID6->RAID5 conversion, this will be a drive which only
has 'Q' blocks on it.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:55 +10:00
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
Joe Perches ad361c9884 Remove multiple KERN_ prefixes from printk formats
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics.  printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.

<level> is now included in the output on each additional use.

Remove all uses of multiple KERN_<level>s in formats.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08 10:30:03 -07:00
NeilBrown e62e58a5ff md: use interruptible wait when duration is controlled by userspace.
User space can set various limits on an md array so that resync waits
when it gets to a certain point, or so that I/O is blocked for a short
while.
When md is waiting against one of these limit, it should use an
interruptible wait so as not to add to the load average, and so are
not to trigger a warning if the wait goes on for too long.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 13:15:35 +10:00
NeilBrown 0909dc448c md: tidy up error paths in md_alloc
As the recent bug in md_alloc showed, having a single exit path for
unlocking and putting is a good idea.  So restructure md_alloc to have
a single mutex_unlock and mddev_put, and use gotos where necessary.

Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 12:27:21 +10:00
NeilBrown 1ec22eb2b4 md: fix error path when duplicate name is found on md device creation.
When an md device is created by name (rather than number) we need to
check that the name is not already in use.  If this check finds a
duplicate, we return an error without dropping the lock or freeing
the newly create mddev.
This patch fixes that.

Cc: stable@kernel.org
Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 12:27:21 +10:00
NeilBrown b8d966efd9 md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.
If we try to modify one of the md/ sysfs files
  suspend_lo or suspend_hi
when the array is not active, we dereference a NULL.
Protect against that.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 11:14:04 +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 8190e754e0 md: remove chunksize rounding from common code.
It is easiest to round sizes to multiples of chunk size in
the personality code for those personalities which care.
Those personalities now do the rounding, so we can
remove that function from common code.

Also remove the upper bound on the size of a chunk, and the lower
bound on the size of a device (1 chunk), neither of which really buy
us anything.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:58 +10:00
NeilBrown 1b57f13223 md: move assignment of ->utime so that it never gets skipped.
Currently the assignment to utime gets skipped for 'external'
metadata.  So move it to the top of the function so that it
always gets effected.
This is of largely cosmetic interest.  Nothing actually depends
on ->utime being right for external arrays.
"mdadm --monitor" does use it for 0.90 and 1.x arrays, but with
mdadm-3.0, this is not important for external metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:19 +10:00
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
NeilBrown ca38805945 md: lock address when changing attributes of component devices
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 10:41:18 -08:00
NeilBrown c5d79adba7 md: allow devices to be shared between md arrays
Currently, a given device is "claimed" by a particular array so that it cannot
be used by other arrays.

This is not ideal for DDF and other metadata schemes which have their own
partitioning concept.

So for externally managed metadata, just claim the device for md in general,
require that "offset" and "size" are set properly for each device, and make
sure that if a device is included in different arrays then the active sections
do not overlap.

This involves adding another flag to the rdev which makes it awkward to set
"->flags = 0" to clear certain flags.  So now clear flags explicitly by name
when we want to clear things.

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 10:41:18 -08:00
NeilBrown 1ec4a9398d md: set and test the ->persistent flag for md devices more consistently
If you try to start an array for which the number of raid disks is listed as
zero, md will currently try to read metadata off any devices that have been
given.  This was done because the value of raid_disks is used to signal
whether array details have been provided by userspace (raid_disks > 0) or must
be read from the devices (raid_disks == 0).

However for an array without persistent metadata (or with externally managed
metadata) this is the wrong thing to do.  So we add a test in do_md_run to
give an error if raid_disks is zero for non-persistent arrays.

This requires that mddev->persistent is set corrently at this point, which it
currently isn't for in-kernel autodetected arrays.

So set ->persistent for autodetect arrays, and remove the settign in
super_*_validate which is now redundant.

Also clear ->persistent when stopping an array so it is consistently zero when
starting an array.

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 10:41:18 -08:00
NeilBrown c620727779 md: allow a maximum extent to be set for resyncing
This allows userspace to control resync/reshape progress and synchronise it
with other activities, such as shared access in a SAN, or backing up critical
sections during a tricky reshape.

Writing a number of sectors (which must be a multiple of the chunk size if
such is meaningful) causes a resync to pause when it gets to that point.

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 10:41:18 -08:00
NeilBrown c303da6d71 md: give userspace control over removing failed devices when external metdata in use
When a device fails, we must not allow an further writes to the array until
the device failure has been recorded in array metadata.  When metadata is
managed externally, this requires some synchronisation...

Allow/require userspace to explicitly remove failed devices from active
service in the array by writing 'none' to the 'slot' attribute.  If this
reduces the number of failed devices to 0, the write block will automatically
be lowered.

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 10:41:18 -08:00
NeilBrown e691063a61 md: support 'external' metadata for md arrays
- Add a state flag 'external' to indicate that the metadata is managed
  externally (by user-space) so important changes need to be
  left of user-space to handle.
  Alternates are non-persistant ('none') where there is no stable metadata -
  after the  array is stopped there is no record of it's status - and
  internal which can be version 0.90 or version 1.x
  These are selected by writing to the 'metadata' attribute.

- move the updating of superblocks (sync_sbs) to after we have checked if
  there are any superblocks or not.

- New array state 'write_pending'.  This means that the metadata records
  the array as 'clean', but a write has been requested, so the metadata has
  to be updated to record a 'dirty' array before the write can continue.
  This change is reported to md by writing 'active' to the array_state
  attribute.

- tidy up marking of sb_dirty:
   - don't set sb_dirty when resync finishes as md_check_recovery
     calls md_update_sb when the sync thread finishes anyway.
   - Don't set sb_dirty in multipath_run as the array might not be dirty.
   - don't mark superblock dirty when switching to 'clean' if there
     is no internal superblock (if external, userspace can choose to
     update the superblock whenever it chooses to).

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 10:41:18 -08:00
Greg Kroah-Hartman c10997f657 Kobject: convert drivers/* from kobject_unregister() to kobject_put()
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:40 -08:00
Greg Kroah-Hartman f9cb074bff Kobject: rename kobject_init_ng() to kobject_init()
Now that the old kobject_init() function is gone, rename
kobject_init_ng() to kobject_init() to clean up the namespace.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:38 -08:00
Greg Kroah-Hartman b2d6db5878 Kobject: rename kobject_add_ng() to kobject_add()
Now that the old kobject_add() function is gone, rename kobject_add_ng()
to kobject_add() to clean up the namespace.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:38 -08:00
Greg Kroah-Hartman 649316b25b Kobject: convert drivers/md/md.c to use kobject_init/add_ng()
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.

Cc: Neil Brown <neilb@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:37 -08:00
Kay Sievers edfaa7c365 Driver core: convert block from raw kobjects to core devices
This moves the block devices to /sys/class/block. It will create a
flat list of all block devices, with the disks and partitions in one
directory. For compatibility /sys/block is created and contains symlinks
to the disks.

  /sys/class/block
  |-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
  |-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1
  |-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10
  |-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5
  |-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6
  |-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7
  |-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8
  |-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9
  `-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

  /sys/block/
  |-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
  `-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:36 -08:00
Greg Kroah-Hartman 3830c62fef Kobject: change drivers/md/md.c to use kobject_init_and_add
Stop using kobject_register, as this way we can control the sending of
the uevent properly, after everything is properly initialized.

Cc: Neil Brown <neilb@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:29 -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
Pavel Emelyanov ba25f9dcc4 Use helpers to obtain task pid in printks
The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:43 -07:00
Iustin Pop d7f3d291a0 md: expose the degraded status of an assembled array through sysfs
The 'degraded' attribute is useful to quickly determine if the array is
degraded, instead of parsing 'mdadm -D' output or relying on the other
techniques (number of working devices against number of defined devices,
etc.).  The md code already keeps track of this attribute, so it's useful to
export it.

Signed-off-by: Iustin Pop <iusty@k1024.org>
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
NeilBrown 2b12ab6d33 md: 'sync_action' in sysfs returns wrong value for readonly arrays
When an array is started read-only, MD_RECOVERY_NEEDED can be set but no
recovery will be running.  This causes 'sync_action' to report the wrong
value.

We could remove the test for MD_RECOVERY_NEEDED, but doing so would leave a
small gap after requesting a sync action, where 'sync_action' would still
report the old value.

So make sure that for a read-only array, 'sync_action' always returns 'idle'.

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
Michael J. Evans 4d936ec1fd md: software Raid autodetect dev list not array
In current release kernels the md module (Software RAID) uses a static
array (dev_t[128]) to store partition/device info temporarily for
autostart.

I discovered this (and that the devices are added as disks/partitions are
discovered at boot) while I was debugging why only one of my MD arrays would
come up whole, while all the others were short a disk.

I eventually discovered that it was enumerating through all of 9 of my 11 hds
(2 had only 4 partitions apiece) while the other 9 have 15 partitions (I
wanted 64 per drive...).  The last partition of the 8th drive in my 9 drive
raid 5 sets wasn't added, thus making the final md array short both a parity
and data disk, and it was started later, elsewhere.

This patch replaces that static array with a list.

[akpm@linux-foundation.org: removed unused var]
Signed-off-by: Michael J. Evans <mjevans1983@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>
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
Greg Kroah-Hartman 19c38de88a kobjects: fix up improper use of the kobject name field
A number of different drivers incorrect access the kobject name field
directly.  This is not correct as the name might not be in the array.
Use the proper accessor function instead.
2007-10-12 14:51:02 -07:00
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 4ad1366376 md: change bitmap_unplug and others to void functions
bitmap_unplug only ever returns 0, so it may as well be void.  Two callers try
to print a message if it returns non-zero, but that message is already printed
by bitmap_file_kick.

write_page returns an error which is not consistently checked.  It always
causes BITMAP_WRITE_ERROR to be set on an error, and that can more
conveniently be checked.

When the return of write_page is checked, an error causes bitmap_file_kick to
be called - so move that call into write_page - and protect against recursive
calls into bitmap_file_kick.

bitmap_update_sb returns an error that is never checked.

So make these 'void' and be consistent about checking the bit.

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>
2007-07-17 10:23:15 -07:00
NeilBrown f0d76d70bc md: check that internal bitmap does not overlap other data
We current completely trust user-space to set up metadata describing an
consistant array.  In particlar, that the metadata, data, and bitmap do not
overlap.

But userspace can be buggy, and it is better to report an error than corrupt
data.  So put in some appropriate checks.

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>
2007-07-17 10:23:15 -07:00
NeilBrown 713f6ab18b md: improve the is_mddev_idle test fix
Don't use 'unsigned' variable to track sync vs non-sync IO, as the only thing
we want to do with them is a signed comparison, and fix up the comment which
had become quite wrong.

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>
2007-07-17 10:23:15 -07:00
NeilBrown df968c4e8d md: improve message about invalid superblock during autodetect
People try to use raid auto-detect with version-1 superblocks (which is not
supported) and get confused when they are told they have an invalid
superblock.

So be more explicit, and say it it is not a valid v0.90 superblock.

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>
2007-07-17 10:23:15 -07:00
Rafael J. Wysocki 8314418629 Freezer: make kernel threads nonfreezable by default
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Dan Williams 685784aaf3 xor: make 'xor_blocks' a library routine for use with async_tx
The async_tx api tries to use a dma engine for an operation, but will fall
back to an optimized software routine otherwise.  Xor support is
implemented using the raid5 xor routines.  For organizational purposes this
routine is moved to a common area.

The following fixes are also made:
* rename xor_block => xor_blocks, suggested by Adrian Bunk
* ensure that xor.o initializes before md.o in the built-in case
* checkpatch.pl fixes
* mark calibrate_xor_blocks __init, Adrian Bunk

Cc: Adrian Bunk <bunk@stusta.de>
Cc: NeilBrown <neilb@suse.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2007-07-13 08:06:14 -07:00
NeilBrown a778b73ff7 md: fix bug with linear hot-add and elsewhere
Adding a drive to a linear array seems to have stopped working, due to changes
elsewhere in md, and insufficient ongoing testing...

So the patch to make linear hot-add work in the first place introduced a
subtle bug elsewhere that interracts poorly with older version of mdadm.

This fixes it all up.

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>
2007-05-23 20:14:14 -07:00
NeilBrown 435b71be20 md: improve the is_mddev_idle test
During a 'resync' or similar activity, md checks if the devices in the
array are otherwise active and winds back resync activity when they are.
This test in done in is_mddev_idle, and it is somewhat fragile - it
sometimes thinks there is non-sync io when there isn't.

The test compares the total sectors of io (disk_stat_read) with the sectors
of resync io (disk->sync_io).  This has problems because total sectors gets
updated when a request completes, while resync io gets updated when the
request is submitted.  The time difference can cause large differenced
between the two which do not actually imply non-resync activity.  The test
currently allows for some fuzz (+/- 4096) but there are some cases when it
is not enough.

The test currently looks for any (non-fuzz) difference, either positive or
negative.  This clearly is not needed.  Any non-sync activity will cause
the total sectors to grow faster than the sync_io count (never slower) so
we only need to look for a positive differences.

If we do this then the amount of in-flight sync io will never cause the
appearance of non-sync IO.  Once enough non-sync IO to worry about starts
happening, resync will be slowed down and the measurements will thus be
more precise (as there is less in-flight) and control of resync will still
be suitably responsive.

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>
2007-05-11 08:29:37 -07:00
Linus Torvalds 44ce6294d0 Revert "md: improve partition detection in md array"
This reverts commit 5b479c91da.

Quoth Neil Brown:

  "It causes an oops when auto-detecting raid arrays, and it doesn't
   seem easy to fix.

   The array may not be 'open' when do_md_run is called, so
   bdev->bd_disk might be NULL, so bd_set_size can oops.

   This whole approach of opening an md device before it has been
   assembled just seems to get more and more painful.  I think I'm going
   to have to come up with something clever to provide both backward
   comparability with usage expectation, and sane integration into the
   rest of the kernel."

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 18:51:36 -07:00
NeilBrown 5b479c91da md: improve partition detection in md array
md currently uses ->media_changed to make sure rescan_partitions
is call on md array after they are assembled.

However that doesn't happen until the array is opened, which is later
than some people would like.

So use blkdev_ioctl to do the rescan immediately that the
array has been assembled.

This means we can remove all the ->change infrastructure as it was only used
to trigger a partition rescan.

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>
2007-05-09 12:30:57 -07:00
NeilBrown 08a02ecd28 md: allow reshape_position for md arrays to be set via sysfs
"reshape_position" records how much progress has been made on a "reshape"
(adding drives, changing layout or chunksize).

When it is set, the number of drives, layout and chunksize can have
two possible values, an old an a new.

So allow these different values to be visible, and allow both old and new to
be set: Set the old ones first, then the reshape_position, then the new
values.

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>
2007-05-09 12:30:57 -07:00
NeilBrown 4d167f0937 md: stop using csum_partial for checksum calculation in md
If CONFIG_NET is not selected, csum_partial is not exported, so md.ko cannot
use it.  We shouldn't really be using csum_partial anyway as it is an
internal-to-networking interface.

So replace it with C code to do the same thing.  Speed is not crucial here, so
something simple and correct is best.

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>
2007-05-09 12:30:57 -07:00
NeilBrown e11e93facc md: move test for whether level supports bitmap to correct place
We need to check for internal-consistency of superblock in load_super.
validate_super is for inter-device consistency.

With the test in the wrong place, a badly created array will confuse md rather
an produce sensible errors.

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>
2007-05-09 12:30:57 -07:00
Martin Peschke c3f94b40e1 md: cleanup: use seq_release_private() where appropriate
We can save some lines of code by using seq_release_private().

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:57 -07:00
Ahmed S. Darwish 50511da3da drivers/md.c: Use ARRAY_SIZE macro when appropriate
Use ARRAY_SIZE macro already defined in kernel.h

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:57 -07:00
Peter Zijlstra f98393a64c mm: remove destroy_dirty_buffers from invalidate_bdev()
Remove the destroy_dirty_buffers argument from invalidate_bdev(), it hasn't
been used in 6 years (so akpm says).

find * -name \*.[ch] | xargs grep -l invalidate_bdev |
while read file; do
	quilt add $file;
	sed -ie 's/invalidate_bdev(\([^,]*\),[^)]*)/invalidate_bdev(\1)/g' $file;
done

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:55 -07:00
NeilBrown 5792a2856a [PATCH] md: avoid a deadlock when removing a device from an md array via sysfs
A device can be removed from an md array via e.g.
  echo remove > /sys/block/md3/md/dev-sde/state

This will try to remove the 'dev-sde' subtree which will deadlock
since
  commit e7b0d26a86

With this patch we run the kobject_del via schedule_work so as to
avoid the deadlock.

Cc: Alan Stern <stern@rowland.harvard.edu>
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>
2007-04-04 21:12:47 -07:00
NeilBrown 5e55e2f5fc [PATCH] md: convert compile time warnings into runtime warnings
...  still not sure why we need this ....

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>
2007-03-27 09:05:15 -07:00
NeilBrown 041ae52e26 [PATCH] md: clear the congested_fn when stopping a raid5
If this mddev and queue got reused for another array that doesn't register a
congested_fn, this function would get called incorretly.

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>
2007-03-27 09:05:14 -07:00
NeilBrown b4c4c7b809 [PATCH] md: restart a (raid5) reshape that has been aborted due to a read/write error
An error always aborts any resync/recovery/reshape on the understanding that
it will immediately be restarted if that still makes sense.  However a reshape
currently doesn't get restarted.  With this patch it does.

To avoid restarting when it is not possible to do work, we call into the
personality to check that a reshape is ok, and strengthen raid5_check_reshape
to fail if there are too many failed devices.

We also break some code out into a separate function: remove_and_add_spares as
the indent level for that code was getting crazy.

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>
2007-03-01 14:53:36 -08:00
NeilBrown d1b5380c7f [PATCH] md: clean out unplug and other queue function on md shutdown
The mddev and queue might be used for another array which does not set these,
so they need to be cleared.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 14:53:36 -08:00
NeilBrown 7dd5e7c3db [PATCH] md: move warning about creating a raid array on partitions of the one device
md tries to warn the user if they e.g.  create a raid1 using two partitions of
the same device, as this does not provide true redundancy.

However it also warns if a raid0 is created like this, and there is nothing
wrong with that.

At the place where the warning is currently printer, we don't necessarily know
what level the array will be, so move the warning from the point where the
device is added to the point where the array is started.

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>
2007-03-01 14:53:36 -08:00
Eric W. Biederman 0b4d414714 [PATCH] sysctl: remove insert_at_head from register_sysctl
The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00
Eric W. Biederman ff1d28efc5 [PATCH] sysctl: md: remove unnecessary insert_at_head flag
The sysctls used by the md driver are have unique binary numbers so remove the
insert_at_head flag as it serves no useful purpose.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:55 -08:00
Arjan van de Ven fa027c2a0a [PATCH] mark struct file_operations const 4
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@sdl.org: dvb fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00
NeilBrown 2a2275d630 [PATCH] md: fix potential memalloc deadlock in md
If a GFP_KERNEL allocation is attempted in md while the mddev_lock is held,
it is possible for a deadlock to eventuate.

This happens if the array was marked 'clean', and the memalloc triggers a
write-out to the md device.

For the writeout to succeed, the array must be marked 'dirty', and that
requires getting the mddev_lock.

So, before attempting a GFP_KERNEL allocation while holding the lock, make
sure the array is marked 'dirty' (unless it is currently read-only).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26 13:51:00 -08:00
NeilBrown 1031be7a5f [PATCH] md: make sure the events count in an md array never returns to zero
Now that we sometimes step the array events count backwards (when
transitioning dirty->clean where nothing else interesting has happened - so
that we don't need to write to spares all the time), it is possible for the
event count to return to zero, which is potentially confusing and triggers and
MD_BUG.

We could possibly remove the MD_BUG, but is just as easy, and probably safer,
to make sure we never return to zero.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26 13:50:59 -08:00
NeilBrown 3f9d7b0d81 [PATCH] md: fix a few problems with the interface (sysfs and ioctl) to md
While developing more functionality in mdadm I found some bugs in md...

- When we remove a device from an inactive array (write 'remove' to
  the 'state' sysfs file - see 'state_store') would should not
  update the superblock information - as we may not have
  read and processed it all properly yet.

- initialise all raid_disk entries to '-1' else the 'slot sysfs file
  will claim '0' for all devices in an array before the array is
  started.

- all '\n' not to be present at the end of words written to
  sysfs files

- when we use SET_ARRAY_INFO to set the md metadata version,
  set the flag to say that there is persistant metadata.

- allow GET_BITMAP_FILE to be called on an array that hasn't
  been started yet.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-22 08:55:51 -08:00
NeilBrown 1757128438 [PATCH] md: assorted md and raid1 one-liners
Fix few bugs that meant that:
  - superblocks weren't alway written at exactly the right time (this
    could show up if the array was not written to - writting to the array
    causes lots of superblock updates and so hides these errors).

  - restarting device recovery after a clean shutdown (version-1 metadata
    only) didn't work as intended (or at all).

1/ Ensure superblock is updated when a new device is added.
2/ Remove an inappropriate test on MD_RECOVERY_SYNC in md_do_sync.
   The body of this if takes one of two branches depending on whether
   MD_RECOVERY_SYNC is set, so testing it in the clause of the if
   is wrong.
3/ Flag superblock for updating after a resync/recovery finishes.
4/ If we find the neeed to restart a recovery in the middle (version-1
   metadata only) make sure a full recovery (not just as guided by
   bitmaps) does get done.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:21 -08:00
Jeff Garzik fdee8ae449 [PATCH] MD: conditionalize some code
The autorun code is only used if this module is built into the static
kernel image.  Adjust #ifdefs accordingly.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:21 -08:00
NeilBrown 0d4ca600fc [PATCH] md: tidy up device-change notification when an md array is stopped
An md array can be stopped leaving all the setting still in place, or it can
torn down and destroyed.  set_capacity and other change notifications only
happen in the latter case, but should happen in both.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:20 -08:00
Josef Sipek c649bb9c55 [PATCH] struct path: convert md
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:47 -08:00
NeilBrown d63a5a74de [PATCH] lockdep: avoid lockdep warning in md
md_open takes ->reconfig_mutex which causes lockdep to complain.  This
(normally) doesn't have deadlock potential as the possible conflict is with a
reconfig_mutex in a different device.

I say "normally" because if a loop were created in the array->member hierarchy
a deadlock could happen.  However that causes bigger problems than a deadlock
and should be fixed independently.

So we flag the lock in md_open as a nested lock.  This requires defining
mutex_lock_interruptible_nested.

Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:39 -08:00
Peter Zijlstra 2e7b651df1 [PATCH] remove the old bd_mutex lockdep annotation
Remove the old complex and crufty bd_mutex annotation.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:38 -08:00
Nigel Cunningham 7dfb71030f [PATCH] Add include/linux/freezer.h and move definitions from sched.h
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:27 -08:00
Rafael J. Wysocki 4b438a23fb [PATCH] md: do not freeze md threads for suspend
If there's a swap file on a software RAID, it should be possible to use this
file for saving the swsusp's suspend image.  Also, this file should be
available to the memory management subsystem when memory is being freed before
the suspend image is created.

For the above reasons it seems that md_threads should not be frozen during the
suspend and the appended patch makes this happen, but then there is the
question if they don't cause any data to be written to disks after the suspend
image has been created, provided that all filesystems are frozen at that time.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-08 18:29:24 -08:00
NeilBrown 2f47130361 [PATCH] md: change ONLINE/OFFLINE events to a single CHANGE event
It turns out that CHANGE is preferred to ONLINE/OFFLINE for various reasons
(not least of which being that udev understands it already).

So remove the recently added KOBJ_OFFLINE (no-one is likely to care anyway)
and change the ONLINE to a CHANGE event

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-08 18:29:23 -08:00
NeilBrown 7870db4c7f [PATCH] md: send online/offline uevents when an md array starts/stops
This allows udev to do something intelligent when an array becomes
available.

Acked-by: Greg KH <greg@kroah.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>
2006-11-03 12:27:55 -08:00
NeilBrown 01ab5662f5 [PATCH] md: simplify checking of available size when resizing an array
When "mdadm --grow --size=xxx" is used to resize an array (use more or less of
each device), we check the new siza against the available space in each
device.

We already have that number recorded in rdev->size, so calculating it is
pointless (and wrong in one obscure case).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28 11:30:51 -07:00
NeilBrown 2b6e845986 [PATCH] md: fix bug where spares don't always get rebuilt properly when they become live
If save_raid_disk is >= 0, then the device could be a device that is already
in sync that is being re-added.  So we need to default this value to -1.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28 11:30:51 -07:00
NeilBrown 1c05b4bc22 [PATCH] md: endian annotation for v1 superblock access
Includes a couple of bugfixes found by sparse.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-21 13:35:05 -07:00
Akinobu Mita e24650c2e7 [PATCH] md: fix /proc/mdstat refcounting
I have seen mdadm oops after successfully unloading md module.

This patch privents from unloading md module while
mdadm is polling /proc/mdstat.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Akinbou Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:43 -07:00
NeilBrown 5842730de1 [PATCH] md: fix bug where new drives added to an md array sometimes don't sync properly
This fixes a bug introduced in 2.6.18.

If a drive is added to a raid1 using older tools (mdadm-1.x or raidtools)
then it will be included in the array without any resync happening.

It has been submitted for 2.6.18.1.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-06 08:53:41 -07:00
Eric Sesterhenn 52e5f9d1cf BUG_ON cleanup for drivers/md/
This changes two if() BUG(); usages to BUG_ON(); so people
can disable it safely.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03 23:33:23 +02:00
NeilBrown 3a0f5bbb1a [PATCH] md: add error reporting to superblock write failure
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 08:04:19 -07:00
NeilBrown e8703fe1f5 [PATCH] md: remove MAX_MD_DEVS which is an arbitrary limit
Once upon a time we needed to fixed limit to the number of md devices,
probably because we preallocated some array.  This need no longer exists, but
we still have an arbitrary limit.

So remove MAX_MD_DEVS and allow as many devices as we can fit into the 'minor'
part of a device number.

Also remove some useless noise at init time (which reports MAX_MD_DEVS) and
remove MD_THREAD_NAME_MAX which hasn't been used for a while.

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 61df9d91e9 [PATCH] md: make messages about resync/recovery etc more specific
It is possible to request a 'check' of an md/raid array where the whole array
is read and consistancies are reported.

This uses the same mechanisms as 'resync' and so reports in the kernel logs
that a resync is being started.  This understandably confuses/worries people.

Also the text in /proc/mdstat suggests a 'resync' is happen when it is just a
check.

This patch changes those messages to be more specific about what is happening.

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
Paul Clements 9b1d1dac18 [PATCH] md: new sysfs interface for setting bits in the write-intent-bitmap
Add a new sysfs interface that allows the bitmap of an array to be dirtied.
The interface is write-only, and is used as follows:

echo "1000" > /sys/block/md2/md/bitmap

(dirty the bit for chunk 1000 [offset 0] in the in-memory and on-disk
bitmaps of array md2)

echo "1000-2000" > /sys/block/md1/md/bitmap

(dirty the bits for chunks 1000-2000 in md1's bitmap)

This is useful, for example, in cluster environments where you may need to
combine two disjoint bitmaps into one (following a server failure, after a
secondary server has taken over the array).  By combining the bitmaps on
the two servers, a full resync can be avoided (This was discussed on the
list back on March 18, 2005, "[PATCH 1/2] md bitmap bug fixes" thread).

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 08:04:17 -07:00
NeilBrown 850b2b420c [PATCH] md: replace magic numbers in sb_dirty with well defined bit flags
Instead of magic numbers (0,1,2,3) in sb_dirty, we have
some flags instead:
MD_CHANGE_DEVS
   Some device state has changed requiring superblock update
   on all devices.
MD_CHANGE_CLEAN
   The array has transitions from 'clean' to 'dirty' or back,
   requiring a superblock update on active devices, but possibly
   not on spares
MD_CHANGE_PENDING
   A superblock update is underway.

We wait for an update to complete by waiting for all flags to be clear.  A
flag can be set at any time, even during an update, without risk that the
change will be lost.

Stop exporting md_update_sb - isn't needed.

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 08:04:17 -07:00
Adrian Bunk fbedac04fa [PATCH] md: the scheduled removal of the START_ARRAY ioctl for md
This patch contains the scheduled removal of the START_ARRAY ioctl for md.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
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 08:04:16 -07:00
NeilBrown 8469219596 [PATCH] md: avoid backward event updates in md superblock when degraded.
If we
  - shut down a clean array,
  - restart with one (or more) drive(s) missing
  - make some changes
  - pause, so that they array gets marked 'clean',
the event count on the superblock of included drives
will be the same as that of the removed drives.
So adding the removed drive back in will cause it
to be included with no resync.

To avoid this, we only update the eventcount backwards when the array
is not degraded.  In this case there can (should) be no non-connected
drives that we can get confused with, and this is the particular case
where updating-backwards is valuable.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:31 -07:00
Andrew Morton d0a0a5ee7a [PATCH] md: fix oops in error-handling
During early MD setup (superblock reading), we don't have a personality yet.
But the error-handling code tries to dereference mddev->pers.  Fix.

Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:17 -07:00
NeilBrown 67463acb64 [PATCH] md: require CAP_SYS_ADMIN for (re-)configuring md devices via sysfs
The ioctl requires CAP_SYS_ADMIN, so sysfs should too.  Note that we don't
require CAP_SYS_ADMIN for reading attributes even though the ioctl does.
There is no reason to limit the read access, and much of the information is
already available via /proc/mdstat

Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:17 -07:00
NeilBrown 80ca3a44f5 [PATCH] md: unify usage of symbolic names for perms
Some places we use number (0660) someplaces names (S_IRUGO).  Change all
numbers to be names, and change 0655 to be what it should be.

Also make some formatting more consistent.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:17 -07:00
NeilBrown ff4e8d9a9f [PATCH] md: fix resync speed calculation for restarted resyncs
We introduced 'io_sectors' recently so we could count the sectors that causes
io during resync separate from sectors which didn't cause IO - there can be a
difference if a bitmap is being used to accelerate resync.

However when a speed is reported, we find the number of sectors processed
recently by subtracting an oldish io_sectors count from a current
'curr_resync' count.  This is wrong because curr_resync counts all sectors,
not just io sectors.

So, add a field to mddev to store the curren io_sectors separately from
curr_resync, and use that in the calculations.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:16 -07:00
NeilBrown 0b8c9de05c [PATCH] md: delay starting md threads until array is completely setup
When an array is started we start one or two threads (two if there is a
reshape or recovery that needs to be completed).

We currently start these *before* the array is completely set up and in
particular before queue->queuedata is set.  If the thread actually starts
very quickly on another CPU, we can end up dereferencing queue->queuedata
and oops.

This patch also makes sure we don't try to start a recovery if a reshape is
being restarted.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:16 -07:00
NeilBrown 31b65a0d38 [PATCH] md: set desc_nr correctly for version-1 superblocks
This has to be done in ->load_super, not ->validate_super

Without this, hot-adding devices to an array doesn't always
work right - though there is a work around in mdadm-2.5.2 to
make this less of an issue.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:16 -07:00
Ingo Molnar 663d440eaa [PATCH] lockdep: annotate blkdev nesting
Teach special (recursive) locking code to the lock validator.

Effects on non-lockdep kernels:

- the introduction of the following function variants:

  extern struct block_device *open_partition_by_devnum(dev_t, unsigned);

  extern int blkdev_put_partition(struct block_device *);

  static int
  blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags);

 which on non-lockdep are the same as open_by_devnum(), blkdev_put()
 and blkdev_get().

- a subclass parameter to do_open(). [unused on non-lockdep]

- a subclass parameter to __blkdev_put(), which is a new internal
  function for the main blkdev_put*() functions. [parameter unused
  on non-lockdep kernels, except for two sanity check WARN_ON()s]

these functions carry no semantical difference - they only express
object dependencies towards the lockdep subsystem.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:10 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Greg Kroah-Hartman ce7b0f46bb [PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed
And remove the now unneeded number field.
Also fixes all drivers that set these fields.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:08 -07:00
Greg Kroah-Hartman ff23eca3e8 [PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree
Also fixes up all files that #include it.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:08 -07:00
Greg Kroah-Hartman 8ab5e4c15b [PATCH] devfs: Remove devfs_remove() function from the kernel tree
Removes the devfs_remove() function and all callers of it.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:07 -07:00
Greg Kroah-Hartman 1a715c5cf9 [PATCH] devfs: Remove devfs_mk_bdev() function from the kernel tree
Removes the devfs_mk_bdev() function and all callers of it.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:06 -07:00
Greg Kroah-Hartman 95dc112a57 [PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree
Removes the devfs_mk_dir() function and all callers of it.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:06 -07:00
Adrian Bunk 0538195424 [PATCH] drivers/md/md.c: make code static
Make needlessly global code static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:40 -07:00
NeilBrown f655675b3f [PATCH] md: Allow the write_mostly flag to be set via sysfs
It appears in /sys/mdX/md/dev-YYY/state
and can be set or cleared by writing 'writemostly' or '-writemostly'
respectively.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:40 -07:00
NeilBrown a94213b1fa [PATCH] md: Allow resync_start to be set and queried via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:40 -07:00
NeilBrown d4dbd0250e [PATCH] md: Allow raid 'layout' to be read and set via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:39 -07:00
NeilBrown 45dc2de1e5 [PATCH] md: Allow rdev state to be set via sysfs
The md/dev-XXX/state file can now be written:

 "faulty" simulates an error on the device
 "remove" removes the device from the array (if it is not busy)

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:39 -07:00
NeilBrown 9e653b6342 [PATCH] md: Set/get state of array via sysfs
This allows the state of an md/array to be directly controlled via sysfs and
adds the ability to stop and array without tearing it down.

Array states/settings:

 clear
     No devices, no size, no level
     Equivalent to STOP_ARRAY ioctl
 inactive
     May have some settings, but array is not active
        all IO results in error
     When written, doesn't tear down array, but just stops it
 suspended (not supported yet)
     All IO requests will block. The array can be reconfigured.
     Writing this, if accepted, will block until array is quiescent
 readonly
     no resync can happen.  no superblocks get written.
     write requests fail
 read-auto
     like readonly, but behaves like 'clean' on a write request.

 clean - no pending writes, but otherwise active.
     When written to inactive array, starts without resync
     If a write request arrives then
       if metadata is known, mark 'dirty' and switch to 'active'.
       if not known, block and switch to write-pending
     If written to an active array that has pending writes, then fails.
 active
     fully active: IO and resync can be happening.
     When written to inactive array, starts with resync

 write-pending (not supported yet)
     clean, but writes are blocked waiting for 'active' to be written.

 active-idle
     like active, but no writes have been seen for a while (100msec).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:39 -07:00
NeilBrown 4254376914 [PATCH] md: Don't write dirty/clean update to spares - leave them alone
- record the 'event' count on each individual device (they
  might sometimes be slightly different now)
- add a new value for 'sb_dirty': '3' means that the super
  block only needs to be updated to record a clean<->dirty
  transition.
- Prefer odd event numbers for dirty states and even numbers
  for clean states
- Using all the above, don't update the superblock on
  a spare device if the update is just doing a clean-dirty
  transition.  To accomodate this, a transition from
  dirty back to clean might now decrement the events counter
  if nothing else has changed.

The net effect of this is that spare drives will not see any IO requests
during normal running of the array, so they can go to sleep if that is what
they want to do.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:39 -07:00
NeilBrown 07d84d109d [PATCH] md: Allow re-add to work on array without bitmaps
When an array has a bitmap, a device can be removed and re-added and only
blocks changes since the removal (as recorded in the bitmap) will be resynced.

It should be possible to do a similar thing to arrays without bitmaps.  i.e.
if a device is removed and re-added and *no* changes have been made in the
interim, then the add should not require a resync.

This patch allows that option.  This means that when assembling an array one
device at a time (e.g.  during device discovery) the array can be enabled
read-only as soon as enough devices are available, but extra devices can still
be added without causing a resync.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:39 -07:00
NeilBrown acc55e2201 [PATCH] md/bitmap: tidy up i_writecount handling in md/bitmap
md/bitmap modifies i_writecount of a bitmap file to make sure that no-one else
writes to it.  The reverting of the change is sometimes done twice, and there
is one error path where it is omitted.

This patch tidies that up.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
NeilBrown d7375ab324 [PATCH] md/bitmap: fix online removal of file-backed bitmaps
When "mdadm --grow /dev/mdX --bitmap=none" is used to remove a filebacked
bitmap, the bitmap was disconnected from the array, but the file wasn't closed
(until the array was stopped).

The file also wasn't closed if adding the bitmap file failed.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
Adrian Bunk 5e56341d02 [PATCH] md: make md_print_devices() static
This patch makes the needlessly global md_print_devices() static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 7c7546ccf6 [PATCH] md: allow a linear array to have drives added while active
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 5fd6c1dce0 [PATCH] md: allow checkpoint of recovery with version-1 superblock
For a while we have had checkpointing of resync.  The version-1 superblock
allows recovery to be checkpointed as well, and this patch implements that.

Due to early carelessness we need to add a feature flag to signal that the
recovery_offset field is in use, otherwise older kernels would assume that a
partially recovered array is in fact fully recovered.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown a8a55c387d [PATCH] md: remove nuisance message at shutdown
At shutdown, we switch all arrays to read-only, which creates a message for
every instantiated array, even those which aren't actually active.

So remove the message for non-active arrays.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 16f17b39f3 [PATCH] md: increase the delay before marking metadata clean, and make it configurable
When a md array has been idle (no writes) for 20msecs it is marked as 'clean'.
 This delay turns out to be too short for some real workloads.  So increase it
to 200msec (the time to update the metadata should be a tiny fraction of that)
and make it sysfs-configurable.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 9443a1d1f7 [PATCH] md: remove useless ioctl warning
This warning was slightly useful back in 2.2 days, but is more an annoyance
now.  It makes it awkward to add new ioctls (that we we are likely to do that
in the current climate, but it is possible).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
NeilBrown c331eb04b9 [PATCH] md: Fix badness in sysfs_notify caused by md_new_event
From: NeilBrown <neilb@suse.de>

If an error is reported by a drive in a RAID array (which is done via
bi_end_io - in interrupt context), we call md_error and md_new_event which
calls sysfs_notify.  However sysfs_notify grabs a mutex and so cannot be
called in interrupt context.

This patch just creates a variant of md_new_event which avoids the sysfs
call, and uses that.  A better fix for later is to arrange for the event to
be called from user-context.

Note: avoiding the sysfs call isn't a problem as an error will not, by
itself, modify the sync_action attribute.  (We do still need to
wake_up(&md_event_waiters) as an error by itself will modify /proc/mdstat).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-31 16:27:11 -07:00
Neil Brown c71d48877e [PATCH] Unlock md devices when stopping them on reboot.
otherwise we get nasty messages about locks not being released.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-26 11:52:11 -07:00
NeilBrown 2adc7d47c4 [PATCH] md: Fix inverted test for 'repair' directive.
We should be able to write 'repair' to /sys/block/mdX/md/sync_action,
however due to and inverted test, that always given EINVAL.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:17 -07:00
Ingo Molnar 5dc5cf7dd2 [PATCH] md: locking fix
- fix mddev_lock() usage bugs in md_attr_show() and md_attr_store().
  [they did not anticipate the possibility of getting a signal]

- remove mddev_lock_uninterruptible() [unused]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-20 07:54:04 -07:00
NeilBrown 4508a7a734 [PATCH] sysfs: Allow sysfs attribute files to be pollable
It works like this:
  Open the file
  Read all the contents.
  Call poll requesting POLLERR or POLLPRI (so select/exceptfds works)
  When poll returns,
     close the file and go to top of loop.
   or lseek to start of file and go back to the 'read'.

Events are signaled by an object manager calling
   sysfs_notify(kobj, dir, attr);

If the dir is non-NULL, it is used to find a subdirectory which
contains the attribute (presumably created by sysfs_create_group).

This has a cost of one int  per attribute, one wait_queuehead per kobject,
one int per open file.

The name "sysfs_notify" may be confused with the inotify
functionality.  Maybe it would be nice to support inotify for sysfs
attributes as well?

This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action
to be pollable

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-04-14 11:41:24 -07:00
NeilBrown 926ce2d8a7 [PATCH] md: Remove some code that can sleep from under a spinlock
And remove the comments that were put in inplace of a fix too....

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
NeilBrown df5b89b323 [PATCH] md: Convert reconfig_sem to reconfig_mutex
... being careful that mutex_trylock is inverted wrt down_trylock

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:03 -08:00
Arjan van de Ven 48c9c27b8b [PATCH] sem2mutex: drivers/md
Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:03 -08:00
NeilBrown 8ddeeae51f [PATCH] md: Fix md grow/size code to correctly find the maximum available space
An md array can be asked to change the amount of each device that it is using,
and in particular can be asked to use the maximum available space.  This
currently only works if the first device is not larger than the rest.  As
'size' gets changed and so 'fit' becomes wrong.  So check if a 'fit' is
required early and don't corrupt it.

Signed-off-by: Doug Ledford <dledford@redhat.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>
2006-03-27 08:45:03 -08:00
NeilBrown e464eafdb4 [PATCH] md: Support suspending of IO to regions of an md array
This allows user-space to access data safely.  This is needed for raid5
reshape as user-space needs to take a backup of the first few stripes before
allowing reshape to commence.

It will also be useful in cluster-aware raid1 configurations so that all
cluster members can leave a section of the array untouched while a
resync/recovery happens.

A 'start' and 'end' of the suspended range are written to 2 sysfs attributes.
Note that only one range can be suspended at a time.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:02 -08:00
NeilBrown 16484bf596 [PATCH] md: Make 'reshape' a possible sync_action action
This allows reshape to be triggerred via sysfs (which is the only way to start
it happening).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:02 -08:00
NeilBrown 63c70c4f3a [PATCH] md: Split reshape handler in check_reshape and start_reshape
check_reshape checks validity and does things that can be done instantly -
like adding devices to raid1.  start_reshape initiates a restriping process to
convert the whole array.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:02 -08:00
NeilBrown f67055780c [PATCH] md: Checkpoint and allow restart of raid5 reshape
We allow the superblock to record an 'old' and a 'new' geometry, and a
position where any conversion is up to.  The geometry allows for changing
chunksize, layout and level as well as number of devices.

When using verion-0.90 superblock, we convert the version to 0.91 while the
conversion is happening so that an old kernel will refuse the assemble the
array.  For version-1, we use a feature bit for the same effect.

When starting an array we check for an incomplete reshape and restart the
reshape process if needed.  If the reshape stopped at an awkward time (like
when updating the first stripe) we refuse to assemble the array, and let
user-space worry about it.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:01 -08:00
NeilBrown 292695531a [PATCH] md: Final stages of raid5 expand code
This patch adds raid5_reshape and end_reshape which will start and finish the
reshape processes.

raid5_reshape is only enabled in CONFIG_MD_RAID5_RESHAPE is set, to discourage
accidental use.

Read the 'help' for the CONFIG_MD_RAID5_RESHAPE entry.

and Make sure that you have backups, just in case.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:01 -08:00
NeilBrown ccfcc3c10b [PATCH] md: Core of raid5 resize process
This patch provides the core of the resize/expand process.

sync_request notices if a 'reshape' is happening and acts accordingly.

It allocated new stripe_heads for the next chunk-wide-stripe in the target
geometry, marking them STRIPE_EXPANDING.

Then it finds which stripe heads in the old geometry can provide data needed
by these and marks them STRIPE_EXPAND_SOURCE.  This causes stripe_handle to
read all blocks on those stripes.

Once all blocks on a STRIPE_EXPAND_SOURCE stripe_head are read, any that are
needed are copied into the corresponding STRIPE_EXPANDING stripe_head.  Once a
STRIPE_EXPANDING stripe_head is full, it is marks STRIPE_EXPAND_READY and then
is written out and released.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:01 -08:00
NeilBrown ad01c9e375 [PATCH] md: Allow stripes to be expanded in preparation for expanding an array
Before a RAID-5 can be expanded, we need to be able to expand the stripe-cache
data structure.

This requires allocating new stripes in a new kmem_cache.  If this succeeds,
we copy cache pages over and release the old stripes and kmem_cache.

We then allocate new pages.  If that fails, we leave the stripe cache at it's
new size.  It isn't worth the effort to shrink it back again.

Unfortuanately this means we need two kmem_cache names as we, for a short
period of time, we have two kmem_caches.  So they are raid5/%s and
raid5/%s-alt

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:01 -08:00
NeilBrown 4588b42e9d [PATCH] md: Update status_resync to handle LARGE devices
status_resync - used by /proc/mdstat to report the status of a resync, assumes
that device sizes will always fit into an 'unsigned long' This is no longer
the case...

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:01 -08:00
NeilBrown 1be7892fff [PATCH] md: Fix the 'failed' count for version-0 superblocks
We are counting failed devices twice, once of the device that is failed, and
once for the hole that has been left in the array.  Remove the former so
'failed' matches 'missing'.  Storing these counts in the superblock is a bit
silly anyway....

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:00 -08:00
NeilBrown c5a10f62c5 [PATCH] md: Add '4' to the list of levels for which bitmaps are supported
I really should make this a function of the personality....

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:00 -08:00
NeilBrown 89e5c8b5b8 [PATCH] md: Make sure QUEUE_FLAG_CLUSTER is set properly for md.
This flag should be set for a virtual device iff it is set for all underlying
devices.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:00 -08:00
Jun'ichi Nomura 5463c7904c [PATCH] dm/md dependency tree in sysfs: md to use bd_claim_by_disk
Use bd_claim_by_disk.

Following symlinks are created if md0 is built from sda and sdb
  /sys/block/md0/slaves/sda --> /sys/block/sda
  /sys/block/md0/slaves/sdb --> /sys/block/sdb
  /sys/block/sda/holders/md0 --> /sys/block/md0
  /sys/block/sdb/holders/md0 --> /sys/block/md0

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:45:00 -08:00
Al Viro 1312f40e11 [PATCH] regularize blk_cleanup_queue() use
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-03-18 18:34:20 -05:00
NeilBrown 8ed75463b9 [PATCH] md: Make sure rdev->size gets set for version-1 superblocks
Sometimes it doesn't so make the code more like the version-0 code which
works.

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
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
NeilBrown 284ae7cab0 [PATCH] md: Handle overflow of mdu_array_info_t->size better
mdu_array_info_t->size is 'int', which isn't big enough for the size (in KB of
each component in) some arrays.

So rather than a random overflow, set size to -1 when it cannot be set
correctly.

To update aspect on an array, userspace will sometimes:
  get_array_info
  change one field
  set_array_info

in this case, we don't want the '-1' in 'size' to change to size, or look like
a size change at all.  So test for that in update_array_info.

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 08:31:59 -08:00
NeilBrown 978f946bb6 [PATCH] md: Don't remove bitmap from md array when switching to read-only
While a read-only array doesn't not really need a bitmap, we should
not remove the bitmap when switching an array to read-only because
 a/ There is no code to re-add the bitmap which switching to read-write,
 b/ There is insufficient locking - the bitmap could be accessed while it is
    being removed.

Cc: Reuben Farrelly <reuben-lkml@reub.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-02 15:07:12 -08:00
NeilBrown f0ca340cd2 [PATCH] md: Make sure array geometry changes persist with version-1 superblocks
super_1_sync only updates fields in the superblock that might have changed.

'raid_disks' and 'size' could have changed, but this information doesn't get
updated....  until this patch.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-02 15:07:11 -08:00
NeilBrown 6d89332b77 [PATCH] md: Fix device-size updates in md
As 'array_size' is a 'sector_t', it may overflow inappropriately when shifted
10 bits.  So We should cast it to a loff_t first.

There are two places with this problem, but the second (in update_raid_disks)
isn't needed so just remove it:
  The only personality that handles ->reshape currently is raid1,
  and it doesn't change the size of the array.
  When added for raid5/6, reshape again won't change the size of the array,
  at least not straight away.
  This code might be need for reshaping 'linear' but linear->shape,
  if implemented, should probably do the i_size_write itself.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-02 15:07:10 -08:00
NeilBrown 17115e0388 [PATCH] md: Clear clevel whenever level is set.
The 'level' of an md array can be set as either a number of a string.  When
one is set, the other must be marked 'undefined'.  This wasn't being done
in one place: where new arrays are created.

Result: if md1 is a raid1, it is stopped and a raid5 is created there, it
might still appear to be a raid1.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-16 23:15:32 -08:00
Neil Brown 1edf80d347 [PATCH] md: remove slashes from disk names when creation dev names in sysfs
e.g. The sx8 driver uses names like sx8/0.

This would make a md component dev name like

   /sys/block/md0/md/dev-sx8/0

which is not allowed.  So we change the '/' to '!' just like
fs/partitions/check.c(register_disk) does.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:49 -08:00
Jes Sorensen 1b1dcc1b57 [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.

Modified-by: Ingo Molnar <mingo@elte.hu>

(finished the conversion)

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-01-09 15:59:24 -08:00
Christoph Hellwig a885c8c431 [PATCH] Add block_device_operations.getgeo block device method
HDIO_GETGEO is implemented in most block drivers, and all of them have to
duplicate the code to copy the structure to userspace, as well as getting
the start sector.  This patch moves that to common code [1] and adds a
->getgeo method to fill out the raw kernel hd_geometry structure.  For many
drivers this means ->ioctl can go away now.

[1] the s390 block drivers are odd in this respect.  xpram sets ->start
    to 4 always which seems more than odd, and the dasd driver shifts
    the start offset around, probably because of it's non-standard
    sector size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@suse.de>
Cc: <mike.miller@hp.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
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 20:13:54 -08:00
NeilBrown 88202a0c84 [PATCH] md: allow sync-speed to be controlled per-device
Also export current (average) speed and status in 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 08:34:10 -08:00
NeilBrown 6d7ff7380b [PATCH] md: support adding new devices to md arrays via sysfs
Writing major:minor to md/new_dev will bind that device to the array.

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 08:34:10 -08:00
NeilBrown 83303b613d [PATCH] md: allow available size of component devices to be set 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 08:34:10 -08:00
Andrew Morton 6961ece46c [PATCH] md-export-rdev-data_offset-via-sysfs-fix
drivers/md/md.c: In function `offset_show':
drivers/md/md.c:1670: warning: long long unsigned int format, different type arg (arg 3)

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:10 -08:00
NeilBrown 93c8cad03f [PATCH] md: export rdev->data_offset 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 014236d2b8 [PATCH] md: expose device slot information via sysfs
This the role that a device has in an array can be viewed and set.

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 2bf071bf50 [PATCH] md: keep better track of dev/array size when assembling md arrays
Move the checks - that dev size is never less than array size - into
bind_rdev_to_array to make sure it always happens properly (there is one place
where currently it doesn't).

Also reject any superblock which claims an array size smaller than the device
in question can hold.

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 08:34:09 -08:00
NeilBrown da943b9912 [PATCH] md: allow md/raid_disks to be settable
If array is active, try to reshape, else just set the value.

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 4dbcdc751c [PATCH] md: count corrected read errors per drive
Store this total in superblock (As appropriate), and make it available to
userspace via sysfs.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -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 8bb93aaca2 [PATCH] md: expose md metadata format in sysfs
Allow it to be set to a particular version, or 'none'.

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 08:34:08 -08:00
NeilBrown a35b0d695d [PATCH] md: allow md array component size to be accessed and set 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 08:34:08 -08:00
NeilBrown 3b34380ae8 [PATCH] md: allow chunk_size to be settable through sysfs
... only before array is started of course.

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 08:34:08 -08:00
NeilBrown 03c902e17f [PATCH] md: fix rdev->pending counts in raid1
When we do a user-requested check/repair, we lose count of the outstanding
requests...

Also make sure that when anything is written to md/sync_action, the
RECOVERY_NEEDED flag is set and the thread is woken up so any changes take
effect.

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 08:34:08 -08:00
Adrian Bunk 07dbd37727 [PATCH] drivers/md/md.c: make md_new_event() static
Make the needlessly global function md_new_event() static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:07 -08:00
NeilBrown 2989ddbd6e [PATCH] md: make a couple of names in md.c static
.. because they aren't used outside md.c

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 08:34:07 -08:00