Commit Graph

695 Commits

Author SHA1 Message Date
Linus Torvalds b4fdcb02f1 Merge branch 'for-3.2/core' of git://git.kernel.dk/linux-block
* 'for-3.2/core' of git://git.kernel.dk/linux-block: (29 commits)
  block: don't call blk_drain_queue() if elevator is not up
  blk-throttle: use queue_is_locked() instead of lockdep_is_held()
  blk-throttle: Take blkcg->lock while traversing blkcg->policy_list
  blk-throttle: Free up policy node associated with deleted rule
  block: warn if tag is greater than real_max_depth.
  block: make gendisk hold a reference to its queue
  blk-flush: move the queue kick into
  blk-flush: fix invalid BUG_ON in blk_insert_flush
  block: Remove the control of complete cpu from bio.
  block: fix a typo in the blk-cgroup.h file
  block: initialize the bounce pool if high memory may be added later
  block: fix request_queue lifetime handling by making blk_queue_cleanup() properly shutdown
  block: drop @tsk from attempt_plug_merge() and explain sync rules
  block: make get_request[_wait]() fail if queue is dead
  block: reorganize throtl_get_tg() and blk_throtl_bio()
  block: reorganize queue draining
  block: drop unnecessary blk_get/put_queue() in scsi_cmd_ioctl() and blk_get_tg()
  block: pass around REQ_* flags instead of broken down booleans during request alloc/free
  block: move blk_throtl prototypes to block/blk.h
  block: fix genhd refcounting in blkio_policy_parse_and_set()
  ...

Fix up trivial conflicts due to "mddev_t" -> "struct mddev" conversion
and making the request functions be of type "void" instead of "int" in
 - drivers/md/{faulty.c,linear.c,md.c,md.h,multipath.c,raid0.c,raid1.c,raid10.c,raid5.c}
 - drivers/staging/zram/zram_drv.c
2011-11-04 17:06:58 -07:00
Paul Gortmaker 056075c764 md: Add module.h to all files using it implicitly
A pending cleanup will mean that module.h won't be implicitly
everywhere anymore.  Make sure the modular drivers in md dir
are actually calling out for <module.h> explicitly in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:18 -04:00
Jens Axboe 5c04b426f2 Merge branch 'v3.1-rc10' into for-3.2/core
Conflicts:
	block/blk-core.c
	include/linux/blkdev.h

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-10-19 14:30:42 +02:00
Chris Dunlop 751e67ca2e md.c: trivial comment fix
Trivial comment fix

Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-19 17:15:15 +11:00
Andrei Warkentin d70ed2e4fa MD: Allow restarting an interrupted incremental recovery.
If an incremental recovery was interrupted, a subsequent
re-add will result in a full recovery, even though an
incremental should be possible (seen with raid1).

Solve this problem by not updating the superblock on the
recovering device until array is not degraded any longer.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-18 12:16:48 +11:00
NeilBrown d30519fc59 md: clear In_sync bit on devices added to an active array.
When we add a device to an active array it can be meaningful to set
the 'insync' flag.  This indicates that the device is in-sync with the
array except for locations recorded in the bitmap.
A bitmap-based recovery can then bring it completely in-sync.

Internally we move that flag to 'saved_raid_disk' but forgot to clear
In_sync like we do in add_new_disk.

So clear In_sync after moving its value to saved_raid_disk.

Reported-by: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-18 12:13:47 +11:00
NeilBrown 84fc4b56db md: rename "mdk_personality" to "md_personality"
"mdk" doesn't mean anything any more.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:58 +11:00
NeilBrown 2b8bf3451d md: remove typedefs: mdk_thread_t -> struct md_thread
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:23 +11:00
NeilBrown fd01b88c75 md: remove typedefs: mddev_t -> struct mddev
Having mddev_t and 'struct mddev_s' is ugly and not preferred

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:47:53 +11:00
NeilBrown 3cb0300200 md: removing typedefs: mdk_rdev_t -> struct md_rdev
The typedefs are just annoying. 'mdk' probably refers to 'md_k.h'
which used to be an include file that defined this thing.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:45:26 +11:00
NeilBrown 36a4e1fe0f md: remove PRINTK and dprintk debugging and use pr_debug
Being able to dynamically enable these make them much more useful.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:17 +11:00
Daniel P. Berrange 2dba6a911c md: don't delay reboot by 1 second if no MD devices exist
The md_notify_reboot() method includes a call to mdelay(1000),
to deal with "exotic SCSI devices" which are too volatile on
reboot. The delay is unconditional. Even if the machine does
not have any block devices, let alone MD devices, the kernel
shutdown sequence is slowed down.

1 second does not matter much with physical hardware, but with
certain virtualization use cases any wasted time in the bootup
& shutdown sequence counts for alot.

* drivers/md/md.c: md_notify_reboot() - only impose a delay if
  there was at least one MD device to be stopped during reboot

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-23 19:54:04 +10:00
NeilBrown 01f96c0a99 md: Avoid waking up a thread after it has been freed.
Two related problems:

1/ some error paths call "md_unregister_thread(mddev->thread)"
   without subsequently clearing ->thread.  A subsequent call
   to mddev_unlock will try to wake the thread, and crash.

2/ Most calls to md_wakeup_thread are protected against the thread
   disappeared either by:
      - holding the ->mutex
      - having an active request, so something else must be keeping
        the array active.
   However mddev_unlock calls md_wakeup_thread after dropping the
   mutex and without any certainty of an active request, so the
   ->thread could theoretically disappear.
   So we need a spinlock to provide some protections.

So change md_unregister_thread to take a pointer to the thread
pointer, and ensure that it always does the required locking, and
clears the pointer properly.

Reported-by: "Moshe Melnikov" <moshe@zadarastorage.com>
Signed-off-by: NeilBrown <neilb@suse.de>
cc: stable@kernel.org
2011-09-21 15:30:20 +10:00
Christoph Hellwig 5a7bbad27a block: remove support for bio remapping from ->make_request
There is very little benefit in allowing to let a ->make_request
instance update the bios device and sector and loop around it in
__generic_make_request when we can archive the same through calling
generic_make_request from the driver and letting the loop in
generic_make_request handle it.

Note that various drivers got the return value from ->make_request and
returned non-zero values for errors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-09-12 12:12:01 +02:00
NeilBrown 27a7b260f7 md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.
0.90 metadata uses an unsigned 32bit number to count the number of
kilobytes used from each device.
This should allow up to 4TB per device.
However we multiply this by 2 (to get sectors) before casting to a
larger type, so sizes above 2TB get truncated.

Also we allow rdev->sectors to be larger than 4TB, so it is possible
for the array to be resized larger than the metadata can handle.
So make sure rdev->sectors never exceeds 4TB when 0.90 metadata is in
used.

Also the sanity check at the end of super_90_load should include level
1 as it used ->size too. (RAID0 and Linear don't use ->size at all).

Reported-by: Pim Zandbergen <P.Zandbergen@macroscoop.nl>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:28 +10:00
NeilBrown 7da64a0abc md: fix clearing of 'blocked' flag in the presence of bad blocks.
When the 'blocked' flag on a device is cleared while there are
unacknowledged bad blocks we must fail the device.  This is needed for
backwards compatability of the interface.

The code currently uses the wrong test for "unacknowledged bad blocks
exist".  Change it to the right test.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-30 16:20:17 +10:00
Namhyung Kim a5bf4df0c8 md: use REQ_NOIDLE flag in md_super_write()
Queue idling is used for the anticipation of immediate
sequencial I/O's but md_super_write() is a kind of one-
shot operation, coupled with md_super_wait(), so the
idling in this case will be just a waste of time.

Specifying REQ_NOIDLE prevents it. Instead of adding
the flag to submit_bio() directly, use pre-defined
macro WRITE_FLUSH_FUA.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:34 +10:00
NeilBrown aeb9b21184 md: ensure changes to 'write-mostly' are reflected in metadata.
The 'write-mostly' flag can be changed through sysfs.
With 0.90 metadata, those changes are reflected in the metadata.
For 1.x metadata, they aren't.

So fix super_1_sync to record 'write-mostly' status.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:08 +10:00
NeilBrown 5ef56c8fec md: report failure if a 'set faulty' request doesn't.
Sometimes a device will refuse to be set faulty.  e.g. RAID1 will
never let the last working device become faulty.

So check if "md_error()" did manage to set the faulty flag and fail
with EBUSY if it didn't.

Resolves-Debian-Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601198
Reported-by: Mike Hommey <mh+reportbug@glandium.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:42:51 +10:00
Linus Torvalds 6140333d36 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (75 commits)
  md/raid10: handle further errors during fix_read_error better.
  md/raid10: Handle read errors during recovery better.
  md/raid10: simplify read error handling during recovery.
  md/raid10: record bad blocks due to write errors during resync/recovery.
  md/raid10:  attempt to fix read errors during resync/check
  md/raid10:  Handle write errors by updating badblock log.
  md/raid10: clear bad-block record when write succeeds.
  md/raid10: avoid writing to known bad blocks on known bad drives.
  md/raid10 record bad blocks as needed during recovery.
  md/raid10: avoid reading known bad blocks during resync/recovery.
  md/raid10 - avoid reading from known bad blocks - part 3
  md/raid10: avoid reading from known bad blocks - part 2
  md/raid10: avoid reading from known bad blocks - part 1
  md/raid10: Split handle_read_error out from raid10d.
  md/raid10: simplify/reindent some loops.
  md/raid5: Clear bad blocks on successful write.
  md/raid5.  Don't write to known bad block on doubtful devices.
  md/raid5: write errors should be recorded as bad blocks if possible.
  md/raid5: use bad-block log to improve handling of uncorrectable read errors.
  md/raid5: avoid reading from known bad blocks.
  ...
2011-07-28 05:50:27 -07:00
NeilBrown e875ecea26 md/raid10 record bad blocks as needed during recovery.
When recovering one or more devices, if all the good devices have
bad blocks we should record a bad block on the device being rebuilt.

If this fails, we need to abort the recovery.

To ensure we don't think that we aborted later than we actually did,
we need to move the check for MD_RECOVERY_INTR earlier in md_do_sync,
in particular before mddev->curr_resync is updated.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown de393cdea6 md: make it easier to wait for bad blocks to be acknowledged.
It is only safe to choose not to write to a bad block if that bad
block is safely recorded in metadata - i.e. if it has been
'acknowledged'.

If it hasn't we need to wait for the acknowledgement.

We support that using rdev->blocked wait and
md_wait_for_blocked_rdev by introducing a new device flag
'BlockedBadBlock'.

This flag is only advisory.
It is cleared whenever we acknowledge a bad block, so that a waiter
can re-check the particular bad blocks that it is interested it.

It should be set by a caller when they find they need to wait.
This (set after test) is inherently racy, but as
md_wait_for_blocked_rdev already has a timeout, losing the race will
have minimal impact.

When we clear "Blocked" was also clear "BlockedBadBlocks" incase it
was set incorrectly (see above race).

We also modify the way we manage 'Blocked' to fit better with the new
handling of 'BlockedBadBlocks' and to make it consistent between
externally managed and internally managed metadata.   This requires
that each raidXd loop checks if the metadata needs to be written and
triggers a write (md_check_recovery) if needed.  Otherwise a queued
write request might cause raidXd to wait for the metadata to write,
and only that thread can write it.

Before writing metadata, we set FaultRecorded for all devices that
are Faulty, then after writing the metadata we clear Blocked for any
device for which the Fault was certainly Recorded.

The 'faulty' device flag now appears in sysfs if the device is faulty
*or* it has unacknowledged bad blocks.  So user-space which does not
understand bad blocks can continue to function correctly.
User space which does, should not assume a device is faulty until it
sees the 'faulty' flag, and then sees the list of unacknowledged bad
blocks is empty.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown d7a9d443bc md: add 'write_error' flag to component devices.
If a device has ever seen a write error, we will want to handle
known-bad-blocks differently.
So create an appropriate state flag and export it via sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:48 +10:00
NeilBrown d2eb35acfd md/raid1: avoid reading from known bad blocks.
Now that we have a bad block list, we should not read from those
blocks.
There are several main parts to this:
  1/ read_balance needs to check for bad blocks, and return not only
     the chosen device, but also how many good blocks are available
     there.
  2/ fix_read_error needs to avoid trying to read from bad blocks.
  3/ read submission must be ready to issue multiple reads to
     different devices as different bad blocks on different devices
     could mean that a single large read cannot be served by any one
     device, but can still be served by the array.
     This requires keeping count of the number of outstanding requests
     per bio.  This count is stored in 'bi_phys_segments'
  4/ retrying a read needs to also be ready to submit a smaller read
     and queue another request for the rest.

This does not yet handle bad blocks when reading to perform resync,
recovery, or check.

'md_trim_bio' will also be used for RAID10, so put it in md.c and
export it.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown 9f2f383078 md: Disable bad blocks and v0.90 metadata.
v0.90 metadata cannot record bad blocks, so when loading metadata
for such a device, set shift to -1.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:47 +10:00
NeilBrown 2699b67223 md: load/store badblock list from v1.x metadata
Space must have been allocated when array was created.
A feature flag is set when the badblock list is non-empty, to
ensure old kernels don't load and trust the whole device.

We only update the on-disk badblocklist when it has changed.
If the badblocklist (or other metadata) is stored on a bad block, we
don't cope very well.

If metadata has no room for bad block, flag bad-blocks as disabled,
and do the same for 0.90 metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:47 +10:00
NeilBrown 16c791a5af md/bad-block-log: add sysfs interface for accessing bad-block-log.
This can show the log (providing it fits in one page) and
allows bad blocks to be 'acknowledged' meaning that they
have safely been recorded in metadata.

Clearing bad blocks is not allowed via sysfs (except for
code testing).  A bad block can only be cleared when
a write to the block succeeds.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:47 +10:00
NeilBrown 2230dfe4cc md: beginnings of bad block management.
This the first step in allowing md to track bad-blocks per-device so
that we can fail individual blocks rather than the whole device.

This patch just adds a data structure for recording bad blocks, with
routines to add, remove, search the list.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:46 +10:00
NeilBrown a519b26dbe md: remove suspicious size_of()
When calling bioset_create we pass the size of the front_pad as
   sizeof(mddev)
which looks suspicious as mddev is a pointer and so it looks like a
common mistake where
   sizeof(*mddev)
was intended.
The size is actually correct as we want to store a pointer in the
front padding of the bios created by the bioset, so make the intent
more explicit by using
   sizeof(mddev_t *)

Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 07:56:24 +10:00
Jonathan Brassow 768e587e18 MD: generate an event when array sync is complete
This patch causes MD to generate an event (for device-mapper) when the
synchronization thread is reaped.  This is expected behavior for device-mapper.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:37 +10:00
Namhyung Kim 65a06f0674 md: get rid of unnecessary casts on page_address()
page_address() returns void pointer, so the casts can be removed.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown 5389042ffa md: change managed of recovery_disabled.
If we hit a read error while recovering a mirror, we want to abort the
recovery without necessarily failing the disk - as having a disk this
a read error is better than not having an array at all.

Currently this is managed with a per-array flag "recovery_disabled"
and is only implemented for RAID1.  For RAID10 we will need finer
grained control as we might want to disable recovery for individual
devices separately.

So push more of the decision making into the personality.
'recovery_disabled' is now a 'cookie' which is copied when the
personality want to disable recovery and is changed when a device is
added to the array as this is used as a trigger to 'try recovery
again'.

This will allow RAID10 to get the control that it needs.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim a478a069b6 md: remove ro check in md_check_recovery()
Commit c89a8eee61 ("Allow faulty devices to be removed from a
readonly array.") added some work on ro array in the function,
but it couldn't be done since we didn't allow the ro array to be
handled from the beginning. Fix it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim 36fad858a7 md: introduce link/unlink_rdev() helpers
There are places where sysfs links to rdev are handled
in a same way. Add the helper functions to consolidate
them.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Kay Sievers f15146380d fs: seq_file - add event counter to simplify poll() support
Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.

All current users are switched over to use the new counter.

Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:50 -04:00
NeilBrown 4274215d24 md: avoid endless recovery loop when waiting for fail device to complete.
If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.

We should check if the device is faulty before considering it to be a
spare.  This will avoid trying to start a recovery that cannot
proceed.

This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.

Cc: stable@kernel.org
Reported-by: Jim Paradis <james.paradis@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-28 16:59:42 +10:00
Namhyung Kim 01393f3d58 md: check ->hot_remove_disk when removing disk
Check pers->hot_remove_disk instead of pers->hot_add_disk in slot_store()
during disk removal. The linear personality only has ->hot_add_disk and
no ->hot_remove_disk, so that removing disk in the array resulted to
following kernel bug:

$ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3]
$ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot
 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<          (null)>]           (null)
 PGD c9f5d067 PUD 8575a067 PMD 0
 Oops: 0010 [#1] SMP
 CPU 2
 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg

 Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO
 RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
 RSP: 0018:ffff880085757df0  EFLAGS: 00010282
 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e
 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000
 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a
 R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff
 R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000
 FS:  00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000)
 Stack:
  ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000
  ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90
  ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98
 Call Trace:
  [<ffffffff8138496a>] ? slot_store+0xaa/0x265
  [<ffffffff81384bae>] rdev_attr_store+0x89/0xa8
  [<ffffffff8115a96a>] sysfs_write_file+0x108/0x144
  [<ffffffff81106b87>] vfs_write+0xb1/0x10d
  [<ffffffff8106e6c0>] ? trace_hardirqs_on_caller+0x111/0x135
  [<ffffffff81106cac>] sys_write+0x4d/0x77
  [<ffffffff814fe702>] system_call_fastpath+0x16/0x1b
 Code:  Bad RIP value.
 RIP  [<          (null)>]           (null)
  RSP <ffff880085757df0>
 CR2: 0000000000000000
 ---[ end trace ba5fc64319a826fb ]---

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:54 +10:00
马建朋 9864c0053d md: Using poll /proc/mdstat can monitor the events of adding a spare disks
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:48 +10:00
Jonathan Brassow 076f968b37 MD: add sync_super to mddev_t struct
Add the 'sync_super' function pointer to MD array structure (struct mddev_s)

If device-mapper (dm-raid.c) is to define its own on-disk superblock and be
able to load it, there must still be a way for MD to initiate superblock
updates.  The simplest way to make this happen is to provide a pointer in
the MD array structure that can be set by device-mapper (or other module)
with a function to do this.  If the function has been set, it will be used;
otherwise, the method with be looked up via 'super_types' as usual.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow 0fd018af37 MD: move thread wakeups into resume
Move personality and sync/recovery thread starting outside md_run.

Moving the wakeup's of the personality and sync/recovery threads out of
md_run and into do_md_run and mddev_resume solves two issues:
1) It allows bitmap_load to be called before the sync_thread is run and
2) when MD personalities are used by device-mapper (dm-raid.c), the start-up
of the array is better alligned with device-mapper primatives
(CTR/resume/suspend/DTR).  I/O - in this case, recovery operations - should
not happen until after a resume has taken place.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow ac42450c7c MD: possible typo
Make message a bit clearer by s/blocks/k/

I chose 'k' vs 'kiB' or 'kB' because it is what is used earlier in the
message.  'k' may be a bit ambigous, but I think it's better than "blocks"
which normally means 512, but means 1024 in MD.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow 68866e425b MD: no sync IO while suspended
Disallow resync I/O while the RAID array is suspended.

Recovery, resync, and metadata I/O should not be allowed while a device is
suspended.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:10:08 +10:00
Jonathan Brassow 629acb6aba MD: no integrity register if no gendisk
Don't attempt md_integrity_register if there is no gendisk struct available.

When MD arrays are built via device-mapper, the gendisk structure is not
available via mddev.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:10:08 +10:00
NeilBrown b098636cf0 md: allow resync_start to be set while an array is active.
The sysfs attribute 'resync_start' (known internally as recovery_cp),
records where a resync is up to.  A value of 0 means the array is
not known to be in-sync at all.  A value of MaxSector means the array
is believed to be fully in-sync.

When the size of member devices of an array (RAID1,RAID4/5/6) is
increased, the array can be increased to match.  This process sets
resync_start to the old end-of-device offset so that the new part of
the array gets resynced.

However with RAID1 (and RAID6) a resync is not technically necessary
and may be undesirable.  So it would be good if the implied resync
after the array is resized could be avoided.

So: change 'resync_start' so the value can be changed while the array
is active, and as a precaution only allow it to be changed while
resync/recovery is 'frozen'.  Changing it once resync has started is
not going to be useful anyway.

This allows the array to be resized without a resync by:
  write 'frozen' to 'sync_action'
  write new size to 'component_size' (this will set resync_start)
  write 'none' to 'resync_start'
  write 'idle' to 'sync_action'.

Also slightly improve some tests on recovery_cp when resizing
raid1/raid5.  Now that an arbitrary value could be set we should be
more careful in our tests.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 15:52:21 +10:00
NeilBrown bedd86b777 md: reject a re-add request that cannot be honoured.
The 'add_new_disk' ioctl can be used to add a device either as a
spare, or as an active disk that just needs to be resynced based on
write-intent-bitmap information (re-add)

Currently if a re-add is requested but fails we add as a spare
instead.  This makes it impossible for user-space to check for
failure.

So change to require that a re-add attempt will either succeed or
completely fail.  User-space can then decide what to do next.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:26:20 +10:00
NeilBrown b0140891a8 md: Fix race when creating a new md device.
There is a race when creating an md device by opening /dev/mdXX.

If two processes do this at much the same time they will follow the
call path
  __blkdev_get -> get_gendisk -> kobj_lookup

The first will call
  -> md_probe -> md_alloc -> add_disk -> blk_register_region

and the race happens when the second gets to kobj_lookup after
add_disk has called blk_register_region but before it returns to
md_alloc.

In the case the second will not call md_probe (as the probe is already
done) but will get a handle on the gendisk, return to __blkdev_get
which will then call md_open (via the ->open) pointer.

As mddev->gendisk hasn't been set yet, md_open will think something is
wrong an return with ERESTARTSYS.

This can loop endlessly while the first thread makes no progress
through add_disk.  Nothing is blocking it, but due to scheduler
behaviour it doesn't get a turn.
So this is essentially a live-lock.

We fix this by simply moving the assignment to mddev->gendisk before
the call the add_disk() so md_open doesn't get confused.
Also move blk_queue_flush earlier because add_disk should be as late
as possible.

To make sure that md_open doesn't complete until md_alloc has done all
that is needed, we take mddev->open_mutex during the last part of
md_alloc.  md_open will wait for this.

This can cause a lock-up on boot so Cc:ing for stable.
For 2.6.36 and earlier a different patch will be needed as the
'blk_queue_flush' call isn't there.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Tested-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Cc: stable@kernel.org
2011-05-11 14:26:17 +10:00
Krzysztof Wojcik fee68723cf md: Cleanup after raid45->raid0 takeover
Problem:
After raid4->raid0 takeover operation, another takeover operation
(e.g raid0->raid10) results "kernel oops".
Root cause:
Variables 'degraded' in mddev structure is not cleared
on raid45->raid0 takeover.

This patch reset this variable.

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20 15:39:53 +10:00
NeilBrown 97658cdd3a md: provide generic support for handling unplug callbacks.
When an md device adds a request to a queue, it can call
mddev_check_plugged.
If this succeeds then we know that the md thread will be woken up
shortly, and ->plug_cnt will be non-zero until then, so some
processing can be delayed.

If it fails, then no unplug callback is expected and the make_request
function needs to do whatever is required to make the request happen.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:42 +10:00
NeilBrown 482c083492 md - remove old plugging code.
md has some plugging infrastructure for RAID5 to use because the
normal plugging infrastructure required a 'request_queue', and when
called from dm, RAID5 doesn't have one of those available.

This relied on the ->unplug_fn callback which doesn't exist any more.

So remove all of that code, both in md and raid5.  Subsequent patches
with restore the plugging functionality.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:42 +10:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Martin K. Petersen 89078d572e md: Fix integrity registration error when no devices are capable
We incorrectly returned -EINVAL when none of the devices in the array
had an integrity profile.  This in turn prevented mdadm from starting
the metadevice.  Fix this so we only return errors on mismatched
profiles and memory allocation failures.

Reported-by: Giacomo Catenazzi <cate@cateee.net>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-28 17:53:29 -07:00
Linus Torvalds 6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Martin K. Petersen a91a2785b2 block: Require subsystems to explicitly allocate bio_set integrity mempool
MD and DM create a new bio_set for every metadevice. Each bio_set has an
integrity mempool attached regardless of whether the metadevice is
capable of passing integrity metadata. This is a waste of memory.

Instead we defer the allocation decision to MD and DM since we know at
metadevice creation time whether integrity passthrough is needed or not.

Automatic integrity mempool allocation can then be removed from
bioset_create() and we make an explicit integrity allocation for the
fs_bio_set.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Acked-by: Mike Snitzer <snizer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-17 11:11:05 +01:00
Linus Torvalds bd2895eead Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix build failure introduced by s/freezeable/freezable/
  workqueue: add system_freezeable_wq
  rds/ib: use system_wq instead of rds_ib_fmr_wq
  net/9p: replace p9_poll_task with a work
  net/9p: use system_wq instead of p9_mux_wq
  xfs: convert to alloc_workqueue()
  reiserfs: make commit_wq use the default concurrency level
  ocfs2: use system_wq instead of ocfs2_quota_wq
  ext4: convert to alloc_workqueue()
  scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
  scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
  misc/iwmc3200top: use system_wq instead of dedicated workqueues
  i2o: use alloc_workqueue() instead of create_workqueue()
  acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
  fs/aio: aio_wq isn't used in memory reclaim path
  input/tps6507x-ts: use system_wq instead of dedicated workqueue
  cpufreq: use system_wq instead of dedicated workqueues
  wireless/ipw2x00: use system_wq instead of dedicated workqueues
  arm/omap: use system_wq in mailbox
  workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
2011-03-16 08:20:19 -07:00
Jens Axboe 4c63f5646e Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/core
Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:58:35 +01:00
Jens Axboe 721a9602e6 block: kill off REQ_UNPLUG
With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:27 +01:00
Jens Axboe 7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00
NeilBrown f0b4f7e2f2 md: Fix - again - partition detection when array becomes active
Revert
    b821eaa572
and
    f3b99be19d

When I wrote the first of these I had a wrong idea about the
lifetime of 'struct block_device'.  It can disappear at any time that
the block device is not open if it falls out of the inode cache.

So relying on the 'size' recorded with it to detect when the
device size has changed and so we need to revalidate, is wrong.

Rather, we really do need the 'changed' attribute stored directly in
the mddev and set/tested as appropriate.

Without this patch, a sequence of:
   mknod / open / close / unlink

(which can cause a block_device to be created and then destroyed)
will result in a rescan of the partition table and consequence removal
and addition of partitions.
Several of these in a row can get udev racing to create and unlink and
other code can get confused.

With the patch, the rescan is only performed when needed and so there
are no races.

This is suitable for any stable kernel from 2.6.35.

Reported-by: "Wojcik, Krzysztof" <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2011-02-24 17:26:41 +11:00
Tejun Heo 43d133c18b Merge branch 'master' into for-2.6.39 2011-02-21 09:43:56 +01:00
NeilBrown 8f5f02c460 md: correctly handle probe of an 'mdp' device.
'mdp' devices are md devices with preallocated device numbers
for partitions. As such it is possible to mknod and open a partition
before opening the whole device.

this causes  md_probe() to be called with a device number of a
partition, which in-turn calls mddev_find with such a number.

However mddev_find expects the number of a 'whole device' and
does the wrong thing with partition numbers.

So add code to mddev_find to remove the 'partition' part of
a device number and just work with the 'whole device'.

This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=28652

Reported-by: hkmaly@bigfoot.com
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: <stable@kernel.org>
2011-02-16 13:58:51 +11:00
NeilBrown cbe6ef1d26 md: don't set_capacity before array is active.
If the desired size of an array is set (via sysfs) before the array is
active (which is the normal sequence), we currrently call set_capacity
immediately.
This means that a subsequent 'open' (as can be caused by some
udev-triggers program) will notice the new size and try to probe for
partitions.  However as the array isn't quite ready yet the read will
fail.  Then when the array is read, as the size doesn't change again
we don't try to re-probe.

So when setting array size via sysfs, only call set_capacity if the
array is already active.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-16 13:58:38 +11:00
Chris Mason e91ece5590 md_make_request: don't touch the bio after calling make_request
md_make_request was calling bio_sectors() for part_stat_add
after it was calling the make_request function.  This is
bad because the make_request function can free the bio and
because the bi_size field can change around.

The fix here was suggested by Jens Axboe.  It saves the
sector count before the make_request call.  I hit this
with CONFIG_DEBUG_PAGEALLOC turned on while trying to break
his pretty fusionio card.

Cc: <stable@kernel.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-08 09:53:28 +11:00
NeilBrown c6751b2bde md: Don't allow slot_store while resync/recovery is happening.
Activating a spare in an array while resync/recovery is already
happening can lead the that spare being marked in-sync when it isn't
really.
So don't allow the 'slot' to be set (this activating the device)
while resync/recovery is happening.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-02 11:57:13 +11:00
NeilBrown 7281f8129c md: don't clear curr_resync_completed at end of resync.
There is no need to set this to zero at this point.  It will be
set to zero by remove_and_add_spares or at the start of
md_do_sync at the latest.
And setting it to zero before MD_RECOVERY_RUNNING is cleared can
make a 'zero' appear briefly in the 'sync_completed' sysfs attribute
just as resync is finishing.

So simply remove this setting to zero.


Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 14:30:27 +11:00
NeilBrown a8c42c7f47 md: Don't use remove_and_add_spares to remove failed devices from a read-only array
remove_and_add_spares is called in two places where the needs really
are very different.
remove_and_add_spares should not be called on an array which is about
to be reshaped as some extra devices might have been manually added
and that would remove them.  However if the array is 'read-auto',
that will currently happen, which is bad.

So in the 'ro != 0' case don't call remove_and_add_spares but simply
remove the failed devices as the comment suggests is needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 13:47:13 +11:00
NeilBrown f21e9ff7f7 md: Remove the AllReserved flag for component devices.
This flag is not needed and is used badly.

Devices that are included in a native-metadata array are reserved
exclusively for that array - and currently have AllReserved set.
They all are bd_claimed for the rdev and so cannot be shared.

Devices that are included in external-metadata arrays can be shared
among multiple arrays - providing there is no overlap.
These are bd_claimed for md in general - not for a particular rdev.

When changing the amount of a device that is used in an array we need
to check for overlap.  This currently includes a check on AllReserved
So even without overlap, sharing with an AllReserved device is not
allowed.
However the bd_claim usage already precludes sharing with these
devices, so the test on AllReserved is not needed.  And in fact it is
wrong.

As this is the only use of AllReserved, simply remove all usage and
definition of AllReserved.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 12:10:09 +11:00
NeilBrown de171cb9a5 md: revert change to raid_disks on failure.
If we try to update_raid_disks and it fails, we should put
'delta_disks' back to zero.  This is important because some code,
such as slot_store, assumes that delta_disks has been validated.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 11:57:42 +11:00
Tejun Heo ada609ee2a workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
WQ_RESCUER is now an internal flag and should only be used in the
workqueue implementation proper.  Use WQ_MEM_RECLAIM instead.

This doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
2011-01-25 14:35:54 +01:00
Tejun Heo 49731baa41 block: restore multiple bd_link_disk_holder() support
Commit e09b457b (block: simplify holder symlink handling) incorrectly
assumed that there is only one link at maximum.  dm may use multiple
links and expects block layer to track reference count for each link,
which is different from and unrelated to the exclusive device holder
identified by @holder when the device is opened.

Remove the single holder assumption and automatic removal of the link
and revive the per-link reference count tracking.  The code
essentially behaves the same as before commit e09b457b sans the
unnecessary kobject reference count dancing.

While at it, note that this facility should not be used by anyone else
than the current ones.  Sysfs symlinks shouldn't be abused like this
and the whole thing doesn't belong in the block layer at all.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Milan Broz <mbroz@redhat.com>
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-14 18:44:22 +01:00
Linus Torvalds 509e4aef44 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: Fix removal of extra drives when converting RAID6 to RAID5
  md: range check slot number when manually adding a spare.
  md/raid5: handle manually-added spares in start_reshape.
  md: fix sync_completed reporting for very large drives (>2TB)
  md: allow suspend_lo and suspend_hi to decrease as well as increase.
  md: Don't let implementation detail of curr_resync leak out through sysfs.
  md: separate meta and data devs
  md-new-param-to_sync_page_io
  md-new-param-to-calc_dev_sboffset
  md: Be more careful about clearing flags bit in ->recovery
  md: md_stop_writes requires mddev_lock.
  md/raid5: use sysfs_notify_dirent_safe to avoid NULL pointer
  md: Ensure no IO request to get md device before it is properly initialised.
  md: Fix single printks with multiple KERN_<level>s
  md: fix regression resulting in delays in clearing bits in a bitmap
  md: fix regression with re-adding devices to arrays with no metadata
2011-01-13 17:30:20 -08:00
NeilBrown bf2cb0dab8 md: Fix removal of extra drives when converting RAID6 to RAID5
When a RAID6 is converted to a RAID5, the extra drive should
be discarded.  However it isn't due to a typo in a comparison.

This bug was introduced in commit e93f68a1fc in 2.6.35-rc4
and is suitable for any -stable since than.

As the extra drive is not removed, the 'degraded' counter is wrong and
so the RAID5 will not respond correctly to a subsequent failure.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown ba1b41b6b4 md: range check slot number when manually adding a spare.
When adding a spare to an active array, we should check the slot
number, but allow it to be larger than raid_disks if a reshape
is being prepared.

Apply the same test when adding a device to an
array-under-construction.  It already had most of the test in place,
but not quite all.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Rémi Rérolle 13ae864bc8 md: fix sync_completed reporting for very large drives (>2TB)
The values exported in the sync_completed file are unsigned long, which
overflows with very large drives, resulting in wrong values reported.

Since sync_completed uses sectors as unit, we'll start getting wrong
values with components larger than 2TB.

This patch simply replaces the use of unsigned long by unsigned long long.

Signed-off-by: Rémi Rérolle <rrerolle@lacie.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown 23ddff3792 md: allow suspend_lo and suspend_hi to decrease as well as increase.
The sysfs attributes 'suspend_lo' and 'suspend_hi' describe a region
to which read/writes are suspended so that the under lying data can be
manipulated without user-space noticing.
Currently the window they describe can only move forwards along the
device.  However this is an unnecessary restriction which will cause
problems with planned developments.
So relax this restriction and allow these endpoints to move
arbitrarily.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown 75d3da43cb md: Don't let implementation detail of curr_resync leak out through sysfs.
mddev->curr_resync has artificial values of '1' and '2' which are used
by the code which ensures only one resync is happening at a time on
any given device.

These values are internal and should never be exposed to user-space
(except when translated appropriately as in the 'pending' status in
/proc/mdstat).

Unfortunately they are as ->curr_resync is assigned to
->curr_resync_completed and that value is directly visible through
sysfs.

So change the assignments to ->curr_resync_completed to get the same
valued from elsewhere in a form that doesn't have the magic '1' or '2'
values.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow a6ff7e089c md: separate meta and data devs
Allow the metadata to be on a separate device from the
data.

This doesn't mean the data and metadata will by on separate
physical devices - it simply gives device-mapper and userspace
tools more flexibility.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow ccebd4c415 md-new-param-to_sync_page_io
Add new parameter to 'sync_page_io'.

The new parameter allows us to distinguish between metadata and data
operations.  This becomes important later when we add the ability to
use separate devices for data and metadata.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
Jonathan Brassow 57b2caa394 md-new-param-to-calc_dev_sboffset
When we allow for separate devices for data and metadata
in a later patch, we will need to be able to calculate
the superblock offset based on more than the bdev.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown 7ebc0be7ff md: Be more careful about clearing flags bit in ->recovery
Setting ->recovery to 0 is generally not a good idea as it could clear
bits that shouldn't be cleared.  In particular, MD_RECOVERY_FROZEN
should only be cleared on explicit request from user-space.

So when we need to clear things, just clear the bits that need
clearing.

As there are a few different places which reap a resync process - and
some do an incomplte job - factor out the code for doing the from
md_check_recovery and call that function instead of open coding part
of it.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown defad61a5b md: md_stop_writes requires mddev_lock.
As md_stop_writes manipulates the sync_thread and calls md_update_sb,
it need to be called with mddev_lock held.

In all internal cases it is, but the symbol is exported for dm-raid to
call and in that case the lock won't be help.
Do make an exported version which takes the lock, and an internal
version which does not.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:33 +11:00
NeilBrown 0ca69886a8 md: Ensure no IO request to get md device before it is properly initialised.
When an md device is in the process of coming on line it is possible
for an IO request (typically a partition table probe) to get through
before the array is fully initialised, which can cause unexpected
behaviour (e.g. a crash).

So explicitly record when the array is ready for IO and don't allow IO
through until then.

There is no possibility for a similar problem when the array is going
off-line as there must only be one 'open' at that time, and it is busy
off-lining the array and so cannot send IO requests.  So no memory
barrier is needed in md_stop()

This has been a bug since commit 409c57f380 in 2.6.30 which
introduced md_make_request.  Before then, each personality would
register its own make_request_fn when it was ready.
This is suitable for any stable kernel from 2.6.30.y onwards.

Cc: <stable@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by:  "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
2011-01-14 09:14:33 +11:00
NeilBrown 6c98791014 md: fix regression resulting in delays in clearing bits in a bitmap
commit 589a594be1 (2.6.37-rc4) fixed a problem were md_thread would
sometimes call the ->run function at a bad time.

If an error is detected during array start up after the md_thread has
been started, the md_thread is killed.  This resulted in the ->run
function being called once.  However the array may not be in a state
that it is safe to call ->run.

However the fix imposed meant that  ->run was not called on a timeout.
This means that when an array goes idle, bitmap bits do not get
cleared promptly.  While the array is busy the bits will still be
cleared when appropriate so this is not very serious.  There is no
risk to data.

Change the test so that we only avoid calling ->run when the thread
is being stopped.  This more explicitly addresses the problem situation.

This is suitable for 2.6.37-stable and any -stable kernel to which
589a594be1 was applied.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:13:53 +11:00
Linus Torvalds 275220f0fc Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  block: ensure that completion error gets properly traced
  blktrace: add missing probe argument to block_bio_complete
  block cfq: don't use atomic_t for cfq_group
  block cfq: don't use atomic_t for cfq_queue
  block: trace event block fix unassigned field
  block: add internal hd part table references
  block: fix accounting bug on cross partition merges
  kref: add kref_test_and_get
  bio-integrity: mark kintegrityd_wq highpri and CPU intensive
  block: make kblockd_workqueue smarter
  Revert "sd: implement sd_check_events()"
  block: Clean up exit_io_context() source code.
  Fix compile warnings due to missing removal of a 'ret' variable
  fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
  block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
  cfq-iosched: don't check cfqg in choose_service_tree()
  fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
  cdrom: export cdrom_check_events()
  sd: implement sd_check_events()
  sr: implement sr_check_events()
  ...
2011-01-13 10:45:01 -08:00
NeilBrown bf572541ab md: fix regression with re-adding devices to arrays with no metadata
Commit 1a855a0606 (2.6.37-rc4) fixed a problem where devices were
re-added when they shouldn't be but caused a regression in a less
common case that means sometimes devices cannot be re-added when they
should be.

In particular, when re-adding a device to an array without metadata
we should always access the device, but after the above commit we
didn't.

This patch sets the In_sync flag in that case so that the re-add
succeeds.

This patch is suitable for any -stable kernel to which 1a855a0606 was
applied.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-12 09:03:35 +11:00
Linus Torvalds 7f8635cc9e Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cciss: fix cciss_revalidate panic
  block: max hardware sectors limit wrapper
  block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead
  blk-throttle: Correct the placement of smp_rmb()
  blk-throttle: Trim/adjust slice_end once a bio has been dispatched
  block: check for proper length of iov entries earlier in blk_rq_map_user_iov()
  drbd: fix for spin_lock_irqsave in endio callback
  drbd: don't recvmsg with zero length
2010-12-20 09:19:46 -08:00
Martin K. Petersen e692cb668f block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead
When stacking devices, a request_queue is not always available. This
forced us to have a no_cluster flag in the queue_limits that could be
used as a carrier until the request_queue had been set up for a
metadevice.

There were several problems with that approach. First of all it was up
to the stacking device to remember to set queue flag after stacking had
completed. Also, the queue flag and the queue limits had to be kept in
sync at all times. We got that wrong, which could lead to us issuing
commands that went beyond the max scatterlist limit set by the driver.

The proper fix is to avoid having two flags for tracking the same thing.
We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the
block layer merging functions. The queue_limit 'no_cluster' is turned
into 'cluster' to avoid double negatives and to ease stacking.
Clustering defaults to being enabled as before. The queue flag logic is
removed from the stacking function, and explicitly setting the cluster
flag is no longer necessary in DM and MD.

Reported-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-17 08:35:53 +01:00
NeilBrown 589a594be1 md: protect against NULL reference when waiting to start a raid10.
When we fail to start a raid10 for some reason, we call
md_unregister_thread to kill the thread that was created.

Unfortunately md_thread() will then make one call into the handler
(raid10d) even though md_wakeup_thread has not been called.  This is
not safe and as md_unregister_thread is called after mddev->private
has been set to NULL, it will definitely cause a NULL dereference.

So fix this at both ends:
 - md_thread should only call the handler if THREAD_WAKEUP has been
   set.
 - raid10 should call md_unregister_thread before setting things
   to NULL just like all the other raid modules do.

This is applicable to 2.6.35 and later.

Cc: stable@kernel.org
Reported-by: "Citizen" <citizen_lee@thecus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 17:02:14 +11:00
NeilBrown 1a855a0606 md: fix bug with re-adding of partially recovered device.
With v0.90 metadata, a hot-spare does not become a full member of the
array until recovery is complete.  So if we re-add such a device to
the array, we know that all of it is as up-to-date as the event count
would suggest, and so it a bitmap-based recovery is possible.

However with v1.x metadata, the hot-spare immediately becomes a full
member of the array, but it record how much of the device has been
recovered.  If the array is stopped and re-assembled recovery starts
from this point.

When such a device is hot-added to an array we currently lose the 'how
much is recovered' information and incorrectly included it as a full
in-sync member (after bitmap-based fixup).
This is wrong and unsafe and could corrupt data.

So be more careful about setting saved_raid_disk - which is what
guides the re-adding of devices back into an array.
The new code matches the code in slot_store which does a similar
thing, which is encouraging.

This is suitable for any -stable kernel.

Reported-by: "Dailey, Nate" <Nate.Dailey@stratus.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:36:28 +11:00
NeilBrown a035fc3e25 md: fix possible deadlock in handling flush requests.
As recorded in
    https://bugzilla.kernel.org/show_bug.cgi?id=24012

it is possible for a flush request through md to hang.  This is due to
an interaction between the recursion avoidance in
generic_make_request, the insistence in md of only having one flush
active at a time, and the possibility of dm (or md) submitting two
flush requests to a device from the one generic_make_request.

If a generic_make_request call into dm causes two flush requests to be
queued (as happens if the dm table has two targets - they get one
each), these two will be queued inside generic_make_request.

Assume they are for the same md device.
The first is processed and causes 1 or more flush requests to be sent
to lower devices.  These get queued within generic_make_request too.
Then the second flush to the md device gets handled and it blocks
waiting for the first flush to complete.  But it won't complete until
the two lower-device requests complete, and they haven't even been
submitted yet as they are on the generic_make_request queue.

The deadlock can be broken by using a separate thread to submit the
requests to lower devices.  md has such a thread readily available:
md_wq.

So use it to submit these requests.

Reported-by: Giacomo Catenazzi <cate@cateee.net>
Tested-by: Giacomo Catenazzi <cate@cateee.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:17:51 +11:00
NeilBrown a7a07e6965 md: move code in to submit_flushes.
submit_flushes is called from exactly one place.
Move the code that is before and after that call into
submit_flushes.

This has not functional change, but will make the next patch
smaller and easier to follow.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:04:25 +11:00
NeilBrown 2b74e12e56 md: remove handling of flush_pending in md_submit_flush_data
None of the functions called between setting flush_pending to 1, and
atomic_dec_and_test can change flush_pending, or will anything
running in any other thread (as ->flush_bio is not NULL).  So the
atomic_dec_and_test will always succeed.
So remove the atomic_sec and the atomic_dec_and_test.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 15:59:01 +11:00
Jens Axboe f30195c502 Merge branch 'cleanup-bd_claim' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into for-2.6.38/core 2010-11-27 19:49:18 +01:00
Darrick J. Wong be20e6c67b md: Call blk_queue_flush() to establish flush/fua support
Before 2.6.37, the md layer had a mechanism for catching I/Os with the
barrier flag set, and translating the barrier into barriers for all
the underlying devices.  With 2.6.37, I/O barriers have become plain
old flushes, and the md code was updated to reflect this.  However,
one piece was left out -- the md layer does not tell the block layer
that it supports flushes or FUA access at all, which results in md
silently dropping flush requests.

Since the support already seems there, just add this one piece of
bookkeeping.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:40:33 +11:00
Justin Maggard c26a44ed1e md: fix return value of rdev_size_change()
When trying to grow an array by enlarging component devices,
rdev_size_store() expects the return value of rdev_size_change() to be
in sectors, but the actual value is returned in KBs.

This functionality was broken by commit
     dd8ac336c1
so this patch is suitable for any kernel since 2.6.30.

Cc: stable@kernel.org
Signed-off-by: Justin Maggard <jmaggard10@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:36:17 +11:00
Tejun Heo d4d7762995 block: clean up blkdev_get() wrappers and their users
After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().

blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.

All users are converted.  Most conversions are mechanical and don't
introduce any behavior difference.  There are several exceptions.

* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
  reason to OR it explicitly on blkdev_put().

* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
  sb->s_mode.

* With the above changes, sb->s_mode now always should contain
  FMODE_EXCL.  WARN_ON_ONCE() added to kill_block_super() to detect
  errors.

The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:18 +01:00
Tejun Heo e525fd89d3 block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
Tejun Heo e09b457bdb block: simplify holder symlink handling
Code to manage symlinks in /sys/block/*/{holders|slaves} are overly
complex with multiple holder considerations, redundant extra
references to all involved kobjects, unused generic kobject holder
support and unnecessary mixup with bd_claim/release functionalities.

Strip it down to what's necessary (single gendisk holder) and make it
use a separate interface.  This is a step for cleaning up
bd_claim/release.  This patch makes dm-table slightly more complex but
it will be simplified again with further changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
2010-11-13 11:55:17 +01:00
Mike Snitzer 77304d2aba block: read i_size with i_size_read()
Convert direct reads of an inode's i_size to using i_size_read().

i_size_{read,write} use a seqcount to protect reads from accessing
incomple writes.  Concurrent i_size_write()s require mutual exclussion
to protect the seqcount that is used by i_size_{read,write}.  But
i_size_read() callers do not need to use additional locking.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10 14:40:53 +01:00
NeilBrown a167f66324 md: use separate bio pool for each md device.
bio_clone and bio_alloc allocate from a common bio pool.
If an md device is stacked with other devices that use this pool, or under
something like swap which uses the pool, then the multiple calls on
the pool can cause deadlocks.

So allocate a local bio pool for each md array and use that rather
than the common pool.

This pool is used both for regular IO and metadata updates.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:15 +11:00
NeilBrown 2b193363ef md: change type of first arg to sync_page_io.
Currently sync_page_io takes a 'bdev'.
Every caller passes 'rdev->bdev'.
We will soon want another field out of the rdev in sync_page_io,
So just pass the rdev instead of the bdev out of it.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:11 +11:00
Tejun Heo e804ac780e md: fix and update workqueue usage
Workqueue usage in md has two problems.

* Flush can be used during or depended upon by memory reclaim, but md
  uses the system workqueue for flush_work which may lead to deadlock.

* md depends on flush_scheduled_work() to achieve exclusion against
  completion of removal of previous instances.  flush_scheduled_work()
  may incur unexpected amount of delay and is scheduled to be removed.

This patch adds two workqueues to md - md_wq and md_misc_wq.  The
former is guaranteed to make forward progress under memory pressure
and serves flush_work.  The latter serves as the flush domain for
other works.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:32:29 +11:00
NeilBrown 4b532c9b8c md: remove md_mutex locking.
lock_kernel calls were recently pushed down into open/release
functions.
md doesn't need that protection.
Then the BKL calls were change to md_mutex.  We don't need those
either.
So remove it all.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:30:21 +11:00
NeilBrown d97a41dc9c md: Fix regression with raid1 arrays without persistent metadata.
A RAID1 which has no persistent metadata, whether internal or
external, will hang on the first write.
This is caused by commit  070dc6dd71
In that case, MD_CHANGE_PENDING never gets cleared.

So during md_update_sb, is neither persistent or external,
clear MD_CHANGE_PENDING.

This is suitable for 2.6.36-stable.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-10-28 17:30:20 +11:00
Linus Torvalds a2887097f2 Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...
2010-10-22 17:07:18 -07:00
Linus Torvalds c37927d435 Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  block: autoconvert trivial BKL users to private mutex
  drivers: autoconvert trivial BKL users to private mutex
  ipmi: autoconvert trivial BKL users to private mutex
  mac: autoconvert trivial BKL users to private mutex
  mtd: autoconvert trivial BKL users to private mutex
  scsi: autoconvert trivial BKL users to private mutex

Fix up trivial conflicts (due to addition of private mutex right next to
deletion of a version string) in drivers/char/pcmcia/cm40[04]0_cs.c
2010-10-22 10:49:54 -07:00
Jens Axboe fa251f8990 Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
	block/blk-core.c
	drivers/block/loop.c
	mm/swapfile.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19 09:13:04 +02:00
Arnd Bergmann 2a48fc0ab2 block: autoconvert trivial BKL users to private mutex
The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.

This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-10-05 15:01:10 +02:00
NeilBrown ddcf3522cf md: fix v1.x metadata update when a disk is missing.
If an array with 1.x metadata is assembled with the last disk missing,
md doesn't properly record the fact that the disk was missing.

This is unlikely to cause a real problem as the event count will be
different to the count on the missing disk so it won't be included in
the array.  However it could still cause confusion.

So make sure we clear all the relevant slots, not just the early ones.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17 13:53:28 +10:00
NeilBrown 126925c090 md: call md_update_sb even for 'external' metadata arrays.
Now that we depend on md_update_sb to clear variable bits in
mddev->flags (rather than trying not to set them) it is important to
always call md_update_sb when appropriate.

md_check_recovery has this job but explicitly avoids it for ->external
metadata arrays.  This is not longer appropraite, or needed.

However we do want to avoid taking the mddev lock if only
MD_CHANGE_PENDING is set as that is not cleared by md_update_sb for
external-metadata arrays.

Reported-by:  "Kwolek, Adam" <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17 13:53:13 +10:00
Tejun Heo e9c7469bb4 md: implment REQ_FLUSH/FUA support
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER.  In the core part (md.c), the following
changes are notable.

* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
  processing of other requests and thus there is no reason to mark the
  queue congested while FLUSH/FUA is in progress.

* REQ_FLUSH/FUA failures are final and its users don't need retry
  logic.  Retry logic is removed.

* Preflush needs to be issued to all member devices but FUA writes can
  be handled the same way as other writes - their processing can be
  deferred to request_queue of member devices.  md_barrier_request()
  is renamed to md_flush_request() and simplified accordingly.

For linear, raid0 and multipath, the core changes are enough.  raid1,
5 and 10 need the following conversions.

* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
  request_queues of member devices.  Barrier related logic removed.

* raid5: Queue draining logic dropped.  FUA bit is propagated through
  biodrain and stripe resconstruction such that all the updated parts
  of the stripe are written out with FUA writes if any of the dirtying
  writes was FUA.  preread_active_stripes handling in make_request()
  is updated as suggested by Neil Brown.

* raid10: FUA bit needs to be propagated to write clones.

linear, raid0, 1, 5 and 10 tested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
NeilBrown 070dc6dd71 md: resolve confusion of MD_CHANGE_CLEAN
MD_CHANGE_CLEAN is used for two different purposes and this leads to
confusion.
One of the purposes is largely mirrored by MD_CHANGE_PENDING which is
not used for anything else, so have MD_CHANGE_PENDING take over that
purpose fully.

The two purposes are:
 1/ tell md_update_sb that an update is needed and that it is just a
   clean/dirty transition.
 2/ tell user-space that an transition from clean to dirty is pending
    (something wants to write), and tell te kernel (by clearin the
    flag) that the transition is OK.

The first purpose remains wit MD_CHANGE_CLEAN, the second is moved
fully to MD_CHANGE_PENDING.

This means that various places which conditionally set or cleared
MD_CHANGE_CLEAN no longer need to be conditional.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:21 +10:00
Dan Williams bd52b74626 md: don't clear MD_CHANGE_CLEAN in md_update_sb() for external arrays
If this bit is cleared in md_update_sb() the kernel will allow writes to the
array if userspace triggers md_allow_write(), e.g. through stripe_cache_size,
when mdmon is not active.  When mdmon is active the array transitions to
active-idle bypassing write-pending, setting up a race for mdmon to set the
array clean before a write arrives.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:20 +10:00
NeilBrown 3a3a5ddb7a Update recovery_offset even when external metadata is used.
The update of ->recovery_offset in sync_sbs is appropriate even then external
metadata is in use.  However sync_sbs is only called when native
metadata is used.

So move that update in to the top of md_update_sb (which is the only
caller of sync_sbs) before the test on ->external.

This moves the update out of ->write_lock protection, but those fields
only need ->reconfig_mutex protection which they still have.

Also move the test on ->persistent up to where ->external is set as
for metadata update purposes they are the same.

Clear MD_CHANGE_DEVS and MD_CHANGE_CLEAN as they can only be confusing
if ->external is set or ->persistent isn't.

Finally move the update of ->utime down as it is only relevent (like
the ->events update) for native metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: "Kwolek, Adam" <adam.kwolek@intel.com>
2010-08-18 11:39:38 +10:00
Linus Torvalds 3d30701b58 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (24 commits)
  md: clean up do_md_stop
  md: fix another deadlock with removing sysfs attributes.
  md: move revalidate_disk() back outside open_mutex
  md/raid10: fix deadlock with unaligned read during resync
  md/bitmap:  separate out loading a bitmap from initialising the structures.
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
  md/bitmap: optimise scanning of empty bitmaps.
  md/bitmap: clean up plugging calls.
  md/bitmap: reduce dependence on sysfs.
  md/bitmap: white space clean up and similar.
  md/raid5: export raid5 unplugging interface.
  md/plug: optionally use plugger to unplug an array during resync/recovery.
  md/raid5: add simple plugging infrastructure.
  md/raid5: export is_congested test
  raid5: Don't set read-ahead when there is no queue
  md: add support for raising dm events.
  md: export various start/stop interfaces
  md: split out md_rdev_init
  md: be more careful setting MD_CHANGE_CLEAN
  md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
  ...
2010-08-10 15:38:19 -07:00
NeilBrown 6e17b02764 md: clean up do_md_stop
There is only one error exit from do_md_stop, so make that more
explicit and discard the 'err' variable.
Also drop the 'revalidate' variable by moving the unlock calls around.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:22:45 +10:00
NeilBrown bb4f1e9d0e md: fix another deadlock with removing sysfs attributes.
Move the deletion of sysfs attributes from reconfig_mutex to
open_mutex didn't really help as a process can try to take
open_mutex while holding reconfig_mutex, so the same deadlock can
happen, just requiring one more process to be involved in the chain.

I looks like I cannot easily use locking to wait for the sysfs
deletion to complete, so don't.

The only things that we cannot do while the deletions are still
pending is other things which can change the sysfs namespace: run,
takeover, stop.  Each of these can fail with -EBUSY.
So set a flag while doing a sysfs deletion, and fail run, takeover,
stop if that flag is set.

This is suitable for 2.6.35.x

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:21:27 +10:00
Dan Williams 147e0b6a63 md: move revalidate_disk() back outside open_mutex
Commit b821eaa5 "md: remove ->changed and related code" moved
revalidate_disk() under open_mutex, and lockdep noticed.

[ INFO: possible circular locking dependency detected ]
2.6.32-mdadm-locking #1
-------------------------------------------------------
mdadm/3640 is trying to acquire lock:
 (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811acecb>] revalidate_disk+0x5b/0x90

but task is already holding lock:
 (&mddev->open_mutex){+.+...}, at: [<ffffffffa055e07a>] do_md_stop+0x4a/0x4d0 [md_mod]

which lock already depends on the new lock.

It is suitable for 2.6.35.x

Cc: <stable@kernel.org>
Reported-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:20:17 +10:00
Arnd Bergmann 6e9624b8ca block: push down BKL into .open and .release
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:25:34 +02:00
Christoph Hellwig 7b6d91daee block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:20:39 +02:00
NeilBrown 69e51b449d md/bitmap: separate out loading a bitmap from initialising the structures.
dm makes this distinction between ->ctr and ->resume, so we need to
too.

Also get the new bitmap_load to clear out the bitmap first, as this is
most consistent with the dm suspend/resume approach

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:34 +10:00
NeilBrown b63d7c2e29 md/bitmap: clean up plugging calls.
1/ use md_unplug in bitmap.c as we will soon be using bitmaps under
  arrays with no queue attached.

2/ Don't bother plugging the queue when we set a bit in the bitmap.
   The reason for this was to encourage as many bits as possible to
   get set before we unplug and write stuff out.
   However every personality already plugs the queue after
   bitmap_startwrite either directly (raid1/raid10) or be setting
   STRIPE_BIT_DELAY which causes the queue to be plugged later
   (raid5).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:32 +10:00
NeilBrown 252ac5221a md/plug: optionally use plugger to unplug an array during resync/recovery.
If an array doesn't have a 'queue' then md_do_sync cannot
unplug it.
In that case it will have a 'plugger', so make that available
to the mddev, and use it to unplug the array if needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:08 +10:00
NeilBrown 2ac8740151 md/raid5: add simple plugging infrastructure.
md/raid5 uses the plugging infrastructure provided by the block layer
and 'struct request_queue'.  However when we plug raid5 under dm there
is no request queue so we cannot use that.

So create a similar infrastructure that is much lighter weight and use
it for raid5.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:08 +10:00
NeilBrown 768a418db1 md: add support for raising dm events.
dm uses scheduled work to raise events to user-space.
So allow md device to have work_structs and schedule them on an error.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown 390ee602a1 md: export various start/stop interfaces
export entry points for starting and stopping md arrays.
This will be used by a module to make md/raid5 work under
dm.
Also stop calling md_stop_writes from md_stop, as that won't
work well with dm - it will want to call the two separately.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown e8bb9a839a md: split out md_rdev_init
This functionality will be needed separately in a subsequent patch, so
split it into it's own exported function.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown 676e42d896 md: be more careful setting MD_CHANGE_CLEAN
When MD_CHANGE_CLEAN is set we might block in md_write_start.
So we should only set it when fairly sure that something will clear
it.

There are two places where it is set so as to encourage a metadata
update to record the progress of resync/recovery.  This should only
be done if the internal metadata update mechanisms are in use, which
can be tested by by inspecting '->persistent'.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown 00bcb4ac7e md: reduce dependence on sysfs.
We will want md devices to live as dm targets where sysfs is not
visible.  So allow md to not connect to sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-21 13:27:53 +10:00
NeilBrown 70fffd0bfa md: Don't update ->recovery_offset when reshaping an array to fewer devices.
When an array is reshaped to have fewer devices, the reshape proceeds
from the end of the devices to the beginning.

If a device happens to be non-In_sync (which is possible but rare)
we would normally update the ->recovery_offset as the reshape
progresses. However that would be wrong as the recover_offset records
that the early part of the device is in_sync, while in fact it would
only be the later part that is in_sync, and in any case the offset
number would be measured from the wrong end of the device.

Relatedly, if after a reshape a spare is discovered to not be
recoverred all the way to the end, not allow spare_active
to incorporate it in the array.

This becomes relevant in the following sample scenario:

A 4 drive RAID5 is converted to a 6 drive RAID6 in a combined
operation.
The RAID5->RAID6 conversion will cause a 5 drive to be included as a
spare, then the 5drive -> 6drive reshape will effectively rebuild that
spare as it progresses.  The 6th drive is treated as in_sync the whole
time as there is never any case that we might consider reading from
it, but must not because there is no valid data.

If we interrupt this reshape part-way through and reverse it to return
to a 5-drive RAID6 (or event a 4-drive RAID5), we don't want to update
the recovery_offset - as that would be wrong - and we don't want to
include that spare as active in the 5-drive RAID6 when the reversed
reshape completed and it will be mostly out-of-sync still.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:18 +10:00
NeilBrown e93f68a1fc md: fix handling of array level takeover that re-arranges devices.
Most array level changes leave the list of devices largely unchanged,
possibly causing one at the end to become redundant.
However conversions between RAID0 and RAID10 need to renumber
all devices (except 0).

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

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

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

Reported-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:33:24 +10:00
NeilBrown f3b99be19d Restore partition detection of newly created md arrays.
Commit  b821eaa572 broke partition
detection for md arrays.

The logic was almost right.  However if revalidate_disk is called
when the device is not yet open, bdev->bd_disk won't be set, so the
flush_disk() Call will not set bd_invalidated.

So when md_open is called we still need to ensure that
->bd_invalidated gets set.  This is easily done with a call to
check_disk_size_change in the place where the offending commit removed
check_disk_change.  At the important times, the size will have changed
from 0 to non-zero, so check_disk_size_change will set bd_invalidated.

Tested-by: Duncan <1i5t5.duncan@cox.net>
Reported-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:31:03 +10:00
NeilBrown 19fdb9eefb Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linus
Conflicts:
	drivers/md/md.c

- Resolved conflict in md_update_sb
- Added extra 'NULL' arg to new instance of sysfs_get_dirent.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-22 08:31:36 +10:00
Eric W. Biederman 3ff195b011 sysfs: Implement sysfs tagged directory support.
The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
NeilBrown be6800a73a md: don't insist on valid event count for spare devices.
Devices which know that they are spares do not really need to have
an event count that matches the rest of the array, so there are no
data-in-sync issues. It is enough that the uuid matches.
So remove the requirement that the event count is up-to-date.

We currently still write out and event count on spares, but this
allows us in a year or 3 to stop doing that completely.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:01 +10:00
NeilBrown a8707c08f4 md: simplify updating of event count to sometimes avoid updating spares.
When updating the event count for a simple clean <-> dirty transition,
we try to avoid updating the spares so they can safely spin-down.
As the event_counts across an array must be +/- 1, this means
decrementing the event_count on a dirty->clean transition.
This is not always safe and we have to avoid the unsafe time.
We current do this with a misguided idea about it being safe or
not depending on whether the event_count is odd or even.  This
approach only works reliably in a few common instances, but easily
falls down.

So instead, simply keep internal state concerning whether it is safe
or not, and always assume it is not safe when an array is first
assembled.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:01 +10:00
NeilBrown 75a73a29e5 md: restore ability of spare drives to spin down.
Some time ago we stopped the clean/active metadata updates
from being written to a 'spare' device in most cases so that
it could spin down and say spun down.  Device failure/removal
etc are still recorded on spares.

However commit 51d5668cb2 broke this 50% of the time,
depending on whether the event count is even or odd.
The change log entry said:

   This means that the alignment between 'odd/even' and
    'clean/dirty' might take a little longer to attain,

how ever the code makes no attempt to create that alignment, so it
could take arbitrarily long.

So when we find that clean/dirty is not aligned with odd/even,
force a second metadata-update immediately.  There are already cases
where a second metadata-update is needed immediately (e.g. when a
device fails during the metadata update).  We just piggy-back on that.

Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-18 15:28:00 +10:00
Dan Williams f2859af671 md: allow integers to be passed to md/level
e.g. allow md to interpret 'echo 4 > md/level' as a request for raid4.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:58 +10:00
Dan Williams bb7f8d2217 md: notify mdstat waiters of level change
Level modifications change the output of mdstat.  The mdmon manager
thread is interested in these events for external metadata management.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:57 +10:00
NeilBrown 9e35b99c7e md: don't unregister the thread in mddev_suspend
This is
 - unnecessary because mddev_suspend is always followed by a call to
   ->stop, and each ->stop unregisters the thread, and
 - a problem as it makes it awkwards to suspend and then resume a
   device as we will want later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:56 +10:00
NeilBrown fafd7fb052 md: factor out init code for an mddev
This is a simple factorisation that makes mddev_find easier to read.


Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown 21a52c6d05 md: pass mddev to make_request functions rather than request_queue
We used to pass the personality make_request function direct
to the block layer so the first argument had to be a queue.
But now we have the intermediary md_make_request so it makes
at lot more sense to pass a struct mddev_s.
It makes it possible to have an mddev without its own queue too.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown cca9cf90c5 md: call md_stop_writes from md_stop
This moves the call to the other side of set_readonly, but that should
not be an issue.
This encapsulates in 'md_stop' all of the functionality for internally
stopping the array, leaving all the interactions with externalities
(sysfs, request_queue, gendisk) in do_md_stop.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown a4bd82d0d0 md: split md_set_readonly out of do_md_stop
Using do_md_stop to set an array to read-only is a little confusing.
Now most of the common code has been factored out, split
md_set_readonly off in to a separate function.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown a047e12540 md: factor md_stop_writes out of do_md_stop.
Further refactoring of do_md_stop.
This one requires some explanation as it takes code from different
places in do_md_stop, so some re-ordering happens.

We only get into this part of do_md_stop if there are no active opens
of the device, so no writes can be happening and the device must have
been flushed.  In md_stop_writes we want to stop any internal sources
of writes - i.e. resync - and flush out the metadata.

The only code that was previously before some of this code is
code to clean up the queue, the mddev, the gendisk, or sysfs, all
of which is probably better after code that makes active changes (i.e.
triggers writes).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown 6177b472ab md: start to refactor do_md_stop
do_md_stop is large and clunky, so hard to understand.

This is a first step of refactoring, pulling two simple
sub-functions out.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown fe60b01428 md: factor do_md_run to separate accesses to ->gendisk
As part of relaxing the binding between an mddev and gendisk,
we separate do_md_run into two functions.
  md_run does all the work internal to md
  do_md_run calls md_run and makes and changes to gendisk
     that are required.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown b821eaa572 md: remove ->changed and related code.
We set ->changed to 1 and call check_disk_change at the end
of md_open so that bd_invalidated would be set and thus
partition rescan would happen appropriately.

Now that we call revalidate_disk directly, which sets bd_invalidates,
that indirection is no longer needed and can be removed.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown 49ce6cea85 md: don't reference gendisk in getgeo
Using ->array_sectors rather than get_capacity() is more
direct and is a step towards relaxing the tight connection
between mddev and gendisk.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
NeilBrown 490773268c md: move io accounting out of personalities into md_make_request
While I generally prefer letting personalities do as much as possible,
given that we have a central md_make_request anyway we may as well use
it to simplify code.
Also this centralises knowledge of ->gendisk which will help later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
Maciej Trela 5cac7861b2 md: notify level changes through sysfs.
Level changes can be very significant, so make sure
to notify them via sysfs.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:49 +10:00