Commit Graph

103 Commits

Author SHA1 Message Date
Neil Brown
1edf80d347 [PATCH] md: remove slashes from disk names when creation dev names in sysfs
e.g. The sx8 driver uses names like sx8/0.

This would make a md component dev name like

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

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

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

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

(finished the conversion)

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

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@suse.de>
Cc: <mike.miller@hp.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:13:54 -08:00
NeilBrown
88202a0c84 [PATCH] md: allow sync-speed to be controlled per-device
Also export current (average) speed and status in sysfs.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:10 -08:00
NeilBrown
6d7ff7380b [PATCH] md: support adding new devices to md arrays via sysfs
Writing major:minor to md/new_dev will bind that device to the array.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:10 -08:00
NeilBrown
83303b613d [PATCH] md: allow available size of component devices to be set via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:10 -08:00
Andrew Morton
6961ece46c [PATCH] md-export-rdev-data_offset-via-sysfs-fix
drivers/md/md.c: In function `offset_show':
drivers/md/md.c:1670: warning: long long unsigned int format, different type arg (arg 3)

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:10 -08:00
NeilBrown
93c8cad03f [PATCH] md: export rdev->data_offset via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -08:00
NeilBrown
014236d2b8 [PATCH] md: expose device slot information via sysfs
This the role that a device has in an array can be viewed and set.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -08:00
NeilBrown
2bf071bf50 [PATCH] md: keep better track of dev/array size when assembling md arrays
Move the checks - that dev size is never less than array size - into
bind_rdev_to_array to make sure it always happens properly (there is one place
where currently it doesn't).

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

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -08:00
NeilBrown
da943b9912 [PATCH] md: allow md/raid_disks to be settable
If array is active, try to reshape, else just set the value.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -08:00
NeilBrown
4dbcdc751c [PATCH] md: count corrected read errors per drive
Store this total in superblock (As appropriate), and make it available to
userspace via sysfs.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -08:00
NeilBrown
d9d166c2a9 [PATCH] md: allow array level to be set textually via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:09 -08:00
NeilBrown
8bb93aaca2 [PATCH] md: expose md metadata format in sysfs
Allow it to be set to a particular version, or 'none'.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:08 -08:00
NeilBrown
a35b0d695d [PATCH] md: allow md array component size to be accessed and set via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:08 -08:00
NeilBrown
3b34380ae8 [PATCH] md: allow chunk_size to be settable through sysfs
... only before array is started of course.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:08 -08:00
NeilBrown
03c902e17f [PATCH] md: fix rdev->pending counts in raid1
When we do a user-requested check/repair, we lose count of the outstanding
requests...

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

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:08 -08:00
Adrian Bunk
07dbd37727 [PATCH] drivers/md/md.c: make md_new_event() static
Make the needlessly global function md_new_event() static.

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

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:07 -08:00
NeilBrown
bce74dac08 [PATCH] md: helper function to match commands written to sysfs files
Commands written to sysfs files may, or my not, be \n terminated.  We want to
accept with case.  For this we use cmd_match.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:07 -08:00
NeilBrown
2604b703b6 [PATCH] md: remove personality numbering from md
md supports multiple different RAID level, each being implemented by a
'personality' (which is often in a separate module).

These personalities have fairly artificial 'numbers'.  The numbers
are use to:
 1- provide an index into an array where the various personalities
    are recorded
 2- identify the module (via an alias) which implements are particular
    personality.

Neither of these uses really justify the existence of personality numbers.
The array can be replaced by a linked list which is searched (array lookup
only happens very rarely).  Module identification can be done using an alias
based on level rather than 'personality' number.

The current 'raid5' modules support two level (4 and 5) but only one
personality.  This slight awkwardness (which was handled in the mapping from
level to personality) can be better handled by allowing raid5 to register 2
personalities.

With this change in place, the core md module does not need to have an
exhaustive list of all possible personalities, so other personalities can be
added independently.

This patch also moves the check for chunksize being non-zero into the ->run
routines for the personalities that need it, rather than having it in core-md.
 This has a side effect of allowing 'faulty' and 'linear' not to have a
chunk-size set.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:06 -08:00
NeilBrown
a8745db232 [PATCH] md: convert recently exported symbol to GPL
...because that seems to be the preferred practice these days.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:06 -08:00
NeilBrown
9ffae0cf3e [PATCH] md: convert md to use kzalloc throughout
Replace multiple kmalloc/memset pairs with kzalloc calls.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:05 -08:00
NeilBrown
2d1f3b5d1b [PATCH] md: clean up 'page' related names in md
Substitute:

  page_cache_get -> get_page
  page_cache_release -> put_page
  PAGE_CACHE_SHIFT -> PAGE_SHIFT
  PAGE_CACHE_SIZE -> PAGE_SIZE
  PAGE_CACHE_MASK -> PAGE_MASK
  __free_page -> put_page

because we aren't using the page cache, we are just using pages.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:05 -08:00
NeilBrown
d7603b7e3a [PATCH] md: make /proc/mdstat pollable
With this patch it is possible to poll /proc/mdstat to detect arrays appearing
or disappearing, to detect failures, recovery starting, recovery completing,
and devices being added and removed.

It is similar to the poll-ability of /proc/mounts, though different in that:

We always report that the file is readable (because face it, it is, even if
only for EOF).

We report POLLPRI when there is a change so that select() can detect
it as an exceptional event.  Not only are these exceptional events, but
that is the mechanism that the current 'mdadm' uses to watch for events
(It also polls after a timeout).
(We also report POLLERR like /proc/mounts).

Finally, we only reset the per-file event counter when the start of the file
is read, rather than when poll() returns an event.  This is more robust as it
means that an fd will continue to report activity to poll/select until the
program clearly responds to that activity.

md_new_event takes an 'mddev' which isn't currently used, but it will be soon.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:05 -08:00
NeilBrown
ddaf22abaa [PATCH] md: attempt to auto-correct read errors in raid1
On a read-error we suspend the array, then synchronously read the block from
other arrays until we find one where we can read it.  Then we try writing the
good data back everywhere and make sure it works.  If any write or subsequent
read fails, only then do we fail the device out of the array.

To be able to suspend the array, we need to also keep track of how many
requests are queued for handling by raid1d.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:03 -08:00
NeilBrown
6cce3b23f6 [PATCH] md: write intent bitmap support for raid10
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:03 -08:00
NeilBrown
b15c2e57f0 [PATCH] md: move bitmap_create to after md array has been initialised
This is important because bitmap_create uses
  mddev->resync_max_sectors
and that doesn't have a valid value until after the array
has been initialised (with pers->run()).
[It doesn't make a difference for current personalities that
 support bitmaps, but will make a difference for raid10]

This has the added advantage of meaning with can move the thread->timeout
manipulation inside the bitmap.c code instead of sprinkling identical code
throughout all personalities.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:03 -08:00
NeilBrown
6ff8d8ec06 [PATCH] md: allow dirty raid[456] arrays to be started at boot
See patch to md.txt for more details

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:34:02 -08:00
Neil Brown
bcb97940f3 [PATCH] md: Change case of raid level reported in sys/mdX/md/level
I had thought that keeping the reported tail level clearly different
from the module name was a good idea, but I've changed my mind.

'raid5' is better and probably less confusing than 'RAID-5'.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-19 16:47:50 -08:00
NeilBrown
b2a2703c28 [PATCH] md: set default_bitmap_offset properly in set_array_info
If an array is created using set_array_info, default_bitmap_offset isn't set
properly meaning that an internal bitmap cannot be hot-added until the array
is stopped and re-assembled.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:25 -08:00
NeilBrown
c0e485216d [PATCH] md: fix is_mddev_idle calculation now that disk/sector accounting happens when request completes
md needs to monitor the rate of requests to its devices when doing
resync/recovery so that it can back-off when there is non-resync IO.  It
does this by comparing resync IO, which it counts, with total IO which is
taken from disk_stats.

disk_stats were recently changed to account sectors when a request
completes instead of when it is queued.  This upsets md's calculations.

We could do the sync_io accounting at the end of requests too, but that has
problems.  If an underlying device is an md array, the accounting will
still be done when the request is submitted.  This could be changed for
some raid levels, but it cannot be changed for raid0 or linear without
substantial code changes.

So instead, we increase the error that is_mddev_idle allows, up to the
maximum amount of resync IO that can be in flight at any time.  The
calculation is current fragile as each personality as different limits for
in-flight resync.  This should be fixed up.

For now, this simple patch fixes the problem.

Increasing the error margin decreases the sensitivity to non-resync IO.  To
partially compensate for this, the time to wait when non-resync IO is
detected is increased so that less steady IO is required to keep the resync
at bay.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-18 07:49:46 -08:00
NeilBrown
93588e2284 [PATCH] md: make md threads interruptible again
Despite the fact that md threads don't need to be signalled, and won't
respond to signals anyway, we need to have an 'interruptible' wait, else
they stay in 'D' state and add to the load average.

(akpm: the signal_pending() test is unneeded - we'll fix that up in the next
round.  For now, leave it there because that's how the code used to be).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15 08:59:19 -08:00
NeilBrown
e8a0033451 [PATCH] md: mark START_ARRAY deprecated with a date
This was marked deprecated "after 2.6" back in the 2.5 days.  But now it
seems there isn't going to be any "after 2.6", and we deprecate by date
now.  So set a date.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-15 08:59:19 -08:00
NeilBrown
bb636547b0 [PATCH] md: document sysfs usage of md, and make a couple of small refinements
Document in Documentation/md.txt the files that now appear in sysfs, and make
a couple of small refinements to exactly when 'level' and 'raid_disks' are
empty, to make it match the documentation.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
7eec314d75 [PATCH] md: improve 'scan_mode' and rename it to 'sync_action'
The current sync_action for an array can be one of

   idle  - nothing happening
   resync - reduncancy being recalcualted
   recover - missing device being recoverred to spare
   check   - user initiated check of redundancy
   repair  - like resync but user-initiated and ignores
             bitmap optimisation.

Each of these strings can also be written to the 'sync_action' file to cause
that action to happen (if appropriate).

While 'sync' is not technically correct, as a recovery is *not* a 'sync', I
think it is the most servicable word here.  Also 'action' is a strong word
than 'mode'.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
787453c239 [PATCH] md: complete conversion of md to use kthreads
There are a few loose ends following the conversion of md to use kthreads:

- Some fields in mdk_thread_t that aren't needed (kthreads does it's own
  completion and manages it's own name).

- thread->run is now never NULL, so no need to check

- Some tests for signal_pending that aren't needed (As we don't use signals
  to stop threads any more)

- Some flush_signals are not needed

- Some waits are interruptible and don't need to be.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
fd9d49cac4 [PATCH] md: ignore auto-readonly flag for arrays where it isn't meaningful
The 'auto-readonly' flag (which suppresses resync and superblock updates until
the first write) is not meaningful for personalities that don't support resync
or superblock writes (raid0, linear, etc).

So clear the setting early to avoid it confusing anything - e.g.  appearing in
/proc/mdstat

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
8e1b39d623 [PATCH] md: only try to print recovery/resync status for personalities that support recovery
The introduction of 'resync=PENDING' (for read-only devices) caused that
message to appear for non-syncable arrays like raid0 and linear.  Simplest
thing is to not try to print any resync info unless the personality clearly
supports it.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
411036fa19 [PATCH] md: split off some md attributes in sysfs to a separate group
Some, but not all, md array support data redundancy and hence support checking
and restoring that redundancy (resync, rebuild).

Some attributes apply specifically to functions involving this redundancy, and
so should only appear for md arrays for which they are meaningful.  i.e.  they
should not appear for raid0, linear, multpath, faulty.

This patch separates these into a distinct group and creates the group only if
the personality supports sync_request.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
96de1e663c [PATCH] md: fix some locking and module refcounting issues with md's use of sysfs
1/ I really should be using the __ATTR macros for defining attributes, so
   that the .owner field get set properly, otherwise modules can be removed
   while sysfs files are open.  This also involves some name changes of _show
   routines.

2/ Always lock the mddev (against reconfiguration) for all sysfs attribute
   access.  This easily avoid certain races and is completely consistant with
   other interfaces (ioctl and /proc/mdstat both always lock against
   reconfiguration).

3/ raid5 attributes must check that the 'conf' structure actually exists
   (the array could have been stopped while an attribute file was open).

4/ A missing 'kfree' from when the raid5_conf_t was converted to have a
   kobject embedded, and then converted back again.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
f637b9f9fc [PATCH] md: make sure /block link in /sys/.../md/ goes to correct devices
If a block_device is a partition, then it's kobject is
  bdev->bd_part->kobj
otherwise (if it is a full device), the kobject is
  bdev->bd_disk->kobj

As md wants back-links to the correct object (whether partition or not), we
need to respect this difference...  (Thus current code shows a link to the
whole device, whether we are using a partition or not, which is wrong).

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
f91de92ed6 [PATCH] md: allow md arrays to be started read-only (module parameter).
When an md array is started, the superblock will be written, and resync may
commense.  This is not good if you want to be completely read-only as, for
example, when preparing to resume from a suspend-to-disk image.

So introduce a module parameter "start_ro" which can be set
to '1' at boot, at module load, or via
  /sys/module/md_mod/parameters/start_ro

When this is set, new arrays get an 'auto-ro' mode, which disables all
internal io (superblock updates, resync, recovery) and is automatically
switched to 'rw' when the first write request arrives.

The array can be set to true 'ro' mode using 'mdadm -r' before the first
write request, or resync can be started without a write using 'mdadm -w'.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
19133a4298 [PATCH] md: Remove attempt to use dynamic names in sysfs for component devices on an MD array.
With version-0.90 superblock, component devices on an md device to not have
any stable name related to the array -(version-1 assigns a fixed index when
a device is added to an array, and this remains despit any hot-swap).

The intial code for making these devices appear in sysfs used dynamic
names, which would change whenever a hot-spare was swapped for a failed or
missing device.  This turns out not to be practical in sysfs for a number
of reasons.

This patch changes then naming of component devices to be based on the
result of 'bdevname'.  This is stable and should be unique.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
a9701a3047 [PATCH] md: support BIO_RW_BARRIER for md/raid1
We can only accept BARRIER requests if all slaves handle
barriers, and that can, of course, change with time....

So we keep track of whether the whole array seems safe for barriers,
and also whether each individual rdev handles barriers.

We initially assumes barriers are OK.

When writing the superblock we try a barrier, and if that fails, we flag
things for no-barriers.  This will usually clear the flags fairly quickly.

If writing the superblock finds that BIO_RW_BARRIER is -ENOTSUPP, we need to
resubmit, so introduce function "md_super_wait" which waits for requests to
finish, and retries ENOTSUPP requests without the barrier flag.

When writing the real raid1, write requests which were BIO_RW_BARRIER but
which aresn't supported need to be retried.  So raid1d is enhanced to do this,
and when any bio write completes (i.e.  no retry needed) we remove it from the
r1bio, so that devices needing retry are easy to find.

We should hardly ever get -ENOTSUPP errors when writing data to the raid.
It should only happen if:
  1/ the device used to support BARRIER, but now doesn't.  Few devices
     change like this, though raid1 can!
or
  2/ the array has no persistent superblock, so there was no opportunity to
     pre-test for barriers when writing the superblock.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
bd926c63b7 [PATCH] md: make md on-disk bitmaps not host-endian
Current bitmaps use set_bit et.al and so are host-endian, which means
not-portable.  Oops.

Define a new version number (4) for which bitmaps are little-endian.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
b2d444d7ad [PATCH] md: convert 'faulty' and 'in_sync' fields to bits in 'flags' field
This has the advantage of removing the confusion caused by 'rdev_t' and
'mddev_t' both having 'in_sync' fields.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
ba22dcbf10 [PATCH] md: improvements to raid5 handling of read errors
Two refinements to the 'attempt-overwrite-on-read-error' mechanism.
1/ If the array is read-only, don't attempt an over-write.
2/ If there are more than max_nr_stripes read errors on a device with
   no success, fail the drive.  This will make sure a dead
   drive will be eventually kicked even when we aren't trying
   to rewrite (which would normally kick a dead drive more quickly.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
007583c925 [PATCH] md: change raid5 sysfs attribute to not create a new directory
There isn't really a need for raid5 attributes to be an a subdirectory,
so this patch moves them from
  /sys/block/mdX/md/raid5/attribute
to
  /sys/block/mdX/md/attribute

This suggests that all md personalities should co-operate about
namespace usage, but that shouldn't be a problem.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
31399d9e56 [PATCH] md: minor MD fixes
1/ Use reduce stack usage, because 'gcc' apparently doesn't overlay
   different variables  that are in separate scopes...

2/ Use test_bit instead of ( .. & 1<< ..) which in this case is buggy.

Thanks to Andrew Morton

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:37 -08:00