When retrying a failed BIO_RW_BARRIER request, we need to keep the reference
in ->nr_pending over the whole retry. Currently, we only hold the reference
if the failed request is the *last* one to finish - which is silly, because it
would normally be the first to finish.
So move the rdev_dec_pending call up into the didn't-fail branch. As the rdev
isn't used in the later code, calling rdev_dec_pending earlier doesn't hurt.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move the test for 'do barrier work' down a bit so that if the first write to a
raid1 is a BIO_RW_BARRIER write, the checking done by superblock writes will
cause the right thing to happen.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Because that is what you get if a BIO_RW_BARRIER isn't supported!
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to hold a reference to rdevs while reading and writing to attempt to
correct read errors. This reference must be taken under an rcu lock.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We should add to the counter for the rdev *after* checking if the rdev is
NULL!!!
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- fix mddev_lock() usage bugs in md_attr_show() and md_attr_store().
[they did not anticipate the possibility of getting a signal]
- remove mddev_lock_uninterruptible() [unused]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It works like this:
Open the file
Read all the contents.
Call poll requesting POLLERR or POLLPRI (so select/exceptfds works)
When poll returns,
close the file and go to top of loop.
or lseek to start of file and go back to the 'read'.
Events are signaled by an object manager calling
sysfs_notify(kobj, dir, attr);
If the dir is non-NULL, it is used to find a subdirectory which
contains the attribute (presumably created by sysfs_create_group).
This has a cost of one int per attribute, one wait_queuehead per kobject,
one int per open file.
The name "sysfs_notify" may be confused with the inotify
functionality. Maybe it would be nice to support inotify for sysfs
attributes as well?
This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action
to be pollable
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
reshape_position is a 64bit field that was not 64bit aligned. So swap with
new_level.
NOTE: this is a user-visible change. However:
- The bad code has not appeared in a released kernel
- This code is still marked 'experimental'
- This only affects version-1 superblock, which are not in wide use
- These field are only used (rather than simply reported) by user-space
tools in extemely rare circumstances : after a reshape crashes in the
first second of the reshape process.
So I believe that, at this stage, the change is safe. Especially if people
heed the 'help' message on use mdadm-2.4.1.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
And remove the comments that were put in inplace of a fix too....
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently a device failure during recovery leaves bits set in the bitmap.
This normally isn't a problem as the offending device will be rejected because
of errors. However if device re-adding is being used with non-persistent
bitmaps, this can 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>
... being careful that mutex_trylock is inverted wrt down_trylock
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When retrying a write due to barrier failure, we don't reset 'remaining', so
it goes negative and never hits 0 again.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
An md array can be asked to change the amount of each device that it is using,
and in particular can be asked to use the maximum available space. This
currently only works if the first device is not larger than the rest. As
'size' gets changed and so 'fit' becomes wrong. So check if a 'fit' is
required early and don't corrupt it.
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
raid5 overloads bi_phys_segments to count the number of blocks that the
request was broken in to so that it knows when the bio is completely handled.
Accessing this must always be done under a spinlock. In one case we also call
bi_end_io under that spinlock, which probably isn't ideal as bi_end_io could
be expensive (even though it isn't allowed to sleep).
So we reducde the range of the spinlock to just accessing bi_phys_segments.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
wait_event_lock_irq puts a ';' after its usage of the 4th arg, so we don't
need to.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This allows user-space to access data safely. This is needed for raid5
reshape as user-space needs to take a backup of the first few stripes before
allowing reshape to commence.
It will also be useful in cluster-aware raid1 configurations so that all
cluster members can leave a section of the array untouched while a
resync/recovery happens.
A 'start' and 'end' of the suspended range are written to 2 sysfs attributes.
Note that only one range can be suspended at a time.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This allows reshape to be triggerred via sysfs (which is the only way to start
it happening).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
check_reshape checks validity and does things that can be done instantly -
like adding devices to raid1. start_reshape initiates a restriping process to
convert the whole array.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Instead of checkpointing at each stripe, only checkpoint when a new write
would overwrite uncheckpointed data. Block any write to the uncheckpointed
area. Arbitrarily checkpoint at least every 3Meg.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We allow the superblock to record an 'old' and a 'new' geometry, and a
position where any conversion is up to. The geometry allows for changing
chunksize, layout and level as well as number of devices.
When using verion-0.90 superblock, we convert the version to 0.91 while the
conversion is happening so that an old kernel will refuse the assemble the
array. For version-1, we use a feature bit for the same effect.
When starting an array we check for an incomplete reshape and restart the
reshape process if needed. If the reshape stopped at an awkward time (like
when updating the first stripe) we refuse to assemble the array, and let
user-space worry about it.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds raid5_reshape and end_reshape which will start and finish the
reshape processes.
raid5_reshape is only enabled in CONFIG_MD_RAID5_RESHAPE is set, to discourage
accidental use.
Read the 'help' for the CONFIG_MD_RAID5_RESHAPE entry.
and Make sure that you have backups, just in case.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch provides the core of the resize/expand process.
sync_request notices if a 'reshape' is happening and acts accordingly.
It allocated new stripe_heads for the next chunk-wide-stripe in the target
geometry, marking them STRIPE_EXPANDING.
Then it finds which stripe heads in the old geometry can provide data needed
by these and marks them STRIPE_EXPAND_SOURCE. This causes stripe_handle to
read all blocks on those stripes.
Once all blocks on a STRIPE_EXPAND_SOURCE stripe_head are read, any that are
needed are copied into the corresponding STRIPE_EXPANDING stripe_head. Once a
STRIPE_EXPANDING stripe_head is full, it is marks STRIPE_EXPAND_READY and then
is written out and released.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to allow that different stripes are of different effective sizes, and
use the appropriate size. Also, when a stripe is being expanded, we must
block any IO attempts until the stripe is stable again.
Key elements in this change are:
- each stripe_head gets a 'disk' field which is part of the key,
thus there can sometimes be two stripe heads of the same area of
the array, but covering different numbers of devices. One of these
will be marked STRIPE_EXPANDING and so won't accept new requests.
- conf->expand_progress tracks how the expansion is progressing and
is used to determine whether the target part of the array has been
expanded yet or not.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Before a RAID-5 can be expanded, we need to be able to expand the stripe-cache
data structure.
This requires allocating new stripes in a new kmem_cache. If this succeeds,
we copy cache pages over and release the old stripes and kmem_cache.
We then allocate new pages. If that fails, we leave the stripe cache at it's
new size. It isn't worth the effort to shrink it back again.
Unfortuanately this means we need two kmem_cache names as we, for a short
period of time, we have two kmem_caches. So they are raid5/%s and
raid5/%s-alt
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The remainder of this batch implements raid5 reshaping. Currently the only
shape change that is supported is added a device, but it is envisioned that
changing the chunksize and layout will also be supported, as well as changing
the level (e.g. 1->5, 5->6).
The reshape process naturally has to move all of the data in the array, and so
should be used with caution. It is believed to work, and some testing does
support this, but wider testing would be great for increasing my confidence.
You will need a version of mdadm newer than 2.3.1 to make use of raid5 growth.
This is because mdadm need to take a copy of a 'critical section' at the
start of the array incase there is a crash at an awkward moment. On restart,
mdadm will restore the critical section and allow reshape to continue.
I hope to release a 2.4-pre by early next week - it still needs a little more
polishing.
This patch:
Previously the array of disk information was included in the raid5 'conf'
structure which was allocated to an appropriate size. This makes it awkward
to change the size of that array. So we split it off into a separate
kmalloced array which will require a little extra indexing, but is much easier
to grow.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
status_resync - used by /proc/mdstat to report the status of a resync, assumes
that device sizes will always fit into an 'unsigned long' This is no longer
the case...
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We are counting failed devices twice, once of the device that is failed, and
once for the hole that has been left in the array. Remove the former so
'failed' matches 'missing'. Storing these counts in the superblock is a bit
silly anyway....
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I really should make this a function of the personality....
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This flag should be set for a virtual device iff it is set for all underlying
devices.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use bd_claim_by_disk.
Following symlinks are created if dm-0 maps to sda:
/sys/block/dm-0/slaves/sda --> /sys/block/sda
/sys/block/sda/holders/dm-0 --> /sys/block/dm-0
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use bd_claim_by_disk.
Following symlinks are created if md0 is built from sda and sdb
/sys/block/md0/slaves/sda --> /sys/block/sda
/sys/block/md0/slaves/sdb --> /sys/block/sdb
/sys/block/sda/holders/md0 --> /sys/block/md0
/sys/block/sdb/holders/md0 --> /sys/block/md0
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Allow drive geometry to be stored with a new DM_DEV_SET_GEOMETRY ioctl.
Device-mapper will now respond to HDIO_GETGEO. If the geometry information is
not available, zero will be returned for all of the parameters.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Store an up-pointer to the owning struct mapped_device in every table when it
is created.
Access it with:
struct mapped_device *dm_table_get_md(struct dm_table *t)
Tables linked to md must be destroyed before the md itself.
Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change dm_get_mdptr() to take a struct mapped_device instead of dev_t.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The patch stores a printable device number in struct mapped_device for use in
warning messages and with a proposed netlink interface.
Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If dm_suspend() is cancelled, bios already added to the deferred list need to
be submitted. Otherwise they remain 'in limbo' until there's a dm_resume().
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Before removing a snapshot, wait for the completion of any kcopyd jobs using
it.
Do this by maintaining a count (nr_jobs) of how many outstanding jobs each
kcopyd_client has.
The snapshot destructor first unregisters the snapshot so that no new kcopyd
jobs (created by writes to the origin) will reference that particular
snapshot. kcopyd_client_destroy() is now run next to wait for the completion
of any outstanding jobs before the snapshot exception structures (that those
jobs reference) are freed.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This flag should be set for a virtual device iff it is set for all
underlying devices.
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We don't know what type sector_t has. Sometimes it's unsigned long, sometimes
it's unsigned long long. For example on ppc64 it's unsigned long with
CONFIG_LBD=n and on x86_64 it's unsigned long long with CONFIG_LBD=n.
The way to handle all of this is to always use unsigned long long and to
always typecast the sector_t when printing it.
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
dm-mirror has potential data corruption problem: while on-disk log shows
that all disk contents are in-sync, actual contents of the disks are not
synchronized. This problem occurs if initial recovery (synching) is
interrupted and resumed.
Attached patch fixes this problem.
Background:
rh_dec() changes the region state from RH_NOSYNC (out-of-sync) to RH_CLEAN
(in-sync), which results in the corresponding bit of clean_bits being set.
This is harmful if on-disk log is used and the map is removed/suspended
before the initial sync is completed. The clean_bits is written down to
the on-disk log at the map removal, and, upon resume, it's read and copied
to sync_bits. Since the recovery process refers to the sync_bits to find a
region to be recovered, the region whose state was changed from RH_NOSYNC
to RH_CLEAN is no longer recovered.
If you haven't applied dm-raid1-read-balancing.patch proposed in dm-devel
sometimes ago, the contents of the mirrored disk just corrupt silently. If
you have, balanced read may get bogus data from out-of-sync disks.
The patch keeps RH_NOSYNC state unchanged. It will be changed to
RH_RECOVERING when recovery starts and get reclaimed when the recovery
completes. So it doesn't leak the region hash entry.
Description:
Keep RH_NOSYNC state unchanged when I/O on the region completes.
rh_dec() changes the region state from RH_NOSYNC (out-of-sync) to RH_CLEAN
(in-sync), which results in the corresponding bit of clean_bits being set.
This is harmful if on-disk log is used and the map is removed/suspended
before the initial sync is completed. The clean_bits is written down to
the on-disk log at the map removal, and, upon resume, it's read and copied
to sync_bits. Since the recovery process refers to the sync_bits to find a
region to be recovered, the region whose state was changed from RH_NOSYNC
to RH_CLEAN is no longer recovered.
If you haven't applied dm-raid1-read-balancing.patch proposed in dm-devel
sometimes ago, the contents of the mirrored disk just corrupt silently. If
you have, balanced read may get bogus data from out-of-sync disks.
The RH_NOSYNC region will be changed to RH_RECOVERING when recovery starts
on the region and get reclaimed when the recovery completes. So it doesn't
leak the region hash entry.
Alasdair said:
I've analysed the relevant part of the state machine and I believe that
the patch is correct.
(Further work on this code is still needed - this patch has the
side-effect of holding onto memory unnecessarily for long periods of time
under certain workloads - but better that than corrupting data.)
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a snapshot becomes invalid, s->valid is set to 0. In this state, a
snapshot can no longer be accessed.
When s->lock is acquired, before doing anything else, s->valid must be checked
to ensure the snapshot remains valid.
This patch eliminates some races (that may cause panics) by adding some
missing checks. At the same time, some unnecessary levels of indentation are
removed and snapshot invalidation is moved into a single function that always
generates a device-mapper event.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
