If the raid1 or raid10 unplug function gets called
from a make_request function (which is very possible) when
there are bios on the current->bio_list list, then it will not
be able to successfully call bitmap_unplug() and it could
need to submit more bios and wait for them to complete.
But they won't complete while current->bio_list is non-empty.
So detect that case and handle the unplugging off to another thread
just like we already do when called from within the scheduler.
RAID1 version of bug was introduced in 3.6, so that part of fix is
suitable for 3.6.y. RAID10 part won't apply.
Cc: stable@vger.kernel.org
Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Reported-by: Peter Maloney <peter.maloney@brockmann-consult.de>
Signed-off-by: NeilBrown <neilb@suse.de>
- raid5 discard has problems
- raid10 replacement devices have problems
- bad block lock seqlock usage has problems
- dm-raid doesn't free everything
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Merge tag 'md-3.7-fixes' of git://neil.brown.name/md
Pull md fixes from NeilBrown:
"Several bug fixes for md in 3.7:
- raid5 discard has problems
- raid10 replacement devices have problems
- bad block lock seqlock usage has problems
- dm-raid doesn't free everything"
* tag 'md-3.7-fixes' of git://neil.brown.name/md:
md/raid10: decrement correct pending counter when writing to replacement.
md/raid10: close race that lose writes lost when replacement completes.
md/raid5: Make sure we clear R5_Discard when discard is finished.
md/raid5: move resolving of reconstruct_state earlier in stripe_handle.
md/raid5: round discard alignment up to power of 2.
md: make sure everything is freed when dm-raid stops an array.
md: Avoid write invalid address if read_seqretry returned true.
md: Reassigned the parameters if read_seqretry returned true in func md_is_badblock.
Request based dm attempts to re-run the request queue off the
request completion path. If used with a driver that potentially does
end_io from its request_fn, we could deadlock trying to recurse
back into request dispatch. Fix this by punting the request queue
run to kblockd.
Tested to fix a quickly reproducible deadlock in such a scenario.
Cc: stable@kernel.org
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When a write to a replacement device completes, we carefully
and correctly found the rdev that the write actually went to
and the blithely called rdev_dec_pending on the primary rdev,
even if this write was to the replacement.
This means that any writes to an array while a replacement
was ongoing would cause the nr_pending count for the primary
device to go negative, so it could never be removed.
This bug has been present since replacement was introduced in
3.3, so it is suitable for any -stable kernel since then.
Reported-by: "George Spelvin" <linux@horizon.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
When a replacement operation completes there is a small window
when the original device is marked 'faulty' and the replacement
still looks like a replacement. The faulty should be removed and
the replacement moved in place very quickly, bit it isn't instant.
So the code write out to the array must handle the possibility that
the only working device for some slot in the replacement - but it
doesn't. If the primary device is faulty it just gives up. This
can lead to corruption.
So make the code more robust: if either the primary or the
replacement is present and working, write to them. Only when
neither are present do we give up.
This bug has been present since replacement was introduced in
3.3, so it is suitable for any -stable kernel since then.
Reported-by: "George Spelvin" <linux@horizon.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
commit 9e44476851
MD: raid5 avoid unnecessary zero page for trim
change raid5 to clear R5_Discard when the complete request is
handled rather than when submitting the per-device discard request.
However it did not clear R5_Discard for the parity device.
This means that if the stripe_head was reused before it expired from
the cache, the setting would be wrong and a hang would result.
Also if the R5_Uptodate bit happens to be set, R5_Discard again
won't be cleared. But R5_Uptodate really should be clear at this point.
So make sure R5_Discard is cleared in all cases, and clear
R5_Uptodate when a 'discard' completes.
Signed-off-by: NeilBrown <neilb@suse.de>
stripe_handle.
The chunk of code in stripe_handle which responds to a
*_result value in reconstruct_state is really the completion
of some processing that happened outside of handle_stripe
(possibly asynchronously) and so should be one of the first
things done in handle_stripe().
After the next patch it will be important that it happens before
handle_stripe_clean_event(), as that will clear some dev->flags
bit that this code tests.
Signed-off-by: NeilBrown <neilb@suse.de>
blkdev_issue_discard currently assumes that the granularity
is a power of 2. So in raid5, round the chosen number up to
avoid embarrassment.
Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
md_stop() would stop an array, but not free various attached
data structures.
For internal arrays, these are freed later in do_md_stop() or
mddev_put(), but they don't apply for dm-raid arrays.
So get md_stop() to free them, and only all it from dm-raid.
For internal arrays we now call __md_stop.
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If read_seqretry returned true and bbp was changed, it will write
invalid address which can cause some serious problem.
This bug was introduced by commit v3.0-rc7-130-g2699b67.
So fix is suitable for 3.0.y thru 3.6.y.
Reported-by: zhuwenfeng@kedacom.com
Tested-by: zhuwenfeng@kedacom.com
Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This bug was introduced by commit(v3.0-rc7-126-g2230dfe).
So fix is suitable for 3.0.y thru 3.6.y.
Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Commit 2863b9eb didn't take into account the changes to add TRIM support to
RAID10 (commit 532a2a3fb). That is, when using dm-raid.c to create the
RAID10 arrays, there is no mddev->gendisk or mddev->queue. The code added
to support TRIM simply assumes that mddev->queue is available without
checking. The result is an oops any time dm-raid.c attempts to create a
RAID10 device.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
setup_conf in raid1.c uses conf->raid_disks before assigning
a value. It is used when including 'Replacement' devices.
The consequence is that assembling an array which contains a
replacement will misbehave and either not include the replacement, or
not include the device being replaced.
Though this doesn't lead directly to data corruption, it could lead to
reduced data safety.
So use mddev->raid_disks, which is initialised, instead.
Bug was introduced by commit c19d57980b
md/raid1: recognise replacements when assembling arrays.
in 3.3, so fix is suitable for 3.3.y thru 3.6.y.
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
in:
fe86cdce block: do not artificially constrain max_sectors for stacking drivers
max_sectors defaults to UINT_MAX. md faulty wasn't using
disk_stack_limits(), so inherited this large value as well.
This triggered a bug in XFS when stressed over md_faulty, when
a very large bio_alloc() failed.
That was on an older kernel, and I can't reproduce exactly the
same thing upstream, but I think the fix is appropriate in any
case.
Thanks to Mike Snitzer for pointing out the problem.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
"discard" support, some dm-raid improvements and other assorted
bits and pieces.
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Merge tag 'md-3.7' of git://neil.brown.name/md
Pull md updates from NeilBrown:
- "discard" support, some dm-raid improvements and other assorted bits
and pieces.
* tag 'md-3.7' of git://neil.brown.name/md: (29 commits)
md: refine reporting of resync/reshape delays.
md/raid5: be careful not to resize_stripes too big.
md: make sure manual changes to recovery checkpoint are saved.
md/raid10: use correct limit variable
md: writing to sync_action should clear the read-auto state.
Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races
md/raid5: make sure to_read and to_write never go negative.
md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write.
md/raid5: protect debug message against NULL derefernce.
md/raid5: add some missing locking in handle_failed_stripe.
MD: raid5 avoid unnecessary zero page for trim
MD: raid5 trim support
md/bitmap:Don't use IS_ERR to judge alloc_page().
md/raid1: Don't release reference to device while handling read error.
raid: replace list_for_each_continue_rcu with new interface
add further __init annotations to crypto/xor.c
DM RAID: Fix for "sync" directive ineffectiveness
DM RAID: Fix comparison of index and quantity for "rebuild" parameter
DM RAID: Add rebuild capability for RAID10
DM RAID: Move 'rebuild' checking code to its own function
...
Use the recently-added bio front_pad field to allocate struct dm_target_io.
Prior to this patch, dm_target_io was allocated from a mempool. For each
dm_target_io, there is exactly one bio allocated from a bioset.
This patch merges these two allocations into one allocation: we create a
bioset with front_pad equal to the size of dm_target_io so that every
bio allocated from the bioset has sizeof(struct dm_target_io) bytes
before it. We allocate a bio and use the bytes before the bio as
dm_target_io.
_tio_cache is removed and the tio_pool mempool is now only used for
request-based devices.
This idea was introduced by Kent Overstreet.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: tj@kernel.org
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Bill Pemberton <wfp5p@viridian.itc.virginia.edu>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The bio prison code will be useful to other future DM targets so
move it to a separate module.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The bio prison code will be useful to share with future DM targets.
Prepare to move this code into a separate module, adding a dm prefix
to structures and functions that will be exported.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Support discards when the pool's block size is not a power of 2.
The block layer assumes discard_granularity is a power of 2 (in
blkdev_issue_discard), so we set this to the largest power of 2 that is
a divides into the number of sectors in each block, but never less than
DATA_DEV_BLOCK_SIZE_MIN_SECTORS.
This patch eliminates the "Discard support must be disabled when the
block size is not a power of 2" constraint that was imposed in commit
55f2b8b ("dm thin: support for non power of 2 pool blocksize"). That
commit was incomplete: using a block size that is not a power of 2
shouldn't mean disabling discard support on the device completely.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu().
dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Use the ACCESS_ONCE macro in dm-bufio and dm-verity where a variable
can be modified asynchronously (through sysfs) and we want to prevent
compiler optimizations that assume that the variable hasn't changed.
(See Documentation/atomic_ops.txt.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Use list_move() instead of list_del() + list_add().
spatch with a semantic match was used to find this.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The mpio dereference should be moved below the BUG_ON NULL test
in multipath_end_io().
spatch with a semantic match was used to found this.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If 'resync_max' is set to 0 (as is often done when starting a
reshape, so the mdadm can remain in control during a sensitive
period), and if the reshape request is initially delayed because
another array using the same array is resyncing or reshaping etc,
when user-space cannot easily tell when the delay changes from being
due to a conflicting reshape, to being due to resync_max = 0.
So introduce a new state: (curr_resync == 3) to reflect this, make
sure it is visible both via /proc/mdstat and via the "sync_completed"
sysfs attribute, and ensure that the event transition from one delay
state to the other is properly notified.
Signed-off-by: NeilBrown <neilb@suse.de>
When a RAID5 is reshaping, conf->raid_disks is increased
before mddev->delta_disks becomes zero.
This can result in check_reshape calling resize_stripes with a
number that is too large. This particularly happens
when md_check_recovery calls ->check_reshape().
If we use ->previous_raid_disks, we don't risk this.
Signed-off-by: NeilBrown <neilb@suse.de>
If you make an array bigger but suppress resync of the new region with
mdadm --grow /dev/mdX --size=max --assume-clean
then stop the array before anything is written to it, the effect of
the "--assume-clean" is lost and the array will resync the new space
when restarted.
So ensure that we update the metadata in the case.
Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Clang complains that we are assigning a variable to itself. This should
be using bad_sectors like the similar earlier check does.
Bug has been present since 3.1-rc1. It is minor but could
conceivably cause corruption or other bad behaviour.
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
In some cases array are started in 'read-auto' state where in
nothing gets written to any device until the array is written
to. The purpose of this is to make accidental auto-assembly
of the wrong arrays less of a risk, and to allow arrays to be
started to read suspend-to-disk images without actually changing
anything (as might happen if the array were dirty and a
resync seemed necessary).
Explicitly writing the 'sync_action' for a read-auto array currently
doesn't clear the read-auto state, so the sync action doesn't
happen, which can be confusing.
So allow any successful write to sync_action to clear any read-auto
state.
Reported-by: Alexander Kühn <alexander.kuehn@nagilum.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Now that multiple threads can handle stripes, it is safer to
use an atomic64_t for resync_mismatches, to avoid update races.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
to_read and to_write are part of the result of analysing
a stripe before handling it.
Their use is to avoid some loops and tests if the values are
known to be zero. Thus it is not a problem if they are a
little bit larger than they should be.
So decrementing them in handle_failed_stripe serves little value, and
due to races it could cause some loops to be skipped incorrectly.
So remove those decrements.
Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
The pr_debug in add_stripe_bio could race with something
changing *bip, so it is best to hold the lock until
after the pr_debug.
Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
We really should hold the stripe_lock while accessing
'toread' else we could race with add_stripe_bio and corrupt
a list.
Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
We want to avoid zero discarded dev page, because it's useless for discard.
But if we don't zero it, another read/write hit such page in the cache and will
get inconsistent data.
To avoid zero the page, we don't set R5_UPTODATE flag after construction is
done. In this way, discard write request is still issued and finished, but read
will not hit the page. If the stripe gets accessed soon, we need reread the
stripe, but since the chance is low, the reread isn't a big deal.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Discard for raid4/5/6 has limitation. If discard request size is
small, we do discard for one disk, but we need calculate parity and
write parity disk. To correctly calculate parity, zero_after_discard
must be guaranteed. Even it's true, we need do discard for one disk
but write another disks, which makes the parity disks wear out
fast. This doesn't make sense. So an efficient discard for raid4/5/6
should discard all data disks and parity disks, which requires the
write pattern to be (A, A+chunk_size, A+chunk_size*2...). If A's size
is smaller than chunk_size, such pattern is almost impossible in
practice. So in this patch, I only handle the case that A's size
equals to chunk_size. That is discard request should be aligned to
stripe size and its size is multiple of stripe size.
Since we can only handle request with specific alignment and size (or
part of the request fitting stripes), we can't guarantee
zero_after_discard even zero_after_discard is true in low level
drives.
The block layer doesn't send down correctly aligned requests even
correct discard alignment is set, so I must filter out.
For raid4/5/6 parity calculation, if data is 0, parity is 0. So if
zero_after_discard is true for all disks, data is consistent after
discard. Otherwise, data might be lost. Let's consider a scenario:
discard a stripe, write data to one disk and write parity disk. The
stripe could be still inconsistent till then depending on using data
from other data disks or parity disks to calculate new parity. If the
disk is broken, we can't restore it. So in this patch, we only enable
discard support if all disks have zero_after_discard.
If discard fails in one disk, we face the similar inconsistent issue
above. The patch will make discard follow the same path as normal
write request. If discard fails, a resync will be scheduled to make
the data consistent. This isn't good to have extra writes, but data
consistency is important.
If a subsequent read/write request hits raid5 cache of a discarded
stripe, the discarded dev page should have zero filled, so the data is
consistent. This patch will always zero dev page for discarded request
stripe. This isn't optimal because discard request doesn't need such
payload. Next patch will avoid it.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When we get a read error, we arrange for raid1d to handle it.
Currently we release the reference on the device. This can result
in
conf->mirrors[read_disk].rdev
being NULL in fix_read_error, if the device happens to get removed
before the read error is handled.
So instead keep the reference until the read error has been fully
handled.
Reported-by: hank <pyu@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This patch replaces list_for_each_continue_rcu() with
list_for_each_entry_continue_rcu() to save a few lines
of code and allow removing list_for_each_continue_rcu().
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
There are two table arguments that can be given to a DM RAID target
that control whether the array is forced to (re)synchronize or skip
initialization: "sync" and "nosync". When "sync" is given, we set
mddev->recovery_cp to 0 in order to cause the device to resynchronize.
This is insufficient if there is a bitmap in use, because the array
will simply look at the bitmap and see that there is no recovery
necessary.
The fix is to skip over the loading of the superblocks when "sync" is
given, causing new superblocks to be written that will force the array
to go through initialization (i.e. synchronization).
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
DM RAID: Fix comparison of index and quantity for "rebuild" parameter
The "rebuild" parameter takes an index argument that starts counting from
zero. The conditional used to validate the index was using '>' rather than
'>=', leaving the door open for an index value that would be 1 too large.
Reported-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
DM RAID: Add code to validate replacement slots for RAID10 arrays
RAID10 can handle 'copies - 1' failures for each mirror group. This code
ensures the user has provided a valid array - one whose devices specified for
rebuild do not exceed the amount of redundancy available.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
DM RAID: Move chunk of code to it's own function
The code that checks whether device replacements/rebuilds are possible given
a specific RAID type is moved to it's own function. It will further expand
when the code to check RAID10 is added. A separate function makes it easier
to read.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
MD RAID10: Fix a couple potential kernel panics if RAID10 is used by dm-raid
When device-mapper uses the RAID10 personality through dm-raid.c, there is no
'gendisk' structure in mddev and some sysfs information is also not populated.
This patch avoids touching those non-existent structures.
Signed-off-by: Jonathan Brassow <jbrassow@rehdat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Some ioctls don't need to take the mutex and doing so can cause
a delay as it is held during super-block update.
So move those ioctls out of the mutex and rely on rcu locking
to ensure we don't access stale data.
Signed-off-by: NeilBrown <neilb@suse.de>
Change the thread parameter, so the thread can carry extra info. Next patch
will use it.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
queuing writes to the md thread means that all requests go through the
one processor which may not be able to keep up with very high request
rates.
So use the plugging infrastructure to submit all requests on unplug.
If a 'schedule' is needed, we fall back on the old approach of handing
the requests to the thread for it to handle.
This is nearly identical to a recent patch which provided similar
functionality to RAID1.
Signed-off-by: NeilBrown <neilb@suse.de>
This makes md raid 10 support TRIM.
If one disk supports discard and another not, or one has
discard_zero_data and another not, there could be inconsistent between
data from such disks. But this should not matter, discarded data is
useless. This will add extra copy in rebuild though.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This makes md raid 1 support TRIM.
If one disk supports discard and another not, or one has discard_zero_data and
another not, there could be inconsistent between data from such disks. But this
should not matter, discarded data is useless. This will add extra copy in rebuild
though.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Linus Torvalds