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The only access in md_seq_show that could suffer from races
not protected by ->lock is walking the rdev list.
This can receive sufficient protection from 'rcu'.
So use rdev_for_each_rcu() and get rid of mddev_lock().
Now reading /proc/mdstat will never block in md_seq_show.
Signed-off-by: NeilBrown <neilb@suse.de>
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This makes it safe to inspect the struct while holding only
the spinlock.
Signed-off-by: NeilBrown <neilb@suse.de>
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Pull two fixes for md from Neil Brown:
- Another live lock, needs backporting
- work-around false positive with new warnings.
* tag 'md/3.19-fixes' of git://neil.brown.name/md:
md/bitmap: fix a might_sleep() warning.
md/raid5: fix another livelock caused by non-aligned writes.
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->pers is already protected by ->reconfig_mutex, and
cannot possibly change when there are threads running or
outstanding IO.
However there are some places where we access ->pers
not in a thread or IO context, and where ->reconfig_mutex
is unnecessarily heavy-weight: level_show and md_seq_show().
So protect all changes, and those accesses, with ->lock.
This is a step toward taking those accesses out from under
reconfig_mutex.
[Fixed missing "mddev->pers" -> "pers" conversion, thanks to
Dan Carpenter <dan.carpenter@oracle.com>]
Signed-off-by: NeilBrown <neilb@suse.de>
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Gather all the changes that can happen atomically and might
be relevant to other code into one place. This will
make it easier to refine the locking.
Note that this puts quite a few things between mddev_detach()
and ->free(). Enabling this was the point of some recent patches.
Signed-off-by: NeilBrown <neilb@suse.de>
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Now that the ->stop function only frees the private data,
rename is accordingly.
Also pass in the private pointer as an arg rather than using
mddev->private. This flexibility will be useful in level_store().
Finally, don't clear ->private. It doesn't make sense to clear
it seeing that isn't what we free, and it is no longer necessary
to clear ->private (it was some time ago before ->to_remove was
introduced).
Setting ->to_remove in ->free() is a bit of a wart, but not a
big problem at the moment.
Signed-off-by: NeilBrown <neilb@suse.de>
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Each md personality has a 'stop' operation which does two
things:
1/ it finalizes some aspects of the array to ensure nothing
is accessing the ->private data
2/ it frees the ->private data.
All the steps in '1' can apply to all arrays and so can be
performed in common code.
This is useful as in the case where we change the personality which
manages an array (in level_store()), it would be helpful to do
step 1 early, and step 2 later.
So split the 'step 1' functionality out into a new mddev_detach().
Signed-off-by: NeilBrown <neilb@suse.de>
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The use of 'rcu' to protect accesses to ->private_data so that
the ->private_data could be updated predates the introduction
of mddev_suspend/mddev_resume.
These are a cleaner mechanism for providing stability while
swapping in a new ->private data - it is used by level_store()
to support changing of raid levels.
So get rid of the RCU stuff and just use mddev_suspend, mddev_resume.
As these function call ->quiesce(), we add an empty function for
linear just like for raid0.
Signed-off-by: NeilBrown <neilb@suse.de>
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There is no locking around calls to merge_bvec_fn(), so
it is possible that calls which coincide with a level (or personality)
change could go wrong.
So create a central dispatch point for these functions and use
rcu_read_lock().
If the array is suspended, reject any merge that can be rejected.
If not, we know it is safe to call the function.
Signed-off-by: NeilBrown <neilb@suse.de>
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There is currently no locking around calls to the 'congested'
bdi function. If called at an awkward time while an array is
being converted from one level (or personality) to another, there
is a tiny chance of running code in an unreferenced module etc.
So add a 'congested' function to the md_personality operations
structure, and call it with appropriate locking from a central
'mddev_congested'.
When the array personality is changing the array will be 'suspended'
so no IO is processed.
If mddev_congested detects this, it simply reports that the
array is congested, which is a safe guess.
As mddev_suspend calls synchronize_rcu(), mddev_congested can
avoid races by included the whole call inside an rcu_read_lock()
region.
This require that the congested functions for all subordinate devices
can be run under rcu_lock. Fortunately this is the case.
Signed-off-by: NeilBrown <neilb@suse.de>
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This lock is used for (slightly) more than helping with writing
superblocks, and it will soon be extended further. So the
name is inappropriate.
Also, the _irq variant hasn't been needed since 2.6.37 as it is
never taking from interrupt or bh context.
So:
-rename write_lock to lock
-document what it protects
-remove _irq ... except in md_flush_request() as there
is no wait_event_lock() (with no _irq). This can be
cleaned up after appropriate changes to wait.h.
Signed-off-by: NeilBrown <neilb@suse.de>
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That last condition is unclear and over cautious.
There are two related issues here.
If a partial write is destined for a missing device, then
either RMW or RCW can work. We must read all the available
block. Only then can the missing blocks be calculated, and
then the parity update performed.
If RMW is not an option, then there is a complication even
without partial writes. If we would need to read a missing
device to perform the reconstruction, then we must first read every
block so the missing device data can be computed.
This is the case for RAID6 (Which currently does not support
RMW) and for times when we don't trust the parity (after a crash)
and so are in the process of resyncing it.
So make these two cases more clear and separate, and perform
the relevant tests more thoroughly.
Signed-off-by: NeilBrown <neilb@suse.de>
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Both the last two cases are only relevant if something has failed and
something needs to be written (but not over-written), and if it is OK
to pre-read blocks at this point. So factor out those tests and
explain them.
Signed-off-by: NeilBrown <neilb@suse.de>
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Some of the conditions in need_this_block have very straight
forward motivation. Separate those out and document them.
Signed-off-by: NeilBrown <neilb@suse.de>
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fetch_block() has a very large and hard to read 'if' condition.
Separate it into its own function so that it can be
made more readable.
Signed-off-by: NeilBrown <neilb@suse.de>
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67f455486d2ea20b2d94d6adf5b9b783d079e321 introduced a call to
md_wakeup_thread() when adding to the delayed_list. However the md
thread is woken up unconditionally just below.
Remove the unnecessary wakeup call.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
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commit 8eb23b9f35aae413140d3fda766a98092c21e9b0
sched: Debug nested sleeps
causes false-positive warnings in RAID5 code.
This annotation removes them and adds a comment
explaining why there is no real problem.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
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If a non-page-aligned write is destined for a device which
is missing/faulty, we can deadlock.
As the target device is missing, a read-modify-write cycle
is not possible.
As the write is not for a full-page, a recontruct-write cycle
is not possible.
This should be handled by logic in fetch_block() which notices
there is a non-R5_OVERWRITE write to a missing device, and so
loads all blocks.
However since commit 67f455486d2ea2, that code requires
STRIPE_PREREAD_ACTIVE before it will active, and those circumstances
never set STRIPE_PREREAD_ACTIVE.
So: in handle_stripe_dirtying, if neither rmw or rcw was possible,
set STRIPE_DELAYED, which will cause STRIPE_PREREAD_ACTIVE be set
after a suitable delay.
Fixes: 67f455486d2ea20b2d94d6adf5b9b783d079e321
Cc: stable@vger.kernel.org (v3.16+)
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
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Prepare to allow blk_rq_prep_clone() to accept clone requests that were
allocated from blk-mq request queues. As such the blk_rq_prep_clone()
caller must first initialize the clone request.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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FAIL mode
You can't modify the metadata in these modes. It's better to fail these
messages immediately than let the block-manager deny write locks on
metadata blocks. Otherwise these failed metadata changes will trigger
'needs_check' to get set in the metadata superblock -- requiring repair
using the thin_check utility.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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Commit 9b1cc9f251 ("dm cache: share cache-metadata object across
inactive and active DM tables") mistakenly ignored the use of ERR_PTR
returns. Restore missing IS_ERR checks and ERR_PTR returns where
appropriate.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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Commit ffcc393641 ("dm: enhance internal suspend and resume interface")
attempted to handle multiple internal suspends on the same device, but
it did that incorrectly. When these functions are called in this order
on the same device the device is no longer suspended, but it should be:
dm_internal_suspend_noflush
dm_internal_suspend_noflush
dm_internal_resume
Fix this bug by maintaining an 'internal_suspend_count' and resuming
the device when this count drops to zero.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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Introduce a new variable to count the number of allocated migration
structures. The existing variable cache->nr_migrations became
overloaded. It was used to:
i) track of the number of migrations in flight for the purposes of
quiescing during suspend.
ii) to estimate the amount of background IO occuring.
Recent discard changes meant that REQ_DISCARD bios are processed with
a migration. Discards are not background IO so nr_migrations was not
incremented. However this could cause quiescing to complete early.
(i) is now handled with a new variable cache->nr_allocated_migrations.
cache->nr_migrations has been renamed cache->nr_io_migrations.
cleanup_migration() is now called free_io_migration(), since it
decrements that variable.
Also, remove the unused cache->next_migration variable that got replaced
with with prealloc_structs a while ago.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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If a DM table is reloaded with an inactive table when the device is not
suspended (normal procedure for LVM2), then there will be two dm-bufio
objects that can diverge. This can lead to a situation where the
inactive table uses bufio to read metadata at the same time the active
table writes metadata -- resulting in the inactive table having stale
metadata buffers once it is promoted to the active table slot.
Fix this by using reference counting and a global list of cache metadata
objects to ensure there is only one metadata object per metadata device.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- Preemptible-RCU fixes, including fixing an old bug in the
interaction of RCU priority boosting and CPU hotplug.
- SRCU updates.
- RCU CPU stall-warning updates.
- RCU torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Support for keyword 'boolean' will be dropped later on.
No functional change.
Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
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SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.
The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.
If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.
text data bss dec hex filename
2007 0 0 2007 7d7 kernel/rcu/srcu.o
Size of arch/powerpc/boot/zImage changes from
text data bss dec hex filename
831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before
829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after
so the savings are about ~2000 bytes.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
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In bio-based DM's clone_endio(), when target_type doesn't implement
.end_io (e.g. linear) r will be always be initialized 0. So if a
WRITE SAME bio fails WRITE SAME will not be disabled as intended.
Fix this by initializing r to error, rather than 0, in clone_endio().
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Fixes: 7eee4ae2db ("dm: disable WRITE SAME if it fails")
Cc: stable@vger.kernel.org
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Commit 80e96c5484be ("dm thin: do not allow thin device activation
while pool is suspended") delayed the initialization of a new thin
device's refcount and completion until after this new thin was added
to the pool's active_thins list and the pool lock is released. This
opens a race with a worker thread that walks the list and calls
thin_get/put, noticing that the refcount goes to 0 and calling
complete, freezing up the system and giving the oops below:
kernel: BUG: unable to handle kernel NULL pointer dereference at (null)
kernel: IP: [<ffffffff810d360b>] __wake_up_common+0x2b/0x90
kernel: Call Trace:
kernel: [<ffffffff810d3683>] __wake_up_locked+0x13/0x20
kernel: [<ffffffff810d3dc7>] complete+0x37/0x50
kernel: [<ffffffffa0595c50>] thin_put+0x20/0x30 [dm_thin_pool]
kernel: [<ffffffffa059aab7>] do_worker+0x667/0x870 [dm_thin_pool]
kernel: [<ffffffff816a8a4c>] ? __schedule+0x3ac/0x9a0
kernel: [<ffffffff810b1aef>] process_one_work+0x14f/0x400
kernel: [<ffffffff810b206b>] worker_thread+0x6b/0x490
kernel: [<ffffffff810b2000>] ? rescuer_thread+0x260/0x260
kernel: [<ffffffff810b6a7b>] kthread+0xdb/0x100
kernel: [<ffffffff810b69a0>] ? kthread_create_on_node+0x170/0x170
kernel: [<ffffffff816ad7ec>] ret_from_fork+0x7c/0xb0
kernel: [<ffffffff810b69a0>] ? kthread_create_on_node+0x170/0x170
Set the thin device's initial refcount and initialize the completion
before adding it to the pool's active_thins list in thin_ctr().
Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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are released
Discard bios and thin device deletion have the potential to release data
blocks. If the thin-pool is in out-of-data-space mode, and blocks were
released, transition the thin-pool back to full write mode.
The correct time to do this is just after the thin-pool metadata commit.
It cannot be done before the commit because the space maps will not
allow immediate reuse of the data blocks in case there's a rollback
following power failure.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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When the pool was in PM_OUT_OF_SPACE mode its process_prepared_discard
function pointer was incorrectly being set to
process_prepared_discard_passdown rather than process_prepared_discard.
This incorrect function pointer meant the discard was being passed down,
but not effecting the mapping. As such any discard that was issued, in
an attempt to reclaim blocks, would not successfully free data space.
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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Pull md updates from Neil Brown:
"Three fixes for md.
I did have a largish set of locking changes queued, but late testing
showed they weren't quite as stable as I thought and while I fixed
what I found, I decided it safer to delay them a release ...
particularly as I'll be AFK for a few weeks. So expect a larger batch
next time :-)"
* tag 'md/3.19' of git://neil.brown.name/md:
md: Check MD_RECOVERY_RUNNING as well as ->sync_thread.
md: fix semicolon.cocci warnings
md/raid5: fetch_block must fetch all the blocks handle_stripe_dirtying wants.
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Pull block layer driver updates from Jens Axboe:
- NVMe updates:
- The blk-mq conversion from Matias (and others)
- A stack of NVMe bug fixes from the nvme tree, mostly from Keith.
- Various bug fixes from me, fixing issues in both the blk-mq
conversion and generic bugs.
- Abort and CPU online fix from Sam.
- Hot add/remove fix from Indraneel.
- A couple of drbd fixes from the drbd team (Andreas, Lars, Philipp)
- With the generic IO stat accounting from 3.19/core, converting md,
bcache, and rsxx to use those. From Gu Zheng.
- Boundary check for queue/irq mode for null_blk from Matias. Fixes
cases where invalid values could be given, causing the device to hang.
- The xen blkfront pull request, with two bug fixes from Vitaly.
* 'for-3.19/drivers' of git://git.kernel.dk/linux-block: (56 commits)
NVMe: fix race condition in nvme_submit_sync_cmd()
NVMe: fix retry/error logic in nvme_queue_rq()
NVMe: Fix FS mount issue (hot-remove followed by hot-add)
NVMe: fix error return checking from blk_mq_alloc_request()
NVMe: fix freeing of wrong request in abort path
xen/blkfront: remove redundant flush_op
xen/blkfront: improve protection against issuing unsupported REQ_FUA
NVMe: Fix command setup on IO retry
null_blk: boundary check queue_mode and irqmode
block/rsxx: use generic io stats accounting functions to simplify io stat accounting
md: use generic io stats accounting functions to simplify io stat accounting
drbd: use generic io stats accounting functions to simplify io stat accounting
md/bcache: use generic io stats accounting functions to simplify io stat accounting
NVMe: Update module version major number
NVMe: fail pci initialization if the device doesn't have any BARs
NVMe: add ->exit_hctx() hook
NVMe: make setup work for devices that don't do INTx
NVMe: enable IO stats by default
NVMe: nvme_submit_async_admin_req() must use atomic rq allocation
NVMe: replace blk_put_request() with blk_mq_free_request()
...
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A recent change to md started the ->sync_thread from a asynchronously
from a work_queue rather than synchronously. This means that there
can be a small window between the time when MD_RECOVERY_RUNNING is set
and when ->sync_thread is set.
So code that checks ->sync_thread might now conclude that the thread
has not been started and (because a lock is held) will not be started.
That is no longer the case.
Most of those places are best fixed by testing MD_RECOVERY_RUNNING
as well. To make this completely reliable, we wake_up(&resync_wait)
after clearing that flag as well as after clearing ->sync_thread.
Other places are better served by flushing the relevant workqueue
to ensure that that if the sync thread was starting, it has now
started. This is particularly best if we are about to stop the
sync thread.
Fixes: ac05f256691fe427a3e84c19261adb0b67dd73c0
Signed-off-by: NeilBrown <neilb@suse.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Significant DM thin-provisioning performance improvements to meet
performance requirements that were requested by the Gluster
distributed filesystem.
Specifically, dm-thinp now takes care to aggregate IO that will be
issued to the same thinp block before issuing IO to the underlying
devices. This really helps improve performance on HW RAID6 devices
that have a writeback cache because it avoids RMW in the HW RAID
controller.
- Some stable fixes: fix leak in DM bufio if integrity profiles were
enabled, use memzero_explicit in DM crypt to avoid any potential for
information leak, and a DM cache fix to properly mark a cache block
dirty if it was promoted to the cache via the overwrite optimization.
- A few simple DM persistent data library fixes
- DM cache multiqueue policy block promotion improvements.
- DM cache discard improvements that take advantage of range
(multiblock) discard support in the DM bio-prison. This allows for
much more efficient bulk discard processing (e.g. when mkfs.xfs
discards the entire device).
- Some small optimizations in DM core and RCU deference cleanups
- DM core changes to suspend/resume code to introduce the new internal
suspend/resume interface that the DM thin-pool target now uses to
suspend/resume active thin devices when the thin-pool must
suspend/resume.
This avoids forcing userspace to track all active thin volumes in a
thin-pool when the thin-pool is suspended for the purposes of
metadata or data space resize.
* tag 'dm-3.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (49 commits)
dm crypt: use memzero_explicit for on-stack buffer
dm space map metadata: fix sm_bootstrap_get_count()
dm space map metadata: fix sm_bootstrap_get_nr_blocks()
dm bufio: fix memleak when using a dm_buffer's inline bio
dm cache: fix spurious cell_defer when dealing with partial block at end of device
dm cache: dirty flag was mistakenly being cleared when promoting via overwrite
dm cache: only use overwrite optimisation for promotion when in writeback mode
dm cache: discard block size must be a multiple of cache block size
dm cache: fix a harmless race when working out if a block is discarded
dm cache: when reloading a discard bitset allow for a different discard block size
dm cache: fix some issues with the new discard range support
dm array: if resizing the array is a noop set the new root to the old one
dm: use rcu_dereference_protected instead of rcu_dereference
dm thin: fix pool_io_hints to avoid looking at max_hw_sectors
dm thin: suspend/resume active thin devices when reloading thin-pool
dm: enhance internal suspend and resume interface
dm thin: do not allow thin device activation while pool is suspended
dm: add presuspend_undo hook to target_type
dm: return earlier from dm_blk_ioctl if target doesn't implement .ioctl
dm thin: remove stale 'trim' message in block comment above pool_message
...
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drivers/md/md.c:7175:43-44: Unneeded semicolon
Removes unneeded semicolon.
Generated by: scripts/coccinelle/misc/semicolon.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
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It is critical that fetch_block() and handle_stripe_dirtying()
are consistent in their analysis of what needs to be loaded.
Otherwise raid5 can wait forever for a block that won't be loaded.
Currently when writing to a RAID5 that is resyncing, to a location
beyond the resync offset, handle_stripe_dirtying chooses a
reconstruct-write cycle, but fetch_block() assumes a
read-modify-write, and a lockup can happen.
So treat that case just like RAID6, just as we do in
handle_stripe_dirtying. RAID6 always does reconstruct-write.
This bug was introduced when the behaviour of handle_stripe_dirtying
was changed in 3.7, so the patch is suitable for any kernel since,
though it will need careful merging for some versions.
Cc: stable@vger.kernel.org (v3.7+)
Fixes: a7854487cd7128a30a7f4f5259de9f67d5efb95f
Reported-by: Henry Cai <henryplusplus@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
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Use memzero_explicit to cleanup sensitive data allocated on stack
to prevent the compiler from optimizing and removing memset() calls.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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Must set 'result' accordingly rather than return it.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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This function isn't right and it causes a static checker warning:
drivers/md/dm-thin.c:3016 maybe_resize_data_dev()
error: potentially using uninitialized 'sb_data_size'.
It should set "*count" and return zero on success the same as the
sm_metadata_get_nr_blocks() function does earlier.
Fixes: 3241b1d3e0aa ('dm: add persistent data library')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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When dm-bufio sets out to use the bio built into a struct dm_buffer to
issue an IO, it needs to call bio_reset after it's done with the bio
so that we can free things attached to the bio such as the integrity
payload. Therefore, inject our own endio callback to take care of
the bio_reset after calling submit_io's end_io callback.
Test case:
1. modprobe scsi_debug delay=0 dif=1 dix=199 ato=1 dev_size_mb=300
2. Set up a dm-bufio client, e.g. dm-verity, on the scsi_debug device
3. Repeatedly read metadata and watch kmalloc-192 leak!
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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device
We never bother caching a partial block that is at the back end of the
origin device. No cell ever gets locked, but the calling code was
assuming it was and trying to release it.
Now the code only releases if the cell has been set to a non NULL
value.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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If the incoming bio is a WRITE and completely covers a block then we
don't bother to do any copying for a promotion operation. Once this is
done the cache block and origin block will be different, so we need to
set it to 'dirty'.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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Overwrite causes the cache block and origin blocks to diverge, which
is only allowed in writeback mode.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
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Otherwise the cache blocks may span two discard blocks, which we don't
handle when doing the discard lookup.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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It is more correct to hold the cell before checking the discard state.
These flags are only used as hints to the policy so this change will
have negligable effect.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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block size
The discard block size can change if the origin changes size or if an
old DM cache is upgraded from using a discard block size that was equal
to cache block size.
To fix this an extent of discarded blocks is established for the purpose
of translating the old discard block size to the new in-core discard
block size and set bits. The old (potentially huge) discard bitset is
left ondisk until it is re-written using the new in-core information on
the next successful DM cache shutdown.
Fixes: 7ae34e777896 ("dm cache: improve discard support")
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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Commit 7ae34e777 ("dm cache: improve discard support") needed to also:
- discontinue having DM core split the discard bios on cache block
boundaries
- calculate the cache's discard_nr_blocks relative to the determined
discard_block_size rather than using oblock_to_dblock()
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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This could've been quite bad (to return success but not update the new
root to point at the old) but in practice the only known consumer of the
dm array code is the DM cache target. And the DM cache target passes in
the same old root to array_resize() anyway.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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Use generic io stats accounting help functions (generic_{start,end}_io_acct)
to simplify io stat accounting.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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