data to a mempool allocation (which offers allocation with cpu locality,
and there is no inter-cpu communication on slab allocation).
A couple dm-thinp stable fixes to address "out-of-data-space" issues.
A dm-multipath fix for a LOCKDEP warning introduced in 3.15-rc1.
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Merge tag 'dm-3.15-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer:
"A dm-crypt fix for a cpu hotplug crash that switches from using
per-cpu data to a mempool allocation (which offers allocation with cpu
locality, and there is no inter-cpu communication on slab allocation).
A couple dm-thinp stable fixes to address "out-of-data-space" issues.
A dm-multipath fix for a LOCKDEP warning introduced in 3.15-rc1"
* tag 'dm-3.15-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm mpath: fix lock order inconsistency in multipath_ioctl
dm thin: add timeout to stop out-of-data-space mode holding IO forever
dm thin: allow metadata commit if pool is in PM_OUT_OF_DATA_SPACE mode
dm crypt: fix cpu hotplug crash by removing per-cpu structure
Commit 3e9f1be1b4 ("dm mpath: remove process_queued_ios()") did not
consistently take the multipath device's spinlock (m->lock) before
calling dm_table_run_md_queue_async() -- which takes the q->queue_lock.
Found with code inspection using hint from reported lockdep warning.
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the pool runs out of data space, dm-thin can be configured to
either error IOs that would trigger provisioning, or hold those IOs
until the pool is resized. Unfortunately, holding IOs until the pool is
resized can result in a cascade of tasks hitting the hung_task_timeout,
which may render the system unavailable.
Add a fixed timeout so IOs can only be held for a maximum of 60 seconds.
If LVM is going to resize a thin-pool that is out of data space it needs
to be prompt about it.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
Commit 3e1a0699 ("dm thin: fix out of data space handling") introduced
a regression in the metadata commit() method by returning an error if
the pool is in PM_OUT_OF_DATA_SPACE mode. This oversight caused a thin
device to return errors even if the default queue_if_no_space ENOSPC
handling mode is used.
Fix commit() to only fail if pool is in PM_READ_ONLY or PM_FAIL mode.
Reported-by: qindehua@163.com
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
The DM crypt target used per-cpu structures to hold pointers to a
ablkcipher_request structure. The code assumed that the work item keeps
executing on a single CPU, so it didn't use synchronization when
accessing this structure.
If a CPU is disabled by writing 0 to /sys/devices/system/cpu/cpu*/online,
the work item could be moved to another CPU. This causes dm-crypt
crashes, like the following, because the code starts using an incorrect
ablkcipher_request:
smpboot: CPU 7 is now offline
BUG: unable to handle kernel NULL pointer dereference at 0000000000000130
IP: [<ffffffffa1862b3d>] crypt_convert+0x12d/0x3c0 [dm_crypt]
...
Call Trace:
[<ffffffffa1864415>] ? kcryptd_crypt+0x305/0x470 [dm_crypt]
[<ffffffff81062060>] ? finish_task_switch+0x40/0xc0
[<ffffffff81052a28>] ? process_one_work+0x168/0x470
[<ffffffff8105366b>] ? worker_thread+0x10b/0x390
[<ffffffff81053560>] ? manage_workers.isra.26+0x290/0x290
[<ffffffff81058d9f>] ? kthread+0xaf/0xc0
[<ffffffff81058cf0>] ? kthread_create_on_node+0x120/0x120
[<ffffffff813464ac>] ? ret_from_fork+0x7c/0xb0
[<ffffffff81058cf0>] ? kthread_create_on_node+0x120/0x120
Fix this bug by removing the per-cpu definition. The structure
ablkcipher_request is accessed via a pointer from convert_context.
Consequently, if the work item is rescheduled to a different CPU, the
thread still uses the same ablkcipher_request.
This change may undermine performance improvements intended by commit
c0297721 ("dm crypt: scale to multiple cpus") on select hardware. In
practice no performance difference was observed on recent hardware. But
regardless, correctness is more important than performance.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Both tagged for -stable.
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Merge tag 'md/3.15-fixes' of git://neil.brown.name/md
Pull md bugfixes from Neil Brown:
"Two bugfixes for md in 3.15
Both tagged for -stable"
* tag 'md/3.15-fixes' of git://neil.brown.name/md:
md: avoid possible spinning md thread at shutdown.
md/raid10: call wait_barrier() for each request submitted.
If an md array with externally managed metadata (e.g. DDF or IMSM)
is in use, then we should not set safemode==2 at shutdown because:
1/ this is ineffective: user-space need to be involved in any 'safemode' handling,
2/ The safemode management code doesn't cope with safemode==2 on external metadata
and md_check_recover enters an infinite loop.
Even at shutdown, an infinite-looping process can be problematic, so this
could cause shutdown to hang.
Cc: stable@vger.kernel.org (any kernel)
Signed-off-by: NeilBrown <neilb@suse.de>
wait_barrier() includes a counter, so we must call it precisely once
(unless balanced by allow_barrier()) for each request submitted.
Since
commit 20d0189b10
block: Introduce new bio_split()
in 3.14-rc1, we don't call it for the extra requests generated when
we need to split a bio.
When this happens the counter goes negative, any resync/recovery will
never start, and "mdadm --stop" will hang.
Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: 20d0189b10
Cc: stable@vger.kernel.org (3.14+)
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: NeilBrown <neilb@suse.de>
A dm-verity fix for an immutable biovec regression that affects 3.14+.
A dm-cache fix to properly quiesce when using writethrough mode (3.14+).
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Merge tag 'dm-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer:
"A few dm-thinp fixes for changes merged in 3.15-rc1.
A dm-verity fix for an immutable biovec regression that affects 3.14+.
A dm-cache fix to properly quiesce when using writethrough mode (3.14+)"
* tag 'dm-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm cache: fix writethrough mode quiescing in cache_map
dm thin: use INIT_WORK_ONSTACK in noflush_work to avoid ODEBUG warning
dm verity: fix biovecs hash calculation regression
dm thin: fix rcu_read_lock being held in code that can sleep
dm thin: irqsave must always be used with the pool->lock spinlock
Commit 2ee57d5873 ("dm cache: add passthrough mode") inadvertently
removed the deferred set reference that was taken in cache_map()'s
writethrough mode support. Restore taking this reference.
This issue was found with code inspection.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
Use INIT_WORK_ONSTACK to silence "ODEBUG: object is on stack, but not
annotated".
Reported-by: Zdeněk Kabeláč <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
I hit another BUG_ON with e240c1839d. In __get_priority_stripe(),
stripe count equals to 0 initially. Between atomic_inc and BUG_ON,
get_active_stripe() finds the stripe. So the stripe count isn't 1 any more.
V2: keeps the BUG_ON suggested by Neil.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Commit 003b5c5719 ("block: Convert drivers
to immutable biovecs") incorrectly converted biovec iteration in
dm-verity to always calculate the hash from a full biovec, but the
function only needs to calculate the hash from part of the biovec (up to
the calculated "todo" value).
Fix this issue by limiting hash input to only the requested data size.
This problem was identified using the cryptsetup regression test for
veritysetup (verity-compat-test).
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
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Merge tag 'md/3.15' of git://neil.brown.name/md
Pull md updates from Neil Brown:
"Just a few md patches for the 3.15 merge window.
Not much happening in md/raid at the moment. Just a few bug fixes
(one for -stable) and a couple of performance tweaks"
* tag 'md/3.15' of git://neil.brown.name/md:
raid5: get_active_stripe avoids device_lock
raid5: make_request does less prepare wait
md: avoid oops on unload if some process is in poll or select.
md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails.
md/bitmap: don't abuse i_writecount for bitmap files.
For sequential workload (or request size big workload), get_active_stripe can
find cached stripe. In this case, we always hold device_lock, which exposes a
lot of lock contention for such workload. If stripe count isn't 0, we don't
need hold the lock actually, since we just increase its count. And this is the
hot code path for such workload. Unfortunately we must delete the BUG_ON.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
In NUMA machine, prepare_to_wait/finish_wait in make_request exposes a
lot of contention for sequential workload (or big request size
workload). For such workload, each bio includes several stripes. So we
can just do prepare_to_wait/finish_wait once for the whold bio instead
of every stripe. This reduces the lock contention completely for such
workload. Random workload might have the similar lock contention too,
but I didn't see it yet, maybe because my stroage is still not fast
enough.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If md-mod is unloaded while some process is in poll() or select(),
then that process maintains a pointer to md_event_waiters, and when
the try to unlink from that list, they will oops.
The procfs infrastructure ensures that ->poll won't be called after
remove_proc_entry, but doesn't provide a wait_queue_head for us to
use, and the waitqueue code doesn't provide a way to remove all
listeners from a waitqueue.
So we need to:
1/ make sure no further references to md_event_waiters are taken (by
setting md_unloading)
2/ wake up all processes currently waiting, and
3/ wait until all those processes have disconnected from our
wait_queue_head.
Reported-by: "majianpeng" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When performing a user-request check/repair (MD_RECOVERY_REQUEST is set)
on a raid1, we allocate multiple bios each with their own set of pages.
If the page allocations for one bio fails, we currently do *not* free
the pages allocated for the previous bios, nor do we free the bio itself.
This patch frees all the already-allocate pages, and makes sure that
all the bios are freed as well.
This bug can cause a memory leak which can ultimately OOM a machine.
It was introduced in 3.10-rc1.
Fixes: a07876064a
Cc: Kent Overstreet <koverstreet@google.com>
Cc: stable@vger.kernel.org (3.10+)
Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
md bitmap code currently tries to use i_writecount to stop any other
process from writing to out bitmap file. But that is really an abuse
and has bit-rotted so locking is all wrong.
So discard that - root should be allowed to shoot self in foot.
Still use it in a much less intrusive way to stop the same file being
used as bitmap on two different array, and apply other checks to
ensure the file is at least vaguely usable for bitmap storage
(is regular, is open for write. Support for ->bmap is already checked
elsewhere).
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
Commit c140e1c4e2 ("dm thin: use per thin device deferred bio lists")
introduced the use of an rculist for all active thin devices. The use
of rcu_read_lock() in process_deferred_bios() can result in a BUG if a
dm_bio_prison_cell must be allocated as a side-effect of bio_detain():
BUG: sleeping function called from invalid context at mm/mempool.c:203
in_atomic(): 1, irqs_disabled(): 0, pid: 6, name: kworker/u8:0
3 locks held by kworker/u8:0/6:
#0: ("dm-" "thin"){.+.+..}, at: [<ffffffff8106be42>] process_one_work+0x192/0x550
#1: ((&pool->worker)){+.+...}, at: [<ffffffff8106be42>] process_one_work+0x192/0x550
#2: (rcu_read_lock){.+.+..}, at: [<ffffffff816360b5>] do_worker+0x5/0x4d0
We can't process deferred bios with the rcu lock held, since
dm_bio_prison_cell allocation may block if the bio-prison's cell mempool
is exhausted.
To fix:
- Introduce a refcount and completion field to each thin_c
- Add thin_get/put methods for adjusting the refcount. If the refcount
hits zero then the completion is triggered.
- Initialise refcount to 1 when creating thin_c
- When iterating the active_thins list we thin_get() whilst the rcu
lock is held.
- After the rcu lock is dropped we process the deferred bios for that
thin.
- When destroying a thin_c we thin_put() and then wait for the
completion -- to avoid a race between the worker thread iterating
from that thin_c and destroying the thin_c.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit c140e1c4e2 ("dm thin: use per thin device deferred bio lists")
incorrectly stopped disabling irqs when taking the pool's spinlock.
Irqs must be disabled when taking the pool's spinlock otherwise a thread
could spin_lock(), then get interrupted to service thin_endio() in
interrupt context, which would then deadlock in spin_lock_irqsave().
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
cache_block_size
. Fix a lock-inversion detected by LOCKDEP in dm-cache
. Fix a dangling bio bug in the dm-thinp target's process_deferred_bios
error path
. Fix corruption due to non-atomic transaction commit which allowed a
metadata superblock to be written before all other metadata was
successfully written -- this is common to all targets that use the
persistent-data library's transaction manager (dm-thinp, dm-cache and
dm-era).
. Various small cleanups in the DM core
. Add the dm-era target which is useful for keeping track of which
blocks were written within a user defined period of time called an
'era'. Use cases include tracking changed blocks for backup software,
and partially invalidating the contents of a cache to restore cache
coherency after rolling back a vendor snapshot.
. Improve the on-disk layout of multithreaded writes to the dm-thin-pool
by splitting the pool's deferred bio list to be a per-thin device list
and then sorting that list using an rb_tree. The subsequent read
throughput of the data written via multiple threads improved by ~70%.
. Simplify the multipath target's handling of queuing IO by pushing
requests back to the request queue rather than queueing the IO
internally.
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Merge tag 'dm-3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper changes from Mike Snitzer:
- Fix dm-cache corruption caused by discard_block_size > cache_block_size
- Fix a lock-inversion detected by LOCKDEP in dm-cache
- Fix a dangling bio bug in the dm-thinp target's process_deferred_bios
error path
- Fix corruption due to non-atomic transaction commit which allowed a
metadata superblock to be written before all other metadata was
successfully written -- this is common to all targets that use the
persistent-data library's transaction manager (dm-thinp, dm-cache and
dm-era).
- Various small cleanups in the DM core
- Add the dm-era target which is useful for keeping track of which
blocks were written within a user defined period of time called an
'era'. Use cases include tracking changed blocks for backup
software, and partially invalidating the contents of a cache to
restore cache coherency after rolling back a vendor snapshot.
- Improve the on-disk layout of multithreaded writes to the
dm-thin-pool by splitting the pool's deferred bio list to be a
per-thin device list and then sorting that list using an rb_tree.
The subsequent read throughput of the data written via multiple
threads improved by ~70%.
- Simplify the multipath target's handling of queuing IO by pushing
requests back to the request queue rather than queueing the IO
internally.
* tag 'dm-3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits)
dm cache: fix a lock-inversion
dm thin: sort the per thin deferred bios using an rb_tree
dm thin: use per thin device deferred bio lists
dm thin: simplify pool_is_congested
dm thin: fix dangling bio in process_deferred_bios error path
dm mpath: print more useful warnings in multipath_message()
dm-mpath: do not activate failed paths
dm mpath: remove extra nesting in map function
dm mpath: remove map_io()
dm mpath: reduce memory pressure when requeuing
dm mpath: remove process_queued_ios()
dm mpath: push back requests instead of queueing
dm table: add dm_table_run_md_queue_async
dm mpath: do not call pg_init when it is already running
dm: use RCU_INIT_POINTER instead of rcu_assign_pointer in __unbind
dm: stop using bi_private
dm: remove dm_get_mapinfo
dm: make dm_table_alloc_md_mempools static
dm: take care to copy the space map roots before locking the superblock
dm transaction manager: fix corruption due to non-atomic transaction commit
...
When suspending a cache the policy is walked and the individual policy
hints written to the metadata via sync_metadata(). This led to this
lock order:
policy->lock
cache_metadata->root_lock
When loading the cache target the policy is populated while the metadata
lock is held:
cache_metadata->root_lock
policy->lock
Fix this potential lock-inversion (ABBA) deadlock in sync_metadata() by
ensuring the cache_metadata root_lock is held whilst all the hints are
written, rather than being repeatedly locked while policy->lock is held
(as was the case with each callout that policy_walk_mappings() made to
the old save_hint() method).
Found by turning on the CONFIG_PROVE_LOCKING ("Lock debugging: prove
locking correctness") build option. However, it is not clear how the
LOCKDEP reported paths can lead to a deadlock since the two paths,
suspending a target and loading a target, never occur at the same time.
But that doesn't mean the same lock-inversion couldn't have occurred
elsewhere.
Reported-by: Marian Csontos <mcsontos@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
A thin-pool will allocate blocks using FIFO order for all thin devices
which share the thin-pool. Because of this simplistic allocation the
thin-pool's space can become fragmented quite easily; especially when
multiple threads are requesting blocks in parallel.
Sort each thin device's deferred_bio_list based on logical sector to
help reduce fragmentation of the thin-pool's ondisk layout.
The following tables illustrate the realized gains/potential offered by
sorting each thin device's deferred_bio_list. An "io size"-sized random
read of the device would result in "seeks/io" fragments being read, with
an average "distance/seek" between each fragment.
Data was written to a single thin device using multiple threads via
iozone (8 threads, 64K for both the block_size and io_size).
unsorted:
io size seeks/io distance/seek
--------------------------------------
4k 0.000 0b
16k 0.013 11m
64k 0.065 11m
256k 0.274 10m
1m 1.109 10m
4m 4.411 10m
16m 17.097 11m
64m 60.055 13m
256m 148.798 25m
1g 809.929 21m
sorted:
io size seeks/io distance/seek
--------------------------------------
4k 0.000 0b
16k 0.000 1g
64k 0.001 1g
256k 0.003 1g
1m 0.011 1g
4m 0.045 1g
16m 0.181 1g
64m 0.747 1011m
256m 3.299 1g
1g 14.373 1g
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Pull block driver update from Jens Axboe:
"On top of the core pull request, here's the pull request for the
driver related changes for 3.15. It contains:
- Improvements for msi-x registration for block drivers (mtip32xx,
skd, cciss, nvme) from Alexander Gordeev.
- A round of cleanups and improvements for drbd from Andreas
Gruenbacher and Rashika Kheria.
- A round of clanups and improvements for bcache from Kent.
- Removal of sleep_on() and friends in DAC960, ataflop, swim3 from
Arnd Bergmann.
- Bug fix for a bug in the mtip32xx async completion code from Sam
Bradshaw.
- Bug fix for accidentally bouncing IO on 32-bit platforms with
mtip32xx from Felipe Franciosi"
* 'for-3.15/drivers' of git://git.kernel.dk/linux-block: (103 commits)
bcache: remove nested function usage
bcache: Kill bucket->gc_gen
bcache: Kill unused freelist
bcache: Rework btree cache reserve handling
bcache: Kill btree_io_wq
bcache: btree locking rework
bcache: Fix a race when freeing btree nodes
bcache: Add a real GC_MARK_RECLAIMABLE
bcache: Add bch_keylist_init_single()
bcache: Improve priority_stats
bcache: Better alloc tracepoints
bcache: Kill dead cgroup code
bcache: stop moving_gc marking buckets that can't be moved.
bcache: Fix moving_pred()
bcache: Fix moving_gc deadlocking with a foreground write
bcache: Fix discard granularity
bcache: Fix another bug recovering from unclean shutdown
bcache: Fix a bug recovering from unclean shutdown
bcache: Fix a journalling reclaim after recovery bug
bcache: Fix a null ptr deref in journal replay
...
Here's the big char/misc driver updates for 3.15-rc1.
Lots of various things here, including the new mcb driver subsystem.
All of these have been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver patches from Greg KH:
"Here's the big char/misc driver updates for 3.15-rc1.
Lots of various things here, including the new mcb driver subsystem.
All of these have been in linux-next for a while"
* tag 'char-misc-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (118 commits)
extcon: Move OF helper function to extcon core and change function name
extcon: of: Remove unnecessary function call by using the name of device_node
extcon: gpio: Use SIMPLE_DEV_PM_OPS macro
extcon: palmas: Use SIMPLE_DEV_PM_OPS macro
mei: don't use deprecated DEFINE_PCI_DEVICE_TABLE macro
mei: amthif: fix checkpatch error
mei: client.h fix checkpatch errors
mei: use cl_dbg where appropriate
mei: fix Unnecessary space after function pointer name
mei: report consistently copy_from/to_user failures
mei: drop pr_fmt macros
mei: make me hw headers private to me hw.
mei: fix memory leak of pending write cb objects
mei: me: do not reset when less than expected data is received
drivers: mcb: Fix build error discovered by 0-day bot
cs5535-mfgpt: Simplify dependencies
spmi: pm: drop bus-level PM suspend/resume routines
spmi: pmic_arb: make selectable on ARCH_QCOM
Drivers: hv: vmbus: Increase the limit on the number of pfns we can handle
pch_phub: Report error writing MAC back to user
...
The thin-pool previously only had a single deferred_bios list that would
collect bios for all thin devices in the pool. Split this per-pool
deferred_bios list out to per-thin deferred_bios_list -- doing so
enables increased parallelism when processing deferred bios. And now
that each thin device has it's own deferred_bios_list we can sort all
bios in the list using logical sector. The requeue code in error
handling path is also cleaner as a side-effect.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
The pool is congested if the pool is in PM_OUT_OF_DATA_SPACE mode. This
is more explicit/clear/efficient than inferring whether or not the pool
is congested by checking if retry_on_resume_list is empty.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
If unable to ensure_next_mapping() we must add the current bio, which
was removed from the @bios list via bio_list_pop, back to the
deferred_bios list before all the remaining @bios.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
The warning message "Unrecognised multipath message received" is
displayed in two different situations in multipath_message(): when the
number of arguments passed is invalid and when the string passed in
argv[0] is not recognized.
Make it easier to identify where the problem is by making these warnings
more specific with additional context for each case.
Signed-off-by: Jose Castillo <jcastillo@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
activate_path() is run without a lock, so the path might be
set to failed before activate_path() had a chance to run.
This patch add a check for ->active in activate_path() to
avoid unnecessary overhead by calling functions which are known
to be failing.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Return early for case when no path exists, and when the
pathgroup isn't ready. This eliminates the need for
extra nesting for the the common case.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
multipath_map() is now just a wrapper around map_io(), so we
can rename map_io() to multipath_map().
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
When multipath needs to requeue I/O in the block layer the per-request
context shouldn't be allocated, as it will be freed immediately
afterwards anyway. Avoiding this memory allocation will reduce memory
pressure during requeuing.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
process_queued_ios() has served 3 functions:
1) select pg and pgpath if none is selected
2) start pg_init if requested
3) dispatch queued IOs when pg is ready
Basically, a call to queue_work(process_queued_ios) can be replaced by
dm_table_run_md_queue_async(), which runs request queue and ends up
calling map_io(), which does 1), 2) and 3).
Exception is when !pg_ready() (which means either pg_init is running or
requested), then multipath_busy() prevents map_io() being called from
request_fn.
If pg_init is running, it should be ok as long as pg_init_done() does
the right thing when pg_init is completed, I.e.: restart pg_init if
!pg_ready() or call dm_table_run_md_queue_async() to kick map_io().
If pg_init is requested, we have to make sure the request is detected
and pg_init will be started. pg_init is requested in 3 places:
a) __choose_pgpath() in map_io()
b) __choose_pgpath() in multipath_ioctl()
c) pg_init retry in pg_init_done()
a) is ok because map_io() calls __pg_init_all_paths(), which does 2).
b) needs a call to __pg_init_all_paths(), which does 2).
c) needs a call to __pg_init_all_paths(), which does 2).
So this patch removes process_queued_ios() and ensures that
__pg_init_all_paths() is called at the appropriate locations.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
There is no reason why multipath needs to queue requests internally for
queue_if_no_path or pg_init; we should rather push them back onto the
request queue.
And while we're at it we can simplify the conditional statement in
map_io() to make it easier to read.
Since mpath no longer does internal queuing of I/O the table info no
longer emits the internal queue_size. Instead it displays 1 if queuing
is being used or 0 if it is not.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Introduce dm_table_run_md_queue_async() to run the request_queue of the
mapped_device associated with a request-based DM table.
Also add dm_md_get_queue() wrapper to extract the request_queue from a
mapped_device.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
This patch moves condition checks as a preparation of following
patches and has no effect on behaviour.
process_queued_ios() is the only caller of __pg_init_all_paths()
and 2 condition checks are moved from outside to inside without
side effects.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Replace rcu_assign_pointer(p, NULL) with RCU_INIT_POINTER(p, NULL).
The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure. And in the
case of the NULL pointer, there is no structure to initialize. So,
rcu_assign_pointer(p, NULL) can be safely converted to
RCU_INIT_POINTER(p, NULL).
Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Device mapper uses the bio structure's bi_private field as a pointer
to dm_target_io or dm_rq_clone_bio_info. But a bio structure is
embedded in the dm_target_io and dm_rq_clone_bio_info structures, so the
pointer to the structure that contains the bio can be found with the
container_of() macro.
Remove the use of bi_private and use container_of() instead.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Remove dm_get_mapinfo() because no target uses it. Targets can allocate
per-bio data using ti->per_bio_data_size, this is much more flexible
than union map_info.
Leave union map_info only for the request-based multipath target's use.
Also delete the unused "unsigned long long ll" field of union map_info.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Make the function dm_table_alloc_md_mempools static because it is not
called from another file.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In theory copying the space map root can fail, but in practice it never
does because we're careful to check what size buffer is needed.
But make certain we're able to copy the space map roots before
locking the superblock.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # drop dm-era and dm-cache changes as needed
The persistent-data library used by dm-thin, dm-cache, etc is
transactional. If anything goes wrong, such as an io error when writing
new metadata or a power failure, then we roll back to the last
transaction.
Atomicity when committing a transaction is achieved by:
a) Never overwriting data from the previous transaction.
b) Writing the superblock last, after all other metadata has hit the
disk.
This commit and the following commit ("dm: take care to copy the space
map roots before locking the superblock") fix a bug associated with (b).
When committing it was possible for the superblock to still be written
in spite of an io error occurring during the preceeding metadata flush.
With these commits we're careful not to take the write lock out on the
superblock until after the metadata flush has completed.
Change the transaction manager's semantics for dm_tm_commit() to assume
all data has been flushed _before_ the single superblock that is passed
in.
As a prerequisite, split the block manager's block unlocking and
flushing by simplifying dm_bm_flush_and_unlock() to dm_bm_flush(). Now
the unlocking must be done separately.
This issue was discovered by forcing io errors at the crucial time
using dm-flakey.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Discard block size not being equal to cache block size causes data
corruption by erroneously avoiding migrations in issue_copy() because
the discard state is being cleared for a group of cache blocks when it
should not.
Completely remove all code that enabled a distinction between the
cache block size and discard block size.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the discard block size is larger than the cache block size we will
not properly quiesce IO to a region that is about to be discarded. This
results in a race between a cache migration where no copy is needed, and
a write to an adjacent cache block that's within the same large discard
block.
Workaround this by limiting the discard_block_size to cache_block_size.
Also limit the max_discard_sectors to cache_block_size.
A more comprehensive fix that introduces range locking support in the
bio_prison and proper quiescing of a discard range that spans multiple
cache blocks is already in development.
Reported-by: Morgan Mears <Morgan.Mears@netapp.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
Cc: stable@vger.kernel.org
dm-era is a target that behaves similar to the linear target. In
addition it keeps track of which blocks were written within a user
defined period of time called an 'era'. Each era target instance
maintains the current era as a monotonically increasing 32-bit
counter.
Use cases include tracking changed blocks for backup software, and
partially invalidating the contents of a cache to restore cache
coherency after rolling back a vendor snapshot.
dm-era is primarily expected to be paired with the dm-cache target.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Uninlined nested functions can cause crashes when using ftrace, as they don't
follow the normal calling convention and confuse the ftrace function graph
tracer as it examines the stack.
Also, nested functions are supported as a gcc extension, but may fail on other
compilers (e.g. llvm).
Signed-off-by: John Sheu <john.sheu@gmail.com>
