Pull cgroup updates from Tejun Heo:
"The bulk of changes are cleanups and preparations for the upcoming
kernfs conversion.
- cgroup_event mechanism which is and will be used only by memcg is
moved to memcg.
- pidlist handling is updated so that it can be served by seq_file.
Also, the list is not sorted if sane_behavior. cgroup
documentation explicitly states that the file is not sorted but it
has been for quite some time.
- All cgroup file handling now happens on top of seq_file. This is
to prepare for kernfs conversion. In addition, all operations are
restructured so that they map 1-1 to kernfs operations.
- Other cleanups and low-pri fixes"
* 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (40 commits)
cgroup: trivial style updates
cgroup: remove stray references to css_id
doc: cgroups: Fix typo in doc/cgroups
cgroup: fix fail path in cgroup_load_subsys()
cgroup: fix missing unlock on error in cgroup_load_subsys()
cgroup: remove for_each_root_subsys()
cgroup: implement for_each_css()
cgroup: factor out cgroup_subsys_state creation into create_css()
cgroup: combine css handling loops in cgroup_create()
cgroup: reorder operations in cgroup_create()
cgroup: make for_each_subsys() useable under cgroup_root_mutex
cgroup: css iterations and css_from_dir() are safe under cgroup_mutex
cgroup: unify pidlist and other file handling
cgroup: replace cftype->read_seq_string() with cftype->seq_show()
cgroup: attach cgroup_open_file to all cgroup files
cgroup: generalize cgroup_pidlist_open_file
cgroup: unify read path so that seq_file is always used
cgroup: unify cgroup_write_X64() and cgroup_write_string()
cgroup: remove cftype->read(), ->read_map() and ->write()
hugetlb_cgroup: convert away from cftype->read()
...
As release_stripe and __release_stripe decrement ->count and then
manipulate ->lru both under ->device_lock, it is important that
get_active_stripe() increments ->count and clears ->lru also under
->device_lock.
However we currently list_del_init ->lru under the lock, but increment
the ->count outside the lock. This can lead to races and list
corruption.
So move the atomic_inc(&sh->count) up inside the ->device_lock
protected region.
Note that we still increment ->count without device lock in the case
where get_free_stripe() was called, and in fact don't take
->device_lock at all in that path.
This is safe because if the stripe_head can be found by
get_free_stripe, then the hash lock assures us the no-one else could
possibly be calling release_stripe() at the same time.
Fixes: 566c09c534
Cc: stable@vger.kernel.org (3.13)
Reported-and-tested-by: Ian Kumlien <ian.kumlien@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This bug was introduced in commit 7e664b3dec ("dm space map metadata:
fix extending the space map").
When extending a dm-thin metadata volume we:
- Switch the space map into a simple bootstrap mode, which allocates
all space linearly from the newly added space.
- Add new bitmap entries for the new space
- Increment the reference counts for those newly allocated bitmap
entries
- Commit changes to disk
- Switch back out of bootstrap mode.
But, the disk commit may allocate space itself, if so this fact will be
lost when switching out of bootstrap mode.
The bug exhibited itself as an error when the bitmap_root, with an
erroneous ref count of 0, was subsequently decremented as part of a
later disk commit. This would cause the disk commit to fail, and thinp
to enter read_only mode. The metadata was not damaged (thin_check
passed).
The fix is to put the increments + commit into a loop, running until
the commit has not allocated extra space. In practise this loop only
runs twice.
With this fix the following device mapper testsuite test passes:
dmtest run --suite thin-provisioning -n thin_remove_works_after_resize
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # depends on commit 7e664b3dec
Here's the big driver core and sysfs patch set for 3.14-rc1.
There's a lot of work here moving sysfs logic out into a "kernfs" to
allow other subsystems to also have a virtual filesystem with the same
attributes of sysfs (handle device disconnect, dynamic creation /
removal as needed / unneeded, etc. This is primarily being done for
the cgroups filesystem, but the goal is to also move debugfs to it when
it is ready, solving all of the known issues in that filesystem as well.
The code isn't completed yet, but all should be stable now (there is a
big section that was reverted due to problems found when testing.)
There's also some other smaller fixes, and a driver core addition that
allows for a "collection" of objects, that the DRM people will be using
soon (it's in this tree to make merges after -rc1 easier.)
All of this has been in linux-next with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core / sysfs patches from Greg KH:
"Here's the big driver core and sysfs patch set for 3.14-rc1.
There's a lot of work here moving sysfs logic out into a "kernfs" to
allow other subsystems to also have a virtual filesystem with the same
attributes of sysfs (handle device disconnect, dynamic creation /
removal as needed / unneeded, etc)
This is primarily being done for the cgroups filesystem, but the goal
is to also move debugfs to it when it is ready, solving all of the
known issues in that filesystem as well. The code isn't completed
yet, but all should be stable now (there is a big section that was
reverted due to problems found when testing)
There's also some other smaller fixes, and a driver core addition that
allows for a "collection" of objects, that the DRM people will be
using soon (it's in this tree to make merges after -rc1 easier)
All of this has been in linux-next with no reported issues"
* tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (113 commits)
kernfs: associate a new kernfs_node with its parent on creation
kernfs: add struct dentry declaration in kernfs.h
kernfs: fix get_active failure handling in kernfs_seq_*()
Revert "kernfs: fix get_active failure handling in kernfs_seq_*()"
Revert "kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq"
Revert "kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()"
Revert "kernfs: remove KERNFS_REMOVED"
Revert "kernfs: restructure removal path to fix possible premature return"
Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"
Revert "kernfs: remove kernfs_addrm_cxt"
Revert "kernfs: make kernfs_get_active() block if the node is deactivated but not removed"
Revert "kernfs: implement kernfs_{de|re}activate[_self]()"
Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
Revert "pci: use device_remove_file_self() instead of device_schedule_callback()"
Revert "scsi: use device_remove_file_self() instead of device_schedule_callback()"
Revert "s390: use device_remove_file_self() instead of device_schedule_callback()"
Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
Revert "kernfs: remove unnecessary NULL check in __kernfs_remove()"
kernfs: remove unnecessary NULL check in __kernfs_remove()
drivers/base: provide an infrastructure for componentised subsystems
...
The cache's policy may have been established using the "default" alias,
which is currently the "mq" policy but the default policy may change in
the future. It is useful to know exactly which policy is being used.
Add a 'real' member to the dm_cache_policy_type structure and have the
"default" dm_cache_policy_type point to the real "mq"
dm_cache_policy_type. Update dm_cache_policy_get_name() to check if
real is set, if so report the name of the real policy (not the alias).
Requested-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 787a996cb2 ("dm thin: add error_if_no_space feature")
mistakenly forgot to increase the number of feature args supported.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Before a write starts we set a bit in the write-intent bitmap.
When the write completes we clear that bit if the write was successful
to all devices. However if the write wasn't fully successful we
should not clear the bit. If the faulty drive is subsequently
re-added, the fact that the bit is still set ensure that we will
re-write the data that is missing.
This logic is mediated by the STRIPE_DEGRADED flag - we only clear the
bitmap bit when this flag is not set.
Currently we correctly set the flag if a write starts when some
devices are failed or missing. But we do *not* set the flag if some
device failed during the write attempt.
This is wrong and can result in clearing the bit inappropriately.
So: set the flag when a write fails.
This bug has been present since bitmaps were introduces, so the fix is
suitable for any -stable kernel.
Reported-by: Ethan Wilson <ethan.wilson@shiftmail.org>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Verify that the cmd parameter passed to md_ioctl() is valid before
doing anything.
This fixes mddev->hold_active being set to 0 when an invalid ioctl
command is passed to md_ioctl() before the array has been configured.
Clearing mddev->hold_active in that case can lead to a livelock
situation when an invalid ioctl number is given to md_ioctl() by a
process when the mddev is currently being opened by another process:
Process 1 Process 2
--------- ---------
md_alloc()
mddev_find()
-> returns a new mddev with
hold_active == UNTIL_IOCTL
add_disk()
-> sends KOBJ_ADD uevent
(sees KOBJ_ADD uevent for device)
md_open()
md_ioctl(INVALID_IOCTL)
-> returns ENODEV and clears
mddev->hold_active
md_release()
md_put()
-> deletes the mddev as
hold_active is 0
md_open()
mddev_find()
-> returns a newly
allocated mddev with
mddev->gendisk == NULL
-> returns with ERESTARTSYS
(kernel restarts the open syscall)
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NeilBrown <neilb@suse.de>
All of these fix real bugs the people have hit, and are tagged
for -stable.
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Merge tag 'md/3.13-fixes' of git://neil.brown.name/md
Pull late md fixes from Neil Brown:
"Half a dozen md bug fixes.
All of these fix real bugs the people have hit, and are tagged for
-stable. Sorry they are late .... Christmas holidays and all that.
Hopefully they can still squeak into 3.13"
* tag 'md/3.13-fixes' of git://neil.brown.name/md:
md: fix problem when adding device to read-only array with bitmap.
md/raid10: fix bug when raid10 recovery fails to recover a block.
md/raid5: fix a recently broken BUG_ON().
md/raid1: fix request counting bug in new 'barrier' code.
md/raid10: fix two bugs in handling of known-bad-blocks.
md/raid5: Fix possible confusion when multiple write errors occur.
This reverts commit be35f48610 ("dm: wait until embedded kobject is
released before destroying a device") and provides an improved fix.
The kobject release code that calls the completion must be placed in a
non-module file, otherwise there is a module unload race (if the process
calling dm_kobject_release is preempted and the DM module unloaded after
the completion is triggered, but before dm_kobject_release returns).
To fix this race, this patch moves the completion code to dm-builtin.c
which is always compiled directly into the kernel if BLK_DEV_DM is
selected.
The patch introduces a new dm_kobject_holder structure, its purpose is
to keep the completion and kobject in one place, so that it can be
accessed from non-module code without the need to export the layout of
struct mapped_device to that code.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
This patch modifies dm-snapshot so that it prefetches the buffers when
loading the exceptions.
The number of buffers read ahead is specified in the DM_PREFETCH_CHUNKS
macro. The current value for DM_PREFETCH_CHUNKS (12) was found to
provide the best performance on a single 15k SCSI spindle. In the
future we may modify this default or make it configurable.
Also, introduce the function dm_bufio_set_minimum_buffers to setup
bufio's number of internal buffers before freeing happens. dm-bufio may
hold more buffers if enough memory is available. There is no guarantee
that the specified number of buffers will be available - if you need a
guarantee, use the argument reserved_buffers for
dm_bufio_client_create.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use dm-bufio for initial loading of the exceptions.
Introduce a new function dm_bufio_forget that frees the given buffer.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Change the functions get_exception, read_exception and insert_exceptions
so that ps->area is passed as an argument.
This patch doesn't change any functionality, but it refactors the code
to allow for a cleaner switch over to using dm-bufio.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The list of initial exceptions is loaded in the target constructor. We
are allowed to allocate memory with GFP_KERNEL at this point. So,
change alloc_completed_exception to use GFP_KERNEL when being called
from the constructor.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
level_store() currently does not make sure the metadata is
updates to reflect the new raid level. It simply sets MD_CHANGE_DEVS.
Any level with a ->thread will quickly notice this and update the
metadata. However RAID0 and Linear do not have a thread so no
metadata update happens until the array is stopped. At that point the
metadata is written.
This is later that we would like. While the delay doesn't risk any
data it can cause confusion. So if there is no md thread, immediately
update the metadata after a level change.
Reported-by: Richard Michael <rmichael@edgeofthenet.org>
Signed-off-by: NeilBrown <neilb@suse.de>
This is the raid10 equivalent of
commit 4f0a5e012c
MD RAID1: Further conditionalize 'fullsync'
If a device in a newly assembled array is not fully recovered we
currently do a fully resync by don't need to.
Signed-off-by: NeilBrown <neilb@suse.de>
When adding a new device into an array it is normally important to
clear any stale data from ->recovery_offset else the new device may
not be recovered properly.
However when re-adding a device which is known to be nearly in-sync,
this is not needed and can be detrimental. The (bitmap-based)
resync will still happen, and further recovery is only needed from
where-ever it was already up to.
So if save_raid_disk is set, signifying a re-add, don't clear
->recovery_offset.
Signed-off-by: NeilBrown <neilb@suse.de>
Since commit d70ed2e4fa
MD: Allow restarting an interrupted incremental recovery.
we don't write out the metadata to devices while they are recovering.
This had a good reason, but has unfortunate consequences. This patch
changes things to make them work better.
At issue is what happens if the array is shut down while a recovery is
happening, particularly a bitmap-guided recovery.
Ideally the recovery should pick up where it left off.
However the metadata cannot represent the state "A recovery is in
process which is guided by the bitmap".
Before the above mentioned commit, we wrote metadata to the device
which said "this is being recovered and it is up to <here>". So after
a restart, a full recovery (not bitmap-guided) would happen from
where-ever it was up to.
After the commit the metadata wasn't updated so it still said "This
device is fully in sync with <this> event count". That leads to a
bitmap-based recovery following the whole bitmap, which should be a
lot less work than a full recovery from some starting point. So this
was an improvement.
However updates some metadata but not all leads to other problems.
In particular, the metadata written to the fully-up-to-date device
record that the array has all devices present (even though some are
recovering). So on restart, mdadm wants to find all devices and
expects them to have current event counts.
Obviously it doesn't (some have old event counts) so (when assembling
with --incremental) it waits indefinitely for the rest of the expected
devices.
It really is wrong to not update all the metadata together. Do that
is bound to cause confusion.
Instead, we should make it possible to record the truth in the
metadata. i.e. we need to be able to record that a device is being
recovered based on the bitmap.
We already have a Feature flag to say that recovery is happening. We
now add another one to say that it is a bitmap-based recovery.
With this we can remove the code that disables the write-out of
metadata on some devices.
So this patch:
- moves the setting of 'saved_raid_disk' from add_new_disk to
the validate_super methods. This makes sure it is always set
properly, both when adding a new device to an array, and when
assembling an array from a collection of devices.
- Adds a metadata flag MD_FEATURE_RECOVERY_BITMAP which is only
used if MD_FEATURE_RECOVERY_OFFSET is set, and record that a
bitmap-based recovery is allowed.
This is only present in v1.x metadata. v0.90 doesn't support
devices which are in the middle of recovery at all.
- Only skips writing metadata to Faulty devices.
- Also allows rdev state to be set to "-insync" via sysfs.
This can be used for external-metadata arrays. When the
'role' is set the device is assumed to be in-sync. If, after
setting the role, we set the state to "-insync", the role is
moved to saved_raid_disk which effectively says the device is
partly in-sync with that slot and needs a bitmap recovery.
Cc: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If an array is started degraded, and then the missing device
is found it can be re-added and a minimal bitmap-based recovery
will bring it fully up-to-date.
If the array is read-only a recovery would not be allowed.
But also if the array is read-only and the missing device was
present very recently, then there could be no need for any
recovery at all, so we simply include the device in the read-only
array without any recovery.
However... if the missing device was removed a little longer ago
it could be missing some updates, but if a bitmap is present it will
be conditionally accepted pending a bitmap-based update. We don't
currently detect this case properly and will include that old
device into the read-only array with no recovery even though it really
needs a recovery.
This patch keeps track of whether a bitmap-based-recovery is really
needed or not in the new Bitmap_sync rdev flag. If that is set,
then the device will not be added to a read-only array.
Cc: Andrei Warkentin <andreiw@vmware.com>
Fixes: d70ed2e4fa
Cc: stable@vger.kernel.org (3.2+)
Signed-off-by: NeilBrown <neilb@suse.de>
commit e875ecea26
md/raid10 record bad blocks as needed during recovery.
added code to the "cannot recover this block" path to record a bad
block rather than fail the whole recovery.
Unfortunately this new case was placed *after* r10bio was freed rather
than *before*, yet it still uses r10bio.
This is will crash with a null dereference.
So move the freeing of r10bio down where it is safe.
Cc: stable@vger.kernel.org (v3.1+)
Fixes: e875ecea26
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>
commit 6d183de407
md/raid5: fix newly-broken locking in get_active_stripe.
simplified a BUG_ON, but removed too much so now it sometimes fires
when it shouldn't.
When the STRIPE_EXPANDING flag is set, the stripe_head might be on a
special list while multiple stripe_heads are collected, or it might
not be on any list, even a 'free' list when the refcount is zero. As
long as STRIPE_EXPANDING is set, it will be found and added back to a
list eventually.
So both of the BUG_ONs which test for the ->lru being empty or not
need to avoid the case where STRIPE_EXPANDING is set.
The patch which broke this was marked for -stable, so this patch needs
to be applied to any branch that received 6d183de4
Fixes: 6d183de407
Cc: stable@vger.kernel.org (any release to which above was applied)
Signed-off-by: NeilBrown <neilb@suse.de>
The new iobarrier implementation in raid1 (which keeps normal writes
and resync activity separate) counts every request what is not before
the current resync point in either next_window_requests or
current_window_requests.
It flags that the request is counted by setting ->start_next_window.
allow_barrier follows this model exactly and decrements one of the
*_window_requests if and only if ->start_next_window is set.
However wait_barrier(), which increments *_window_requests uses a
slightly different test for setting -.start_next_window (which is set
from the return value of this function).
So there is a possibility of the counts getting out of sync, and this
leads to the resync hanging.
So change wait_barrier() to return a non-zero value in exactly the
same cases that it increments *_window_requests.
But was introduced in 3.13-rc1.
Reported-by: Bruno Wolff III <bruno@wolff.to>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68061
Fixes: 79ef3a8aa1
Cc: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If we discover a bad block when reading we split the request and
potentially read some of it from a different device.
The code path of this has two bugs in RAID10.
1/ we get a spin_lock with _irq, but unlock without _irq!!
2/ The calculation of 'sectors_handled' is wrong, as can be clearly
seen by comparison with raid1.c
This leads to at least 2 warnings and a probable crash is a RAID10
ever had known bad blocks.
Cc: stable@vger.kernel.org (v3.1+)
Fixes: 856e08e237
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>
commit 5d8c71f9e5
md: raid5 crash during degradation
Fixed a crash in an overly simplistic way which could leave
R5_WriteError or R5_MadeGood set in the stripe cache for devices
for which it is no longer relevant.
When those devices are removed and spares added the flags are still
set and can cause incorrect behaviour.
commit 14a75d3e07
md/raid5: preferentially read from replacement device if possible.
Fixed the same bug if a more effective way, so we can now revert
the original commit.
Reported-and-tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Cc: stable@vger.kernel.org (3.2+ - 3.2 will need a different fix though)
Fixes: 5d8c71f9e5
Signed-off-by: NeilBrown <neilb@suse.de>
Trivial: remove the few stray references to css_id, which itself
was removed in v3.13's 2ff2a7d03b "cgroup: kill css_id".
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Improve cache_status to emit:
<metadata block size> <#used metadata blocks>/<#total metadata blocks>
<cache block size> <#used cache blocks>/<#total cache blocks>
...
Adding the block sizes allows for easier calculation of the overall size
of both the metadata and cache devices. Adding <#total cache blocks>
provides useful context for how much of the cache is used.
Unfortunately these additions to the status will require updates to
users' scripts that monitor the cache status. But these changes help
provide more comprehensive information about the cache device and will
simplify tools that are being developed to manage dm-cache devices --
because they won't need to issue 3 operations to cobble together the
information that we can easily provide via a single status ioctl.
While updating the status documentation in cache.txt spaces were
tabify'd.
Requested-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
dm_btree_find_lowest_key is the reciprocal of dm_btree_find_highest_key.
Factor out common code for dm_btree_find_{highest,lowest}_key.
dm_btree_find_lowest_key is needed for an upcoming DM target, as such it
is best to get this interface in place.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
We need to return -EINTR after a split because we invalidated iterators
(and freed the btree node) - but if we were finished inserting, we don't
want to redo the traversal.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
When deciding what order to reuse buckets we take into account both the bucket's
priority (which indicates lru order) and also the amount of live data in that
bucket. The way they were scaled together wasn't as correct as it could be...
this patch improves and documents it.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Checks if two keys have equivalent header fields.
(good enough for replacement or merging)
Used in bch_bkey_try_merge, and replacing a key
in the btree.
Signed-off-by: Nicholas Swenson <nks@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Added generic header checks to bch_bkey_try_merge,
which then calls the bkey specific function
Removed extraneous checks from bch_extent_merge
Signed-off-by: Nicholas Swenson <nks@daterainc.com>
We're in the process of turning bset.c into library code, so none of the code in
that file should know about struct cache_set or struct btree - so, move the
btree traversal part of the stats code to sysfs.c.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
More disentangling bset.c from the rest of the bcache code - soon, the
sorting routines won't have any dependencies on any outside structs.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Only use extent comparison for comparing extents, so we're not using
START_KEY() on other key types (i.e. btree pointers)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Getting away from KEY_PTRS and moving toward KEY_U64s - and getting rid of magic
2s
Also - split out the part that checks against journal entry size so as to avoid
a dependancy on struct cache_set in bset.c
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Now that we've got code for raid5/6 stripe awareness, bcache just needs
to know about the stripes and when writing partial stripes is expensive
- we probably don't want to enable this optimization for raid1 or 10,
even though they have stripes. So add a flag to queue_limits.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
This error path shouldn't have been hit in practice.. and we've got reworked
reserve code coming soon so that it shouldn't _ever_ be bit... but if we've got
code for this error path it should be correct.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
We need a reserve for allocating buckets for new btree nodes - and now that
we've got multiple btrees, it really needs to be per btree.
This reworks the reserves so we've got separate freelists for each reserve
instead of watermarks, which seems to make things a bit cleaner, and it adds
some code so that btree_split() can make sure the reserve is available before it
starts.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Unnecessary since a bucket that has dirty pointers pointing to it can
never be invalidated - and skipping it is a measurable performance
boost, since the bucket gen will usually be a cache miss.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
We were unnecessarily waiting on a journal write to complete when we just needed
to start a journal write and start setting up the next one.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
The real fix is where we check the bytes we need against how much is
remaining - we also need to check for a journal entry bigger than our
buffer, we'll never write those and it would be bad if we tried to read
one.
Also improve the diagnostic messages.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
The code that handles overlapping extents that we've just read back in from disk
was depending on the behaviour of the code that handles overlapping extents as
we're inserting into a btree node in the case of an insert that forced an
existing extent to be split: on insert, if we had to split we'd also insert a
new extent to represent the top part of the old extent - and then that new
extent would get written out.
The code that read the extents back in thus not bother with splitting extents -
if it saw an extent that ovelapped in the middle of an older extent, it would
trim the old extent to only represent the bottom part, assuming that the
original insert would've inserted a new extent to represent the top part.
I still haven't figured out _how_ it can happen, but I'm now pretty convinced
(and testing has confirmed) that there's some kind of an obscure corner case
(probably involving extent merging, and multiple overwrites in different sets)
that breaks this. The fix is to change the mergesort fixup code to split extents
itself when required.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
When extending a metadata space map we should do the first commit whilst
still in bootstrap mode -- a mode where all blocks get allocated in the
new area.
That way the commit overhead is allocated from the newly added space.
Otherwise we risk running out of space.
With this fix, and the previous commit "dm space map common: make sure
new space is used during extend", the following device mapper testsuite
test passes:
dmtest run --suite thin-provisioning -n /resize_metadata_no_io/
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
When extending a low level space map we should update nr_blocks at
the start so the new space is used for the index entries.
Otherwise extend can fail, e.g.: sm_metadata_extend call sequence
that fails:
-> sm_ll_extend
-> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block
=> returns -ENOSPC because smm->begin == smm->ll.nr_blocks
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
There may be other parts of the kernel holding a reference on the dm
kobject. We must wait until all references are dropped before
deallocating the mapped_device structure.
The dm_kobject_release method signals that all references are dropped
via completion. But dm_kobject_release doesn't free the kobject (which
is embedded in the mapped_device structure).
This is the sequence of operations:
* when destroying a DM device, call kobject_put from dm_sysfs_exit
* wait until all users stop using the kobject, when it happens the
release method is called
* the release method signals the completion and should return without
delay
* the dm device removal code that waits on the completion continues
* the dm device removal code drops the dm_mod reference the device had
* the dm device removal code frees the mapped_device structure that
contains the kobject
Using kobject this way should avoid the module unload race that was
mentioned at the beginning of this thread:
https://lkml.org/lkml/2014/1/4/83
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
The comparison is always true and the compiler optimizes it out anyway.
Milan offered additional context relative to the original commit
784aae735d ("dm: add name and uuid to sysfs") which introduced the code:
"I think it is just relict of some experiments before I committed this
simple embedded sysfs kobj handling".
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In case CONFIG_DEBUG_OBJECTS_WORK is defined, it is needed to
call destroy_work_on_stack() which frees the debug object to pair
with INIT_WORK_ONSTACK().
Signed-off-by: Liu, Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Internally the mq policy maintains a promotion threshold variable. If
the hit count of a block not in the cache goes above this threshold it
gets promoted to the cache.
This patch introduces three new tunables that allow you to tweak the
promotion threshold by adding a small value. These adjustments depend
on the io type:
read_promote_adjustment: READ io, default 4
write_promote_adjustment: WRITE io, default 8
discard_promote_adjustment: READ/WRITE io to a discarded block, default 1
If you're trying to quickly warm a new cache device you may wish to
reduce these to encourage promotion. Remember to switch them back to
their defaults after the cache fills though.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The pool mode must not be switched until after the corresponding pool
process_* methods have been established. Otherwise, because
set_pool_mode() isn't interlocked with the IO path for performance
reasons, the IO path can end up executing process_* operations that
don't match the mode. This patch eliminates problems like the following
(as seen on really fast PCIe SSD storage when transitioning the pool's
mode from PM_READ_ONLY to PM_WRITE):
kernel: device-mapper: thin: 253:2: reached low water mark for data device: sending event.
kernel: device-mapper: thin: 253:2: no free data space available.
kernel: device-mapper: thin: 253:2: switching pool to read-only mode
kernel: device-mapper: thin: 253:2: switching pool to write mode
kernel: ------------[ cut here ]------------
kernel: WARNING: CPU: 11 PID: 7564 at drivers/md/dm-thin.c:995 handle_unserviceable_bio+0x146/0x160 [dm_thin_pool]()
...
kernel: Workqueue: dm-thin do_worker [dm_thin_pool]
kernel: 00000000000003e3 ffff880308831cc8 ffffffff8152ebcb 00000000000003e3
kernel: 0000000000000000 ffff880308831d08 ffffffff8104c46c ffff88032502a800
kernel: ffff880036409000 ffff88030ec7ce00 0000000000000001 00000000ffffffc3
kernel: Call Trace:
kernel: [<ffffffff8152ebcb>] dump_stack+0x49/0x5e
kernel: [<ffffffff8104c46c>] warn_slowpath_common+0x8c/0xc0
kernel: [<ffffffff8104c4ba>] warn_slowpath_null+0x1a/0x20
kernel: [<ffffffffa001e2c6>] handle_unserviceable_bio+0x146/0x160 [dm_thin_pool]
kernel: [<ffffffffa001f276>] process_bio_read_only+0x136/0x180 [dm_thin_pool]
kernel: [<ffffffffa0020b75>] process_deferred_bios+0xc5/0x230 [dm_thin_pool]
kernel: [<ffffffffa0020d31>] do_worker+0x51/0x60 [dm_thin_pool]
kernel: [<ffffffff81067823>] process_one_work+0x183/0x490
kernel: [<ffffffff81068c70>] worker_thread+0x120/0x3a0
kernel: [<ffffffff81068b50>] ? manage_workers+0x160/0x160
kernel: [<ffffffff8106e86e>] kthread+0xce/0xf0
kernel: [<ffffffff8106e7a0>] ? kthread_freezable_should_stop+0x70/0x70
kernel: [<ffffffff8153b3ec>] ret_from_fork+0x7c/0xb0
kernel: [<ffffffff8106e7a0>] ? kthread_freezable_should_stop+0x70/0x70
kernel: ---[ end trace 3f00528e08ffa55c ]---
kernel: device-mapper: thin: pool mode is PM_WRITE not PM_READ_ONLY like expected!?
dm-thin.c:995 was the WARN_ON_ONCE(get_pool_mode(pool) != PM_READ_ONLY);
at the top of handle_unserviceable_bio(). And as the additional
debugging I had conveys: the pool mode was _not_ PM_READ_ONLY like
expected, it was already PM_WRITE, yet pool->process_bio was still set
to process_bio_read_only().
Also, while fixing this up, reduce logging of redundant pool mode
transitions by checking new_mode is different from old_mode.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
The pool's error_if_no_space flag can easily serve the same purpose that
no_free_space did, namely: control whether handle_unserviceable_bio()
will error a bio or requeue it.
This is cleaner since error_if_no_space is established when the pool's
features are processed during table load. So it avoids managing the
no_free_space flag by taking the pool's spinlock.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the pool runs out of data or metadata space, the pool can either
queue or error the IO destined to the data device. The default is to
queue the IO until more space is added.
An admin may now configure the pool to error IO when no space is
available by setting the 'error_if_no_space' feature when loading the
thin-pool table.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Now that we switch the pool to read-only mode when the data device runs
out of space it causes active writers to get IO errors once we resume
after resizing the data device.
If no_free_space is set, save bios to the 'retry_on_resume_list' and
requeue them on resume (once the data or metadata device may have been
resized).
With this patch the resize_io test passes again (on slower storage):
dmtest run --suite thin-provisioning -n /resize_io/
Later patches fix some subtle races associated with the pool mode
transitions done as part of the pool's -ENOSPC handling. These races
are exposed on fast storage (e.g. PCIe SSD).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Factor out_of_data_space() out of alloc_data_block(). Eliminate the use
of 'no_free_space' as a latch in alloc_data_block() -- this is no longer
needed now that we switch to read-only mode when we run out of data or
metadata space. In a later patch, the 'no_free_space' flag will be
eliminated entirely (in favor of checking metadata rather than relying
on a transient flag).
Move no metdata space handling into metdata_operation_failed(). Set
no_free_space when metadata space is exhausted too. This is useful,
because it offers consistency, for the following patch that will requeue
data IOs if no_free_space.
Also, rename no_space() to retry_bios_on_resume().
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Introduce metadata_operation_failed() wrappers, around set_pool_mode(),
to assist with improving the consistency of how metadata failures are
handled. Logging is improved and metadata operation failures trigger
read-only mode immediately.
Also, eliminate redundant set_pool_mode() calls in the two
alloc_data_block() caller's error paths.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Factor check_low_water_mark() out of alloc_data_block().
Change a couple unsigned flags in the pool structure to bool.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Mappings could be processed in descending logical block order,
particularly if buffered IO is used. This could adversely affect the
latency of IO processing. Fix this by adding mappings to the end of the
'prepared_mappings' and 'prepared_discards' lists.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Also, move 'err' member in dm_thin_new_mapping structure to eliminate 4
byte hole (reduces size from 88 bytes to 80).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
DM's persistent-data library is now used my multiple targets so
exclusive references to "pool" or "thin provisioning" need to be
cleaned up. Adjust Kconfig's DM_DEBUG_BLOCK_STACK_TRACING text
and remove "pool" from a block manager error message.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
The "unable to allocate new metadata block" error can be a particularly
verbose error if there is a systemic issue with the metadata device.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Starting with commit c0820cf5ad ("dm: introduce per_bio_data"),
device mapper has the capability to pre-allocate a target-specific
structure with the bio.
This patch changes dm-delay to use this facility instead of a slab cache
and mempool.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A device mapper table is allocated in the following way:
* The function dm_table_create is called, it gets the number of targets
as an argument -- it allocates a targets array accordingly.
* For each target, we call dm_table_add_target.
If we add more targets than were specified in dm_table_create, the
function dm_table_add_target reallocates the targets array. However,
this reallocation code is wrong - it moves the targets array to a new
location, while some target constructors hold pointers to the array in
the old location.
The following DM target drivers save the pointer to the target
structure, so they corrupt memory if the target array is moved:
multipath, raid, mirror, snapshot, stripe, switch, thin, verity.
Under normal circumstances, the reallocation function is not called
(because dm_table_create is called with the correct number of targets),
so the buggy reallocation code is not used.
Prior to the fix "dm table: fail dm_table_create on dm_round_up
overflow", the reallocation code could only be used in case the user
specifies too large a value in param->target_count, such as 0xffffffff.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If a snapshot is created and later deleted the origin dm_thin_device's
snapshotted_time will have been updated to reflect the snapshot's
creation time. The 'shared' flag in the dm_thin_lookup_result struct
returned from dm_thin_find_block() is an approximation based on
snapshotted_time -- this is done to avoid 0(n), or worse, time
complexity. In this case, the shared flag would be true.
But because the 'shared' flag reflects an approximation a block can be
incorrectly assumed to be shared (e.g. false positive for 'shared'
because the snapshot no longer exists). This could result in discards
issued to a thin device not being passed down to the pool's underlying
data device.
To fix this we double check that a thin block is really still in-use
after a mapping is removed using dm_pool_block_is_used(). If the
reference count for a block is now zero the discard is allowed to be
passed down.
Also add a 'definitely_not_shared' member to the dm_thin_new_mapping
structure -- reflects that the 'shared' flag in the response from
dm_thin_find_block() can only be held as definitive if false is
returned.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1043527
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
As additional members are added to the dm_thin_new_mapping structure
care should be taken to make sure they get initialized before use.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
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Merge tag 'v3.13-rc6' into for-3.14/core
Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.
Fixup merge issues related to the immutable biovec changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Conflicts:
block/blk-flush.c
fs/btrfs/check-integrity.c
fs/btrfs/extent_io.c
fs/btrfs/scrub.c
fs/logfs/dev_bdev.c
Pull block fixes from Jens Axboe:
- fix for a memory leak on certain unplug events
- a collection of bcache fixes from Kent and Nicolas
- a few null_blk fixes and updates form Matias
- a marking of static of functions in the stec pci-e driver
* 'for-linus' of git://git.kernel.dk/linux-block:
null_blk: support submit_queues on use_per_node_hctx
null_blk: set use_per_node_hctx param to false
null_blk: corrections to documentation
null_blk: warning on ignored submit_queues param
null_blk: refactor init and init errors code paths
null_blk: documentation
null_blk: mem garbage on NUMA systems during init
drivers: block: Mark the functions as static in skd_main.c
bcache: New writeback PD controller
bcache: bugfix for race between moving_gc and bucket_invalidate
bcache: fix for gc and writeback race
bcache: bugfix - moving_gc now moves only correct buckets
bcache: fix for gc crashing when no sectors are used
bcache: Fix heap_peek() macro
bcache: Fix for can_attach_cache()
bcache: Fix dirty_data accounting
bcache: Use uninterruptible sleep in writeback
bcache: kthread don't set writeback task to INTERUPTIBLE
block: fix memory leaks on unplugging block device
bcache: fix sparse non static symbol warning
The old writeback PD controller could get into states where it had throttled all
the way down and take way too long to recover - it was too complicated to really
understand what it was doing.
This rewrites a good chunk of it to hopefully be simpler and make more sense,
and it also pays more attention to units which should make the behaviour a bit
easier to understand.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
There is a possibility for a bucket to be invalidated by the allocator
while moving_gc was copying it's contents to another bucket, if the
bucket only held cached data. To prevent this moving checks for
a stale ptr (to an invalidated bucket), before and after reads.
It it finds one, it simply ignores moving that data. This only
affects bcache if the moving_gc was turned on, note that it's
off by default.
Signed-off-by: Nicholas Swenson <nks@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Garbage collector needs to check keys in the writeback keybuf to
make sure it's not invalidating buckets to which the writeback
keys point to.
Signed-off-by: Nicholas Swenson <nks@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Removed gc_move_threshold because picking buckets only by
threshold could lead moving extra buckets (ei. if there are
buckets at the threshold that aren't supposed to be moved
do to space considerations).
This is replaced by a GC_MOVE bit in the gc_mark bitmask.
Now only marked buckets get moved.
Signed-off-by: Nicholas Swenson <nks@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Dirty data accounting wasn't quite right - firstly, we were adding the key we're
inserting after it could have merged with another dirty key already in the
btree, and secondly we could sometimes pass the wrong offset to
bcache_dev_sectors_dirty_add() for dirty data we were overwriting - which is
important when tracking dirty data by stripe.
NOTE FOR BACKPORTERS: For 3.10 (and 3.11?) there's other accounting fixes
necessary that got squashed in with other patches; the full patch against 3.10
is 408cc2f47eeac93a, available at:
git://evilpiepirate.org/~kent/linux-bcache.git bcache-3.10-writeback-fixes
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 2a46036..4a12b2f 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1817,7 +1817,8 @@ static bool fix_overlapping_extents(struct btree *b, struct bkey *insert,
if (KEY_START(k) > KEY_START(insert) + sectors_found)
goto check_failed;
- if (KEY_PTRS(replace_key) != KEY_PTRS(k))
+ if (KEY_PTRS(k) != KEY_PTRS(replace_key) ||
+ KEY_DIRTY(k) != KEY_DIRTY(replace_key))
goto check_failed;
/* skip past gen */
at the beginning (schedule_timout_interuptible) and others
do his on their own
This prevents wrong load average calculation (load of 1 per thread)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
A fix for possible memory corruption during DM table load, fix a
possible leak of snapshot space in case of a crash, fix a possible
deadlock due to a shared workqueue in the delay target, fix to
initialize read-only module parameters that are used to export metrics
for dm stats and dm bufio.
Quite a few stable fixes were identified for both the thin-provisioning
and caching targets as a result of increased regression testing using
the device-mapper-test-suite (dmts). The most notable of these are the
reference counting fixes for the space map btree that is used by the
dm-array interface -- without these the dm-cache metadata will leak,
resulting in dm-cache devices running out of metadata blocks. Also,
some important fixes related to the thin-provisioning target's
transition to read-only mode on error.
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Merge tag 'dm-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer:
"A set of device-mapper fixes for 3.13.
A fix for possible memory corruption during DM table load, fix a
possible leak of snapshot space in case of a crash, fix a possible
deadlock due to a shared workqueue in the delay target, fix to
initialize read-only module parameters that are used to export metrics
for dm stats and dm bufio.
Quite a few stable fixes were identified for both the thin-
provisioning and caching targets as a result of increased regression
testing using the device-mapper-test-suite (dmts). The most notable
of these are the reference counting fixes for the space map btree that
is used by the dm-array interface -- without these the dm-cache
metadata will leak, resulting in dm-cache devices running out of
metadata blocks. Also, some important fixes related to the
thin-provisioning target's transition to read-only mode on error"
* tag 'dm-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm array: fix a reference counting bug in shadow_ablock
dm space map: disallow decrementing a reference count below zero
dm stats: initialize read-only module parameter
dm bufio: initialize read-only module parameters
dm cache: actually resize cache
dm cache: update Documentation for invalidate_cblocks's range syntax
dm cache policy mq: fix promotions to occur as expected
dm thin: allow pool in read-only mode to transition to read-write mode
dm thin: re-establish read-only state when switching to fail mode
dm thin: always fallback the pool mode if commit fails
dm thin: switch to read-only mode if metadata space is exhausted
dm thin: switch to read only mode if a mapping insert fails
dm space map metadata: return on failure in sm_metadata_new_block
dm table: fail dm_table_create on dm_round_up overflow
dm snapshot: avoid snapshot space leak on crash
dm delay: fix a possible deadlock due to shared workqueue
An old array block could have its reference count decremented below
zero when it is being replaced in the btree by a new array block.
The fix is to increment the old ablock's reference count just before
inserting a new ablock into the btree.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
The old behaviour, returning -EINVAL if a ref_count of 0 would be
decremented, was removed in commit f722063 ("dm space map: optimise
sm_ll_dec and sm_ll_inc"). To fix this regression we return an error
code from the mutator function pointer passed to sm_ll_mutate() and have
dec_ref_count() return -EINVAL if the old ref_count is 0.
Add a DMERR to reflect the potential seriousness of this error.
Also, add missing dm_tm_unlock() to sm_ll_mutate()'s error path.
With this fix the following dmts regression test now passes:
dmtest run --suite cache -n /metadata_use_kernel/
The next patch fixes the higher-level dm-array code that exposed this
regression.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.12+
kernfs has just been separated out from sysfs and we're already in
full conflict mode. Nothing can make the situation any worse. Let's
take the chance to name things properly.
This patch performs the following renames.
* s/sysfs_elem_dir/kernfs_elem_dir/
* s/sysfs_elem_symlink/kernfs_elem_symlink/
* s/sysfs_elem_attr/kernfs_elem_file/
* s/sysfs_dirent/kernfs_node/
* s/sd/kn/ in kernfs proper
* s/parent_sd/parent/
* s/target_sd/target/
* s/dir_sd/parent/
* s/to_sysfs_dirent()/rb_to_kn()/
* misc renames of local vars when they conflict with the above
Because md, mic and gpio dig into sysfs details, this patch ends up
modifying them. All are sysfs_dirent renames and trivial. While we
can avoid these by introducing a dummy wrapping struct sysfs_dirent
around kernfs_node, given the limited usage outside kernfs and sysfs
proper, I don't think such workaround is called for.
This patch is strictly rename only and doesn't introduce any
functional difference.
- mic / gpio renames were missing. Spotted by kbuild test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The module parameter stats_current_allocated_bytes in dm-mod is
read-only. This parameter informs the user about memory
consumption. It is not supposed to be changed by the user.
However, despite being read-only, this parameter can be set on
modprobe or insmod command line:
modprobe dm-mod stats_current_allocated_bytes=12345
The kernel doesn't expect that this variable can be non-zero at module
initialization and if the user sets it, it results in warning.
This patch initializes the variable in the module init routine, so
that user-supplied value is ignored.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.12+
Some module parameters in dm-bufio are read-only. These parameters
inform the user about memory consumption. They are not supposed to be
changed by the user.
However, despite being read-only, these parameters can be set on
modprobe or insmod command line, for example:
modprobe dm-bufio current_allocated_bytes=12345
The kernel doesn't expect that these variables can be non-zero at module
initialization and if the user sets them, it results in BUG.
This patch initializes the variables in the module init routine, so that
user-supplied values are ignored.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.2+
Commit f494a9c6b1 ("dm cache: cache
shrinking support") broke cache resizing support.
dm_cache_resize() is called with cache->cache_size before it gets
updated to new_size, so it is a no-op. But the dm-cache superblock is
updated with the new_size even though the backing dm-array is not
resized. Fix this by passing the new_size to dm_cache_resize().
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Micro benchmarks that repeatedly issued IO to a single block were
failing to cause a promotion from the origin device to the cache. Fix
this by not updating the stats during map() if -EWOULDBLOCK will be
returned.
The mq policy will only update stats, consider migration, etc, once per
tick period (a unit of time established between dm-cache core and the
policies).
When the IO thread calls the policy's map method, if it would like to
migrate the associated block it returns -EWOULDBLOCK, the IO then gets
handed over to a worker thread which handles the migration. The worker
thread calls map again, to check the migration is still needed (avoids a
race among other things). *BUT*, before this fix, if we were still in
the same tick period the stats were already updated by the previous map
call -- so the migration would no longer be requested.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A thin-pool may be in read-only mode because the pool's data or metadata
space was exhausted. To allow for recovery, by adding more space to the
pool, we must allow a pool to transition from PM_READ_ONLY to PM_WRITE
mode. Otherwise, running out of space will render the pool permanently
read-only.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
If the thin-pool transitioned to fail mode and the thin-pool's table
were reloaded for some reason: the new table's default pool mode would
be read-write, though it will transition to fail mode during resume.
When the pool mode transitions directly from PM_WRITE to PM_FAIL we need
to re-establish the intermediate read-only state in both the metadata
and persistent-data block manager (as is usually done with the normal
pool mode transition sequence: PM_WRITE -> PM_READ_ONLY -> PM_FAIL).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Rename commit_or_fallback() to commit(). Now all previous calls to
commit() will trigger the pool mode to fallback if the commit fails.
Also, check the error returned from commit() in alloc_data_block().
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Switch the thin pool to read-only mode in alloc_data_block() if
dm_pool_alloc_data_block() fails because the pool's metadata space is
exhausted.
Differentiate between data and metadata space in messages about no
free space available.
This issue was noticed with the device-mapper-test-suite using:
dmtest run --suite thin-provisioning -n /exhausting_metadata_space_causes_fail_mode/
The quantity of errors logged in this case must be reduced.
before patch:
device-mapper: thin: 253:4: reached low water mark for metadata device: sending event.
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map common: dm_tm_shadow_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map common: dm_tm_shadow_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map common: dm_tm_shadow_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map common: dm_tm_shadow_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map common: dm_tm_shadow_block() failed
<snip ... these repeat for a _very_ long while ... >
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: 253:4: commit failed: error = -28
device-mapper: thin: 253:4: switching pool to read-only mode
after patch:
device-mapper: thin: 253:4: reached low water mark for metadata device: sending event.
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: 253:4: no free metadata space available.
device-mapper: thin: 253:4: switching pool to read-only mode
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
Switch the thin pool to read-only mode when dm_thin_insert_block() fails
since there is little reason to expect the cause of the failure to be
resolved without further action by user space.
This issue was noticed with the device-mapper-test-suite using:
dmtest run --suite thin-provisioning -n /exhausting_metadata_space_causes_fail_mode/
The quantity of errors logged in this case must be reduced.
before patch:
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: dm_thin_insert_block() failed
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map metadata: unable to allocate new metadata block
<snip ... these repeat for a long while ... >
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: space map common: dm_tm_shadow_block() failed
device-mapper: thin: 253:4: no free metadata space available.
device-mapper: thin: 253:4: switching pool to read-only mode
after patch:
device-mapper: space map metadata: unable to allocate new metadata block
device-mapper: thin: 253:4: dm_thin_insert_block() failed: error = -28
device-mapper: thin: 253:4: switching pool to read-only mode
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
The dm_round_up function may overflow to zero. In this case,
dm_table_create() must fail rather than go on to allocate an empty array
with alloc_targets().
This fixes a possible memory corruption that could be caused by passing
too large a number in "param->target_count".
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
There is a possible leak of snapshot space in case of crash.
The reason for space leaking is that chunks in the snapshot device are
allocated sequentially, but they are finished (and stored in the metadata)
out of order, depending on the order in which copying finished.
For example, supposed that the metadata contains the following records
SUPERBLOCK
METADATA (blocks 0 ... 250)
DATA 0
DATA 1
DATA 2
...
DATA 250
Now suppose that you allocate 10 new data blocks 251-260. Suppose that
copying of these blocks finish out of order (block 260 finished first
and the block 251 finished last). Now, the snapshot device looks like
this:
SUPERBLOCK
METADATA (blocks 0 ... 250, 260, 259, 258, 257, 256)
DATA 0
DATA 1
DATA 2
...
DATA 250
DATA 251
DATA 252
DATA 253
DATA 254
DATA 255
METADATA (blocks 255, 254, 253, 252, 251)
DATA 256
DATA 257
DATA 258
DATA 259
DATA 260
Now, if the machine crashes after writing the first metadata block but
before writing the second metadata block, the space for areas DATA 250-255
is leaked, it contains no valid data and it will never be used in the
future.
This patch makes dm-snapshot complete exceptions in the same order they
were allocated, thus fixing this bug.
Note: when backporting this patch to the stable kernel, change the version
field in the following way:
* if version in the stable kernel is {1, 11, 1}, change it to {1, 12, 0}
* if version in the stable kernel is {1, 10, 0} or {1, 10, 1}, change it
to {1, 10, 2}
Userspace reads the version to determine if the bug was fixed, so the
version change is needed.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Pull block layer fixes from Jens Axboe:
"A small collection of fixes for the current series. It contains:
- A fix for a use-after-free of a request in blk-mq. From Ming Lei
- A fix for a blk-mq bug that could attempt to dereference a NULL rq
if allocation failed
- Two xen-blkfront small fixes
- Cleanup of submit_bio_wait() type uses in the kernel, unifying
that. From Kent
- A fix for 32-bit blkg_rwstat reading. I apologize for this one
looking mangled in the shortlog, it's entirely my fault for missing
an empty line between the description and body of the text"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: fix use-after-free of request
blk-mq: fix dereference of rq->mq_ctx if allocation fails
block: xen-blkfront: Fix possible NULL ptr dereference
xen-blkfront: Silence pfn maybe-uninitialized warning
block: submit_bio_wait() conversions
Update of blkg_stat and blkg_rwstat may happen in bh context
Move the bio->bi_remaining increment into dm_unhook_bio() so the
overwrite_endio() handler works as expected.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fixes the following sparse warning:
drivers/md/bcache/btree.c:2220:5: warning:
symbol 'btree_insert_fn' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
commit 566c09c534 raid5: relieve lock contention in get_active_stripe()
modified the locking in get_active_stripe() reducing the range
protected by the (highly contended) device_lock.
Unfortunately it reduced the range too much opening up some races.
One race can occur if get_priority_stripe runs between the
test on sh->count and device_lock being taken.
This will mean that sh->lru is not empty while get_active_stripe
thinks ->count is zero resulting in a 'BUG' firing.
Another race happens if __release_stripe is called immediately
after sh->count is tested and found to be non-zero. If STRIPE_HANDLE
is not set, get_active_stripe should increment ->active_stripes
when it increments ->count from 0, but as it didn't think it was 0,
it doesn't.
Extending device_lock to cover the test on sh->count close these
races.
While we are here, fix the two BUG tests:
-If count is zero, then lru really must not be empty, or we've
lock the stripe_head somehow - no other tests are relevant.
-STRIPE_ON_RELEASE_LIST is completely independent of ->lru so
testing it is pointless.
Reported-and-tested-by: Brassow Jonathan <jbrassow@redhat.com>
Reviewed-by: Shaohua Li <shli@kernel.org>
Fixes: 566c09c534
Signed-off-by: NeilBrown <neilb@suse.de>
commit 7a0a5355cb md: Don't test all of mddev->flags at once.
made most tests on mddev->flags safer, but missed one.
When
commit 260fa034ef md: avoid deadlock when dirty buffers during md_stop.
added MD_STILL_CLOSED, this caused md_check_recovery to misbehave.
It can think there is something to do but find nothing. This can
lead to the md thread spinning during array shutdown.
https://bugzilla.kernel.org/show_bug.cgi?id=65721
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Fixes: 260fa034ef
Cc: stable@vger.kernel.org (3.12)
Signed-off-by: NeilBrown <neilb@suse.de>
In alloc_thread_groups, worker_groups is a pointer to an array,
not an array of pointers.
So
worker_groups[i]
is wrong. It should be
&(*worker_groups)[i]
Found-by: coverity
Fixes: 60aaf93385
Reported-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
It was being open coded in a few places.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The new bio_split() can split arbitrary bios - it's not restricted to
single page bios, like the old bio_split() (previously renamed to
bio_pair_split()). It also has different semantics - it doesn't allocate
a struct bio_pair, leaving it up to the caller to handle completions.
Then convert the existing bio_pair_split() users to the new bio_split()
- and also nvme, which was open coding bio splitting.
(We have to take that BUG_ON() out of bio_integrity_trim() because this
bio_split() needs to use it, and there's no reason it has to be used on
bios marked as cloned; BIO_CLONED doesn't seem to have clearly
documented semantics anyways.)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Neil Brown <neilb@suse.de>
This is prep work for introducing a more general bio_split().
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: NeilBrown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Sage Weil <sage@inktank.com>
This adds a generic mechanism for chaining bio completions. This is
going to be used for a bio_split() replacement, and it turns out to be
very useful in a fair amount of driver code - a fair number of drivers
were implementing this in their own roundabout ways, often painfully.
Note that this means it's no longer to call bio_endio() more than once
on the same bio! This can cause problems for drivers that save/restore
bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all
- in all but the simplest cases they'd be better off just cloning the
bio, and immutable biovecs is making bio cloning cheaper. But for now,
we add a bio_endio_nodec() for these cases.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Now that drivers have been converted to the new bvec_iter primitives,
there's no need to trim the bvec before we submit it; and we can't trim
it once we start sharing bvecs.
It used to be that passing a partially completed bio (i.e. one with
nonzero bi_idx) to generic_make_request() was a dangerous thing -
various drivers would choke on such things. But with immutable biovecs
and our new bio splitting that shares the biovecs, submitting partially
completed bios has to work (and should work, now that all the drivers
have been completed to the new primitives)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
We need to convert the dm code to the new bvec_iter primitives which
respect bi_bvec_done; they also allow us to drastically simplify dm's
bio splitting code.
Also, it's no longer necessary to save/restore the bvec array anymore -
driver conversions for immutable bvecs are done, so drivers should never
be modifying it.
Also kill bio_sector_offset(), dm was the only user and it doesn't make
much sense anymore.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
bio_clone() just got more expensive - however, most users of bio_clone()
don't actually need to modify the biovec. If they aren't modifying the
biovec, and they can guarantee that the original bio isn't freed before
the clone (also true in most cases), we can just point the clone at the
original bio's biovec.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Now that we've got a mechanism for immutable biovecs -
bi_iter.bi_bvec_done - we need to convert drivers to use primitives that
respect it instead of using the bvec array directly.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: NeilBrown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
When we start sharing biovecs, keeping bi_vcnt accurate for splits is
going to be error prone - and unnecessary, if we refactor some code.
So bio_segments() has to go - but most of the existing users just needed
to know if the bio had multiple segments, which is easier - add a
bio_multiple_segments() for them.
(Two of the current uses of bio_segments() are going to go away in a
couple patches, but the current implementation of bio_segments() is
unsafe as soon as we start doing driver conversions for immutable
biovecs - so implement a dumb version for bisectability, it'll go away
in a couple patches)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
More prep work for immutable biovecs - with immutable bvecs drivers
won't be able to use the biovec directly, they'll need to use helpers
that take into account bio->bi_iter.bi_bvec_done.
This updates callers for the new usage without changing the
implementation yet.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: Jim Paris <jim@jtan.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: support@lsi.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
Cc: cbe-oss-dev@lists.ozlabs.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: DL-MPTFusionLinux@lsi.com
Cc: linux-scsi@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-fsdevel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mm@kvack.org
Acked-by: Geoff Levand <geoff@infradead.org>
For immutable biovecs, we'll be introducing a new bio_iovec() that uses
our new bvec iterator to construct a biovec, taking into account
bvec_iter->bi_bvec_done - this patch updates existing users for the new
usage.
Some of the existing users really do need a pointer into the bvec array
- those uses are all going to be removed, but we'll need the
functionality from immutable to remove them - so for now rename the
existing bio_iovec() -> __bio_iovec(), and it'll be removed in a couple
patches.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
This patch doesn't itself have any functional changes, but immutable
biovecs are going to add a bi_bvec_done member to bi_iter, which will
need to be saved too here.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Bcache has a hack to avoid cloning the biovec if it's all full pages -
but with immutable biovecs coming this won't be necessary anymore.
For now, we remove the special case and always clone the bvec array so
that the immutable biovec patches are simpler.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
It was being open coded in a few places.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Acked-by: NeilBrown <neilb@suse.de>
Mostly optimisations and obscure bug fixes.
- raid5 gets less lock contention
- raid1 gets less contention between normal-io and resync-io
during resync.
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Merge tag 'md/3.13' of git://neil.brown.name/md
Pull md update from Neil Brown:
"Mostly optimisations and obscure bug fixes.
- raid5 gets less lock contention
- raid1 gets less contention between normal-io and resync-io during
resync"
* tag 'md/3.13' of git://neil.brown.name/md:
md/raid5: Use conf->device_lock protect changing of multi-thread resources.
md/raid5: Before freeing old multi-thread worker, it should flush them.
md/raid5: For stripe with R5_ReadNoMerge, we replace REQ_FLUSH with REQ_NOMERGE.
UAPI: include <asm/byteorder.h> in linux/raid/md_p.h
raid1: Rewrite the implementation of iobarrier.
raid1: Add some macros to make code clearly.
raid1: Replace raise_barrier/lower_barrier with freeze_array/unfreeze_array when reconfiguring the array.
raid1: Add a field array_frozen to indicate whether raid in freeze state.
md: Convert use of typedef ctl_table to struct ctl_table
md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes.
md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.
md: fix some places where mddev_lock return value is not checked.
raid5: Retry R5_ReadNoMerge flag when hit a read error.
raid5: relieve lock contention in get_active_stripe()
raid5: relieve lock contention in get_active_stripe()
wait: add wait_event_cmd()
md/raid5.c: add proper locking to error path of raid5_start_reshape.
md: fix calculation of stacking limits on level change.
raid5: Use slow_path to release stripe when mddev->thread is null
For R5_ReadNoMerge,it mean this bio can't merge with other bios or
request.It used REQ_FLUSH to achieve this. But REQ_NOMERGE can do the
same work.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
There is an iobarrier in raid1 because of contention between normal IO and
resync IO. It suspends all normal IO when resync/recovery happens.
However if normal IO is out side the resync window, there is no contention.
So this patch changes the barrier mechanism to only block IO that
could contend with the resync that is currently happening.
We partition the whole space into five parts.
|---------|-----------|------------|----------------|-------|
start next_resync start_next_window end_window
start + RESYNC_WINDOW = next_resync
next_resync + NEXT_NORMALIO_DISTANCE = start_next_window
start_next_window + NEXT_NORMALIO_DISTANCE = end_window
Firstly we introduce some concepts:
1 - RESYNC_WINDOW: For resync, there are 32 resync requests at most at the
same time. A sync request is RESYNC_BLOCK_SIZE(64*1024).
So the RESYNC_WINDOW is 32 * RESYNC_BLOCK_SIZE, that is 2MB.
2 - NEXT_NORMALIO_DISTANCE: the distance between next_resync
and start_next_window. It also indicates the distance between
start_next_window and end_window.
It is currently 3 * RESYNC_WINDOW_SIZE but could be tuned if
this turned out not to be optimal.
3 - next_resync: the next sector at which we will do sync IO.
4 - start: a position which is at most RESYNC_WINDOW before
next_resync.
5 - start_next_window: a position which is NEXT_NORMALIO_DISTANCE
beyond next_resync. Normal-io after this position doesn't need to
wait for resync-io to complete.
6 - end_window: a position which is 2 * NEXT_NORMALIO_DISTANCE beyond
next_resync. This also doesn't need to wait, but is counted
differently.
7 - current_window_requests: the count of normalIO between
start_next_window and end_window.
8 - next_window_requests: the count of normalIO after end_window.
NormalIO will be partitioned into four types:
NormIO1: the end sector of bio is smaller or equal the start
NormIO2: the start sector of bio larger or equal to end_window
NormIO3: the start sector of bio larger or equal to
start_next_window.
NormIO4: the location between start_next_window and end_window
|--------|-----------|--------------------|----------------|-------------|
| start | next_resync | start_next_window | end_window |
NormIO1 NormIO4 NormIO4 NormIO3 NormIO2
For NormIO1, we don't need any io barrier.
For NormIO4, we used a similar approach to the original iobarrier
mechanism. The normalIO and resyncIO must be kept separate.
For NormIO2/3, we add two fields to struct r1conf: "current_window_requests"
and "next_window_requests". They indicate the count of active
requests in the two window.
For these, we don't wait for resync io to complete.
For resync action, if there are NormIO4s, we must wait for it.
If not, we can proceed.
But if resync action reaches start_next_window and
current_window_requests > 0 (that is there are NormIO3s), we must
wait until the current_window_requests becomes zero.
When current_window_requests becomes zero, start_next_window also
moves forward. Then current_window_requests will replaced by
next_window_requests.
There is a problem which when and how to change from NormIO2 to
NormIO3. Only then can sync action progress.
We add a field in struct r1conf "start_next_window".
A: if start_next_window == MaxSector, it means there are no NormIO2/3.
So start_next_window = next_resync + NEXT_NORMALIO_DISTANCE
B: if current_window_requests == 0 && next_window_requests != 0, it
means start_next_window move to end_window
There is another problem which how to differentiate between
old NormIO2(now it is NormIO3) and NormIO2.
For example, there are many bios which are NormIO2 and a bio which is
NormIO3. NormIO3 firstly completed, so the bios of NormIO2 became NormIO3.
We add a field in struct r1bio "start_next_window".
This is used to record the position conf->start_next_window when the call
to wait_barrier() is made in make_request().
In allow_barrier(), we check the conf->start_next_window.
If r1bio->stat_next_window == conf->start_next_window, it means
there is no transition between NormIO2 and NormIO3.
If r1bio->start_next_window != conf->start_next_window, it mean
there was a transition between NormIO2 and NormIO3. There can only
have been one transition. So it only means the bio is old NormIO2.
For one bio, there may be many r1bio's. So we make sure
all the r1bio->start_next_window are the same value.
If we met blocked_dev in make_request(), it must call allow_barrier
and wait_barrier. So the former and the later value of
conf->start_next_window will be change.
If there are many r1bio's with differnet start_next_window,
for the relevant bio, it depend on the last value of r1bio.
It will cause error. To avoid this, we must wait for previous r1bios
to complete.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
In a subsequent patch, we'll use some const parameters.
Using macros will make the code clearly.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
We used to use raise_barrier to suspend normal IO while we reconfigure
the array. However raise_barrier will soon only suspend some normal
IO, not all. So we need something else.
Change it to use freeze_array.
But freeze_array not only suspends normal io, it also suspends
resync io.
For the place where call raise_barrier for reconfigure, it isn't a
problem.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Because the following patch will rewrite the content between normal IO
and resync IO. So we used a parameter to indicate whether raid is in freeze
array.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When raid5 recovery hits a fresh badblock, this badblock will flagged as unack
badblock until md_update_sb() is called.
But md_stop will take reconfig lock which means raid5d can't call
md_update_sb() in md_check_recovery(), the badblock will always
be unack, so raid5d thread enters an infinite loop and md_stop_write()
can never stop sync_thread. This causes deadlock.
To solve this, when STOP_ARRAY ioctl is issued and sync_thread is
running, we need set md->recovery FROZEN and INTR flags and wait for
sync_thread to stop before we (re)take reconfig lock.
This requires that raid5 reshape_request notices MD_RECOVERY_INTR
(which it probably should have noticed anyway) and stops waiting for a
metadata update in that case.
Reported-by: Jianpeng Ma <majianpeng@gmail.com>
Reported-by: Bian Yu <bianyu@kedacom.com>
Signed-off-by: NeilBrown <neilb@suse.de>
We currently use kthread_should_stop() in various places in the
sync/reshape code to abort early.
However some places set MD_RECOVERY_INTR but don't immediately call
md_reap_sync_thread() (and we will shortly get another one).
When this happens we are relying on md_check_recovery() to reap the
thread and that only happen when it finishes normally.
So MD_RECOVERY_INTR must lead to a normal finish without the
kthread_should_stop() test.
So replace all relevant tests, and be more careful when the thread is
interrupted not to acknowledge that latest step in a reshape as it may
not be fully committed yet.
Also add a test on MD_RECOVERY_INTR in the 'is_mddev_idle' loop
so we don't wait have to wait for the speed to drop before we can abort.
Signed-off-by: NeilBrown <neilb@suse.de>
Sometimes we need to lock and mddev and cannot cope with
failure due to interrupt.
In these cases we should use mutex_lock, not mutex_lock_interruptible.
Signed-off-by: NeilBrown <neilb@suse.de>
Because of block layer merge, one bio fails will cause other bios
which belongs to the same request fails, so raid5_end_read_request
will record all these bios as badblocks.
If retry request with R5_ReadNoMerge flag to avoid bios merge,
badblocks can only record sector which is bad exactly.
test:
hdparm --yes-i-know-what-i-am-doing --make-bad-sector 300000 /dev/sdb
mdadm -C /dev/md0 -l5 -n3 /dev/sd[bcd] --assume-clean
mdadm /dev/md0 -f /dev/sdd
mdadm /dev/md0 -r /dev/sdd
mdadm --zero-superblock /dev/sdd
mdadm /dev/md0 -a /dev/sdd
1. Without this patch:
cat /sys/block/md0/md/rd*/bad_blocks
299776 256
299776 256
2. With this patch:
cat /sys/block/md0/md/rd*/bad_blocks
300000 8
300000 8
Signed-off-by: Bian Yu <bianyu@kedacom.com>
Signed-off-by: NeilBrown <neilb@suse.de>
track empty inactive list count, so md_raid5_congested() can use it to make
decision.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Linus Torvalds