Change dm-linear to implement direct_access function,
linear_direct_access(), which maps sector and calls direct_access
function of its physical target device.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Change mapped device to implement direct_access function,
dm_blk_direct_access(), which calls a target direct_access function.
'struct target_type' is extended to have target direct_access interface.
This function limits direct accessible size to the dm_target's limit
with max_io_len().
Add dm_table_supports_dax() to iterate all targets and associated block
devices to check for DAX support. To add DAX support to a DM target the
target must only implement the direct_access function.
Add a new dm type, DM_TYPE_DAX_BIO_BASED, which indicates that mapped
device supports DAX and is bio based. This new type is used to assure
that all target devices have DAX support and remain that way after
QUEUE_FLAG_DAX is set in mapped device.
At initial table load, QUEUE_FLAG_DAX is set to mapped device when setting
DM_TYPE_DAX_BIO_BASED to the type. Any subsequent table load to the
mapped device must have the same type, or else it fails per the check in
table_load().
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Instead of a flag and an index just make sure an index of 0 means
no need to free the bvec array. Also move the constants related
to the bvec pools together and use a consistent naming scheme for
them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces. For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense. Any check for READA is replaced with an
explicit check for REQ_RAHEAD. Also remove the READA alias for
REQ_RAHEAD.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The discard passdown was being issued after the block was unmapped,
which meant the block could be reprovisioned whilst the passdown discard
was still in flight.
We can only identify unshared blocks (safe to do a passdown a discard
to) once they're unmapped and their ref count hits zero. Block ref
counts are now used to guard against concurrent allocation of these
blocks that are being discarded. So now we unmap the block, issue
passdown discards, and the immediately increment ref counts for regions
that have been discarded via passed down (this is safe because
allocation occurs within the same thread). We then decrement ref counts
once the passdown discard IO is complete -- signaling these blocks may
now be allocated.
This fixes the potential for corruption that was reported here:
https://www.redhat.com/archives/dm-devel/2016-June/msg00311.html
Reported-by: Dennis Yang <dennisyang@qnap.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm_btree_find_next_single() can short-circuit the search for a block
with a return of -ENODATA if all entries are higher than the search key
passed to lower_bound().
This hasn't been a problem because of the way the btree has been used by
DM thinp. But it must be fixed now in preparation for fixing the race
in DM thinp's handling of simultaneous block discard vs allocation.
Otherwise, once that fix is in place, some of the blocks in a discard
would not be unmapped as expected.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
RAID10 random read performance is lower than expected due to excessive spinlock
utilisation which is required mostly for rebuild/resync. Simplify allow_barrier
as it's in IO path and encounters a lot of unnecessary congestion.
As lower_barrier just takes a lock in order to decrement a counter, convert
counter (nr_pending) into atomic variable and remove the spin lock. There is
also a congestion for wake_up (it uses lock internally) so call it only when
it's really needed. As wake_up is not called constantly anymore, ensure process
waiting to raise a barrier is notified when there are no more waiting IOs.
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Changeset 6791875e2e has added early return from a function so there is no
sysfs notification for 'active' and 'clean' state change.
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
md loads raidX modules and increments module refcount each time level
has changed but does not decrement it. You are unable to unload raid0
module after reshape because raid0 reshape changes level to raid4
and back to raid0.
Signed-off-by: Aleksey Obitotskiy <aleksey.obitotskiy@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The md code stores the exact time of the last error in the
last_read_error variable using a timespec structure. It only
ever uses the seconds portion of that though, so we can
use a scalar for it.
There won't be an overflow in 2038 here, because it already
used monotonic time and 32-bit is enough for that, but I've
decided to use time64_t for consistency in the conversion.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shaohua Li <shli@fb.com>
raid_io_hints() was retrieving the number of data stripes used for the
calculation of io_opt from struct r5conf, which is not defined for raid0
mappings.
Base the calculation on the in-core raid_set structure instead.
Also, adjust to use to_bytes() for the sector -> bytes conversion
throughout.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use 'unsigned int' where appropriate.
Return negative errors.
Correct an indentation.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
So far we tried to rely on the SCSI 'all target ports' bit to register
all path, but for many setups this didn't work properly as the different
paths are seen as separate initiators to the target instead of multiple
ports of the same initiator. Because of that we'll stop setting the
'all target ports' bit in SCSI, and let device mapper handle iterating
over the device for each path and register them manually.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit d548b34b06 ("dm: reduce the queue delay used in dm_request_fn
from 100ms to 10ms") always intended the value to be 10 msecs -- it
just expressed it in jiffies because earlier commit 7eaceaccab ("block:
remove per-queue plugging") did.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Fixes: d548b34b06 ("dm: reduce the queue delay used in dm_request_fn from 100ms to 10ms")
Cc: stable@vger.kernel.org # 4.1+ -- stable@ backports must be applied to drivers/md/dm.c
Add "delta_disks" constructor argument support to raid1 to allow for
consistent userspace disk addition/removal handling.
Fix raid_status() to report all raid disks with status and table output
on disk adding reshapes, not just the ones listed on the mddev; optimize
its rebuild and writemostly output.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Enhance rs_reshape_requested() check function to be more transparent and
fix its raid10 check.
Streamline the constructor by factoring out reshaping preparation into
fucntion rs_prepare_reshape().
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Resizing a RAID set during recovery can be allowed, because the MD
resynchronization thread will either stop any ongoing recovery in case
of shrinking below the current recovery position or carry on recovery
to the new size if the set is growing.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add function rs_setup_recovery() to allow for defined setup of RAID set
recovery in the constructor.
Will be called with dev_sectors={0, rdev->sectors, MaxSectors} to
recover a new or enforced sync, grown or not to be synhronized RAID set
respectively.
Prevents recovery on raid0, which doesn't support it.
Enforces recovery on raid6 to ensure properly defined Syndromes
mandatory for that MD personality are being created.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Check return value of kthread_run() in dm_old_init_request_queue().
Reported-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
We have assigned sb->block_size before the switch,
so remove the redundant one.
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Eric Wheeler <bcache@lists.ewheeler.net>
Signed-off-by: Jens Axboe <axboe@fb.com>
There is no return in continue_at(), update the documentation.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Cache_sb is not used in cache_alloc, and we have copied
sb info to cache->sb already, remove it.
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
do_div was replaced with div64_u64 at some point, causing a bug with
block calculation due to incompatible semantics of the two functions.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Fixes: a739ff3f54 ("dm verity: add support for forward error correction")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Merge the two DM_PARAMS_[KV]MALLOC flags into a single flag.
Doing so avoids the crashes seen with previous attempts to consolidate
buffer management to use kvfree() without first flagging that memory had
actually been allocated.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Avoid that sparse complains about assigning a __le64 value to a u64
variable. Remove the (u64) casts since these are superfluous. This
patch does not change the behavior of the source code.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A newly introduced function has 'const int' as the return type,
but as "make W=1" reports, that has no meaning:
drivers/md/dm-raid.c:510:18: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]
This changes the return type to plain 'int'.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 33e53f0685 ("dm raid: introduce extended superblock and new raid types to support takeover/reshaping")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Superblock updates where bogus causing some takovers/reshapes to fail.
Introduce new runtime flag (RT_FLAG_KEEP_RS_FROZEN) to keep a raid set
frozen when a layout change was requested. Userpace will immediately
reload the table w/o the flags requesting such change once they made it
to the superblocks and any change of recovery/reshape offsets has to be
avoided until after read.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add bool functions rs_is_recovering and rs_is_reshaping()
to test for ongoing recovery/reshaping respectively in order
to reject respective requests on ongoing ones.
Remove ctr array size check, because ti->len and array
sectors will differ during disk addition/removal reshape.
Use __is_raid10_near() rather than type string compare.
Introduce rs_check_reshape() and rs_start_reshape(),
use the former in the ctr to reject bogus rehsape requests
and the latter in preresume to actually start a reshape.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add rs_is_reshapable(), rs_data_stripes(), rs_reshape_requested(),
rs_set_dev_and_array_sectors() and rs_adjust_data_offsets()
Remove superfluous check for reshape message
Correct runtime bit definitions to be incremental
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
It is more intuitive to manage each raid level's features in terms of
what is supported rather than what isn't supported.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Renamed functions and variables with leading single underscore to have a
double underscore. Renamed some functions to have better names. Folded
functions that were split out without reason.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Also update module description to "raid0/1/10/4/5/6 target"
Reported by Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
No idea what Heinz was doing with the versioning but upstream commit
4c9971ca6a ("dm raid: make sure no feature flags are set in metadata")
bumped to 1.8.0 already.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
There ti_error_* wrappers added very little. No other DM target has
ever gone to such lengths to wrap setting ti->error.
Also fixes some NULL derefences via rs->ti->error.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The target's status interface has to provide the new 'data_offset' value
to allow userspace to retrieve the kernels offset to the data on each
raid device of a raid set. This is the base for out-of-place reshaping
required to not write over any data during reshaping (e.g. change
raid6_zr -> raid6_nc):
- add rs_set_cur() to be able to start up existing array in case of no
takeover; use in ctr on takeover check
- enhance raid_status()
- add supporting functions to get resync/reshape progress and raid
device status chars
- fixup rebuild table line output race, which does miss to emit
'rebuild N' on fully synced/rebuild devices, because it is relying on
the transient 'In_sync' raid device flag
- add new status line output for 'data_offset', which'll later be used
for out-of-place reshaping
- fixup takeover not working for all levels
- fixup raid0 message interface oops caused by missing checks
for the md threads, which don't exist in case of raid0
- remove ALL_FREEZE_FLAGS not needed for takeover
- adjust comments
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add raid level takeover support allowing arbitrary takeovers between
raid levels supported by md personalities (i.e. raid0, raid1/10 and
raid4/5/6):
- add rs_config_{backup|restore} function to allow for temporary
storing ctr requested layout changes and restore them for takeover
conersion decision after the superblocks got loaded and analyzed
- add members to store layout to 'struct raid_set' (not mandatory
for takeover but needed for reshape in later patch)
- add rebuild_disks bitfield to 'struct raid_set' and set bits in ctr
to use in setting up takeover (base to address a 'rebuild' related
raid_status() table line bug and needed as well for reshape in future
patch)
- add runtime flags and respective manipulation functions to be able to
control e.g. wrting of superlocks to the preresume function on
takeover and (later) reshape
- add functions to detect takeover, check it's valid (mandatory here to
avoid failing on md_run()), setup for it and use in the ctr; those
will be likely moved out once reshaping gets added to simplify the
ctr
- start raid set readonly in ctr and switch to readwrite, optionally
updating superblocks, in preresume in order to allow suspend to
quiesce any active table before (which involves superblock updates);
this ensures the proper sequence of writing the current and any new
takeover(/reshape) metadata
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add transferring the new takeover/reshape related superblock
members introduced to the super_sync() function:
- add/move supporting functions
- add failed devices bitfield transfer functions to retrieve the
bitfield from superblock format or update it in the superblock
- add code to transfer all new members
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Support the follwoing arguments in the ctr parameter parser:
- add 'delta_disks', 'data_offset' taking int and sector respectively
- 'raid10_use_near_sets' bool argument to optionally select
near sets with supporting raid10 mappings
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add new members to the dm-raid superblock and new raid types to support
takeover/reshape.
Add all necessary members needed to support takeover and reshape in one
go -- aiming to limit the amount of changes to the superblock layout.
This is a larger patch due to the new superblock members, their related
flags, validation of both and involved API additions/changes:
- add additional members to keep track of:
- state about forward/backward reshaping
- reshape position
- new level, layout, stripe size and delta disks
- data offset to current and new data for out-of-place reshapes
- failed devices bitfield extensions to keep track of max raid devices
- adjust super_validate() to cope with new superblock members
- adjust super_init_validation() to cope with new superblock members
- add definitions for ctr flags supporting delta disks etc.
- add new raid types (raid6_n_6 etc.)
- add new raid10 supporting function API (_is_raid10_*())
- adjust to changed raid10 supporting function API
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Every time a device is removed with ->hot_remove_disk() a synchronize_rcu() call is made
which can delay several milliseconds in some case.
If lots of devices fail at once - as could happen with a large RAID10 where one set
of devices are removed all at once - these delays can add up to be very inconcenient.
As failure is not reversible we can check for that first, setting a
separate flag if it is found, and then all synchronize_rcu() once for
all the flagged devices. Then ->hot_remove_disk() function can skip the
synchronize_rcu() step if the flag is set.
fix build error(Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
It is important that we never increment rdev->nr_pending on a Faulty
device as ->hot_remove_disk() assumes that once the Faulty flag is visible
no code will take a new reference.
Some places take a new reference after only check In_sync. This should
be safe as the two are changed together. However to make the code more
obviously safe, add checks for 'Faulty' as well.
Note: the actual rule is:
Never increment nr_pending if Faulty is set and Blocked is clear,
never clear Faulty, and never set Blocked without holding a reference
through nr_pending.
fix build error (Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Being in the middle of resync is no longer protection against failed
rdevs disappearing. So add rcu protection.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The rdev could be freed while handle_failed_sync is running, so
rcu protection is needed.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Since remove_and_add_spares() was added to hot_remove_disk() it has
been possible for an rdev to be hot-removed while fix_read_error()
was running, so we need to be more careful, and take a reference to
the rdev while performing IO.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
'mirror' is only used to find 'rdev', several times.
So just find 'rdev' once, and use it instead.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Both functions use conf->mirrors[mirror].rdev several times, so
improve readability by storing this in a local variable.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
'tmp' is only ever used to extract 'tmp->rdev', so just use 'rdev' directly.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
rdev already holds conf->mirrors[d].rdev, so no need to load it again.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
mirrors[].rdev can become NULL at any point unless:
- a counted reference is held
- ->reconfig_mutex is held, or
- rcu_read_lock() is held
Reshape isn't always suitably careful as in the past rdev couldn't be
removed during reshape. It can now, so add protection.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
mirrors[].rdev can become NULL at any point unless:
- a counted reference is held
- ->reconfig_mutex is held, or
- rcu_read_lock() is held
Previously they could not become NULL during a resync/recovery/reshape either.
However when remove_and_add_spares() was added to hot_remove_disk(), that
changed.
So raid10_sync_request didn't previously need to protect rdev access,
but now it does.
Fix missed check(Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
mirrors[].rdev can become NULL at any point unless:
- a counted reference is held
- ->reconfig_mutex is held, or
- rcu_read_lock() is held
raid10_status holds none of these. So add rcu_read_lock()
protection.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
If you have a raid10 with a replacement device that is resyncing -
e.g. after a crash before the replacement was complete - the write to
the replacement will increment nr_pending on the wrong device, which
will lead to strangeness.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Re-checking the faulty flag here brings no value.
The comment about "risk" refers to the risk that the device could
be in the process of being removed by ->hot_remove_disk().
However providing that the ->nr_pending count is incremented inside
an rcu_read_locked() region, there is no risk of that happening.
This is because the rdev pointer (in the personalities array) is set
to NULL before synchronize_rcu(), and ->nr_pending is tested
afterwards. If the rcu_read_locked region happens before the
synchronize_rcu(), the test will see that nr_pending has been incremented.
If it happens afterwards, the rdev pointer will be NULL so there is nothing
to increment.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
When the HOT_REMOVE_DISK ioctl is used to remove a device, we
call remove_and_add_spares() which will remove it from the personality
if possible. This improves the chances that the removal will succeed.
When writing "remove" to dev-XX/state, we don't. So that can fail more easily.
So add the remove_and_add_spares() into "remove" handling.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
A performance drop of mkfs has been observed on RAID10 during resync
since commit 09314799e4 ("md: remove 'go_faster' option from
->sync_request()"). Resync sends so many IOs it slows down non-resync
IOs significantly (few times). Add a short delay to a resync. The
previous long sleep (1s) has proven unnecessary, even very short delay
brings performance right.
The change also applied to raid1. The problem has not been observed on
raid1, however it shares barriers code with raid10 so it might be an
issue for some setup too.
Suggested-by: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20160609134555.GA9104@proton.igk.intel.com
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This is a simple check before updating the superblock. It should update
the superblock when update_size return 0.
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Make use if raid type rt_is_*() bool functions for simplification and
consistency reasons.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
- add _test_flags() function
- use it to simplify rs_check_for_invalid_flags()
- use _test_flag() throughout
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reject invalid flag combinations to avoid potential data corruption or
failing raid set construction:
- add definitions for constructor flag combinations and invalid flags
per level
- add bool test functions for the various raid types
(also will be used by future reshaping enhancements)
- introduce rs_check_for_invalid_flags() and _invalid_flags()
to perform the validity checks
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Provide necessary infrastructure to handle ctr flags and their names
and cleanup setting ti->error:
- comment constructor flags
- introduce constructor flag manipulation
- introduce ti_error_*() functions to simplify
setting the error message (use in other targets?)
- introduce array to hold ctr flag <-> flag name mapping
- introduce argument name by flag functions for that array
- use those functions throughout the ctr call path
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
- use dm_arg_set API in ctr and its callees parse_raid_params() and dev_parms()
- introduce _in_range() function to check a value is in a [ min, max ] range;
this is to support more callers in parsing parameters etc. in the future
- correct comment on MAX_RAID_DEVICES
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
alloc_workqueue replaces deprecated create_workqueue().
Dedicated workqueues have been used since bcache_wq and moving_gc_wq
are workqueues for writes and are being used on a memory reclaim path.
WQ_MEM_RECLAIM has been set to ensure forward progress under memory
pressure.
Since there are only a fixed number of work items, explicit concurrency
limit is unnecessary here.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Allow a user to specify an optional feature 'queue_mode <mode>' where
<mode> may be "bio", "rq" or "mq" -- which corresponds to bio-based,
request_fn rq-based, and blk-mq rq-based respectively.
If the queue_mode feature isn't specified the default for the
"multipath" target is still "rq" but if dm_mod.use_blk_mq is set to Y
it'll default to mode "mq".
This new queue_mode feature introduces the ability for each multipath
device to have its own queue_mode (whereas before this feature all
multipath devices effectively had to have the same queue_mode).
This commit also goes a long way to eliminate the awkward (ab)use of
DM_TYPE_*, the associated filter_md_type() and other relatively fragile
and difficult to maintain code.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add "multipath-bio" target that offers a bio-based multipath target as
an alternative to the request-based "multipath" target -- but in a
following commit "multipath-bio" will immediately be replaced by a new
"queue_mode" feature for the "multipath" target which will allow
bio-based mode to be selected.
When DM multipath was originally converted from bio-based to
request-based the motivation for the change was better dynamic load
balancing (by leveraging block core's request-based IO schedulers, for
merging and sorting, _before_ DM multipath would make the decision on
where to steer the IO -- based on path load and/or availability).
More background is available in this "Request-based Device-mapper
multipath and Dynamic load balancing" paper:
https://www.kernel.org/doc/ols/2007/ols2007v2-pages-235-244.pdf
But we've now come full circle where significantly faster storage
devices no longer need IOs to be made larger to drive optimal IO
performance. And even if they do there have been changes to the block
and filesystem layers that help ensure upper layers are constructing
larger IOs. In addition, SCSI's differentiated IO errors will propagate
through to bio-based IO completion hooks -- so that eliminates another
historic justiciation for request-based DM multipath. Lastly, the block
layer's immutable biovec changes have made bio cloning cheaper than it
has ever been; whereas request cloning is still relatively expensive
(both on a CPU usage and memory footprint level).
As such, bio-based DM multipath offers the promise of a more efficient
IO path for high IOPs devices that are, or will be, emerging.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add some seperation between bio-based and request-based DM core code.
'struct mapped_device' and other DM core only structures and functions
have been moved to dm-core.h and all relevant DM core .c files have been
updated to include dm-core.h rather than dm.h
DM targets should _never_ include dm-core.h!
[block core merge conflict resolution from Stephen Rothwell]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Instead of overloading the discard support with the REQ_SECURE flag.
Use the opportunity to rename the queue flag as well, and remove the
dead checks for this flag in the RAID 1 and RAID 10 drivers that don't
claim support for secure erase.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
