Commit Graph

101 Commits

Author SHA1 Message Date
Heinz Mauelshagen 0095dbc98b dm raid: fix rs_set_capacity on growing reshape
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:22 -04:00
Heinz Mauelshagen 9d9d939c80 dm raid: make rs_set_capacity to work on shrinking reshape
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:22 -04:00
Heinz Mauelshagen 6ee0bae9c8 dm raid: enhance comments in takeover checks
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:21 -04:00
Heinz Mauelshagen ae3c6cfff9 dm raid: remove bogus comment and fix comment typos
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:20 -04:00
Heinz Mauelshagen 75dd3b9ecb dm raid: more restricting data_offset value checks
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:19 -04:00
Heinz Mauelshagen 5fa146b25b dm raid: reject too many write_mostly devices
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:19 -04:00
Heinz Mauelshagen 0a7b818892 dm raid: the sync_page_io() metadata_op argument is bool
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:18 -04:00
Heinz Mauelshagen 0d851d14b8 dm raid: prohibit to pass in both sync and nosync ctr flags
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:17 -04:00
Heinz Mauelshagen ff4a88bf1c dm raid: avoid superfluous memory barriers on static metadata
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-18 15:37:17 -04:00
Arnd Bergmann 68c1c4d5ea dm raid: don't use 'const' in function return
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>
2016-06-16 12:09:54 -04:00
Heinz Mauelshagen 6e20902e8f dm raid: fix failed takeover/reshapes by keeping raid set frozen
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>
2016-06-14 18:52:14 -04:00
Heinz Mauelshagen 4257e085e2 dm raid: support to change bitmap region size
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-14 18:52:13 -04:00
Heinz Mauelshagen 9dbd1aa3a8 dm raid: add reshaping support to the target
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>
2016-06-14 18:52:12 -04:00
Heinz Mauelshagen 40ba37e564 dm raid: add prerequisite functions and definitions for reshaping
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>
2016-06-14 18:52:11 -04:00
Heinz Mauelshagen a30cbc0d1c dm raid: inverse check for flags from invalid to valid flags
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>
2016-06-14 17:25:02 -04:00
Mike Snitzer e6ca5e1a03 dm raid: various code cleanups
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>
2016-06-14 17:25:01 -04:00
Mike Snitzer bfcee0e312 dm raid: rename functions that alloc and free struct raid_set
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-14 17:25:01 -04:00
Mike Snitzer 4286325b4b dm raid: remove all the bitops wrappers
Removes obfuscation that is of little value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-14 17:25:00 -04:00
Mike Snitzer bb91a63fcc dm raid: rename _in_range to __within_range
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-14 17:24:59 -04:00
Mike Snitzer ef9b85a651 dm raid: add missing "dm-raid0" module alias
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>
2016-06-14 17:24:59 -04:00
Mike Snitzer 3fa6cf3821 dm raid: rename _argname_by_flag to dm_raid_arg_name_by_flag
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-14 17:24:58 -04:00
Mike Snitzer 9b6e542329 dm raid: bump to v1.9.0 and make the extended SB feature flag reflect it
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>
2016-06-14 17:24:57 -04:00
Mike Snitzer bd83a4c4f8 dm raid: remove ti_error_* wrappers
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>
2016-06-14 17:24:57 -04:00
Mike Snitzer 43157840fd dm raid: tabify appropriate whitespace
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-14 17:24:56 -04:00
Heinz Mauelshagen 3a1c1ef2fd dm raid: enhance status interface and fixup takeover/raid0
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>
2016-06-14 17:24:55 -04:00
Heinz Mauelshagen ecbfb9f118 dm raid: add raid level takeover support
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>
2016-06-14 17:24:46 -04:00
Heinz Mauelshagen 7b34df74d2 dm raid: enhance super_sync() to support new superblock members
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>
2016-06-14 17:09:35 -04:00
Heinz Mauelshagen 4763e543a6 dm raid: add new reshaping/raid10 format table line options to parameter parser
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>
2016-06-14 17:09:34 -04:00
Heinz Mauelshagen 33e53f0685 dm raid: introduce extended superblock and new raid types to support takeover/reshaping
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>
2016-06-14 17:09:32 -04:00
Heinz Mauelshagen 676fa5ad6e dm raid: use rt_is_raid*() in all appropriate checks
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>
2016-06-13 14:40:28 -04:00
Heinz Mauelshagen ad51d7f1d1 dm raid: more use of flag testing wrappers
- 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>
2016-06-13 14:40:28 -04:00
Heinz Mauelshagen f090279eaf dm raid: check constructor arguments for invalid raid level/argument combinations
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>
2016-06-13 14:40:27 -04:00
Heinz Mauelshagen 702108d194 dm raid: cleanup / provide infrastructure
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>
2016-06-13 14:40:24 -04:00
Heinz Mauelshagen 92c83d79b0 dm raid: use dm_arg_set API in constructor
- 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>
2016-06-13 12:00:40 -04:00
Heinz Mauelshagen 73c6f239a8 dm raid: rename variable 'ret' to 'r' to conform to other dm code
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-13 12:00:40 -04:00
Mike Christie 796a5cf083 md: use bio op accessors
Separate the op from the rq_flag_bits and have md
set/get the bio using bio_set_op_attrs/bio_op.

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>
2016-06-07 13:41:38 -06:00
Heinz Mauelshagen 4c9971ca6a dm raid: make sure no feature flags are set in metadata
Given we don't yet support any feature flags in the dm-raid ondisk
metadata (see: 'features' member of 'struct dm_raid_superblock'),
add a check to ensure no flags are actually set, if any features are
set reject the activation of the RAID mapping.

This is to prevent possible data corruption in case of a kernel
downgrade when there'll potentially be feature flags set by a future
dm-raid target.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-05-13 09:03:51 -04:00
Mikulas Patocka 042745ee53 dm raid: fix round up of default region size
Commit 3a0f9aaee0 ("dm raid: round region_size to power of two")
intended to make sure that the default region size is a power of two.
However, the logic in that commit is incorrect and sets the variable
region_size to 0 or 1, depending on whether min_region_size is a power
of two.

Fix this logic, using roundup_pow_of_two(), so that region_size is
properly rounded up to the next power of two.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 3a0f9aaee0 ("dm raid: round region_size to power of two")
Cc: stable@vger.kernel.org # v3.8+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-10-02 12:02:31 -04:00
Kent Overstreet 8ae126660f block: kill merge_bvec_fn() completely
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own ->merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-13 12:31:57 -06:00
Heinz Mauelshagen 0cf4503174 dm raid: add support for the MD RAID0 personality
Add dm-raid access to the MD RAID0 personality to enable single zone
striping.

The following changes enable that access:
- add type definition to raid_types array
- make bitmap creation conditonal in super_validate(), because
  bitmaps are not allowed in raid0
- set rdev->sectors to the data image size in super_validate()
  to allow the raid0 personality to calculate the MD array
  size properly
- use mdddev(un)lock() functions instead of direct mutex_(un)lock()
  (wrapped in here because it's a trivial change)
- enhance raid_status() to always report full sync for raid0
  so that userspace checks for 100% sync will succeed and allow
  for resize (and takeover/reshape once added in future paches)
- enhance raid_resume() to not load bitmap in case of raid0
- add merge function to avoid data corruption (seen with readahead)
  that resulted from bio payloads that grew too large.  This problem
  did not occur with the other raid levels because it either did not
  apply without striping (raid1) or was avoided via stripe caching.
- raise version to 1.7.0 because of the raid0 API change

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29 14:19:00 -04:00
Heinz Mauelshagen c76d53f43e dm raid: a few cleanups
- ensure maximum device limit in superblock
- rename DMPF_* (print flags) to CTR_FLAG_* (constructor flags)
  and their respective struct raid_set member
- use strcasecmp() in raid10_format_to_md_layout() as in the constructor

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29 14:19:00 -04:00
Heinz Mauelshagen 0f4106b32f dm raid: fixup documentation for discard support
Remove comment above parse_raid_params() that claims
"devices_handle_discard_safely" is a table line argument when it is
actually is a module parameter.

Also, backfill dm-raid target version 1.6.0 documentation.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-29 14:18:59 -04:00
Linus Torvalds 802ea9d864 - Most significant change this cycle is request-based DM now supports
stacking ontop of blk-mq devices.  This blk-mq support changes the
   model request-based DM uses for cloning a request to relying on
   calling blk_get_request() directly from the underlying blk-mq device.
   Early consumer of this code is Intel's emerging NVMe hardware; thanks
   to Keith Busch for working on, and pushing for, these changes.
 
 - A few other small fixes and cleanups across other DM targets.
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Merge tag 'dm-3.20-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper changes from Mike Snitzer:

 - The most significant change this cycle is request-based DM now
   supports stacking ontop of blk-mq devices.  This blk-mq support
   changes the model request-based DM uses for cloning a request to
   relying on calling blk_get_request() directly from the underlying
   blk-mq device.

   An early consumer of this code is Intel's emerging NVMe hardware;
   thanks to Keith Busch for working on, and pushing for, these changes.

 - A few other small fixes and cleanups across other DM targets.

* tag 'dm-3.20-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: inherit QUEUE_FLAG_SG_GAPS flags from underlying queues
  dm snapshot: remove unnecessary NULL checks before vfree() calls
  dm mpath: simplify failure path of dm_multipath_init()
  dm thin metadata: remove unused dm_pool_get_data_block_size()
  dm ioctl: fix stale comment above dm_get_inactive_table()
  dm crypt: update url in CONFIG_DM_CRYPT help text
  dm bufio: fix time comparison to use time_after_eq()
  dm: use time_in_range() and time_after()
  dm raid: fix a couple integer overflows
  dm table: train hybrid target type detection to select blk-mq if appropriate
  dm: allocate requests in target when stacking on blk-mq devices
  dm: prepare for allocating blk-mq clone requests in target
  dm: submit stacked requests in irq enabled context
  dm: split request structure out from dm_rq_target_io structure
  dm: remove exports for request-based interfaces without external callers
2015-02-12 16:36:31 -08:00
Dan Carpenter 3ca5a21a9c dm raid: fix a couple integer overflows
My static checker complains that if "num_raid_params" is UINT_MAX then
the "if (num_raid_params + 1 > argc) {" check doesn't work as intended.

The other change is that I moved the "if (argc != (num_raid_devs * 2))"
condition forward a few lines so it was before the call to
context_alloc().  If we had an integer overflow inside that function
then it would lead to an immediate crash.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-09 13:06:48 -05:00
NeilBrown 5c675f83c6 md: make ->congested robust against personality changes.
There is currently no locking around calls to the 'congested'
bdi function.  If called at an awkward time while an array is
being converted from one level (or personality) to another, there
is a tiny chance of running code in an unreferenced module etc.

So add a 'congested' function to the md_personality operations
structure, and call it with appropriate locking from a central
'mddev_congested'.

When the array personality is changing the array will be 'suspended'
so no IO is processed.
If mddev_congested detects this, it simply reports that the
array is congested, which is a safe guess.
As mddev_suspend calls synchronize_rcu(), mddev_congested can
avoid races by included the whole call inside an rcu_read_lock()
region.
This require that the congested functions for all subordinate devices
can be run under rcu_lock.  Fortunately this is the case.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00
Heinz Mauelshagen d20c4b08be dm raid: fix inaccessible superblocks causing oops in configure_discard_support
Commit 48cf06bc5f ("dm raid: add discard support for RAID levels 4, 5
and 6") did not properly handle missing metadata device(s).  A failing
read of the superblock causes the metadata and data devices to be
removed from the dev array in struct raid_set, setting references to
both devices to NULL.  configure_discard_support() nonetheless tries to
access the data dev unconditionally causing an oops.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-29 14:53:27 -04:00
Heinz Mauelshagen 40d43c4b4c dm raid: ensure superblock's size matches device's logical block size
The dm-raid superblock (struct dm_raid_superblock) is padded to 512
bytes and that size is being used to read it in from the metadata
device into one preallocated page.

Reading or writing this on a 512-byte sector device works fine but on
a 4096-byte sector device this fails.

Set the dm-raid superblock's size to the logical block size of the
metadata device, because IO at that size is guaranteed too work.  Also
add a size check to avoid silent partial metadata loss in case the
superblock should ever grow past the logical block size or PAGE_SIZE.

[includes pointer math fix from Dan Carpenter]
Reported-by: "Liuhua Wang" <lwang@suse.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-10-21 09:32:15 -04:00
Heinz Mauelshagen 48cf06bc5f dm raid: add discard support for RAID levels 4, 5 and 6
In case of RAID levels 4, 5 and 6 we have to verify each RAID members'
ability to zero data on discards to avoid stripe data corruption -- if
discard_zeroes_data is not set for each RAID member discard support must
be disabled.  But given the uncertainty of whether or not a RAID member
properly supports zeroing data on discard we require the user to
explicitly allow discard support on RAID levels 4, 5, and 6 by setting
a dm-raid module paramter, e.g.: dm-raid.devices_handle_discard_safely=Y
Otherwise, discards could cause data corruption on RAID4/5/6.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:36 -04:00
Heinz Mauelshagen 75b8e04bbf dm raid: add discard support for RAID levels 1 and 10
Discard support is not enabled for RAID levels 4, 5, and 6 at this time
due to concerns about unreliable discard_zeroes_data support on some
hardware.  Otherwise, discards could cause stripe data corruption
(classic example of bad apples spoiling the bunch).

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:36 -04:00
Jonathan Brassow c4a3955145 MD: Remember the last sync operation that was performed
MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-26 12:38:24 +10:00