treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

dm: add dust target

2019-04-30T20:37:19+00:00

Add the dm-dust target, which simulates the behavior of bad sectors at arbitrary locations, and the ability to enable the emulation of the read failures at an arbitrary time. This target behaves similarly to a linear target. At a given time, the user can send a message to the target to start failing read requests on specific blocks. When the failure behavior is enabled, reads of blocks configured "bad" will fail with EIO. Writes of blocks configured "bad" will result in the following: 1. Remove the block from the "bad block list". 2. Successfully complete the write. After this point, the block will successfully contain the written data, and will service reads and writes normally. This emulates the behavior of a "remapped sector" on a hard disk drive. dm-dust provides logging of which blocks have been added or removed to the "bad block list", as well as logging when a block has been removed from the bad block list. These messages can be used alongside the messages from the driver using a dm-dust device to analyze the driver's behavior when a read fails at a given time. (This logging can be reduced via a "quiet" mode, if desired.) NOTE: If the block size is larger than 512 bytes, only the first sector of each "dust block" is detected. Placing a limiting layer above a dust target, to limit the minimum I/O size to the dust block size, will ensure proper emulation of the given large block size. Signed-off-by: Bryan Gurney Co-developed-by: Joe Shimkus Co-developed-by: John Dorminy Co-developed-by: John Pittman Co-developed-by: Thomas Jaskiewicz Signed-off-by: Mike Snitzer

dm: add support to directly boot to a mapped device

2019-03-05T19:53:50+00:00

Add a "create" module parameter, which allows device-mapper targets to be configured at boot time. This enables early use of DM targets in the boot process (as the root device or otherwise) without the need of an initramfs. The syntax used in the boot param is based on the concise format from the dmsetup tool to follow the rule of least surprise: dmsetup table --concise /dev/mapper/lroot Which is: dm-mod.create=,,,,[,

+][;,,,,

+]+] Where, ::= The device name. ::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | "" ::= The device minor number | "" ::= "ro" | "rw"

::= ::= "verity" | "linear" | ... For example, the following could be added in the boot parameters: dm-mod.create="lroot,,,rw, 0 4096 linear 98:16 0, 4096 4096 linear 98:32 0" root=/dev/dm-0 Only the targets that were tested are allowed and the ones that don't change any block device when the device is create as read-only. For example, mirror and cache targets are not allowed. The rationale behind this is that if the user makes a mistake, choosing the wrong device to be the mirror or the cache can corrupt data. The only targets initially allowed are: * crypt * delay * linear * snapshot-origin * striped * verity Co-developed-by: Will Drewry Co-developed-by: Kees Cook Co-developed-by: Enric Balletbo i Serra Signed-off-by: Helen Koike Reviewed-by: Kees Cook Signed-off-by: Mike Snitzer

dm: remove legacy request-based IO path

2018-10-11T15:36:09+00:00

dm supports both, and since we're killing off the legacy path in general, get rid of it in dm. Signed-off-by: Jens Axboe Signed-off-by: Mike Snitzer

dm: add writecache target

2018-06-08T15:59:51+00:00

The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka Signed-off-by: Colin Ian King # fix missing goto Signed-off-by: Ross Zwisler # fix compilation issue with !DAX Signed-off-by: Dan Carpenter # use msecs_to_jiffies Acked-by: Dan Williams # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer

dax, dm: allow device-mapper to operate without dax support

2018-04-03T12:41:19+00:00

Change device-mapper's DAX dependency to require the presence of at least one DAX_DRIVER. This allows device-mapper to be built without bringing the DAX core along which is especially wasteful when there are no DAX drivers, like BLK_DEV_PMEM, configured. Cc: Alasdair Kergon Reported-by: Bart Van Assche Reported-by: kbuild test robot Reported-by: Arnd Bergmann Reviewed-by: Mike Snitzer Signed-off-by: Dan Williams

dm: add unstriped target

2018-01-17T14:16:00+00:00

This device mapper "unstriped" target remaps and unstripes I/O so it is issued solely on a single drive in a HW RAID0 or dm-striped target. In a 4 drive HW RAID0 the striped target exposes 1/4th of the LBA range as a virtual drive. Each I/O to that virtual drive will only be issued to the 1 drive that was selected of the 4 drives in the HW RAID0. This unstriped target is most useful for Intel NVMe drives that have multiple cores but that do not have firmware control to pin separate LBA ranges to each discrete cpu core. Signed-off-by: Scott Bauer Signed-off-by: Heinz Mauelshagen Acked-by: Keith Busch Signed-off-by: Mike Snitzer

md-cluster: update document for raid10

2017-11-02T04:32:25+00:00

Signed-off-by: Guoqing Jiang Signed-off-by: Shaohua Li

dm zoned: drive-managed zoned block device target

2017-06-19T15:05:20+00:00

The dm-zoned device mapper target provides transparent write access to zoned block devices (ZBC and ZAC compliant block devices). dm-zoned hides to the device user (a file system or an application doing raw block device accesses) any constraint imposed on write requests by the device, equivalent to a drive-managed zoned block device model. Write requests are processed using a combination of on-disk buffering using the device conventional zones and direct in-place processing for requests aligned to a zone sequential write pointer position. A background reclaim process implemented using dm_kcopyd_copy ensures that conventional zones are always available for executing unaligned write requests. The reclaim process overhead is minimized by managing buffer zones in a least-recently-written order and first targeting the oldest buffer zones. Doing so, blocks under regular write access (such as metadata blocks of a file system) remain stored in conventional zones, resulting in no apparent overhead. dm-zoned implementation focus on simplicity and on minimizing overhead (CPU, memory and storage overhead). For a 14TB host-managed disk with 256 MB zones, dm-zoned memory usage per disk instance is at most about 3 MB and as little as 5 zones will be used internally for storing metadata and performing buffer zone reclaim operations. This is achieved using zone level indirection rather than a full block indirection system for managing block movement between zones. dm-zoned primary target is host-managed zoned block devices but it can also be used with host-aware device models to mitigate potential device-side performance degradation due to excessive random writing. Zoned block devices can be formatted and checked for use with the dm-zoned target using the dmzadm utility available at: https://github.com/hgst/dm-zoned-tools Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Bart Van Assche [Mike Snitzer partly refactored Damien's original work to cleanup the code] Signed-off-by: Mike Snitzer

Merge tag 'for-4.12/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2017-05-06T02:31:06+00:00

Pull device mapper fixes from Mike Snitzer: - DM cache metadata fixes to short-circuit operations that require the metadata not be in 'fail_io' mode. Otherwise crashes are possible. - a DM cache fix to address the inability to adapt to continuous IO that happened to also reflect a changing working set (which required old blocks be demoted before the new working set could be promoted) - a DM cache smq policy cleanup that fell out from reviewing the above - fix the Kconfig help text for CONFIG_DM_INTEGRITY * tag 'for-4.12/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache metadata: fail operations if fail_io mode has been established dm integrity: improve the Kconfig help text for DM_INTEGRITY dm cache policy smq: cleanup free_target_met() and clean_target_met() dm cache policy smq: allow demotions to happen even during continuous IO

kernel/linux.git/drivers/md/Kconfig, branch v5.2.16