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2019-11-20dm: Fix Kconfig indentationKrzysztof Kozlowski1-27/+27
Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ /\t/' -i */Kconfig Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-12dm: add clone targetNikos Tsironis1-0/+14
Add the dm-clone target, which allows cloning of arbitrary block devices. dm-clone produces a one-to-one copy of an existing, read-only source device into a writable destination device: It presents a virtual block device which makes all data appear immediately, and redirects reads and writes accordingly. The main use case of dm-clone is to clone a potentially remote, high-latency, read-only, archival-type block device into a writable, fast, primary-type device for fast, low-latency I/O. The cloned device is visible/mountable immediately and the copy of the source device to the destination device happens in the background, in parallel with user I/O. When the cloning completes, the dm-clone table can be removed altogether and be replaced, e.g., by a linear table, mapping directly to the destination device. For further information and examples of how to use dm-clone, please read Documentation/admin-guide/device-mapper/dm-clone.rst Suggested-by: Vangelis Koukis <vkoukis@arrikto.com> Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-03dm crypt: switch to ESSIV crypto API templateArd Biesheuvel1-0/+1
Replace the explicit ESSIV handling in the dm-crypt driver with calls into the crypto API, which now possesses the capability to perform this processing within the crypto subsystem. Note that we reorder the AEAD cipher_api string parsing with the TFM instantiation: this is needed because cipher_api is mangled by the ESSIV handling, and throws off the parsing of "authenc(" otherwise. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23dm verity: add root hash pkcs#7 signature verificationJaskaran Khurana1-0/+12
The verification is to support cases where the root hash is not secured by Trusted Boot, UEFI Secureboot or similar technologies. One of the use cases for this is for dm-verity volumes mounted after boot, the root hash provided during the creation of the dm-verity volume has to be secure and thus in-kernel validation implemented here will be used before we trust the root hash and allow the block device to be created. The signature being provided for verification must verify the root hash and must be trusted by the builtin keyring for verification to succeed. The hash is added as a key of type "user" and the description is passed to the kernel so it can look it up and use it for verification. Adds CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG which can be turned on if root hash verification is needed. Kernel commandline dm_verity module parameter 'require_signatures' will indicate whether to force root hash signature verification (for all dm verity volumes). Signed-off-by: Jaskaran Khurana <jaskarankhurana@linux.microsoft.com> Tested-and-Reviewed-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-15docs: device-mapper: move it to the admin-guideMauro Carvalho Chehab1-1/+1
The DM support describes lots of aspects related to mapped disk partitions from the userspace PoV. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-06-14docs: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
The conversion is actually: - add blank lines and indentation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
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 <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-30dm: add dust targetBryan Gurney1-0/+9
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 <bgurney@redhat.com> Co-developed-by: Joe Shimkus <jshimkus@redhat.com> Co-developed-by: John Dorminy <jdorminy@redhat.com> Co-developed-by: John Pittman <jpittman@redhat.com> Co-developed-by: Thomas Jaskiewicz <tjaskiew@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-03-05dm: add support to directly boot to a mapped deviceHelen Koike1-0/+12
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=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+] Where, <name> ::= The device name. <uuid> ::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | "" <minor> ::= The device minor number | "" <flags> ::= "ro" | "rw" <table> ::= <start_sector> <num_sectors> <target_type> <target_args> <target_type> ::= "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 <wad@chromium.org> Co-developed-by: Kees Cook <keescook@chromium.org> Co-developed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Helen Koike <helen.koike@collabora.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-11dm: remove legacy request-based IO pathJens Axboe1-11/+0
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 <axboe@kernel.dk> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08dm: add writecache targetMikulas Patocka1-0/+11
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 <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-04-03dax, dm: allow device-mapper to operate without dax supportDan Williams1-1/+1
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 <agk@redhat.com> Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com> Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-01-17dm: add unstriped targetScott Bauer1-0/+7
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 <scott.bauer@intel.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Acked-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-01md-cluster: update document for raid10Guoqing Jiang1-2/+3
Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-06-19dm zoned: drive-managed zoned block device targetDamien Le Moal1-0/+17
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 <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [Mike Snitzer partly refactored Damien's original work to cleanup the code] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-05Merge tag 'for-4.12/dm-fixes' of ↵Linus Torvalds1-2/+13
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm 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
2017-05-05Merge tag 'libnvdimm-for-4.12' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has been in multiple -next releases. There were a few late breaking fixes and small features that got added in the last couple days, but the whole set has received a build success notification from the kbuild robot. Change summary: - Region media error reporting: A libnvdimm region device is the parent to one or more namespaces. To date, media errors have been reported via the "badblocks" attribute attached to pmem block devices for namespaces in "raw" or "memory" mode. Given that namespaces can be in "device-dax" or "btt-sector" mode this new interface reports media errors generically, i.e. independent of namespace modes or state. This subsequently allows userspace tooling to craft "ACPI 6.1 Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error" requests and submit them via the ioctl path for NVDIMM root bus devices. - Introduce 'struct dax_device' and 'struct dax_operations': Prompted by a request from Linus and feedback from Christoph this allows for dax capable drivers to publish their own custom dax operations. This fixes the broken assumption that all dax operations are related to a persistent memory device, and makes it easier for other architectures and platforms to add customized persistent memory support. - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is available for storage appliance applications to manually trigger memory controllers to drain write-pending buffers that would otherwise be flushed automatically by the platform ADR (asynchronous-DRAM-refresh) mechanism at a power loss event. Support for "locked" DIMMs is included to prevent namespaces from surfacing when the namespace label data area is locked. Finally, fixes for various reported deadlocks and crashes, also tagged for -stable. - ACPI / nfit driver updates: General updates of the nfit driver to add DSM command overrides, ACPI 6.1 health state flags support, DSM payload debug available by default, and various fixes. Acknowledgements that came after the branch was pushed: - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock": Tested-by: Yi Zhang <yizhan@redhat.com> - commit 23f498448362 "libnvdimm: rework region badblocks clearing" Tested-by: Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits) libnvdimm, pfn: fix 'npfns' vs section alignment libnvdimm: handle locked label storage areas libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED brd: fix uninitialized use of brd->dax_dev block, dax: use correct format string in bdev_dax_supported device-dax: fix sysfs attribute deadlock libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking" libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering libnvdimm: rework region badblocks clearing acpi, nfit: kill ACPI_NFIT_DEBUG libnvdimm: fix clear length of nvdimm_forget_poison() libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify libnvdimm, region: sysfs trigger for nvdimm_flush() libnvdimm: fix phys_addr for nvdimm_clear_poison x86, dax, pmem: remove indirection around memcpy_from_pmem() block: remove block_device_operations ->direct_access() block, dax: convert bdev_dax_supported() to dax_direct_access() filesystem-dax: convert to dax_direct_access() Revert "block: use DAX for partition table reads" ext2, ext4, xfs: retrieve dax_device for iomap operations ...
2017-05-04dm integrity: improve the Kconfig help text for DM_INTEGRITYMike Snitzer1-2/+13
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Milan Broz <gmazyland@gmail.com>
2017-05-03Merge tag 'for-4.12/dm-changes' of ↵Linus Torvalds1-8/+11
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - A major update for DM cache that reduces the latency for deciding whether blocks should migrate to/from the cache. The bio-prison-v2 interface supports this improvement by enabling direct dispatch of work to workqueues rather than having to delay the actual work dispatch to the DM cache core. So the dm-cache policies are much more nimble by being able to drive IO as they see fit. One immediate benefit from the improved latency is a cache that should be much more adaptive to changing workloads. - Add a new DM integrity target that emulates a block device that has additional per-sector tags that can be used for storing integrity information. - Add a new authenticated encryption feature to the DM crypt target that builds on the capabilities provided by the DM integrity target. - Add MD interface for switching the raid4/5/6 journal mode and update the DM raid target to use it to enable aid4/5/6 journal write-back support. - Switch the DM verity target over to using the asynchronous hash crypto API (this helps work better with architectures that have access to off-CPU algorithm providers, which should reduce CPU utilization). - Various request-based DM and DM multipath fixes and improvements from Bart and Christoph. - A DM thinp target fix for a bio structure leak that occurs for each discard IFF discard passdown is enabled. - A fix for a possible deadlock in DM bufio and a fix to re-check the new buffer allocation watermark in the face of competing admin changes to the 'max_cache_size_bytes' tunable. - A couple DM core cleanups. * tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (50 commits) dm bufio: check new buffer allocation watermark every 30 seconds dm bufio: avoid a possible ABBA deadlock dm mpath: make it easier to detect unintended I/O request flushes dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit() dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH dm: introduce enum dm_queue_mode to cleanup related code dm mpath: verify __pg_init_all_paths locking assumptions at runtime dm: verify suspend_locking assumptions at runtime dm block manager: remove an unused argument from dm_block_manager_create() dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue() dm mpath: delay requeuing while path initialization is in progress dm mpath: avoid that path removal can trigger an infinite loop dm mpath: split and rename activate_path() to prepare for its expanded use dm ioctl: prevent stack leak in dm ioctl call dm integrity: use previously calculated log2 of sectors_per_block dm integrity: use hex2bin instead of open-coded variant dm crypt: replace custom implementation of hex2bin() dm crypt: remove obsolete references to per-CPU state dm verity: switch to using asynchronous hash crypto API dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues ...
2017-04-20dm: add dax_device and dax_operations supportDan Williams1-0/+1
Allocate a dax_device to represent the capacity of a device-mapper instance. Provide a ->direct_access() method via the new dax_operations indirection that mirrors the functionality of the current direct_access support via block_device_operations. Once fs/dax.c has been converted to use dax_operations the old dm_blk_direct_access() will be removed. A new helper dm_dax_get_live_target() is introduced to separate some of the dm-specifics from the direct_access implementation. This enabling is only for the top-level dm representation to upper layers. Converting target direct_access implementations is deferred to a separate patch. Cc: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-30dm raid: select the Kconfig option CONFIG_MD_RAID0Mikulas Patocka1-0/+1
Since the commit 0cf4503174c1 ("dm raid: add support for the MD RAID0 personality"), the dm-raid subsystem can activate a RAID-0 array. Therefore, add MD_RAID0 to the dependencies of DM_RAID, so that MD_RAID0 will be selected when DM_RAID is selected. Fixes: 0cf4503174c1 ("dm raid: add support for the MD RAID0 personality") Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-28Fix dead URLs to ftp.kernel.orgSeongJae Park1-1/+1
URLs to ftp.kernel.org are still exist though the service is closed [0]. This commit fixes the URLs to use www.kernel.org instead. [0] https://www.kernel.org/shutting-down-ftp-services.html Signed-off-by: SeongJae Park <sj38.park@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-24dm: add integrity targetMikulas Patocka1-0/+10
The dm-integrity target emulates a block device that has additional per-sector tags that can be used for storing integrity information. A general problem with storing integrity tags with every sector is that writing the sector and the integrity tag must be atomic - i.e. in case of crash, either both sector and integrity tag or none of them is written. To guarantee write atomicity the dm-integrity target uses a journal. It writes sector data and integrity tags into a journal, commits the journal and then copies the data and integrity tags to their respective location. The dm-integrity target can be used with the dm-crypt target - in this situation the dm-crypt target creates the integrity data and passes them to the dm-integrity target via bio_integrity_payload attached to the bio. In this mode, the dm-crypt and dm-integrity targets provide authenticated disk encryption - if the attacker modifies the encrypted device, an I/O error is returned instead of random data. The dm-integrity target can also be used as a standalone target, in this mode it calculates and verifies the integrity tag internally. In this mode, the dm-integrity target can be used to detect silent data corruption on the disk or in the I/O path. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-07dm cache: significant rework to leverage dm-bio-prison-v2Joe Thornber1-8/+0
The cache policy interfaces have been updated to work well with the new bio-prison v2 interface's ability to queue work immediately (promotion, demotion, etc) -- overriding benefit being reduced latency on processing IO through the cache. Previously such work would be left for the DM cache core to queue on various lists and then process in batches later -- this caused a serious delay in latency for IO driven by the cache. The background tracker code was factored out so that all cache policies can make use of it. Also, the "cleaner" policy has been removed and is now a variant of the smq policy that simply disallows migrations. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-14dm block manager: make block locking optionalJoe Thornber1-1/+9
The block manager's locking is useful for catching cycles that may result from certain btree metadata corruption. But in general it serves as a developer tool to catch bugs in code. Unless you're finding that DM thin provisioning is hanging due to infinite loops within the block manager's access to btree nodes you can safely disable this feature. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> # do/while(0) macro fix Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-03-10dm: add missing newline between DM_DEBUG_BLOCK_STACK_TRACING and DM_BUFIOMike Snitzer1-0/+1
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-03-10dm cache: make the 'mq' policy an alias for 'smq'Joe Thornber1-10/+0
smq seems to be performing better than the old mq policy in all situations, as well as using a quarter of the memory. Make 'mq' an alias for 'smq' when choosing a cache policy. The tunables that were present for the old mq are faked, and have no effect. mq should be considered deprecated now. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm verity: add support for forward error correctionSami Tolvanen1-0/+12
Add support for correcting corrupted blocks using Reed-Solomon. This code uses RS(255, N) interleaved across data and hash blocks. Each error-correcting block covers N bytes evenly distributed across the combined total data, so that each byte is a maximum distance away from the others. This makes it possible to recover from several consecutive corrupted blocks with relatively small space overhead. In addition, using verity hashes to locate erasures nearly doubles the effectiveness of error correction. Being able to detect corrupted blocks also improves performance, because only corrupted blocks need to corrected. For a 2 GiB partition, RS(255, 253) (two parity bytes for each 253-byte block) can correct up to 16 MiB of consecutive corrupted blocks if erasures can be located, and 8 MiB if they cannot, with 16 MiB space overhead. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm bufio: store stacktrace in buffers to help find buffer leaksMikulas Patocka1-0/+9
The option DM_DEBUG_BLOCK_STACK_TRACING is moved from persistent-data directory to device mapper directory because it will now be used by persistent-data and bufio. When the option is enabled, each bufio buffer stores the stacktrace of the last dm_bufio_get(), dm_bufio_read() or dm_bufio_new() call that increased the hold count to 1. The buffer's stacktrace is printed if the buffer was not released before the bufio client is destroyed. When DM_DEBUG_BLOCK_STACK_TRACING is enabled, any bufio buffer leaks are considered warnings - i.e. the kernel continues afterwards. If not enabled, buffer leaks are considered BUGs and the kernel with crash. Reasoning on this disposition is: if we only ever warned on buffer leaks users would generally ignore them and the problematic code would never get fixed. Successfully used to find source of bufio leaks fixed with commit fce079f63c3 ("dm btree: fix bufio buffer leaks in dm_btree_del() error path"). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-09raid5-cache: add crc32c Kconfig dependencyArnd Bergmann1-0/+1
The recent change of the raid5-cache code to use crc32c instead of crc32 causes link errors when CONFIG_LIBCRC32C is disabled: drivers/built-in.o: In function crc32c' core.c:(.text+0x1c6060): undefined reference to `crc32c' This adds an explicit 'select' statement like all other users of this function do. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 5cb2fbd6ea0d ("raid5-cache: use crc32c checksum") Signed-off-by: NeilBrown <neilb@suse.com>
2015-09-11Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds1-1/+1
Pull second round of SCSI updates from James Bottomley: "There's one late arriving patch here (added today), fixing a build issue which the scsi_dh patch set in here uncovered. Other than that, everything has been incubated in -next and the checkers for a week. The major pieces of this patch are a set patches facilitating better integration between scsi and scsi_dh (the device handling layer used by multi-path; all the dm parts are acked by Mike Snitzer). This also includes driver updates for mp3sas, scsi_debug and an assortment of bug fixes" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (50 commits) scsi_dh: fix randconfig build error scsi: fix scsi_error_handler vs. scsi_host_dev_release race fcoe: Convert use of __constant_htons to htons mpt2sas: setpci reset kernel oops fix pm80xx: Don't override ts->stat on IO_OPEN_CNX_ERROR_HW_RESOURCE_BUSY lpfc: Fix possible use-after-free and double free in lpfc_mbx_cmpl_rdp_page_a2() bfa: Fix incorrect de-reference of pointer bfa: Fix indentation scsi_transport_sas: Remove check for SAS expander when querying bay/enclosure IDs. scsi_debug: resp_request: remove unused variable scsi_debug: fix REPORT LUNS Well Known LU scsi_debug: schedule_resp fix input variable check scsi_debug: make dump_sector static scsi_debug: vfree is null safe so drop the check scsi_debug: use SCSI_W_LUN_REPORT_LUNS instead of SAM2_WLUN_REPORT_LUNS; scsi_debug: define pr_fmt() for consistent logging mpt2sas: Refcount fw_events and fix unsafe list usage mpt2sas: Refcount sas_device objects and fix unsafe list usage scsi_dh: return SCSI_DH_NOTCONN in scsi_dh_activate() scsi_dh: don't allow to detach device handlers at runtime ...
2015-09-11scsi_dh: fix randconfig build errorChristoph Hellwig1-1/+1
It looks like the Kconfig check that was meant to fix this (commit fe9233fb6914a0eb20166c967e3020f7f0fba2c9 [SCSI] scsi_dh: fix kconfig related build errors) was actually reversed, but no-one noticed until the new set of patches which separated DM and SCSI_DH). Fixes: fe9233fb6914a0eb20166c967e3020f7f0fba2c9 Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-08-07dm: Spelling s/consitent/consistent/Geert Uytterhoeven1-1/+1
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Jiri Kosina <jkosina@suse.com>
2015-07-27dm crypt: update wiki page URLBaruch Siach1-1/+1
Cryptsetup moved to gitlab. This is a leftover from commit e44f23b32dc7 (dm crypt: update URLs to new cryptsetup project page, 2015-04-05). Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-11dm cache: add stochastic-multi-queue (smq) policyJoe Thornber1-0/+12
The stochastic-multi-queue (smq) policy addresses some of the problems with the current multiqueue (mq) policy. Memory usage ------------ The mq policy uses a lot of memory; 88 bytes per cache block on a 64 bit machine. SMQ uses 28bit indexes to implement it's data structures rather than pointers. It avoids storing an explicit hit count for each block. It has a 'hotspot' queue rather than a pre cache which uses a quarter of the entries (each hotspot block covers a larger area than a single cache block). All these mean smq uses ~25bytes per cache block. Still a lot of memory, but a substantial improvement nontheless. Level balancing --------------- MQ places entries in different levels of the multiqueue structures based on their hit count (~ln(hit count)). This means the bottom levels generally have the most entries, and the top ones have very few. Having unbalanced levels like this reduces the efficacy of the multiqueue. SMQ does not maintain a hit count, instead it swaps hit entries with the least recently used entry from the level above. The over all ordering being a side effect of this stochastic process. With this scheme we can decide how many entries occupy each multiqueue level, resulting in better promotion/demotion decisions. Adaptability ------------ The MQ policy maintains a hit count for each cache block. For a different block to get promoted to the cache it's hit count has to exceed the lowest currently in the cache. This means it can take a long time for the cache to adapt between varying IO patterns. Periodically degrading the hit counts could help with this, but I haven't found a nice general solution. SMQ doesn't maintain hit counts, so a lot of this problem just goes away. In addition it tracks performance of the hotspot queue, which is used to decide which blocks to promote. If the hotspot queue is performing badly then it starts moving entries more quickly between levels. This lets it adapt to new IO patterns very quickly. Performance ----------- In my tests SMQ shows substantially better performance than MQ. Once this matures a bit more I'm sure it'll become the default policy. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-24Merge tag 'md/4.1' of git://neil.brown.name/mdLinus Torvalds1-0/+16
Pull md updates from Neil Brown: "More updates that usual this time. A few have performance impacts which hould mostly be positive, but RAID5 (in particular) can be very work-load ensitive... We'll have to wait and see. Highlights: - "experimental" code for managing md/raid1 across a cluster using DLM. Code is not ready for general use and triggers a WARNING if used. However it is looking good and mostly done and having in mainline will help co-ordinate development. - RAID5/6 can now batch multiple (4K wide) stripe_heads so as to handle a full (chunk wide) stripe as a single unit. - RAID6 can now perform read-modify-write cycles which should help performance on larger arrays: 6 or more devices. - RAID5/6 stripe cache now grows and shrinks dynamically. The value set is used as a minimum. - Resync is now allowed to go a little faster than the 'mininum' when there is competing IO. How much faster depends on the speed of the devices, so the effective minimum should scale with device speed to some extent" * tag 'md/4.1' of git://neil.brown.name/md: (58 commits) md/raid5: don't do chunk aligned read on degraded array. md/raid5: allow the stripe_cache to grow and shrink. md/raid5: change ->inactive_blocked to a bit-flag. md/raid5: move max_nr_stripes management into grow_one_stripe and drop_one_stripe md/raid5: pass gfp_t arg to grow_one_stripe() md/raid5: introduce configuration option rmw_level md/raid5: activate raid6 rmw feature md/raid6 algorithms: xor_syndrome() for SSE2 md/raid6 algorithms: xor_syndrome() for generic int md/raid6 algorithms: improve test program md/raid6 algorithms: delta syndrome functions raid5: handle expansion/resync case with stripe batching raid5: handle io error of batch list RAID5: batch adjacent full stripe write raid5: track overwrite disk count raid5: add a new flag to track if a stripe can be batched raid5: use flex_array for scribble data md raid0: access mddev->queue (request queue member) conditionally because it is not set when accessed from dm-raid md: allow resync to go faster when there is competing IO. md: remove 'go_faster' option from ->sync_request() ...
2015-04-15dm: add log writes targetJosef Bacik1-0/+16
Introduce a new target that is meant for file system developers to test file system integrity at particular points in the life of a file system. We capture all write requests and associated data and log them to a separate device for later replay. There is a userspace utility to do this replay. The idea behind this is to give file system developers a tool to verify that the file system is always consistent. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Zach Brown <zab@zabbo.net> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-15dm: add 'use_blk_mq' module param and expose in per-device ro sysfs attrMike Snitzer1-0/+11
Request-based DM's blk-mq support defaults to off; but a user can easily change the default using the dm_mod.use_blk_mq module/boot option. Also, you can check what mode a given request-based DM device is using with: cat /sys/block/dm-X/dm/use_blk_mq This change enabled further cleanup and reduced work (e.g. the md->io_pool and md->rq_pool isn't created if using blk-mq). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-23Create a separate module for clustering supportGoldwyn Rodrigues1-0/+16
Tagged as EXPERIMENTAL for now. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-19Merge branch 'kconfig' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kconfig updates from Michal Marek: "Yann E Morin was supposed to take over kconfig maintainership, but this hasn't happened. So I'm sending a few kconfig patches that I collected: - Fix for missing va_end in kconfig - merge_config.sh displays used if given too few arguments - s/boolean/bool/ in Kconfig files for consistency, with the plan to only support bool in the future" * 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kconfig: use va_end to match corresponding va_start merge_config.sh: Display usage if given too few arguments kconfig: use bool instead of boolean for type definition attributes
2015-02-12Merge tag 'dm-3.20-changes' of ↵Linus Torvalds1-3/+2
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
2015-02-09dm crypt: update url in CONFIG_DM_CRYPT help textLoic Pefferkorn1-3/+2
Update the obsolete url in the CONFIG_DM_CRYPT help text. Signed-off-by: Loic Pefferkorn <loic@loicp.eu> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-01-07kconfig: use bool instead of boolean for type definition attributesChristoph Jaeger1-2/+2
Support for keyword 'boolean' will be dropped later on. No functional change. Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com Signed-off-by: Christoph Jaeger <cj@linux.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-06rcu: Make SRCU optional by using CONFIG_SRCUPranith Kumar1-0/+1
SRCU is not necessary to be compiled by default in all cases. For tinification efforts not compiling SRCU unless necessary is desirable. The current patch tries to make compiling SRCU optional by introducing a new Kconfig option CONFIG_SRCU which is selected when any of the components making use of SRCU are selected. If we do not select CONFIG_SRCU, srcu.o will not be compiled at all. text data bss dec hex filename 2007 0 0 2007 7d7 kernel/rcu/srcu.o Size of arch/powerpc/boot/zImage changes from text data bss dec hex filename 831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before 829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after so the savings are about ~2000 bytes. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
2014-03-27dm: add era targetJoe Thornber1-0/+11
dm-era is a target that behaves similar to the linear target. In addition it keeps track of which blocks were written within a user defined period of time called an 'era'. Each era target instance maintains the current era as a monotonically increasing 32-bit counter. Use cases include tracking changed blocks for backup software, and partially invalidating the contents of a cache to restore cache coherency after rolling back a vendor snapshot. dm-era is primarily expected to be paired with the dm-cache target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-03dm: fix Kconfig indentationMike Snitzer1-10/+0
Since DM_DEBUG_BLOCK_STACK_TRACING is a DM_PERSISTENT_DATA config option move it from drivers/md/Kconfig to drivers/md/persistent-data/Kconfig. Doing so fixes indentation for other DM config options. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-14dm sysfs: fix a module unload raceMikulas Patocka1-0/+4
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
2014-01-14dm snapshot: use dm-bufioMikulas Patocka1-0/+1
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>
2014-01-07dm persistent data: cleanup dm-thin specific references in textMike Snitzer1-3/+3
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>
2013-11-09dm: fix Kconfig menu indentationMikulas Patocka1-11/+11
The option DM_LOG_USERSPACE is sub-option of DM_MIRROR, so place it right after DM_MIRROR. Doing so fixes various other Device mapper targets/features to be properly nested under "Device mapper support". Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>