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* dm: add statistics supportMikulas Patocka2013-09-051-0/+186
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support the collection of I/O statistics on user-defined regions of a DM device. If no regions are defined no statistics are collected so there isn't any performance impact. Only bio-based DM devices are currently supported. Each user-defined region specifies a starting sector, length and step. Individual statistics will be collected for each step-sized area within the range specified. The I/O statistics counters for each step-sized area of a region are in the same format as /sys/block/*/stat or /proc/diskstats but extra counters (12 and 13) are provided: total time spent reading and writing in milliseconds. All these counters may be accessed by sending the @stats_print message to the appropriate DM device via dmsetup. The creation of DM statistics will allocate memory via kmalloc or fallback to using vmalloc space. At most, 1/4 of the overall system memory may be allocated by DM statistics. The admin can see how much memory is used by reading /sys/module/dm_mod/parameters/stats_current_allocated_bytes See Documentation/device-mapper/statistics.txt for more details. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: add data block size limits to DocumentationCarlos Maiolino2013-08-231-7/+8
| | | | | | | | | | | Inform users that the data block size can't be any arbitrary number, i.e. its value must be between 64KB and 1GB. Also, it should be a multiple of 64KB. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm cache: add data block size limits to code and DocumentationMike Snitzer2013-08-231-1/+2
| | | | | | | | | | | | Place upper bound on the cache's data block size (1GB). Inform users that the data block size can't be any arbitrary number, i.e. its value must be between 32KB and 1GB. Also, it should be a multiple of 32KB. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm cache: document metadata device is exclussive to a cacheMike Snitzer2013-08-231-1/+2
| | | | | | | | A cache's metadata device may not be shared by multiple cache devices. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* Merge tag 'dm-3.11-changes' of ↵Linus Torvalds2013-07-111-0/+126
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm Pull device-mapper changes from Alasdair G Kergon: "Add a device-mapper target called dm-switch to provide a multipath framework for storage arrays that dynamically reconfigure their preferred paths for different device regions. Fix a bug in the verity target that prevented its use with some specific sizes of devices. Improve some locking mechanisms in the device-mapper core and bufio. Add Mike Snitzer as a device-mapper maintainer. A few more clean-ups and fixes" * tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: dm: add switch target dm: update maintainers dm: optimize reorder structure dm: optimize use SRCU and RCU dm bufio: submit writes outside lock dm cache: fix arm link errors with inline dm verity: use __ffs and __fls dm flakey: correct ctr alloc failure mesg dm verity: remove pointless comparison dm: use __GFP_HIGHMEM in __vmalloc dm verity: fix inability to use a few specific devices sizes dm ioctl: set noio flag to avoid __vmalloc deadlock dm mpath: fix ioctl deadlock when no paths
| * dm: add switch targetJim Ramsay2013-07-101-0/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dm-switch is a new target that maps IO to underlying block devices efficiently when there is a large number of fixed-sized address regions but there is no simple pattern to allow for a compact mapping representation such as dm-stripe. Though we have developed this target for a specific storage device, Dell EqualLogic, we have made an effort to keep it as general purpose as possible in the hope that others may benefit. Originally developed by Jim Ramsay. Simplified by Mikulas Patocka. Signed-off-by: Jim Ramsay <jim_ramsay@dell.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2013-07-041-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "The usual stuff from trivial tree" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits) treewide: relase -> release Documentation/cgroups/memory.txt: fix stat file documentation sysctl/net.txt: delete reference to obsolete 2.4.x kernel spinlock_api_smp.h: fix preprocessor comments treewide: Fix typo in printk doc: device tree: clarify stuff in usage-model.txt. open firmware: "/aliasas" -> "/aliases" md: bcache: Fixed a typo with the word 'arithmetic' irq/generic-chip: fix a few kernel-doc entries frv: Convert use of typedef ctl_table to struct ctl_table sgi: xpc: Convert use of typedef ctl_table to struct ctl_table doc: clk: Fix incorrect wording Documentation/arm/IXP4xx fix a typo Documentation/networking/ieee802154 fix a typo Documentation/DocBook/media/v4l fix a typo Documentation/video4linux/si476x.txt fix a typo Documentation/virtual/kvm/api.txt fix a typo Documentation/early-userspace/README fix a typo Documentation/video4linux/soc-camera.txt fix a typo lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment ...
| * | doc: fix misspellings with 'codespell' toolAnatol Pomozov2013-05-281-1/+1
| |/ | | | | | | | | Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | MD: Remember the last sync operation that was performedJonathan Brassow2013-06-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | DM RAID: Add ability to restore transiently failed devices on resumeJonathan Brassow2013-06-141-0/+1
|/ | | | | | | | | | | | | | | DM RAID: Add ability to restore transiently failed devices on resume This patch adds code to the resume function to check over the devices in the RAID array. If any are found to be marked as failed and their superblocks can be read, an attempt is made to reintegrate them into the array. This allows the user to refresh the array with a simple suspend and resume of the array - rather than having to load a completely new table, allocate and initialize all the structures and throw away the old instantiation. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Add message/status support for changing sync actionJonathan Brassow2013-04-241-17/+67
| | | | | | | | | | | | | | | | | DM RAID: Add message/status support for changing sync action This patch adds a message interface to dm-raid to allow the user to more finely control the sync actions being performed by the MD driver. This gives the user the ability to initiate "check" and "repair" (i.e. scrubbing). Two additional fields have been appended to the status output to provide more information about the type of sync action occurring and the results of those actions, specifically: <sync_action> and <mismatch_cnt>. These new fields will always be populated. This is essentially the device-mapper way of doing what MD controls through the 'sync_action' sysfs file and shows through the 'mismatch_cnt' sysfs file. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge tag 'md-3.9' of git://neil.brown.name/mdLinus Torvalds2013-03-051-7/+37
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md updates from NeilBrown: "Mostly little bugfixes. Only "feature" is a new RAID10 layout which slightly improves the number of sets of devices that can concurrently fail, without data loss." * tag 'md-3.9' of git://neil.brown.name/md: md: expedite metadata update when switching read-auto -> active md: remove CONFIG_MULTICORE_RAID456 md/raid1,raid10: fix deadlock with freeze_array() md/raid0: improve error message when converting RAID4-with-spares to RAID0 md: raid0: fix error return from create_stripe_zones. md: fix two bugs when attempting to resize RAID0 array. DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2) MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) MD RAID10: Minor non-functional code changes md: raid1,10: Handle REQ_WRITE_SAME flag in write bios md: protect against crash upon fsync on ro array
| * DM RAID: Add support for MD's RAID10 "far" and "offset" algorithmsJonathan Brassow2013-02-261-7/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms Until now, dm-raid.c only supported the "near" algorthm of MD's RAID10 implementation. This patch adds support for the "far" and "offset" algorithms, but only with the improved redundancy that is brought with the introduction of the 'use_far_sets' bit, which shifts copied stripes according to smaller sets vs the entire array. That is, the 17th bit of the 'layout' variable that defines the RAID10 implementation will always be set. (More information on how the 'layout' variable selects the RAID10 algorithm can be found in the opening comments of drivers/md/raid10.c.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | dm cache: add cleaner policyHeinz Mauelshagen2013-03-011-0/+5
| | | | | | | | | | | | | | | | | | | | A simple cache policy that writes back all data to the origin. This is used to decommission a dm cache by emptying it. Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: add mq policyJoe Thornber2013-03-011-0/+72
| | | | | | | | | | | | | | | | | | | | A cache policy that uses a multiqueue ordered by recent hit count to select which blocks should be promoted and demoted. This is meant to be a general purpose policy. It prioritises reads over writes. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm: add cache targetJoe Thornber2013-03-011-0/+243
|/ | | | | | | | | | | | | | | | Add a target that allows a fast device such as an SSD to be used as a cache for a slower device such as a disk. A plug-in architecture was chosen so that the decisions about which data to migrate and when are delegated to interchangeable tunable policy modules. The first general purpose module we have developed, called "mq" (multiqueue), follows in the next patch. Other modules are under development. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* DM-RAID: Fix RAID10's check for sufficient redundancyJonathan Brassow2013-01-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before attempting to activate a RAID array, it is checked for sufficient redundancy. That is, we make sure that there are not too many failed devices - or devices specified for rebuild - to undermine our ability to activate the array. The current code performs this check twice - once to ensure there were not too many devices specified for rebuild by the user ('validate_rebuild_devices') and again after possibly experiencing a failure to read the superblock ('analyse_superblocks'). Neither of these checks are sufficient. The first check is done properly but with insufficient information about the possible failure state of the devices to make a good determination if the array can be activated. The second check is simply done wrong in the case of RAID10 because it doesn't account for the independence of the stripes (i.e. mirror sets). The solution is to use the properly written check ('validate_rebuild_devices'), but perform the check after the superblocks have been read and we know which devices have failed. This gives us one check instead of two and performs it in a location where it can be done right. Only RAID10 was affected and it was affected in the following ways: - the code did not properly catch the condition where a user specified a device for rebuild that already had a failed device in the same mirror set. (This condition would, however, be caught at a deeper level in MD.) - the code triggers a false positive and denies activation when devices in independent mirror sets have failed - counting the failures as though they were all in the same set. The most likely place this error was introduced (or this patch should have been included) is in commit 4ec1e369 - first introduced in v3.7-rc1. Consequently this fix should also go in v3.7.y, however there is a small conflict on the .version in raid_target, so I'll submit a separate patch to -stable. Cc: stable@vger.kernel.org Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Add rebuild capability for RAID10Jonathan Brassow2012-10-111-0/+9
| | | | | | | | | | | DM RAID: Add code to validate replacement slots for RAID10 arrays RAID10 can handle 'copies - 1' failures for each mirror group. This code ensures the user has provided a valid array - one whose devices specified for rebuild do not exceed the amount of redundancy available. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge branch 'for-next' of git://neil.brown.name/mdLinus Torvalds2012-08-011-0/+26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md updates from NeilBrown. * 'for-next' of git://neil.brown.name/md: DM RAID: Add support for MD RAID10 md/RAID1: Add missing case for attempting to repair known bad blocks. md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE. md/raid1: don't abort a resync on the first badblock. md: remove duplicated test on ->openers when calling do_md_stop() raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer md/raid1: prevent merging too large request md/raid1: read balance chooses idlest disk for SSD md/raid1: make sequential read detection per disk based MD RAID10: Export md_raid10_congested MD: Move macros from raid1*.h to raid1*.c MD RAID1: rename mirror_info structure MD RAID10: rename mirror_info structure MD RAID10: Fix compiler warning. raid5: add a per-stripe lock raid5: remove unnecessary bitmap write optimization raid5: lockless access raid5 overrided bi_phys_segments raid5: reduce chance release_stripe() taking device_lock
| * DM RAID: Add support for MD RAID10Jonathan Brassow2012-08-011-0/+26
| | | | | | | | | | | | | | Support the MD RAID10 personality through dm-raid.c Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | dm thin: add read only and fail io modesJoe Thornber2012-07-271-1/+23
|/ | | | | | | | | | | | | | | Add read-only and fail-io modes to thin provisioning. If a transaction commit fails the pool's metadata device will transition to "read-only" mode. If a commit fails once already in read-only mode the transition to "fail-io" mode occurs. Once in fail-io mode the pool and all associated thin devices will report a status of "Fail". Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm stripe: support for non power of 2 chunksizeMike Snitzer2012-07-271-2/+2
| | | | | | | | | | Support non-power-of-2 chunk sizes with dm striping for proper alignment of stripe IO on storage that has non-power-of-2 optimal IO sizes (e.g. RAID6 10+2). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm stripe: fix size testMikulas Patocka2012-07-271-2/+1
| | | | | | | | | | | | | | | | | | | dm-stripe is supposed to ensure that all the space allocated to the stripes is fully used and that all stripes are the same size. This patch fixes the test. It checks that device length is divisible by the chunk size and checks that the resulting quotient is divisible by the number of stripes (which is equivalent to testing if device length is divisible by chunk_size * stripes). Previously, the code only tested that the number of sectors in the target was divisible by each of the chunk size and the number of stripes separately, which could leave entire stripes unused. (A setup that genuinely needs some stripes to be shorter than others can be created by concatenating striped targets.) Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: verity fix documentationMilan Broz2012-07-031-85/+46
| | | | | | | | | | | | Veritysetup is now part of cryptsetup package. Remove on-disk header description (which is not parsed in kernel) and point users to cryptsetup where it the format is documented. Mention units for block size paramaters. Fix target line specification and dmsetup parameters. Signed-off-by: Milan Broz <mbroz@redhat.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: provide userspace access to pool metadataJoe Thornber2012-06-031-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements two new messages that can be sent to the thin pool target allowing it to take a snapshot of the _metadata_. This, read-only snapshot can be accessed by userland, concurrently with the live target. Only one metadata snapshot can be held at a time. The pool's status line will give the block location for the current msnap. Since version 0.1.5 of the userland thin provisioning tools, the thin_dump program displays the msnap as follows: thin_dump -m <msnap root> <metadata dev> Available here: https://github.com/jthornber/thin-provisioning-tools Now that userland can access the metadata we can do various things that have traditionally been kernel side tasks: i) Incremental backups. By using metadata snapshots we can work out what blocks have changed over time. Combined with data snapshots we can ensure the data doesn't change while we back it up. A short proof of concept script can be found here: https://github.com/jthornber/thinp-test-suite/blob/master/incremental_backup_example.rb ii) Migration of thin devices from one pool to another. iii) Merging snapshots back into an external origin. iv) Asyncronous replication. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add verity targetMikulas Patocka2012-03-281-0/+194
| | | | | | | | | | | | | | | | | | | | This device-mapper target creates a read-only device that transparently validates the data on one underlying device against a pre-generated tree of cryptographic checksums stored on a second device. Two checksum device formats are supported: version 0 which is already shipping in Chromium OS and version 1 which incorporates some improvements. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Signed-off-by: Will Drewry <wad@chromium.org> Signed-off-by: Elly Jones <ellyjones@chromium.org> Cc: Milan Broz <mbroz@redhat.com> Cc: Olof Johansson <olofj@chromium.org> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: add pool target flags to control discardJoe Thornber2012-03-281-1/+7
| | | | | | | | | | | | | Add dm thin target arguments to control discard support. ignore_discard: Disables discard support no_discard_passdown: Don't pass discards down to the underlying data device, but just remove the mapping within the thin provisioning target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: support read only external snapshot originsJoe Thornber2012-03-281-1/+38
| | | | | | | | | | | | | | | | | Support the use of an external _read only_ device as an origin for a thin device. Any read to an unprovisioned area of the thin device will be passed through to the origin. Writes trigger allocation of new blocks as usual. One possible use case for this would be VM hosts that want to run guests on thinly-provisioned volumes but have the base image on another device (possibly shared between many VMs). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: relax hard limit on the maximum size of a metadata deviceMike Snitzer2012-03-281-3/+5
| | | | | | | | | | | | | | | | | | The thin metadata format can only make use of a device that is <= THIN_METADATA_MAX_SECTORS (currently 15.9375 GB). Therefore, there is no practical benefit to using a larger device. However, it may be that other factors impose a certain granularity for the space that is allocated to a device (E.g. lvm2 can impose a coarse granularity through the use of large, >= 1 GB, physical extents). Rather than reject a larger metadata device, during thin-pool device construction, switch to allowing it but issue a warning if a device larger than THIN_METADATA_MAX_SECTORS_WARNING (16 GB) is provided. Any space over 15.9375 GB will not be used. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: correct commentsJoe Thornber2012-03-281-10/+0
| | | | | | | | | | | Remove documentation for unimplemented 'trim' message. I'd planned a 'trim' target message for shrinking thin devices, but this is better handled via the discard ioctl. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Documentation: Fix multiple typo in DocumentationMasanari Iida2012-03-072-2/+2
| | | | | | Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Documentation: Fix typo in thin-provisioning.txtMasanari Iida2012-02-211-1/+1
| | | | | | | | Correct spelling "descibes" to "describes" in Documentation/device-mapper/thin-provisioning.txt Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* dm log userspace: fix comment hyphensJonathan Brassow2011-10-311-1/+1
| | | | | | | Fix comments: clustered-disk needs a hyphen not an underscore. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add thin provisioning targetJoe Thornber2011-10-311-0/+285
| | | | | | | | | | | | | | | | | | | | | | | | | | Initial EXPERIMENTAL implementation of device-mapper thin provisioning with snapshot support. The 'thin' target is used to create instances of the virtual devices that are hosted in the 'thin-pool' target. The thin-pool target provides data sharing among devices. This sharing is made possible using the persistent-data library in the previous patch. The main highlight of this implementation, compared to the previous implementation of snapshots, is that it allows many virtual devices to be stored on the same data volume, simplifying administration and allowing sharing of data between volumes (thus reducing disk usage). Another big feature is support for arbitrary depth of recursive snapshots (snapshots of snapshots of snapshots ...). The previous implementation of snapshots did this by chaining together lookup tables, and so performance was O(depth). This new implementation uses a single data structure so we don't get this degradation with depth. For further information and examples of how to use this, please read Documentation/device-mapper/thin-provisioning.txt Signed-off-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add persistent data libraryJoe Thornber2011-10-311-0/+84
| | | | | | | | | | | | | | | The persistent-data library offers a re-usable framework for the storage and management of on-disk metadata in device-mapper targets. It's used by the thin-provisioning target in the next patch and in an upcoming hierarchical storage target. For further information, please read Documentation/device-mapper/persistent-data.txt Signed-off-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm crypt: optionally support discard requestsMilan Broz2011-08-021-1/+20
| | | | | | | | | | | | | | | | | | | Add optional parameter field to dmcrypt table and support "allow_discards" option. Discard requests bypass crypt queue processing. Bio is simple remapped to underlying device. Note that discard will be never enabled by default because of security consequences. It is up to the administrator to enable it for encrypted devices. (Note that userspace cryptsetup does not understand new optional parameters yet. Support for this will come later. Until then, you should use 'dmsetup' to enable and disable this.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: support metadata devicesJonathan Brassow2011-08-021-6/+6
| | | | | | | | | | | | | | | | | | | | | | Add the ability to parse and use metadata devices to dm-raid. Although not strictly required, without the metadata devices, many features of RAID are unavailable. They are used to store a superblock and bitmap. The role, or position in the array, of each device must be recorded in its superblock. This is to help with fault handling, array reshaping, and sanity checks. RAID 4/5/6 devices must be loaded in a specific order: in this way, the 'array_position' field helps validate the correctness of the mapping when it is loaded. It can be used during reshaping to identify which devices are added/removed. Fault handling is impossible without this field. For example, when a device fails it is recorded in the superblock. If this is a RAID1 device and the offending device is removed from the array, there must be a way during subsequent array assembly to determine that the failed device was the one removed. This is done by correlating the 'array_position' field and the bit-field variable 'failed_devices'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: add write_mostly parameterJonathan Brassow2011-08-021-1/+3
| | | | | | | | | | Add the write_mostly parameter to RAID1 dm-raid tables. This allows the user to set the WriteMostly flag on a RAID1 device that should normally be avoided for read I/O. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: add region_size parameterJonathan Brassow2011-08-021-0/+4
| | | | | | | | | | Allow the user to specify the region_size. Ensures that the supplied value meets md's constraints, viz. the number of regions does not exceed 2^21. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: improve table parameters documentationJonathan Brassow2011-08-021-46/+78
| | | | | | | | Add more information about some dm-raid table parameters and clarify how parameters are printed when 'dmsetup table' is issued. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: add corrupt_bio_byte featureMike Snitzer2011-08-021-0/+19
| | | | | | | | | Add corrupt_bio_byte feature to simulate corruption by overwriting a byte at a specified position with a specified value during intervals when the device is "down". Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: add drop_writesMike Snitzer2011-08-021-6/+23
| | | | | | | | Add 'drop_writes' option to drop writes silently while the device is 'down'. Reads are not touched. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* dm: add flakey targetJosef Bacik2011-03-241-0/+17
| | | | | | | | | | | | This target is the same as the linear target except that it returns I/O errors periodically. It's been found useful in simulating failing devices for testing purposes. I needed a dm target to do some failure testing on btrfs's raid code, and Mike pointed me at this. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge branch 'master' into for-nextJiri Kosina2011-02-152-1/+76
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| * dm: raid456 basic supportNeilBrown2011-01-131-0/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is the skeleton for the DM target that will be the bridge from DM to MD (initially RAID456 and later RAID1). It provides a way to use device-mapper interfaces to the MD RAID456 drivers. As with all device-mapper targets, the nominal public interfaces are the constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO and STATUSTYPE_TABLE). The CTR table looks like the following: 1: <s> <l> raid \ 2: <raid_type> <#raid_params> <raid_params> \ 3: <#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN> Line 1 contains the standard first three arguments to any device-mapper target - the start, length, and target type fields. The target type in this case is "raid". Line 2 contains the arguments that define the particular raid type/personality/level, the required arguments for that raid type, and any optional arguments. Possible raid types include: raid4, raid5_la, raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc. (again, raid1 is planned for the future.) The list of required and optional parameters is the same for all the current raid types. The required parameters are positional, while the optional parameters are given as key/value pairs. The possible parameters are as follows: <chunk_size> Chunk size in sectors. [[no]sync] Force/Prevent RAID initialization [rebuild <idx>] Rebuild the drive indicated by the index [daemon_sleep <ms>] Time between bitmap daemon work to clear bits [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_write_behind <value>] See '-write-behind=' (man mdadm) [stripe_cache <sectors>] Stripe cache size for higher RAIDs Line 3 contains the list of devices that compose the array in metadata/data device pairs. If the metadata is stored separately, a '-' is given for the metadata device position. If a drive has failed or is missing at creation time, a '-' can be given for both the metadata and data drives for a given position. Examples: # RAID4 - 4 data drives, 1 parity # No metadata devices specified to hold superblock/bitmap info # Chunk size of 1MiB # (Lines separated for easy reading) 0 1960893648 raid \ raid4 1 2048 \ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 # RAID4 - 4 data drives, 1 parity (no metadata devices) # Chunk size of 1MiB, force RAID initialization, # min recovery rate at 20 kiB/sec/disk 0 1960893648 raid \ raid4 4 2048 min_recovery_rate 20 sync\ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 Performing a 'dmsetup table' should display the CTR table used to construct the mapping (with possible reordering of optional parameters). Performing a 'dmsetup status' will yield information on the state and health of the array. The output is as follows: 1: <s> <l> raid \ 2: <raid_type> <#devices> <1 health char for each dev> <resync_ratio> Line 1 is standard DM output. Line 2 is best shown by example: 0 1960893648 raid raid4 5 AAAAA 2/490221568 Here we can see the RAID type is raid4, there are 5 devices - all of which are 'A'live, and the array is 2/490221568 complete with recovery. Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm crypt: add multi key capabilityMilan Broz2011-01-131-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds generic multikey handling to be used in following patch for Loop-AES mode compatibility. This patch extends mapping table to optional keycount and implements generic multi-key capability. With more keys defined the <key> string is divided into several <keycount> sections and these are used for tfms. The tfm is used according to sector offset (sector 0->tfm[0], sector 1->tfm[1], sector N->tfm[N modulo keycount]) (only power of two values supported for keycount here). Because of tfms per-cpu allocation, this mode can be take a lot of memory on large smp systems. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Max Vozeler <max@hinterhof.net>
* | Documentation: dm-crypt: update cryptsetup homepageAndrea Gelmini2011-01-131-1/+1
|/ | | | | | Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Acked-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Documentation: update broken web addresses.Justin P. Mattock2010-08-041-1/+1
| | | | | | | | | | | | | | | | | | Below you will find an updated version from the original series bunching all patches into one big patch updating broken web addresses that are located in Documentation/* Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult, the best way to deal with these is to use web.archive.org to locate these addresses that are outdated. Now there are also some addresses pointing to .spec files some are located, but some(after searching on the companies site)where still no where to be found. In this case I just changed the address to the company site this way the users can contact the company and they can locate them for the users. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Thomas Weber <weber@corscience.de> Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Cc: Paulo Marques <pmarques@grupopie.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* dm: document when snapshot has finished mergingMike Snitzer2010-03-061-0/+44
| | | | | | | | Update Documentation/device-mapper/snapshot.txt to cover "How to determine when a snapshot has finished merging". Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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