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2012-10-12dm thin: move bio_prison code to separate moduleMike Snitzer1-0/+8
The bio prison code will be useful to other future DM targets so move it to a separate module. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-08-02Merge tag 'md-3.6' of git://neil.brown.name/mdLinus Torvalds1-2/+3
Pull additional md update from NeilBrown: "This contains a few patches that depend on plugging changes in the block layer so needed to wait for those. It also contains a Kconfig fix for the new RAID10 support in dm-raid." * tag 'md-3.6' of git://neil.brown.name/md: md/dm-raid: DM_RAID should select MD_RAID10 md/raid1: submit IO from originating thread instead of md thread. raid5: raid5d handle stripe in batch way raid5: make_request use batch stripe release
2012-08-02md/dm-raid: DM_RAID should select MD_RAID10NeilBrown1-2/+3
Now that DM_RAID supports raid10, it needs to select that code to ensure it is included. Cc: Jonathan Brassow <jbrassow@redhat.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-27dm persistent data: remove debug space map checkerJoe Thornber1-9/+0
Remove debug space map checker from dm persistent data. The space map checker is a wrapper for other space maps that double checks the reference counts are correct. It holds all these reference counts in memory rather than on disk, so uses a lot of memory and is thus restricted to small pools. As yet, this checker hasn't found any issues, but has caused a few of its own due to people turning it on by default with larger pools. Removing. 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>
2012-03-28dm: add verity targetMikulas Patocka1-0/+20
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>
2012-03-28dm raid: no longer experimentalAlasdair G Kergon1-2/+2
The dm raid module (using md) is becoming the preferred way of creating long-lived mirrors through userspace LVM so remove the EXPERIMENTAL tag. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28dm uevent: no longer experimentalAlasdair G Kergon1-2/+2
Drop EXPERIMENTAL tag from dm-uevent. It's not changed for a while and some userspace tools are relying upon it. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31dm: add thin provisioning targetJoe Thornber1-0/+28
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>
2011-10-31dm: add bufioMikulas Patocka1-0/+8
The dm-bufio interface allows you to do cached I/O on devices, holding recently-read blocks in memory and performing delayed writes. We don't use buffer cache or page cache already present in the kernel, because: * we need to handle block sizes larger than a page * we can't allocate memory to perform reads or we'd have deadlocks Currently, when a cache is required, we limit its size to a fraction of available memory. Usage can be viewed and changed in /sys/module/dm_bufio/parameters/ . The first user is thin provisioning, but more dm users are planned. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02dm raid: support metadata devicesJonathan Brassow1-2/+3
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>
2011-03-24dm: add flakey targetJosef Bacik1-0/+6
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>
2011-01-13dm: raid456 basic supportNeilBrown1-0/+24
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>
2010-08-09Merge branch 'async' of macbook:git/btrfs-unstableDavid Woodhouse1-17/+1
Conflicts: drivers/md/Makefile lib/raid6/unroll.pl
2010-05-18md: remove EXPERIMENTAL designation from RAID10NeilBrown1-2/+2
RAID10 has been available for quite a while now and is quite well tested, so we can remove the EXPERIMENTAL designation. Reported-by: Eric MSP Veith <eveith@wwweb-library.net> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: revise Kconfig help for MD_MULTIPATHNeilBrown1-5/+4
Make it clear in the config message that MD_MULTIPATH is not under active development. Cc: Oren Held <orenhe@il.ibm.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-29async_tx: Move ASYNC_RAID6_TEST option to crypto/async_tx/, fix dependenciesDavid Woodhouse1-13/+0
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-10-29md: Factor out RAID6 algorithms into lib/David Woodhouse1-5/+2
We'll want to use these in btrfs too. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-09-08Merge branch 'dmaengine' into async-tx-nextDan Williams1-0/+30
Conflicts: crypto/async_tx/async_xor.c drivers/dma/ioat/dma_v2.h drivers/dma/ioat/pci.c drivers/md/raid5.c
2009-08-29md/raid456: distribute raid processing over multiple coresDan Williams1-0/+11
Now that the resources to handle stripe_head operations are allocated percpu it is possible for raid5d to distribute stripe handling over multiple cores. This conversion also adds a call to cond_resched() in the non-multicore case to prevent one core from getting monopolized for raid operations. Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29md/raid6: asynchronous raid6 operationsDan Williams1-0/+2
[ Based on an original patch by Yuri Tikhonov ] The raid_run_ops routine uses the asynchronous offload api and the stripe_operations member of a stripe_head to carry out xor+pq+copy operations asynchronously, outside the lock. The operations performed by RAID-6 are the same as in the RAID-5 case except for no support of STRIPE_OP_PREXOR operations. All the others are supported: STRIPE_OP_BIOFILL - copy data into request buffers to satisfy a read request STRIPE_OP_COMPUTE_BLK - generate missing blocks (1 or 2) in the cache from the other blocks STRIPE_OP_BIODRAIN - copy data out of request buffers to satisfy a write request STRIPE_OP_RECONSTRUCT - recalculate parity for new data that has entered the cache STRIPE_OP_CHECK - verify that the parity is correct The flow is the same as in the RAID-5 case, and reuses some routines, namely: 1/ ops_complete_postxor (renamed to ops_complete_reconstruct) 2/ ops_complete_compute (updated to set up to 2 targets uptodate) 3/ ops_run_check (renamed to ops_run_check_p for xor parity checks) [neilb@suse.de: fixes to get it to pass mdadm regression suite] Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: raid6 recovery self testDan Williams1-0/+13
Port drivers/md/raid6test/test.c to use the async raid6 recovery routines. This is meant as a unit test for raid6 acceleration drivers. In addition to the 16-drive test case this implements tests for the 4-disk and 5-disk special cases (dma devices can not generically handle less than 2 sources), and adds a test for the D+Q case. Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-22dm raid1: add userspace logJonthan Brassow1-0/+11
This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: add service time load balancerKiyoshi Ueda1-0/+10
This patch adds a service time oriented dynamic load balancer, dm-service-time, which selects the path with the shortest estimated service time for the incoming I/O. The service time is estimated by dividing the in-flight I/O size by a performance value of each path. The performance value can be given as a table argument at the table loading time. If no performance value is given, all paths are considered equal. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: add queue length load balancerKiyoshi Ueda1-0/+9
This patch adds a dynamic load balancer, dm-queue-length, which balances the number of in-flight I/Os across the paths. The code is based on the patch posted by Stefan Bader: https://www.redhat.com/archives/dm-devel/2005-October/msg00050.html Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-03-31md: remove CONFIG_MD_RAID_RESHAPE config option.NeilBrown1-29/+0
This was only needed when the code was experimental. Most of it is well tested now, so the option is no longer useful. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid6: move raid6 data processing to raid6_pq.koDan Williams1-0/+4
Move the raid6 data processing routines into a standalone module (raid6_pq) to prepare them to be called from async_tx wrappers and other non-md drivers/modules. This precludes a circular dependency of raid456 needing the async modules for data processing while those modules in turn depend on raid456 for the base level synchronous raid6 routines. To support this move: 1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h 2/ The raid6_call, recovery calls, and table symbols are exported 3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to compile Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-12raid, fastboot: hide RAID autodetect option if MD is compiled as a moduleAlan Jenkins1-1/+1
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-12raid: make RAID autodetect default a KConfig optionArjan van de Ven1-0/+14
RAID autodetect has the side effect of requiring synchronisation of all device drivers, which can make the boot several seconds longer (I've measured 7 on one of my laptops).... even for systems that don't have RAID setup for the root filesystem (the only FS where this matters). This patch makes the default for autodetect a config option; either way the user can always override via the kernel command line. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: NeilBrown <neilb@suse.de>
2008-07-15[SCSI] scsi_dh: fix kconfig related build errorsChandra Seetharaman1-1/+5
Do not automatically "select" SCSI_DH for dm-multipath. If SCSI_DH doesn't exist,just do not allow hardware handlers to be used. Handle SCSI_DH being a module also. Make sure it doesn't allow DM_MULTIPATH to be compiled in when SCSI_DH is a module. [jejb: added comment for Kconfig syntax] Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05[SCSI] scsi_dh: Remove hardware handlers from dmChandra Seetharaman1-18/+0
This patch removes the 3 hardware handlers that currently exist under dm as the functionality is moved to SCSI layer in the earlier patches. [jejb: removed more makefile hunks and rejection fixes] Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05[SCSI] scsi_dh: Use SCSI device handler in dm-multipathChandra Seetharaman1-0/+1
This patch converts dm-mpath to use scsi device handlers instead of dm's hardware handlers. This patch does not add any new functionality. Old behaviors remain and userspace tools work as is except that arguments supplied with hardware handler are ignored. One behavioral exception is: Activation of a path is synchronous in this patch, opposed to the older behavior of being asynchronous (changed in patch 07: scsi_dh: Add a single threaded workqueue for initializing a path) Note: There is no need to get a reference for the device handler module (as it was done in the dm hardware handler case) here as the reference is held when the device was first found. Instead we check and make sure that support for the specified device is present at table load time. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-02-08dm: targets no longer experimentalAlasdair G Kergon1-12/+12
Drop the EXPERIMENTAL tag from well-established device-mapper targets, so the newer ones stand out better. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-12-20dm mpath: hp requires scsiPaul Mundt1-1/+1
With CONFIG_SCSI=n __scsi_print_sense() is never linked in. drivers/built-in.o: In function `hp_sw_end_io': dm-mpath-hp-sw.c:(.text+0x914f8): undefined reference to `__scsi_print_sense' Caught with a randconfig on current git. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-20dm: add uevent to coreMike Anderson1-0/+6
This patch adds a uevent skeleton to device-mapper. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-20dm mpath: add hp handlerDave Wysochanski1-0/+6
This patch adds the most basic dm-multipath hardware support for the HP active/passive arrays. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-08-24DM_MULTIPATH_RDAC: "scsi_normalize_sense" undefinedRandy Dunlap1-1/+1
DM_MULTIPATH_RDAC uses SCSI API(s) and is for a SCSI device, so add SCSI to its depends on to prevent build errors. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> [ Tested and Verified by Chandra Seetharaman ] Acked-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Use menuconfig objects II - MDJan Engelhardt1-10/+5
Change Kconfig objects from "menu, config" into "menuconfig" so that the user can disable the whole feature without having to enter the menu first. Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Acked-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-13Merge branch 'ioat-md-accel-for-linus' of ↵Linus Torvalds1-0/+2
git://lost.foo-projects.org/~dwillia2/git/iop * 'ioat-md-accel-for-linus' of git://lost.foo-projects.org/~dwillia2/git/iop: (28 commits) ioatdma: add the unisys "i/oat" pci vendor/device id ARM: Add drivers/dma to arch/arm/Kconfig iop3xx: surface the iop3xx DMA and AAU units to the iop-adma driver iop13xx: surface the iop13xx adma units to the iop-adma driver dmaengine: driver for the iop32x, iop33x, and iop13xx raid engines md: remove raid5 compute_block and compute_parity5 md: handle_stripe5 - request io processing in raid5_run_ops md: handle_stripe5 - add request/completion logic for async expand ops md: handle_stripe5 - add request/completion logic for async read ops md: handle_stripe5 - add request/completion logic for async check ops md: handle_stripe5 - add request/completion logic for async compute ops md: handle_stripe5 - add request/completion logic for async write ops md: common infrastructure for running operations with raid5_run_ops md: raid5_run_ops - run stripe operations outside sh->lock raid5: replace custom debug PRINTKs with standard pr_debug raid5: refactor handle_stripe5 and handle_stripe6 (v3) async_tx: add the async_tx api xor: make 'xor_blocks' a library routine for use with async_tx dmaengine: make clients responsible for managing channels dmaengine: refactor dmaengine around dma_async_tx_descriptor ...
2007-07-13async_tx: add the async_tx apiDan Williams1-1/+2
The async_tx api provides methods for describing a chain of asynchronous bulk memory transfers/transforms with support for inter-transactional dependencies. It is implemented as a dmaengine client that smooths over the details of different hardware offload engine implementations. Code that is written to the api can optimize for asynchronous operation and the api will fit the chain of operations to the available offload resources. I imagine that any piece of ADMA hardware would register with the 'async_*' subsystem, and a call to async_X would be routed as appropriate, or be run in-line. - Neil Brown async_tx exploits the capabilities of struct dma_async_tx_descriptor to provide an api of the following general format: struct dma_async_tx_descriptor * async_<operation>(..., struct dma_async_tx_descriptor *depend_tx, dma_async_tx_callback cb_fn, void *cb_param) { struct dma_chan *chan = async_tx_find_channel(depend_tx, <operation>); struct dma_device *device = chan ? chan->device : NULL; int int_en = cb_fn ? 1 : 0; struct dma_async_tx_descriptor *tx = device ? device->device_prep_dma_<operation>(chan, len, int_en) : NULL; if (tx) { /* run <operation> asynchronously */ ... tx->tx_set_dest(addr, tx, index); ... tx->tx_set_src(addr, tx, index); ... async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param); } else { /* run <operation> synchronously */ ... <operation> ... async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param); } return tx; } async_tx_find_channel() returns a capable channel from its pool. The channel pool is organized as a per-cpu array of channel pointers. The async_tx_rebalance() routine is tasked with managing these arrays. In the uniprocessor case async_tx_rebalance() tries to spread responsibility evenly over channels of similar capabilities. For example if there are two copy+xor channels, one will handle copy operations and the other will handle xor. In the SMP case async_tx_rebalance() attempts to spread the operations evenly over the cpus, e.g. cpu0 gets copy channel0 and xor channel0 while cpu1 gets copy channel 1 and xor channel 1. When a dependency is specified async_tx_find_channel defaults to keeping the operation on the same channel. A xor->copy->xor chain will stay on one channel if it supports both operation types, otherwise the transaction will transition between a copy and a xor resource. Currently the raid5 implementation in the MD raid456 driver has been converted to the async_tx api. A driver for the offload engines on the Intel Xscale series of I/O processors, iop-adma, is provided in a later commit. With the iop-adma driver and async_tx, raid456 is able to offload copy, xor, and xor-zero-sum operations to hardware engines. On iop342 tiobench showed higher throughput for sequential writes (20 - 30% improvement) and sequential reads to a degraded array (40 - 55% improvement). For the other cases performance was roughly equal, +/- a few percentage points. On a x86-smp platform the performance of the async_tx implementation (in synchronous mode) was also +/- a few percentage points of the original implementation. According to 'top' on iop342 CPU utilization drops from ~50% to ~15% during a 'resync' while the speed according to /proc/mdstat doubles from ~25 MB/s to ~50 MB/s. The tiobench command line used for testing was: tiobench --size 2048 --block 4096 --block 131072 --dir /mnt/raid --numruns 5 * iop342 had 1GB of memory available Details: * if CONFIG_DMA_ENGINE=n the asynchronous path is compiled away by making async_tx_find_channel a static inline routine that always returns NULL * when a callback is specified for a given transaction an interrupt will fire at operation completion time and the callback will occur in a tasklet. if the the channel does not support interrupts then a live polling wait will be performed * the api is written as a dmaengine client that requests all available channels * In support of dependencies the api implicitly schedules channel-switch interrupts. The interrupt triggers the cleanup tasklet which causes pending operations to be scheduled on the next channel * Xor engines treat an xor destination address differently than a software xor routine. To the software routine the destination address is an implied source, whereas engines treat it as a write-only destination. This patch modifies the xor_blocks routine to take a an explicit destination address to mirror the hardware. Changelog: * fixed a leftover debug print * don't allow callbacks in async_interrupt_cond * fixed xor_block changes * fixed usage of ASYNC_TX_XOR_DROP_DEST * drop dma mapping methods, suggested by Chris Leech * printk warning fixups from Andrew Morton * don't use inline in C files, Adrian Bunk * select the API when MD is enabled * BUG_ON xor source counts <= 1 * implicitly handle hardware concerns like channel switching and interrupts, Neil Brown * remove the per operation type list, and distribute operation capabilities evenly amongst the available channels * simplify async_tx_find_channel to optimize the fast path * introduce the channel_table_initialized flag to prevent early calls to the api * reorganize the code to mimic crypto * include mm.h as not all archs include it in dma-mapping.h * make the Kconfig options non-user visible, Adrian Bunk * move async_tx under crypto since it is meant as 'core' functionality, and the two may share algorithms in the future * move large inline functions into c files * checkpatch.pl fixes * gpl v2 only correction Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-By: NeilBrown <neilb@suse.de>
2007-07-13xor: make 'xor_blocks' a library routine for use with async_txDan Williams1-0/+1
The async_tx api tries to use a dma engine for an operation, but will fall back to an optimized software routine otherwise. Xor support is implemented using the raid5 xor routines. For organizational purposes this routine is moved to a common area. The following fixes are also made: * rename xor_block => xor_blocks, suggested by Adrian Bunk * ensure that xor.o initializes before md.o in the built-in case * checkpatch.pl fixes * mark calibrate_xor_blocks __init, Adrian Bunk Cc: Adrian Bunk <bunk@stusta.de> Cc: NeilBrown <neilb@suse.de> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2007-07-12dm mpath: rdacChandra Seetharaman1-0/+6
This patch supports LSI/Engenio devices in RDAC mode. Like dm-emc it requires userspace support. In your multipath.conf file you must have: path_checker rdac hardware_handler "1 rdac" prio_callout "/sbin/mpath_prio_tpc /dev/%n" And you also then must have a updated multipath tools release which has rdac support. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09dm: delay targetHeinz Mauelshagen1-0/+9
New device-mapper target that can delay I/O (for testing). Reads can be separated from writes, redirected to different underlying devices and delayed by differing amounts of time. Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-10[CRYPTO] dm-crypt: Select CRYPTO_CBCHerbert Xu1-0/+1
As CBC is the default chaining method for cryptoloop, we should select it from cryptoloop to ease the transition. Spotted by Rene Herman. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] md: remove 'experimental' classification from raid5 reshapeNeilBrown1-4/+6
I have had enough success reports not to believe that this is safe for 2.6.19. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm: add debug macroBryn Reeves1-0/+8
Add CONFIG_DM_DEBUG and DMDEBUG() macro. Signed-off-by: Bryn Reeves <breeves@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-30[PATCH] BLOCK: Make it possible to disable the block layer [try #6]David Howells1-0/+3
Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-06-26[PATCH] md: Fix Kconfig errorakpm@osdl.org1-1/+1
RAID5 recently changed to RAID456 Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: md Kconfig speeling feexJustin Piszcz1-3/+3
I was experimenting with Linux SW raid today and found a spelling error when reading the help menus... (and fly spell found more). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: merge raid5 and raid6 codeNeilBrown1-26/+12
There is a lot of commonality between raid5.c and raid6main.c. This patches merges both into one module called raid456. This saves a lot of code, and paves the way for online raid5->raid6 migrations. There is still duplication, e.g. between handle_stripe5 and handle_stripe6. This will probably be cleaned up later. Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] md: make sure 64bit fields in version-1 metadata are 64-bit alignedNeilBrown1-5/+6
reshape_position is a 64bit field that was not 64bit aligned. So swap with new_level. NOTE: this is a user-visible change. However: - The bad code has not appeared in a released kernel - This code is still marked 'experimental' - This only affects version-1 superblock, which are not in wide use - These field are only used (rather than simply reported) by user-space tools in extemely rare circumstances : after a reshape crashes in the first second of the reshape process. So I believe that, at this stage, the change is safe. Especially if people heed the 'help' message on use mdadm-2.4.1. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>