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* dm snapshot: disallow the COW and origin devices from being identicalDingXiang2016-03-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Otherwise loading a "snapshot" table using the same device for the origin and COW devices, e.g.: echo "0 20971520 snapshot 253:3 253:3 P 8" | dmsetup create snap will trigger: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 [ 1958.979934] IP: [<ffffffffa040efba>] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1958.989655] PGD 0 [ 1958.991903] Oops: 0000 [#1] SMP ... [ 1959.059647] CPU: 9 PID: 3556 Comm: dmsetup Tainted: G IO 4.5.0-rc5.snitm+ #150 ... [ 1959.083517] task: ffff8800b9660c80 ti: ffff88032a954000 task.ti: ffff88032a954000 [ 1959.091865] RIP: 0010:[<ffffffffa040efba>] [<ffffffffa040efba>] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.104295] RSP: 0018:ffff88032a957b30 EFLAGS: 00010246 [ 1959.110219] RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000001 [ 1959.118180] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff880329334a00 [ 1959.126141] RBP: ffff88032a957b50 R08: 0000000000000000 R09: 0000000000000001 [ 1959.134102] R10: 000000000000000a R11: f000000000000000 R12: ffff880330884d80 [ 1959.142061] R13: 0000000000000008 R14: ffffc90001c13088 R15: ffff880330884d80 [ 1959.150021] FS: 00007f8926ba3840(0000) GS:ffff880333440000(0000) knlGS:0000000000000000 [ 1959.159047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1959.165456] CR2: 0000000000000098 CR3: 000000032f48b000 CR4: 00000000000006e0 [ 1959.173415] Stack: [ 1959.175656] ffffc90001c13040 ffff880329334a00 ffff880330884ed0 ffff88032a957bdc [ 1959.183946] ffff88032a957bb8 ffffffffa040f225 ffff880329334a30 ffff880300000000 [ 1959.192233] ffffffffa04133e0 ffff880329334b30 0000000830884d58 00000000569c58cf [ 1959.200521] Call Trace: [ 1959.203248] [<ffffffffa040f225>] dm_exception_store_create+0x1d5/0x240 [dm_snapshot] [ 1959.211986] [<ffffffffa040d310>] snapshot_ctr+0x140/0x630 [dm_snapshot] [ 1959.219469] [<ffffffffa0005c44>] ? dm_split_args+0x64/0x150 [dm_mod] [ 1959.226656] [<ffffffffa0005ea7>] dm_table_add_target+0x177/0x440 [dm_mod] [ 1959.234328] [<ffffffffa0009203>] table_load+0x143/0x370 [dm_mod] [ 1959.241129] [<ffffffffa00090c0>] ? retrieve_status+0x1b0/0x1b0 [dm_mod] [ 1959.248607] [<ffffffffa0009e35>] ctl_ioctl+0x255/0x4d0 [dm_mod] [ 1959.255307] [<ffffffff813304e2>] ? memzero_explicit+0x12/0x20 [ 1959.261816] [<ffffffffa000a0c3>] dm_ctl_ioctl+0x13/0x20 [dm_mod] [ 1959.268615] [<ffffffff81215eb6>] do_vfs_ioctl+0xa6/0x5c0 [ 1959.274637] [<ffffffff81120d2f>] ? __audit_syscall_entry+0xaf/0x100 [ 1959.281726] [<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70 [ 1959.288814] [<ffffffff81216449>] SyS_ioctl+0x79/0x90 [ 1959.294450] [<ffffffff8167e4ae>] entry_SYSCALL_64_fastpath+0x12/0x71 ... [ 1959.323277] RIP [<ffffffffa040efba>] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.333090] RSP <ffff88032a957b30> [ 1959.336978] CR2: 0000000000000098 [ 1959.344121] ---[ end trace b049991ccad1169e ]--- Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1195899 Cc: stable@vger.kernel.org Signed-off-by: Ding Xiang <dingxiang@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: rename target's per_bio_data_size to per_io_data_sizeMike Snitzer2016-02-221-3/+3
| | | | | | Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: set DM_TARGET_WILDCARD feature on "error" targetMike Snitzer2016-02-221-0/+7
| | | | | | | | | | | | | The DM_TARGET_WILDCARD feature indicates that the "error" target may replace any target; even immutable targets. This feature will be useful to preserve the ability to replace the "multipath" target even once it is formally converted over to having the DM_TARGET_IMMUTABLE feature. Also, implicit in the DM_TARGET_WILDCARD feature flag being set is that .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined in the target_type. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: refactor ioctl handlingChristoph Hellwig2015-10-311-3/+3
| | | | | | | | | | | | | This moves the call to blkdev_ioctl and the argument checking to DM core code, and only leaves a callout to find the block device to operate on in the targets. This simplifies the code and allows us to pass through ioctl-like command using other methods in the next patch. Also split out a helper around calling the prepare_ioctl method that will be reused for persistent reservation handling. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* block: kill merge_bvec_fn() completelyKent Overstreet2015-08-131-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@kernel.org> Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* dm: remove unnecessary wrapper around blk_lld_busyMike Snitzer2015-03-311-5/+0
| | | | | | | There is no need for DM to export a wrapper around the already exported blk_lld_busy(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm snapshot: suspend merging snapshot when doing exception handoverMikulas Patocka2015-02-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "dm snapshot: suspend origin when doing exception handover" commit fixed a exception store handover bug associated with pending exceptions to the "snapshot-origin" target. However, a similar problem exists in snapshot merging. When snapshot merging is in progress, we use the target "snapshot-merge" instead of "snapshot-origin". Consequently, during exception store handover, we must find the snapshot-merge target and suspend its associated mapped_device. To avoid lockdep warnings, the target must be suspended and resumed without holding _origins_lock. Introduce a dm_hold() function that grabs a reference on a mapped_device, but unlike dm_get(), it doesn't crash if the device has the DMF_FREEING flag set, it returns an error in this case. In snapshot_resume() we grab the reference to the origin device using dm_hold() while holding _origins_lock (_origins_lock guarantees that the device won't disappear). Then we release _origins_lock, suspend the device and grab _origins_lock again. NOTE to stable@ people: When backporting to kernels 3.18 and older, use dm_internal_suspend and dm_internal_resume instead of dm_internal_suspend_fast and dm_internal_resume_fast. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* dm: allocate requests in target when stacking on blk-mq devicesMike Snitzer2015-02-091-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For blk-mq request-based DM the responsibility of allocating a cloned request is transfered from DM core to the target type. Doing so enables the cloned request to be allocated from the appropriate blk-mq request_queue's pool (only the DM target, e.g. multipath, can know which block device to send a given cloned request to). Care was taken to preserve compatibility with old-style block request completion that requires request-based DM _not_ acquire the clone request's queue lock in the completion path. As such, there are now 2 different request-based DM target_type interfaces: 1) the original .map_rq() interface will continue to be used for non-blk-mq devices -- the preallocated clone request is passed in from DM core. 2) a new .clone_and_map_rq() and .release_clone_rq() will be used for blk-mq devices -- blk_get_request() and blk_put_request() are used respectively from these hooks. dm_table_set_type() was updated to detect if the request-based target is being stacked on blk-mq devices, if so DM_TYPE_MQ_REQUEST_BASED is set. DM core disallows switching the DM table's type after it is set. This means that there is no mixing of non-blk-mq and blk-mq devices within the same request-based DM table. [This patch was started by Keith and later heavily modified by Mike] Tested-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: remove exports for request-based interfaces without external callersMike Snitzer2015-02-091-3/+0
| | | | | | | Remove exports for dm_dispatch_request, dm_requeue_unmapped_request, and dm_kill_unmapped_request. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: add presuspend_undo hook to target_typeMike Snitzer2014-11-191-0/+2
| | | | | | | | The DM thin-pool target now must undo the changes performed during pool_presuspend() so introduce presuspend_undo hook in target_type. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm: remove symbol export for dm_set_device_limitsMike Snitzer2014-06-041-7/+1
| | | | | | | There is no need for code other than DM core to use dm_set_device_limits so remove its EXPORT_SYMBOL_GPL. Also, cleanup a couple whitespace nits. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: introduce dm_accept_partial_bioMikulas Patocka2014-06-031-0/+2
| | | | | | | | | | The function dm_accept_partial_bio allows the target to specify how many sectors of the current bio it will process. If the target only wants to accept part of the bio, it calls dm_accept_partial_bio and the DM core sends the rest of the data in next bio. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm table: add dm_table_run_md_queue_asyncMike Snitzer2014-03-271-0/+5
| | | | | | | | | | | | Introduce dm_table_run_md_queue_async() to run the request_queue of the mapped_device associated with a request-based DM table. Also add dm_md_get_queue() wrapper to extract the request_queue from a mapped_device. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
* dm: remove dm_get_mapinfoMikulas Patocka2014-03-271-3/+0
| | | | | | | | | | | | Remove dm_get_mapinfo() because no target uses it. Targets can allocate per-bio data using ti->per_bio_data_size, this is much more flexible than union map_info. Leave union map_info only for the request-based multipath target's use. Also delete the unused "unsigned long long ll" field of union map_info. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm mpath: disable WRITE SAME if it failsMike Snitzer2013-09-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Workaround the SCSI layer's problematic WRITE SAME heuristics by disabling WRITE SAME in the DM multipath device's queue_limits if an underlying device disabled it. The WRITE SAME heuristics, with both the original commit 5db44863b6eb ("[SCSI] sd: Implement support for WRITE SAME") and the updated commit 66c28f971 ("[SCSI] sd: Update WRITE SAME heuristics"), default to enabling WRITE SAME(10) even without successfully determining it is supported. After the first failed WRITE SAME the SCSI layer will disable WRITE SAME for the device (by setting sdkp->device->no_write_same which results in 'max_write_same_sectors' in device's queue_limits to be set to 0). When a device is stacked ontop of such a SCSI device any changes to that SCSI device's queue_limits do not automatically propagate up the stack. As such, a DM multipath device will not have its WRITE SAME support disabled. This causes the block layer to continue to issue WRITE SAME requests to the mpath device which causes paths to fail and (if mpath IO isn't configured to queue when no paths are available) it will result in actual IO errors to the upper layers. This fix doesn't help configurations that have additional devices stacked ontop of the mpath device (e.g. LVM created linear DM devices ontop). A proper fix that restacks all the queue_limits from the bottom of the device stack up will need to be explored if SCSI will continue to use this model of optimistically allowing op codes and then disabling them after they fail for the first time. Before this patch: EXT4-fs (dm-6): mounted filesystem with ordered data mode. Opts: (null) device-mapper: multipath: XXX snitm debugging: got -EREMOTEIO (-121) device-mapper: multipath: XXX snitm debugging: failing WRITE SAME IO with error=-121 end_request: critical target error, dev dm-6, sector 528 dm-6: WRITE SAME failed. Manually zeroing. device-mapper: multipath: Failing path 8:112. end_request: I/O error, dev dm-6, sector 4616 dm-6: WRITE SAME failed. Manually zeroing. end_request: I/O error, dev dm-6, sector 4616 end_request: I/O error, dev dm-6, sector 5640 end_request: I/O error, dev dm-6, sector 6664 end_request: I/O error, dev dm-6, sector 7688 end_request: I/O error, dev dm-6, sector 524288 Buffer I/O error on device dm-6, logical block 65536 lost page write due to I/O error on dm-6 JBD2: Error -5 detected when updating journal superblock for dm-6-8. end_request: I/O error, dev dm-6, sector 524296 Aborting journal on device dm-6-8. end_request: I/O error, dev dm-6, sector 524288 Buffer I/O error on device dm-6, logical block 65536 lost page write due to I/O error on dm-6 JBD2: Error -5 detected when updating journal superblock for dm-6-8. # cat /sys/block/sdh/queue/write_same_max_bytes 0 # cat /sys/block/dm-6/queue/write_same_max_bytes 33553920 After this patch: EXT4-fs (dm-6): mounted filesystem with ordered data mode. Opts: (null) device-mapper: multipath: XXX snitm debugging: got -EREMOTEIO (-121) device-mapper: multipath: XXX snitm debugging: WRITE SAME I/O failed with error=-121 end_request: critical target error, dev dm-6, sector 528 dm-6: WRITE SAME failed. Manually zeroing. # cat /sys/block/sdh/queue/write_same_max_bytes 0 # cat /sys/block/dm-6/queue/write_same_max_bytes 0 It should be noted that WRITE SAME support wasn't enabled in DM multipath until v3.10. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org # 3.10+
* dm: add statistics supportMikulas Patocka2013-09-051-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: optimize use SRCU and RCUMikulas Patocka2013-07-101-3/+3
| | | | | | | | | | | | | | | | | | | | | | This patch removes "io_lock" and "map_lock" in struct mapped_device and "holders" in struct dm_table and replaces these mechanisms with sleepable-rcu. Previously, the code would call "dm_get_live_table" and "dm_table_put" to get and release table. Now, the code is changed to call "dm_get_live_table" and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and dm_put_live_table unlocks it. dm_get_live_table_fast/dm_put_live_table_fast can be used instead of dm_get_live_table/dm_put_live_table. These *_fast functions use non-sleepable RCU, so the caller must not block between them. If the code changes active or inactive dm table, it must call dm_sync_table before destroying the old table. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: document iterate_devicesAlasdair G Kergon2013-05-101-0/+15
| | | | | | Document iterate_devices in device-mapper.h. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add target num_write_bios fnAlasdair G Kergon2013-03-011-0/+15
| | | | | | | | | | | | | | | Add a num_write_bios function to struct target. If an instance of a target sets this, it will be queried before the target's mapping function is called on a write bio, and the response controls the number of copies of the write bio that the target will receive. This provides a convenient way for a target to send the same data to more than one device. The new cache target uses this in writethrough mode, to send the data both to the cache and the backing device. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename request variables to biosAlasdair G Kergon2013-03-011-15/+15
| | | | | | | | | | Use 'bio' in the name of variables and functions that deal with bios rather than 'request' to avoid confusion with the normal block layer use of 'request'. No functional changes. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: fix truncated status stringsMikulas Patocka2013-03-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid returning a truncated table or status string instead of setting the DM_BUFFER_FULL_FLAG when the last target of a table fills the buffer. When processing a table or status request, the function retrieve_status calls ti->type->status. If ti->type->status returns non-zero, retrieve_status assumes that the buffer overflowed and sets DM_BUFFER_FULL_FLAG. However, targets don't return non-zero values from their status method on overflow. Most targets returns always zero. If a buffer overflow happens in a target that is not the last in the table, it gets noticed during the next iteration of the loop in retrieve_status; but if a buffer overflow happens in the last target, it goes unnoticed and erroneously truncated data is returned. In the current code, the targets behave in the following way: * dm-crypt returns -ENOMEM if there is not enough space to store the key, but it returns 0 on all other overflows. * dm-thin returns errors from the status method if a disk error happened. This is incorrect because retrieve_status doesn't check the error code, it assumes that all non-zero values mean buffer overflow. * all the other targets always return 0. This patch changes the ti->type->status function to return void (because most targets don't use the return code). Overflow is detected in retrieve_status: if the status method fills up the remaining space completely, it is assumed that buffer overflow happened. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: remove map_infoMikulas Patocka2012-12-211-4/+2
| | | | | | | | This patch removes map_info from bio-based device mapper targets. map_info is still used for request-based targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: move target request nr to dm_target_ioMikulas Patocka2012-12-211-4/+10
| | | | | | | | | | This patch moves target_request_nr from map_info to dm_target_io and makes it accessible with dm_bio_get_target_request_nr. This patch is a preparation for the next patch that removes map_info. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: introduce per_bio_dataMikulas Patocka2012-12-211-0/+30
| | | | | | | | | | | | | | | | | | | | | Introduce a field per_bio_data_size in struct dm_target. Targets can set this field in the constructor. If a target sets this field to a non-zero value, "per_bio_data_size" bytes of auxiliary data are allocated for each bio submitted to the target. These data can be used for any purpose by the target and help us improve performance by removing some per-target mempools. Per-bio data is accessed with dm_per_bio_data. The argument data_size must be the same as the value per_bio_data_size in dm_target. If the target has a pointer to per_bio_data, it can get a pointer to the bio with dm_bio_from_per_bio_data() function (data_size must be the same as the value passed to dm_per_bio_data). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: prepare to support WRITE SAMEMike Snitzer2012-12-211-0/+5
| | | | | | | | | | | Allow targets to opt in to WRITE SAME support by setting 'num_write_same_requests' in the dm_target structure. A dm device will only advertise WRITE SAME support if all its targets and all its underlying devices support it. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: commit before gathering statusAlasdair G Kergon2012-07-271-1/+1
| | | | | | | | | | | | | | | | Commit outstanding metadata before returning the status for a dm thin pool so that the numbers reported are as up-to-date as possible. The commit is not performed if the device is suspended or if the DM_NOFLUSH_FLAG is supplied by userspace and passed to the target through a new 'status_flags' parameter in the target's dm_status_fn. The userspace dmsetup tool will support the --noflush flag with the 'dmsetup status' and 'dmsetup wait' commands from version 1.02.76 onwards. Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: use bool bitfields in struct dm_targetAlasdair G Kergon2012-07-271-3/+3
| | | | | | Use boolean bit fields for flags in struct dm_target. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: allow targets to request flushes regardless of underlying device supportJoe Thornber2012-07-271-0/+6
| | | | | | | | | | | Allow targets to override the 'supports flush' calculation. Set 'flush_supported' if a target needs to receive flushes regardless of whether or not its underlying devices have support. 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: introduce split_discard_requestsMikulas Patocka2012-07-271-0/+6
| | | | | | | | | | | | This patch introduces a new variable split_discard_requests. It can be set by targets so that discard requests are split on max_io_len boundaries. When split_discard_requests is not set, discard requests are only split on boundaries between targets, as was the case before this patch. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: support non power of two target max_io_lenMike Snitzer2012-07-271-2/+7
| | | | | | | | | | | | | Remove the restriction that limits a target's specified maximum incoming I/O size to be a power of 2. Rename this setting from 'split_io' to the less-ambiguous 'max_io_len'. Change it from sector_t to uint32_t, which is plenty big enough, and introduce a wrapper function dm_set_target_max_io_len() to set it. Use sector_div() to process it now that it is not necessarily a power of 2. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: remove unused flush target methodJoe Thornber2012-07-271-2/+0
| | | | | | | | | | Remove unused dm_flush_fn .flush target method from header. This was left-over from the FLUSH/FUA conversion and is no longer used. 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 table: add immutable featureAlasdair G Kergon2011-10-311-0/+7
| | | | | | | | | | Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed with any other target type, and once loaded into a device, it cannot be replaced with a table containing a different type. The thin provisioning pool device will use this. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: add always writeable featureAlasdair G Kergon2011-10-311-0/+7
| | | | | | | | | Add a target feature flag DM_TARGET_ALWAYS_WRITEABLE to indicate that a target does not support read-only mode. The initial implementation of the thin provisioning target uses this. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: add singleton featureAlasdair G Kergon2011-10-311-4/+10
| | | | | | | | | | | Introduce the concept of a singleton table which contains exactly one target. If a target type sets the DM_TARGET_SINGLETON feature bit device-mapper will ensure that any table that includes that target contains no others. The thin provisioning pool target uses this. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: use local printk ratelimitNamhyung Kim2011-10-311-4/+13
| | | | | | | | | printk_ratelimit() shares global ratelimiting state with all other subsystems, so its usage is discouraged. Instead, define and use dm's local state. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm crypt: always disable discard_zeroes_dataMilan Broz2011-09-251-0/+5
| | | | | | | | | | | | | | If optional discard support in dm-crypt is enabled, discards requests bypass the crypt queue and blocks of the underlying device are discarded. For the read path, discarded blocks are handled the same as normal ciphertext blocks, thus decrypted. So if the underlying device announces discarded regions return zeroes, dm-crypt must disable this flag because after decryption there is just random noise instead of zeroes. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: share target argument parsing functionsMike Snitzer2011-08-021-0/+43
| | | | | | | | Move multipath target argument parsing code into dm-table so other targets can share it. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: allow targets to support discards internallyMike Snitzer2011-05-291-0/+6
| | | | | | | | Permit a target to support discards regardless of whether or not all its underlying devices do. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* md/dm - remove remains of plug_fn callback.NeilBrown2011-04-181-1/+0
| | | | | | | Now that unplugging is done differently, the unplug_fn callback is never called, so it can be completely discarded. Signed-off-by: NeilBrown <neilb@suse.de>
* block: remove per-queue pluggingJens Axboe2011-03-101-5/+0
| | | | | | | | Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* dm: per target unplug callback supportNeilBrown2011-01-131-0/+1
| | | | | | | | | | Add per-target unplug callback support. 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: introduce target callbacks and congestion callbackNeilBrown2011-01-131-0/+11
| | | | | | | | | | | | | | | | | | DM currently implements congestion checking by checking on congestion in each component device. For raid456 we need to also check if the stripe cache is congested. Add per-target congestion checker callback support. Extending the target_callbacks structure with additional callback functions allows for establishing multiple callbacks per-target (a callback is also needed for unplug). 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: factor out max_io_len_target_boundaryMike Snitzer2010-08-121-0/+6
| | | | | | | | | | | | Split max_io_len_target_boundary out of max_io_len so that the discard support can make use of it without duplicating max_io_len code. Avoiding max_io_len's split_io logic enables DM's discard support to submit the entire discard request to a target. But discards must still be split on target boundaries. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: linear support discardMike Snitzer2010-08-121-0/+6
| | | | | | | | | | | | | | | | | Allow discards to be passed through to linear mappings if at least one underlying device supports it. Discards will be forwarded only to devices that support them. A target that supports discards should set num_discard_requests to indicate how many times each discard request must be submitted to it. Verify table's underlying devices support discards prior to setting the associated DM device as capable of discards (via QUEUE_FLAG_DISCARD). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename map_info flush_request to target_request_nrMike Snitzer2010-08-121-2/+2
| | | | | | | | 'target_request_nr' is a more generic name that reflects the fact that it will be used for both flush and discard support. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: remove unused dm_get_device range parametersNikanth Karthikesan2010-03-061-3/+2
| | | | | | | | Remove unused parameters(start and len) of dm_get_device() and fix the callers. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: export suspended state to targetsKiyoshi Ueda2009-12-101-0/+1
| | | | | | | | | | This patch adds the exported dm_suspended() function so that targets can check whether or not they are suspended. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename dm_suspended to dm_suspended_mdKiyoshi Ueda2009-12-101-1/+0
| | | | | | | | | | | This patch renames dm_suspended() to dm_suspended_md() and keeps it internal to dm. No functional change. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: keep old table until after resume succeededAlasdair G Kergon2009-12-101-1/+3
| | | | | | | | | | | | When swapping a new table into place, retain the old table until its replacement is in place. An old check for an empty table is removed because this is enforced in populate_table(). __unbind() becomes redundant when followed by __bind(). Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename dm_get_table to dm_get_live_tableAlasdair G Kergon2009-12-101-1/+1
| | | | | | Rename dm_get_table to dm_get_live_table. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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