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path: root/drivers/md/dm-mpath.c
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2010-03-06dm table: remove unused dm_get_device range parametersNikanth Karthikesan
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>
2010-03-06dm mpath: refactor pg_initKiyoshi Ueda
This patch pulls the pg_init path activation code out of process_queued_ios() into a new function. 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> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06dm mpath: wait for pg_init completion when suspendingKiyoshi Ueda
When suspending the device we must wait for all I/O to complete, but pg-init may be still in progress even after flushing the workqueue for kmpath_handlerd in multipath_postsuspend. This patch waits for pg-init completion correctly in multipath_postsuspend(). 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>
2010-03-06dm mpath: hold io until all pg_inits completedKiyoshi Ueda
m->queue_io is set to block processing I/Os, and it needs to be kept while pg-init, which issues multiple path activations, is in progress. But m->queue is cleared when a path activation completes without error in pg_init_done(), even while other path activations are in progress. That may cause undesired -EIO on paths which are not complete activation. This patch fixes that by not clearing m->queue_io until all path activations complete. (Before the hardware handlers were moved into the SCSI layer, pg_init only used one path.) 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>
2010-03-06dm mpath: avoid storing private suspended stateKiyoshi Ueda
'suspended' flag in struct multipath was introduced to check whether the multipath target is in suspended state, but the same check is done through dm_suspended() now, so remove the flag and related code. 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>
2010-03-06dm mpath: skip activate_path for failed pathsMoger, Babu
This patch adds two minor fixes while processing device mapper path activation. Skip failed paths while calling activate_path. If the path is already failed then activate_path will fail for sure. We don't have to call in that case. In some case this might cause prolonged retries unnecessarily. Change the misleading message if the path being activated fails with SCSI_DH_NOSYS. Signed-off-by: Babu Moger <babu.moger@lsi.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06dm mpath: pass struct pgpath to pg init doneMoger, Babu
This patch removes some unnecessary argument casting. There is no functional change with this patch. Passes 'struct pgpath' through to pg_init_done() instead of the enclosed 'struct dm_path'. Tested the changes with LSI storage.. CC: Chandra Seetharaman <chandra.seetharaman@us.ibm.com> Signed-off-by: Babu Moger <babu.moger@lsi.com> Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm mpath: reject messages when device is suspendedKiyoshi Ueda
This patch rejects messages that can generate I/O while the device itself is suspended. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm mpath: prevent io from work queue while suspendedMike Anderson
Reject messages that can generate I/O while the device itself is suspended. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm mpath: add mutex to synchronize adding and flushing workMike Anderson
Add a mutex to allow possible creators of new work to synchronize with flushing work queues. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm mpath: flush workqueues before suspend completesKiyoshi Ueda
This patch stops the remaining dm-mpath activity during the suspend sequence by flushing workqueues in postsuspend function. The current dm-mpath target may not be quiet even after suspend completes because some workqueues (e.g. device_handler's work, event handling) are not flushed during the suspend sequence, even though suspended devices/targets are supposed to be quiet in this state. 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>
2009-12-04[SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronousChandra Seetharaman
Make scsi_dh_activate() function asynchronous, by taking in two additional parameters, one is the callback function and the other is the data to call the callback function with. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] scsi_dh: Use scsi_dh_set_params() in multipath.Chandra Seetharaman
Use scsi_dh_set_params() set parameters provided. Save the parameters in parse_hw_handler() and use it in parse_path(). Reported-by: Eddie Williams <Eddie.Williams@steeleye.com> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Tested-by: Eddie Williams <Eddie.Williams@steeleye.com> Cc: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-07-23dm table: pass correct dev area size to device_area_is_validMike Snitzer
Incorrect device area lengths are being passed to device_area_is_valid(). The regression appeared in 2.6.31-rc1 through commit 754c5fc7ebb417b23601a6222a6005cc2e7f2913. With the dm-stripe target, the size of the target (ti->len) was used instead of the stripe_width (ti->len/#stripes). An example of a consequent incorrect error message is: device-mapper: table: 254:0: sdb too small for target Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: change to be request basedKiyoshi Ueda
This patch converts dm-multipath target to request-based from bio-based. Basically, the patch just converts the I/O unit from struct bio to struct request. In the course of the conversion, it also changes the I/O queueing mechanism. The change in the I/O queueing is described in details as follows. I/O queueing mechanism change ----------------------------- In I/O submission, map_io(), there is no mechanism change from bio-based, since the clone request is ready for retry as it is. However, in I/O complition, do_end_io(), there is a mechanism change from bio-based, since the clone request is not ready for retry. In do_end_io() of bio-based, the clone bio has all needed memory for resubmission. So the target driver can queue it and resubmit it later without memory allocations. The mechanism has almost no overhead. On the other hand, in do_end_io() of request-based, the clone request doesn't have clone bios, so the target driver can't resubmit it as it is. To resubmit the clone request, memory allocation for clone bios is needed, and it takes some overheads. To avoid the overheads just for queueing, the target driver doesn't queue the clone request inside itself. Instead, the target driver asks dm core for queueing and remapping the original request of the clone request, since the overhead for queueing is just a freeing memory for the clone request. As a result, the target driver doesn't need to record/restore the information of the original request for resubmitting the clone request. So dm_bio_details in dm_mpath_io is removed. multipath_busy() --------------------- The target driver returns "busy", only when the following case: o The target driver will map I/Os, if map() function is called and o The mapped I/Os will wait on underlying device's queue due to their congestions, if map() function is called now. In other cases, the target driver doesn't return "busy". Otherwise, dm core will keep the I/Os and the target driver can't do what it wants. (e.g. the target driver can't map I/Os now, so wants to kill I/Os.) Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm target:s introduce iterate devices fnMike Snitzer
Add .iterate_devices to 'struct target_type' to allow a function to be called for all devices in a DM target. Implemented it for all targets except those in dm-snap.c (origin and snapshot). (The raid1 version number jumps to 1.12 because we originally reserved 1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors' instead.) Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: martin.petersen@oracle.com
2009-06-22dm mpath: add start_io and nr_bytes to path selectorsKiyoshi Ueda
This patch makes two additions to the dm path selector interface for dynamic load balancers: o a new hook, start_io() o a new parameter 'nr_bytes' to select_path()/start_io()/end_io() to pass the size of the I/O start_io() is called when a target driver actually submits I/O to the selected path. Path selectors can use it to start accounting of the I/O. (e.g. counting the number of in-flight I/Os.) The start_io hook is based on the patch posted by Stefan Bader: https://www.redhat.com/archives/dm-devel/2005-October/msg00050.html nr_bytes, the size of the I/O, is so path selectors can take the size of the I/O into account when deciding which path to use. dm-service-time uses it to estimate service time, for example. (Added the nr_bytes member to dm_mpath_io instead of using existing details.bi_size, since request-based dm patch deletes it.) 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>
2009-06-22dm mpath: support barriersMikulas Patocka
Flush support for dm-multipath target. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: flush keventd queue in destructorMikulas Patocka
The commit fe9cf30eb8186ef267d1868dc9f12f2d0f40835a moves dm table event submission from kmultipath queue to kernel kevent queue to avoid a deadlock. There is a possibility of race condition because kevent queue is not flushed in the multipath destructor. The scenario is: - some event happens and is queued to keventd - keventd thread is delayed due to scheuling latency or some other work - multipath device is destroyed - keventd now attempts to process work_struct that is residing in already released memory. The patch flushes the keventd queue in multipath constructor. I've already fixed similar bug in dm-raid1. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
2009-06-22dm mpath: call activate fn for each path in pg_initChandra Seetharaman
Fixed a problem affecting reinstatement of passive paths. Before we moved the hardware handler from dm to SCSI, it performed a pg_init for a path group and didn't maintain any state about each path in hardware handler code. But in SCSI dh, such state is now maintained, as we want to fail I/O early on a path if it is not the active path. All the hardware handlers have a state now and set to active or some form of inactive. They have prep_fn() which uses this state to fail the I/O without it ever being sent to the device. So in effect when dm-multipath calls scsi_dh_activate(), activate is sent to only one path and the "state" of that path is changed appropriately to "active" while other paths in the same path group are never changed as they never got an "activate". In order make sure all the paths in a path group gets their state set properly when a pg_init happens, we need to call scsi_dh_activate() on all paths in a path group. Doing this at the hardware handler layer is not a good option as we want the multipath layer to define the relationship between path and path groups and not the hardware handler. Attached patch sends an "activate" on each path in a path group when a path group is switched. It also sends an activate when a path is reinstated. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: change attached scsi_dhHannes Reinecke
When specifying a different hardware handler via multipath features we should be able to override the built-in defaults. The problem here is the hardware table from scsi_dh is compiled in and cannot be changed from userland. The multipath.conf OTOH is purely user-defined and, what's more, the user might have a valid reason for modifying it. (EG EMC Clariion can well be run in PNR mode even though ALUA is active, or the user might want to try ALUA on any as-of-yet unknown devices) So _not_ allowing multipath to override the device handler setting will just add to the confusion and makes error tracking even more difficult. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: validate hw_handler argument countMikulas Patocka
Fix arg count parsing error in hw handlers. Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22dm mpath: validate table argument countMikulas Patocka
The parser reads the argument count as a number but doesn't check that sufficient arguments are supplied. This command triggers the bug: dmsetup create mpath --table "0 `blockdev --getsize /dev/mapper/cr0` multipath 0 0 2 1 round-robin 1000 0 1 1 /dev/mapper/cr0 round-robin 0 1 1 /dev/mapper/cr1 1000" kernel BUG at drivers/md/dm-mpath.c:530! Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-15block: move bio list helpers into bio.hChristoph Hellwig
It's used by DM and MD and generally useful, so move the bio list helpers into bio.h. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-06dm mpath: move trigger_event to system workqueueAlasdair G Kergon
The same workqueue is used both for sending uevents and processing queued I/O. Deadlock has been reported in RHEL5 when sending a uevent was blocked waiting for the queued I/O to be processed. Use scheduled_work() for the asynchronous uevents instead. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-01-06dm: consolidate target deregistration error handlingMikulas Patocka
Change dm_unregister_target to return void and use BUG() for error reporting. dm_unregister_target can only fail because of programming bug in the target driver. It can't fail because of user's behavior or disk errors. This patch changes unregister_target to return void and use BUG if someone tries to unregister non-registered target or unregister target that is in use. This patch removes code duplication (testing of error codes in all dm targets) and reports bugs in just one place, in dm_unregister_target. In some target drivers, these return codes were ignored, which could lead to a situation where bugs could be missed. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-11-13dm mpath: warn if args ignoredChandra Seetharaman
Currently dm ignores the parameters provided to hardware handlers without providing any notifications to the user. This patch just prints a warning message so that the user knows that the arguments are ignored. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-11-13dm mpath: avoid attempting to activate null pathChandra Seetharaman
Path activation code is called even when the pgpath is NULL. This could lead to a panic in activate_path(). Such a panic is seen in -rt kernel. This problem has been there before the pg_init() was moved to a workqueue. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdevLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits) [PATCH] kill the rest of struct file propagation in block ioctls [PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET [PATCH] get rid of blkdev_locked_ioctl() [PATCH] get rid of blkdev_driver_ioctl() [PATCH] sanitize blkdev_get() and friends [PATCH] remember mode of reiserfs journal [PATCH] propagate mode through swsusp_close() [PATCH] propagate mode through open_bdev_excl/close_bdev_excl [PATCH] pass fmode_t to blkdev_put() [PATCH] kill the unused bsize on the send side of /dev/loop [PATCH] trim file propagation in block/compat_ioctl.c [PATCH] end of methods switch: remove the old ones [PATCH] switch sr [PATCH] switch sd [PATCH] switch ide-scsi [PATCH] switch tape_block [PATCH] switch dcssblk [PATCH] switch dasd [PATCH] switch mtd_blkdevs [PATCH] switch mmc ...
2008-10-21dm: remove dm header from targetsMikulas Patocka
Change #include "dm.h" to #include <linux/device-mapper.h> in all targets. Targets should not need direct access to internal DM structures. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-21[PATCH] introduce __blkdev_driver_ioctl()Al Viro
Analog of blkdev_driver_ioctl() with sane arguments. For now uses fake struct file, by the end of the series it won't and blkdev_driver_ioctl() will become a wrapper around it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] lose unused arguments in dm ioctl callbacksAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-13[SCSI] block: separate failfast into multiple bits.Mike Christie
Multipath is best at handling transport errors. If it gets a device error then there is not much the multipath layer can do. It will just access the same device but from a different path. This patch breaks up failfast into device, transport and driver errors. The multipath layers (md and dm mutlipath) only ask the lower levels to fast fail transport errors. The user of failfast, read ahead, will ask to fast fail on all errors. Note that blk_noretry_request will return true if any failfast bit is set. This allows drivers that do not support the multipath failfast bits to continue to fail on any failfast error like before. Drivers like scsi that are able to fail fast specific errors can check for the specific fail fast type. In the next patch I will convert scsi. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: dm: detect lost queue dm: publish dm_vcalloc dm: publish dm_table_unplug_all dm: publish dm_get_mapinfo dm: export struct dm_dev dm crypt: avoid unnecessary wait when splitting bio dm crypt: tidy ctx pending dm crypt: fix async inc_pending dm crypt: move dec_pending on error into write_io_submit dm crypt: remove inc_pending from write_io_submit dm crypt: tidy write loop pending dm crypt: tidy crypt alloc dm crypt: tidy inc pending dm exception store: use chunk_t for_areas dm exception store: introduce area_location function dm raid1: kcopyd should stop on error if errors handled dm mpath: remove is_active from struct dm_path dm mpath: use more error codes Fixed up trivial conflict in drivers/md/dm-mpath.c manually.
2008-10-10dm mpath: remove is_active from struct dm_pathKiyoshi Ueda
This patch moves 'is_active' from struct dm_path to struct pgpath as it does not need exporting. 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>
2008-10-10dm mpath: use more error codesBenjamin Marzinski
This patch allows path errors from the multipath ctr function to propagate up to userspace as errno values from the ioctl() call. This is in response to https://www.redhat.com/archives/dm-devel/2008-May/msg00000.html and https://bugzilla.redhat.com/show_bug.cgi?id=444421 The patch only lets through the errors that it needs to in order to get the path errors from parse_path(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-09dm: Call blk_abort_queue on failed pathsMike Anderson
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-01dm mpath: add missing path switching lockingChandra Seetharaman
Moving the path activation to workqueue along with scsi_dh patches introduced a race. It is due to the fact that the current_pgpath (in the multipath data structure) can be modified if changes happen in any of the paths leading to the lun. If the changes lead to current_pgpath being set to NULL, then it leads to the invalid access which results in the panic below. This patch fixes that by storing the pgpath to activate in the multipath data structure and properly protecting it. Note that if activate_path is called twice in succession with different pgpath, with the second one being called before the first one is done, then activate path will be called twice for the second pgpath, which is fine. Unable to handle kernel paging request for data at address 0x00000020 Faulting instruction address: 0xd000000000aa1844 cpu 0x1: Vector: 300 (Data Access) at [c00000006b987a80] pc: d000000000aa1844: .activate_path+0x30/0x218 [dm_multipath] lr: c000000000087a2c: .run_workqueue+0x114/0x204 sp: c00000006b987d00 msr: 8000000000009032 dar: 20 dsisr: 40000000 current = 0xc0000000676bb3f0 paca = 0xc0000000006f3680 pid = 2528, comm = kmpath_handlerd enter ? for help [c00000006b987da0] c000000000087a2c .run_workqueue+0x114/0x204 [c00000006b987e40] c000000000088b58 .worker_thread+0x120/0x144 [c00000006b987f00] c00000000008ca70 .kthread+0x78/0xc4 [c00000006b987f90] c000000000027cc8 .kernel_thread+0x4c/0x68 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-26[SCSI] scsi_dh: attach to hardware handler from dm-mpathHannes Reinecke
multipath keeps a separate device table which may be more current than the built-in one. So we should make sure to always call ->attach whenever a multipath map with hardware handler is instantiated. And we should call ->detach on removal, too. [sekharan: update as per comments from agk] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-21dm mpath: fix test for reinstate_pathAlasdair G Kergon
Fix test for reinstate_path method before attempting to use it. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Julia Lawall <julia@diku.dk>
2008-07-21dm mpath: return parameter errorMikulas Patocka
Return a specific error message if there are an invalid number of multipath arguments. This invalid command returns an "Unknown error" because the ti->error field is not set dmsetup create --table '0 2 multipath 0 0 1 1 round-robin 0 1 1 /dev/sdh' mpath0 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-21dm mpath: free path selector on invalid argsMikulas Patocka
Free path selector if the arguments are invalid. This command (note that it is invalid) causes reference leak on module "dm_round_robin" and prevents the module from being removed. dmsetup create --table '0 2 multipath 0 0 1 1 round-robin /dev/sdh' mpath0 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-15[SCSI] scsi_dh: fix kconfig related build errorsChandra Seetharaman
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 dm_pg_init_completeChandra Seetharaman
This patch just removes the dm layer's path initialization completion routine. This is separated from the other patch(scsi_dh: Use SCSI device handler in dm-multipath) Just to make that patch more readable. 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: Add a single threaded workqueue for initializing pathsChandra Seetharaman
Before this patch set (SCSI hardware handlers), initialization of a path was done asynchronously. Doing that requires a workqueue in each device/hardware handler module and leads to unneccessary complication in the device handler code, making it difficult to read the code and follow the state diagram. Moving that workqueue to this level makes the device handler code simpler. Hence, the workqueue is moved to dm level. A new workqueue is added instead of adding it to the existing workqueue (kmpathd) for the following reasons: 1. Device activation has to happen faster, stacking them along with the other workqueue might lead to unnecessary delay in the activation of the path. 2. The effect could be felt the other way too. i.e the current events that are handled by the existing workqueue might get a delayed response. 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 Seetharaman
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 mpath: add missing staticAlasdair G Kergon
A static declaration missing. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-20dm mpath: send ueventsMike Anderson
This patch adds calls to dm_path_event for a failed path and a reinstated path. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-20dm mpath: add retry pg initDave Wysochanski
This patch allows a failed path group initialisation command to be retried. It adds a generic MP_RETRY flag and a "pg_init_retries" feature to device-mapper multipath which limits the number of retries. 1. A hw handler sends a path initialization command to the storage and the command completes with an error code indicating the command should be retried. 2. The hardware handler calls dm_pg_init_complete() with MP_RETRY set in err_flags to ask the dm multipath core to retry. 3. If the retry limit has not been exceeded, pg_init() is retried. Otherwise fail_path() is called. If you are using the userspace multipath-tools or device-mapper-multipath package, you can set pg_init_retries in the 'device' section of your /etc/multipath.conf file. For example: features "2 pg_init_retries 7" The number of PG retries attempted is reported in the 'dmsetup status' output. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Acked-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown
As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>