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* dm mpath: fix ioctl deadlock when no pathsHannes Reinecke2013-08-04
| | | | | | | | | | | | | | | | | | | | | | commit 6c182cd88d179cbbd06f4f8a8a19b6977940753f upstream. When multipath needs to retry an ioctl the reference to the current live table needs to be dropped. Otherwise a deadlock occurs when all paths are down: - dm_blk_ioctl takes a reference to the current table and spins in multipath_ioctl(). - A new table is being loaded, but upon resume the process hangs in dm_table_destroy() waiting for references to drop to zero. With this patch the reference to the old table is dropped prior to retry, thereby avoiding the deadlock. Signed-off-by: Hannes Reinecke <hare@suse.de> Cc: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm mpath: enable WRITE SAME supportMike Snitzer2013-05-10
| | | | | | | | | Enable WRITE SAME support in dm multipath. As far as multipath is concerned it is just another write request. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Tested-by: Bharata B Rao <bharata.rao@gmail.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename request variables to biosAlasdair G Kergon2013-03-01
| | | | | | | | | | 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 Patocka2013-03-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 mpath: fix check for null mpio in end_io fnWei Yongjun2012-10-12
| | | | | | | | | | | The mpio dereference should be moved below the BUG_ON NULL test in multipath_end_io(). spatch with a semantic match was used to found this. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2012-10-02
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull workqueue changes from Tejun Heo: "This is workqueue updates for v3.7-rc1. A lot of activities this round including considerable API and behavior cleanups. * delayed_work combines a timer and a work item. The handling of the timer part has always been a bit clunky leading to confusing cancelation API with weird corner-case behaviors. delayed_work is updated to use new IRQ safe timer and cancelation now works as expected. * Another deficiency of delayed_work was lack of the counterpart of mod_timer() which led to cancel+queue combinations or open-coded timer+work usages. mod_delayed_work[_on]() are added. These two delayed_work changes make delayed_work provide interface and behave like timer which is executed with process context. * A work item could be executed concurrently on multiple CPUs, which is rather unintuitive and made flush_work() behavior confusing and half-broken under certain circumstances. This problem doesn't exist for non-reentrant workqueues. While non-reentrancy check isn't free, the overhead is incurred only when a work item bounces across different CPUs and even in simulated pathological scenario the overhead isn't too high. All workqueues are made non-reentrant. This removes the distinction between flush_[delayed_]work() and flush_[delayed_]_work_sync(). The former is now as strong as the latter and the specified work item is guaranteed to have finished execution of any previous queueing on return. * In addition to the various bug fixes, Lai redid and simplified CPU hotplug handling significantly. * Joonsoo introduced system_highpri_wq and used it during CPU hotplug. There are two merge commits - one to pull in IRQ safe timer from tip/timers/core and the other to pull in CPU hotplug fixes from wq/for-3.6-fixes as Lai's hotplug restructuring depended on them." Fixed a number of trivial conflicts, but the more interesting conflicts were silent ones where the deprecated interfaces had been used by new code in the merge window, and thus didn't cause any real data conflicts. Tejun pointed out a few of them, I fixed a couple more. * 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits) workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending() workqueue: use cwq_set_max_active() helper for workqueue_set_max_active() workqueue: introduce cwq_set_max_active() helper for thaw_workqueues() workqueue: remove @delayed from cwq_dec_nr_in_flight() workqueue: fix possible stall on try_to_grab_pending() of a delayed work item workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback() workqueue: use __cpuinit instead of __devinit for cpu callbacks workqueue: rename manager_mutex to assoc_mutex workqueue: WORKER_REBIND is no longer necessary for idle rebinding workqueue: WORKER_REBIND is no longer necessary for busy rebinding workqueue: reimplement idle worker rebinding workqueue: deprecate __cancel_delayed_work() workqueue: reimplement cancel_delayed_work() using try_to_grab_pending() workqueue: use mod_delayed_work() instead of __cancel + queue workqueue: use irqsafe timer for delayed_work workqueue: clean up delayed_work initializers and add missing one workqueue: make deferrable delayed_work initializer names consistent workqueue: cosmetic whitespace updates for macro definitions workqueue: deprecate system_nrt[_freezable]_wq workqueue: deprecate flush[_delayed]_work_sync() ...
| * workqueue: deprecate flush[_delayed]_work_sync()Tejun Heo2012-08-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | flush[_delayed]_work_sync() are now spurious. Mark them deprecated and convert all users to flush[_delayed]_work(). If you're cc'd and wondering what's going on: Now all workqueues are non-reentrant and the regular flushes guarantee that the work item is not pending or running on any CPU on return, so there's no reason to use the sync flushes at all and they're going away. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mattia Dongili <malattia@linux.it> Cc: Kent Yoder <key@linux.vnet.ibm.com> Cc: David Airlie <airlied@linux.ie> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Bryan Wu <bryan.wu@canonical.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-wireless@vger.kernel.org Cc: Anton Vorontsov <cbou@mail.ru> Cc: Sangbeom Kim <sbkim73@samsung.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Petr Vandrovec <petr@vandrovec.name> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Avi Kivity <avi@redhat.com>
* | dm mpath: only retry ioctl when no paths if queue_if_no_path setMike Snitzer2012-09-26
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there are no paths and multipath receives an ioctl, it waits until a path becomes available. This behaviour is incorrect if the "queue_if_no_path" setting was not specified, as then the ioctl should be rejected immediately, which this patch now does. commit 35991652b ("dm mpath: allow ioctls to trigger pg init") should have checked if queue_if_no_path was configured before queueing IO. Checking for the queue_if_no_path feature, like is done in map_io(), allows the following table load to work without blocking in the multipath_ioctl retry loop: echo "0 1024 multipath 0 0 0 0" | dmsetup create mpath_nodevs Without this fix the multipath_ioctl will block with the following stack trace: blkid D 0000000000000002 0 23936 1 0x00000000 ffff8802b89e5cd8 0000000000000082 ffff8802b89e5fd8 0000000000012440 ffff8802b89e4010 0000000000012440 0000000000012440 0000000000012440 ffff8802b89e5fd8 0000000000012440 ffff88030c2aab30 ffff880325794040 Call Trace: [<ffffffff814ce099>] schedule+0x29/0x70 [<ffffffff814cc312>] schedule_timeout+0x182/0x2e0 [<ffffffff8104dee0>] ? lock_timer_base+0x70/0x70 [<ffffffff814cc48e>] schedule_timeout_uninterruptible+0x1e/0x20 [<ffffffff8104f840>] msleep+0x20/0x30 [<ffffffffa0000839>] multipath_ioctl+0x109/0x170 [dm_multipath] [<ffffffffa06bfb9c>] dm_blk_ioctl+0xbc/0xd0 [dm_mod] [<ffffffff8122a408>] __blkdev_driver_ioctl+0x28/0x30 [<ffffffff8122a79e>] blkdev_ioctl+0xce/0x730 [<ffffffff811970ac>] block_ioctl+0x3c/0x40 [<ffffffff8117321c>] do_vfs_ioctl+0x8c/0x340 [<ffffffff81166293>] ? sys_newfstat+0x33/0x40 [<ffffffff81173571>] sys_ioctl+0xa1/0xb0 [<ffffffff814d70a9>] system_call_fastpath+0x16/0x1b Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.5+ Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: commit before gathering statusAlasdair G Kergon2012-07-27
| | | | | | | | | | | | | | | | 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 mpath: add retain_attached_hw_handler featureMike Snitzer2012-07-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A SCSI device handler might get attached to a device during the initial device scan. We do not necessarily want to override this when loading a multipath table, so this patch adds a new multipath feature argument "retain_attached_hw_handler". During SCSI device scan all loaded SCSI device handlers will be consulted for a match (via scsi_dh's provided .match). If a match is found that device handler will be attached. We need a way to have userspace multipathd's provided 'hw_handler' not override the already attached hardware handler. When specifying the new feature 'retain_attached_hw_handler' multipath will use the currently attached hardware handler instead of trying to attach the one specified during table load. If no hardware handler is attached the specified hardware handler will still be used. Leverages scsi_dh_attach's ability to increment the scsi_dh's reference count if the same scsi_dh name is provided when attaching - currently attached scsi_dh name is determined with scsi_dh_attached_handler_name. Depends upon commit 7e8a74b177f17d100916b6ad415450f7c9508691 ("[SCSI] scsi_dh: add scsi_dh_attached_handler_name"). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Tested-by: Babu Moger <babu.moger@netapp.com> Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: allow ioctls to trigger pg initMikulas Patocka2012-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | After the failure of a group of paths, any alternative paths that need initialising do not become available until further I/O is sent to the device. Until this has happened, ioctls return -EAGAIN. With this patch, new paths are made available in response to an ioctl too. The processing of the ioctl gets delayed until this has happened. Instead of returning an error, we submit a work item to kmultipathd (that will potentially activate the new path) and retry in ten milliseconds. Note that the patch doesn't retry an ioctl if the ioctl itself fails due to a path failure. Such retries should be handled intelligently by the code that generated the ioctl in the first place, noting that some SCSI commands should not be retried because they are not idempotent (XOR write commands). For commands that could be retried, there is a danger that if the device rejected the SCSI command, the path could be errorneously marked as failed, and the request would be retried on another path which might fail too. It can be determined if the failure happens on the device or on the SCSI controller, but there is no guarantee that all SCSI drivers set these flags correctly. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: delay retry of bypassed pgMike Christie2012-06-02
| | | | | | | | | | | | | | If I/O needs retrying and only bypassed priority groups are available, set the pg_init_delay_retry flag to wait before retrying. If, for example, the reason for the bypass is that the controller is getting reset or there is a firmware upgrade happening, retrying right away would cause a flood of log messages and retries for what could be a few seconds or even several minutes. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: reduce size of struct multipathMike Snitzer2012-06-02
| | | | | | | | | | | Move multipath structure's 'lock' and 'queue_size' members to eliminate two 4-byte holes. Also use a bit within a single unsigned int for each existing flag (saves 8-bytes). This allows future flags to be added without each consuming an unsigned int. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: check if scsi_dh module already loaded before trying to loadMike Snitzer2012-05-11
| | | | | | | | | | | | If the requested scsi_dh module is already loaded then skip request_module(). Multipath table loads can hang in an unnecessary __request_module. Reported-by: Ben Marzinski <bmarzins@redhat.com> Cc: stable@kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: reject trailing characters in sccanf inputMikulas Patocka2012-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | Device mapper uses sscanf to convert arguments to numbers. The problem is that the way we use it ignores additional unmatched characters in the scanned string. For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number, but also it will match number with some garbage appended, like "123abc". As a result, device mapper accepts garbage after some numbers. For example the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"' will pass without an error. This patch fixes all sscanf uses in device mapper. It appends "%c" with a pointer to a dummy character variable to every sscanf statement. The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds only if string is a null-terminated number (optionally preceded by some whitespace characters). If there is some character appended after the number, sscanf matches "%c", writes the character to the dummy variable and returns 2. We check the return value for 1 and consequently reject numbers with some garbage appended. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: detect invalid map_contextJun'ichi Nomura2012-03-28
| | | | | | | | | | | | | The map_context pointer should always be set. However, we have reports that upon requeuing it is not set correctly. So add set and clear functions with a BUG_ON() to track the issue properly. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Snitzer <snitzer@redhat.com> Acked-by: Hannes Reinecke <hare@suse.de> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: do not forward ioctls from logical volumes to the underlying devicePaolo Bonzini2012-01-14
| | | | | | | | | | | | A logical volume can map to just part of underlying physical volume. In this case, it must be treated like a partition. Based on a patch from Alasdair G Kergon. Cc: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm table: share target argument parsing functionsMike Snitzer2011-08-02
| | | | | | | | 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 mpath: fix potential NULL pointer in feature arg processingMike Snitzer2011-08-02
| | | | | | | | | Avoid dereferencing a NULL pointer if the number of feature arguments supplied is fewer than indicated. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
* atomic: use <linux/atomic.h>Arun Sharma2011-07-26
| | | | | | | | | | | | | | This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm mpath: do not fail paths after integrity errorsMartin K. Petersen2011-05-29
| | | | | | | | | | | Integrity errors need to be passed to the owner of the integrity metadata for processing. Consequently EILSEQ should be passed up the stack. Cc: stable@kernel.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: allow table load with no priority groupsMike Snitzer2011-03-24
| | | | | | | | | | | | | | | | | | | | | | | | This patch adjusts the multipath target to allow a table with both 0 priority groups and 0 for the initial priority group number. If any mpath device is held open when all paths in the last priority group have failed, userspace multipathd will attempt to reload the associated DM table to reflect the fact that the device no longer has any priority groups. But the reload attempt always failed because the multipath target did not allow 0 priority groups. All multipath target messages related to priority group (enable_group, disable_group, switch_group) will handle a priority group of 0 (will cause error). When reloading a multipath table with 0 priority groups, userspace multipathd must be updated to specify an initial priority group number of 0 (rather than 1). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Babu Moger <babu.moger@lsi.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: fail message ioctl if specified path is not validMike Snitzer2011-03-24
| | | | | | | | | | | | | | | | | | | | | | | | Fail the reinstate_path and fail_path message ioctl if the specified path is not valid. The message ioctl would succeed for the 'reinistate_path' and 'fail_path' messages even if action was not taken because the specified device was not a valid path of the multipath device. Before, when /dev/vdb is not a path of mpathb: $ dmsetup message mpathb 0 reinstate_path /dev/vdb $ echo $? 0 After: $ dmsetup message mpathb 0 reinstate_path /dev/vdb device-mapper: message ioctl failed: Invalid argument Command failed $ echo $? 1 Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* [SCSI] dm mpath: propagate target errors immediatelyHannes Reinecke2011-02-12
| | | | | | | | | | | | | | | | DM now has more information about the nature of the underlying storage failure. Path failure is avoided if a request failed due to a target error. Instead the target error is immediately passed up the stack. Discard requests that fail due to non-target errors may now be retried. Errors restricted to the path will be retried or returned if no paths are available, irregarding the no_path_retry setting. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
* dm mpath: delay activate_path retry on SCSI_DH_RETRYChandra Seetharaman2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a user-configurable 'pg_init_delay_msecs' feature. Use this feature to specify the number of milliseconds to delay before retrying scsi_dh_activate, when SCSI_DH_RETRY is returned. SCSI Device Handlers return SCSI_DH_IMM_RETRY if we could retry activation immediately and SCSI_DH_RETRY in cases where it is better to retry after some delay. Currently we immediately retry scsi_dh_activate irrespective of SCSI_DH_IMM_RETRY and SCSI_DH_RETRY. The 'pg_init_delay_msecs' feature may be provided during table create or load, e.g.: dmsetup create --table "0 20971520 multipath 3 queue_if_no_path \ pg_init_delay_msecs 2500 ..." mpatha The default for 'pg_init_delay_msecs' is 2000 milliseconds. Maximum configurable delay is 60000 milliseconds. Specifying a 'pg_init_delay_msecs' of 0 will cause immediate retry. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Acked-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: convert workqueues to alloc_orderedTejun Heo2011-01-13
| | | | | | | | | | Convert all create[_singlethread]_work() users to the new alloc[_ordered]_workqueue(). This conversion is mechanical and doesn't introduce any behavior change. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: dont use flush_scheduled_workTejun Heo2011-01-13
| | | | | | | | | | flush_scheduled_work() is being deprecated. Flush the used work directly instead. In all dm targets, the only work which uses system_wq is ->trigger_event. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: disable blk_abort_queueMike Snitzer2011-01-13
| | | | | | | | | | | | | | | | | | | | | Revert commit 224cb3e981f1b2f9f93dbd49eaef505d17d894c2 dm: Call blk_abort_queue on failed paths Multipath began to use blk_abort_queue() to allow for lower latency path deactivation. This was found to cause list corruption: the cmd gets blk_abort_queued/timedout run on it and the scsi eh somehow is able to complete and run scsi_queue_insert while scsi_request_fn is still trying to process the request. https://www.redhat.com/archives/dm-devel/2010-November/msg00085.html Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: stable@kernel.org
* dm mpath: support discardMike Snitzer2010-08-11
| | | | | | | | | | | | | | | | | | Enable discard support in the DM multipath target. This discard support depends on a few discard-specific fixes to the block layer's request stacking driver methods. Discard requests are optional so don't allow a failed discard to trigger path failures. If there is a real problem with a given path the barriers associated with the discard (either before or after the discard) will cause path failure. That said, unconditionally passing discard failures up the stack is not ideal. This must be fixed once DM has more information about the nature of the underlying storage failure. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
* dm mpath: fix NULL pointer dereference when path parameters missingAlasdair G Kergon2010-08-11
| | | | | | | | | multipath_ctr() forgets to return an error after detecting missing path parameters. Fix this. Signed-off-by: Patrick LoPresti <lopresti@gmail.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: remove unused dm_get_device range parametersNikanth Karthikesan2010-03-05
| | | | | | | | 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 mpath: refactor pg_initKiyoshi Ueda2010-03-05
| | | | | | | | | | | 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>
* dm mpath: wait for pg_init completion when suspendingKiyoshi Ueda2010-03-05
| | | | | | | | | | | | | 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>
* dm mpath: hold io until all pg_inits completedKiyoshi Ueda2010-03-05
| | | | | | | | | | | | | | | | | | 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>
* dm mpath: avoid storing private suspended stateKiyoshi Ueda2010-03-05
| | | | | | | | | | | '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>
* dm mpath: skip activate_path for failed pathsMoger, Babu2010-03-05
| | | | | | | | | | | | | 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>
* dm mpath: pass struct pgpath to pg init doneMoger, Babu2010-03-05
| | | | | | | | | | | | | | | 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>
* dm mpath: reject messages when device is suspendedKiyoshi Ueda2009-12-10
| | | | | | | | | | 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>
* dm mpath: prevent io from work queue while suspendedMike Anderson2009-12-10
| | | | | | | | | 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>
* dm mpath: add mutex to synchronize adding and flushing workMike Anderson2009-12-10
| | | | | | | | | 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>
* dm mpath: flush workqueues before suspend completesKiyoshi Ueda2009-12-10
| | | | | | | | | | | | | | 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>
* [SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronousChandra Seetharaman2009-12-04
| | | | | | | | | 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>
* [SCSI] scsi_dh: Use scsi_dh_set_params() in multipath.Chandra Seetharaman2009-08-22
| | | | | | | | | | | | 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>
* dm table: pass correct dev area size to device_area_is_validMike Snitzer2009-07-23
| | | | | | | | | | | | | | | | 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>
* dm mpath: change to be request basedKiyoshi Ueda2009-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm target:s introduce iterate devices fnMike Snitzer2009-06-22
| | | | | | | | | | | | | | 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
* dm mpath: add start_io and nr_bytes to path selectorsKiyoshi Ueda2009-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm mpath: support barriersMikulas Patocka2009-06-22
| | | | | | | Flush support for dm-multipath target. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm mpath: flush keventd queue in destructorMikulas Patocka2009-06-22
| | | | | | | | | | | | | | | | | | | | | 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
* dm mpath: call activate fn for each path in pg_initChandra Seetharaman2009-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
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