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* 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: use RCU_INIT_POINTER instead of rcu_assign_pointer in __unbindMonam Agarwal2014-03-271-1/+1
| | | | | | | | | | | | | Replace rcu_assign_pointer(p, NULL) with RCU_INIT_POINTER(p, NULL). The rcu_assign_pointer() ensures that the initialization of a structure is carried out before storing a pointer to that structure. And in the case of the NULL pointer, there is no structure to initialize. So, rcu_assign_pointer(p, NULL) can be safely converted to RCU_INIT_POINTER(p, NULL). Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: stop using bi_privateMikulas Patocka2014-03-271-4/+3
| | | | | | | | | | | | | Device mapper uses the bio structure's bi_private field as a pointer to dm_target_io or dm_rq_clone_bio_info. But a bio structure is embedded in the dm_target_io and dm_rq_clone_bio_info structures, so the pointer to the structure that contains the bio can be found with the container_of() macro. Remove the use of bi_private and use container_of() instead. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: remove dm_get_mapinfoMikulas Patocka2014-03-271-10/+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>
* Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-blockLinus Torvalds2014-01-301-161/+28
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block IO changes from Jens Axboe: "The major piece in here is the immutable bio_ve series from Kent, the rest is fairly minor. It was supposed to go in last round, but various issues pushed it to this release instead. The pull request contains: - Various smaller blk-mq fixes from different folks. Nothing major here, just minor fixes and cleanups. - Fix for a memory leak in the error path in the block ioctl code from Christian Engelmayer. - Header export fix from CaiZhiyong. - Finally the immutable biovec changes from Kent Overstreet. This enables some nice future work on making arbitrarily sized bios possible, and splitting more efficient. Related fixes to immutable bio_vecs: - dm-cache immutable fixup from Mike Snitzer. - btrfs immutable fixup from Muthu Kumar. - bio-integrity fix from Nic Bellinger, which is also going to stable" * 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits) xtensa: fixup simdisk driver to work with immutable bio_vecs block/blk-mq-cpu.c: use hotcpu_notifier() blk-mq: for_each_* macro correctness block: Fix memory leak in rw_copy_check_uvector() handling bio-integrity: Fix bio_integrity_verify segment start bug block: remove unrelated header files and export symbol blk-mq: uses page->list incorrectly blk-mq: use __smp_call_function_single directly btrfs: fix missing increment of bi_remaining Revert "block: Warn and free bio if bi_end_io is not set" block: Warn and free bio if bi_end_io is not set blk-mq: fix initializing request's start time block: blk-mq: don't export blk_mq_free_queue() block: blk-mq: make blk_sync_queue support mq block: blk-mq: support draining mq queue dm cache: increment bi_remaining when bi_end_io is restored block: fixup for generic bio chaining block: Really silence spurious compiler warnings block: Silence spurious compiler warnings block: Kill bio_pair_split() ...
| * dm: Refactor for new bio cloning/splittingKent Overstreet2013-11-231-154/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to convert the dm code to the new bvec_iter primitives which respect bi_bvec_done; they also allow us to drastically simplify dm's bio splitting code. Also, it's no longer necessary to save/restore the bvec array anymore - driver conversions for immutable bvecs are done, so drivers should never be modifying it. Also kill bio_sector_offset(), dm was the only user and it doesn't make much sense anymore. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Reviewed-by: Mike Snitzer <snitzer@redhat.com>
| * block: Abstract out bvec iteratorKent Overstreet2013-11-231-12/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
* | dm sysfs: fix a module unload raceMikulas Patocka2014-01-141-15/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit be35f48610 ("dm: wait until embedded kobject is released before destroying a device") and provides an improved fix. The kobject release code that calls the completion must be placed in a non-module file, otherwise there is a module unload race (if the process calling dm_kobject_release is preempted and the DM module unloaded after the completion is triggered, but before dm_kobject_release returns). To fix this race, this patch moves the completion code to dm-builtin.c which is always compiled directly into the kernel if BLK_DEV_DM is selected. The patch introduces a new dm_kobject_holder structure, its purpose is to keep the completion and kobject in one place, so that it can be accessed from non-module code without the need to export the layout of struct mapped_device to that code. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | dm: wait until embedded kobject is released before destroying a deviceMikulas Patocka2014-01-071-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There may be other parts of the kernel holding a reference on the dm kobject. We must wait until all references are dropped before deallocating the mapped_device structure. The dm_kobject_release method signals that all references are dropped via completion. But dm_kobject_release doesn't free the kobject (which is embedded in the mapped_device structure). This is the sequence of operations: * when destroying a DM device, call kobject_put from dm_sysfs_exit * wait until all users stop using the kobject, when it happens the release method is called * the release method signals the completion and should return without delay * the dm device removal code that waits on the completion continues * the dm device removal code drops the dm_mod reference the device had * the dm device removal code frees the mapped_device structure that contains the kobject Using kobject this way should avoid the module unload race that was mentioned at the beginning of this thread: https://lkml.org/lkml/2014/1/4/83 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | dm: remove pointless kobject comparison in dm_get_from_kobjectMikulas Patocka2014-01-071-6/+0
|/ | | | | | | | | | | | | The comparison is always true and the compiler optimizes it out anyway. Milan offered additional context relative to the original commit 784aae735d ("dm: add name and uuid to sysfs") which introduced the code: "I think it is just relict of some experiments before I committed this simple embedded sysfs kobj handling". Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: allow remove to be deferredMikulas Patocka2013-11-091-3/+44
| | | | | | | | | | | | | | | | | | | | | | | | | This patch allows the removal of an open device to be deferred until it is closed. (Previously such a removal attempt would fail.) The deferred remove functionality is enabled by setting the flag DM_DEFERRED_REMOVE in the ioctl structure on DM_DEV_REMOVE or DM_REMOVE_ALL ioctl. On return from DM_DEV_REMOVE, the flag DM_DEFERRED_REMOVE indicates if the device was removed immediately or flagged to be removed on close - if the flag is clear, the device was removed. On return from DM_DEV_STATUS and other ioctls, the flag DM_DEFERRED_REMOVE is set if the device is scheduled to be removed on closure. A device that is scheduled to be deleted can be revived using the message "@cancel_deferred_remove". This message clears the DMF_DEFERRED_REMOVE flag so that the device won't be deleted on close. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: add reserved_bio_based_ios module parameterMike Snitzer2013-09-231-1/+16
| | | | | | | | | | | | | | | | Allow user to change the number of IOs that are reserved by bio-based DM's mempools by writing to this file: /sys/module/dm_mod/parameters/reserved_bio_based_ios The default value is RESERVED_BIO_BASED_IOS (16). The maximum allowed value is RESERVED_MAX_IOS (1024). Export dm_get_reserved_bio_based_ios() for use by DM targets and core code. Switch to sizing dm-io's mempool and bioset using DM core's configurable 'reserved_bio_based_ios'. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Frank Mayhar <fmayhar@google.com>
* dm: add reserved_rq_based_ios module parameterMike Snitzer2013-09-231-1/+37
| | | | | | | | | | | | | | | | | Allow user to change the number of IOs that are reserved by request-based DM's mempools by writing to this file: /sys/module/dm_mod/parameters/reserved_rq_based_ios The default value is RESERVED_REQUEST_BASED_IOS (256). The maximum allowed value is RESERVED_MAX_IOS (1024). Export dm_get_reserved_rq_based_ios() for use by DM targets and core code. Switch to sizing dm-mpath's mempool using DM core's configurable 'reserved_rq_based_ios'. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Frank Mayhar <fmayhar@google.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com>
* dm: lower bio-based mempool reservationMike Snitzer2013-09-231-4/+5
| | | | | | | | | | | | | | | | Bio-based device mapper processing doesn't need larger mempools (like request-based DM does), so lower the number of reserved entries for bio-based operation. 16 was already used for bio-based DM's bioset but mistakenly wasn't used for it's _io_cache. Formalize difference between bio-based and request-based defaults by introducing RESERVED_BIO_BASED_IOS and RESERVED_REQUEST_BASED_IOS. (based on older code from Mikulas Patocka) Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Frank Mayhar <fmayhar@google.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com>
* dm mpath: disable WRITE SAME if it failsMike Snitzer2013-09-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Patocka2013-09-051-3/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ioctl: increase granularity of type_lock when loading tableMike Snitzer2013-09-051-0/+2
| | | | | | | | | | | | | | | Hold the mapped device's type_lock before calling populate_table() since it is where the table's type is determined based on the specified targets. There is no need to allow concurrent table loads to race to establish the table's targets or type. This eliminates the need to grab the lock in dm_table_set_type(). Also verify that the type_lock is held in both dm_set_md_type() and dm_get_md_type(). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: stop using WQ_NON_REENTRANTTejun Heo2013-08-231-2/+1
| | | | | | | | | | | | dbf2576e37 ("workqueue: make all workqueues non-reentrant") made WQ_NON_REENTRANT no-op and the flag is going away. Remove its usages. This patch doesn't introduce any behavior changes. 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> Acked-by: Joe Thornber <ejt@redhat.com>
* dm: optimize reorder structureMikulas Patocka2013-07-101-7/+7
| | | | | | | | | | | This reorder actually improves performance by 20% (from 39.1s to 32.8s) on x86-64 quad core Opteron. I have no explanation for this, possibly it makes some other entries are better cache-aligned. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: optimize use SRCU and RCUMikulas Patocka2013-07-101-67/+93
| | | | | | | | | | | | | | | | | | | | | | 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 mpath: fix ioctl deadlock when no pathsHannes Reinecke2013-07-101-1/+8
| | | | | | | | | | | | | | | | | | | 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> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* block_device_operations->release() should return voidAl Viro2013-05-071-3/+1
| | | | | | | | | The value passed is 0 in all but "it can never happen" cases (and those only in a couple of drivers) *and* it would've been lost on the way out anyway, even if something tried to pass something meaningful. Just don't bother. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Revert "block: add missing block_bio_complete() tracepoint"Linus Torvalds2013-04-181-0/+1
| | | | | | | | | | | | | | | | | | | | This reverts commit 3a366e614d0837d9fc23f78cdb1a1186ebc3387f. Wanlong Gao reports that it causes a kernel panic on his machine several minutes after boot. Reverting it removes the panic. Jens says: "It's not quite clear why that is yet, so I think we should just revert the commit for 3.9 final (which I'm assuming is pretty close). The wifi is crap at the LSF hotel, so sending this email instead of queueing up a revert and pull request." Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Requested-by: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm: add target num_write_bios fnAlasdair G Kergon2013-03-011-7/+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: merge io_pool and tio_poolJun'ichi Nomura2013-03-011-49/+27
| | | | | | | | | | | | | | | | | | This patch merges io_pool and tio_pool into io_pool and cleans up related functions. Though device-mapper used to have 2 pools of objects for each dm device, the use of bioset frontbad for per-bio data has shrunk the number of pools to 1 for both bio-based and request-based device types. (See c0820cf5 "dm: introduce per_bio_data" and 94818742 "dm: Use bioset's front_pad for dm_rq_clone_bio_info") So dm no longer has to maintain 2 different pointers. No functional changes. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: remove unused _rq_bio_info_cacheJun'ichi Nomura2013-03-011-21/+10
| | | | | | | | Remove _rq_bio_info_cache, which is no longer used. No functional changes. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: fix limits initialization when there are no data devicesMike Christie2013-03-011-5/+7
| | | | | | | | | | | | | | | | | | dm_calculate_queue_limits will first reset the provided limits to defaults using blk_set_stacking_limits; whereby defeating the purpose of retaining the original live table's limits -- as was intended via commit 3ae706561637331aa578e52bb89ecbba5edcb7a9 ("dm: retain table limits when swapping to new table with no devices"). Fix this improper limits initialization (in the no data devices case) by avoiding the call to dm_calculate_queue_limits. [patch header revised by Mike Snitzer] Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v3.6+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: refactor bio cloningAlasdair G Kergon2013-03-011-68/+96
| | | | | | | Refactor part of the bio splitting and cloning code to try to make it easier to understand. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename bio cloning functionsAlasdair G Kergon2013-03-011-32/+31
| | | | | | | | | | | Rename functions involved in splitting and cloning bios. The sequence of functions is now: (1) __split_and_process* - entry point that selects the processing strategy (2) __send* - prepare the details for each bio needed and loop through them (3) __clone_and_map* - creates a clone and maps it Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: rename request variables to biosAlasdair G Kergon2013-03-011-23/+23
| | | | | | | | | | 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: clean up clone_bioAlasdair G Kergon2013-03-011-45/+57
| | | | | | | | | | | Remove the no-longer-used struct bio_set argument from clone_bio and split_bvec. Use tio->ti in __map_bio() instead of passing in ti. Factor out some code for setting up cloned bios. Take target_request_nr as a parameter to alloc_tio(). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: do not replace bioset for request based dmJun'ichi Nomura2013-03-011-9/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a regression introduced in v3.8, which causes oops like this when dm-multipath is used: general protection fault: 0000 [#1] SMP RIP: 0010:[<ffffffff810fe754>] [<ffffffff810fe754>] mempool_free+0x24/0xb0 Call Trace: <IRQ> [<ffffffff81187417>] bio_put+0x97/0xc0 [<ffffffffa02247a5>] end_clone_bio+0x35/0x90 [dm_mod] [<ffffffff81185efd>] bio_endio+0x1d/0x30 [<ffffffff811f03a3>] req_bio_endio.isra.51+0xa3/0xe0 [<ffffffff811f2f68>] blk_update_request+0x118/0x520 [<ffffffff811f3397>] blk_update_bidi_request+0x27/0xa0 [<ffffffff811f343c>] blk_end_bidi_request+0x2c/0x80 [<ffffffff811f34d0>] blk_end_request+0x10/0x20 [<ffffffffa000b32b>] scsi_io_completion+0xfb/0x6c0 [scsi_mod] [<ffffffffa000107d>] scsi_finish_command+0xbd/0x120 [scsi_mod] [<ffffffffa000b12f>] scsi_softirq_done+0x13f/0x160 [scsi_mod] [<ffffffff811f9fd0>] blk_done_softirq+0x80/0xa0 [<ffffffff81044551>] __do_softirq+0xf1/0x250 [<ffffffff8142ee8c>] call_softirq+0x1c/0x30 [<ffffffff8100420d>] do_softirq+0x8d/0xc0 [<ffffffff81044885>] irq_exit+0xd5/0xe0 [<ffffffff8142f3e3>] do_IRQ+0x63/0xe0 [<ffffffff814257af>] common_interrupt+0x6f/0x6f <EOI> [<ffffffffa021737c>] srp_queuecommand+0x8c/0xcb0 [ib_srp] [<ffffffffa0002f18>] scsi_dispatch_cmd+0x148/0x310 [scsi_mod] [<ffffffffa000a38e>] scsi_request_fn+0x31e/0x520 [scsi_mod] [<ffffffff811f1e57>] __blk_run_queue+0x37/0x50 [<ffffffff811f1f69>] blk_delay_work+0x29/0x40 [<ffffffff81059003>] process_one_work+0x1c3/0x5c0 [<ffffffff8105b22e>] worker_thread+0x15e/0x440 [<ffffffff8106164b>] kthread+0xdb/0xe0 [<ffffffff8142db9c>] ret_from_fork+0x7c/0xb0 The regression was introduced by the change c0820cf5 "dm: introduce per_bio_data", where dm started to replace bioset during table replacement. For bio-based dm, it is good because clone bios do not exist during the table replacement. For request-based dm, however, (not-yet-mapped) clone bios may stay in request queue and survive during the table replacement. So freeing the old bioset could cause the oops in bio_put(). Since the size of front_pad may change only with bio-based dm, it is not necessary to replace bioset for request-based dm. Reported-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-blockLinus Torvalds2013-02-281-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO core bits from Jens Axboe: "Below are the core block IO bits for 3.9. It was delayed a few days since my workstation kept crashing every 2-8h after pulling it into current -git, but turns out it is a bug in the new pstate code (divide by zero, will report separately). In any case, it contains: - The big cfq/blkcg update from Tejun and and Vivek. - Additional block and writeback tracepoints from Tejun. - Improvement of the should sort (based on queues) logic in the plug flushing. - _io() variants of the wait_for_completion() interface, using io_schedule() instead of schedule() to contribute to io wait properly. - Various little fixes. You'll get two trivial merge conflicts, which should be easy enough to fix up" Fix up the trivial conflicts due to hlist traversal cleanups (commit b67bfe0d42ca: "hlist: drop the node parameter from iterators"). * 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits) block: remove redundant check to bd_openers() block: use i_size_write() in bd_set_size() cfq: fix lock imbalance with failed allocations drivers/block/swim3.c: fix null pointer dereference block: don't select PERCPU_RWSEM block: account iowait time when waiting for completion of IO request sched: add wait_for_completion_io[_timeout] writeback: add more tracepoints block: add block_{touch|dirty}_buffer tracepoint buffer: make touch_buffer() an exported function block: add @req to bio_{front|back}_merge tracepoints block: add missing block_bio_complete() tracepoint block: Remove should_sort judgement when flush blk_plug block,elevator: use new hashtable implementation cfq-iosched: add hierarchical cfq_group statistics cfq-iosched: collect stats from dead cfqgs cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats() blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock block: RCU free request_queue blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge() ...
| * block: add missing block_bio_complete() tracepointTejun Heo2013-01-141-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bio completion didn't kick block_bio_complete TP. Only dm was explicitly triggering the TP on IO completion. This makes block_bio_complete TP useless for tracers which want to know about bios, and all other bio based drivers skip generating blktrace completion events. This patch makes all bio completions via bio_endio() generate block_bio_complete TP. * Explicit trace_block_bio_complete() invocation removed from dm and the trace point is unexported. * @rq dropped from trace_block_bio_complete(). bios may fly around w/o queue associated. Verifying and accessing the assocaited queue belongs to TP probes. * blktrace now gets both request and bio completions. Make it ignore bio completions if request completion path is happening. This makes all bio based drivers generate blktrace completion events properly and makes the block_bio_complete TP actually useful. v2: With this change, block_bio_complete TP could be invoked on sg commands which have bio's with %NULL bi_bdev. Update TP assignment code to check whether bio->bi_bdev is %NULL before dereferencing. Signed-off-by: Tejun Heo <tj@kernel.org> Original-patch-by: Namhyung Kim <namhyung@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | dm: convert to idr_alloc()Tejun Heo2013-02-271-39/+15
| | | | | | | | | | | | | | | | | | Convert to the much saner new idr interface. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | dm: don't use idr_remove_all()Tejun Heo2013-02-271-1/+0
| | | | | | | | | | | | | | | | | | | | idr_destroy() can destroy idr by itself and idr_remove_all() is being deprecated. Drop its usage. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | dm: fix write same requests countingAlasdair G Kergon2013-01-311-2/+4
|/ | | | | | | | | | | | When processing write same requests, fix dm to send the configured number of WRITE SAME requests to the target rather than the number of discards, which is not always the same. Device-mapper WRITE SAME support was introduced by commit 23508a96cd2e857d57044a2ed7d305f2d9daf441 ("dm: add WRITE SAME support"). Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com>
* dm: remove map_infoMikulas Patocka2012-12-211-2/+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 Patocka2012-12-211-1/+2
| | | | | | | | | | 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 Patocka2012-12-211-18/+15
| | | | | | | | | | | | | | | | | | | | | 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: add WRITE SAME supportMike Snitzer2012-12-211-5/+39
| | | | | | | | | | | | | WRITE SAME bios have a payload that contain a single page. When cloning WRITE SAME bios DM has no need to modify the bi_io_vec attributes (and doing so would be detrimental). DM need only alter the start and end of the WRITE SAME bio accordingly. Rather than duplicate __clone_and_map_discard, factor out a common function that is also used by __clone_and_map_write_same. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: fix deadlock with request based dm and queue request_fn recursionJens Axboe2012-11-231-1/+7
| | | | | | | | | | | | | | Request based dm attempts to re-run the request queue off the request completion path. If used with a driver that potentially does end_io from its request_fn, we could deadlock trying to recurse back into request dispatch. Fix this by punting the request queue run to kblockd. Tested to fix a quickly reproducible deadlock in such a scenario. Cc: stable@kernel.org Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* dm: store dm_target_io in bio front_padMikulas Patocka2012-10-121-59/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | Use the recently-added bio front_pad field to allocate struct dm_target_io. Prior to this patch, dm_target_io was allocated from a mempool. For each dm_target_io, there is exactly one bio allocated from a bioset. This patch merges these two allocations into one allocation: we create a bioset with front_pad equal to the size of dm_target_io so that every bio allocated from the bioset has sizeof(struct dm_target_io) bytes before it. We allocate a bio and use the bytes before the bio as dm_target_io. _tio_cache is removed and the tio_pool mempool is now only used for request-based devices. This idea was introduced by Kent Overstreet. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: tj@kernel.org Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Bill Pemberton <wfp5p@viridian.itc.virginia.edu> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-blockLinus Torvalds2012-10-111-52/+22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO update from Jens Axboe: "Core block IO bits for 3.7. Not a huge round this time, it contains: - First series from Kent cleaning up and generalizing bio allocation and freeing. - WRITE_SAME support from Martin. - Mikulas patches to prevent O_DIRECT crashes when someone changes the block size of a device. - Make bio_split() work on data-less bio's (like trim/discards). - A few other minor fixups." Fixed up silent semantic mis-merge as per Mikulas Patocka and Andrew Morton. It is due to the VM no longer using a prio-tree (see commit 6b2dbba8b6ac: "mm: replace vma prio_tree with an interval tree"). So make set_blocksize() use mapping_mapped() instead of open-coding the internal VM knowledge that has changed. * 'for-3.7/core' of git://git.kernel.dk/linux-block: (26 commits) block: makes bio_split support bio without data scatterlist: refactor the sg_nents scatterlist: add sg_nents fs: fix include/percpu-rwsem.h export error percpu-rw-semaphore: fix documentation typos fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declared blockdev: turn a rw semaphore into a percpu rw semaphore Fix a crash when block device is read and block size is changed at the same time block: fix request_queue->flags initialization block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue() block: ioctl to zero block ranges block: Make blkdev_issue_zeroout use WRITE SAME block: Implement support for WRITE SAME block: Consolidate command flag and queue limit checks for merges block: Clean up special command handling logic block/blk-tag.c: Remove useless kfree block: remove the duplicated setting for congestion_threshold block: reject invalid queue attribute values block: Add bio_clone_bioset(), bio_clone_kmalloc() block: Consolidate bio_alloc_bioset(), bio_kmalloc() ...
| * block: Add bio_clone_bioset(), bio_clone_kmalloc()Kent Overstreet2012-09-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, there was bio_clone() but it only allocated from the fs bio set; as a result various users were open coding it and using __bio_clone(). This changes bio_clone() to become bio_clone_bioset(), and then we add bio_clone() and bio_clone_kmalloc() as wrappers around it, making use of the functionality the last patch adedd. This will also help in a later patch changing how bio cloning works. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: Boaz Harrosh <bharrosh@panasas.com> CC: Jeff Garzik <jeff@garzik.org> Acked-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * dm: Use bioset's front_pad for dm_rq_clone_bio_infoKent Overstreet2012-09-091-28/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, dm_rq_clone_bio_info needed to be freed by the bio's destructor to avoid a memory leak in the blk_rq_prep_clone() error path. This gets rid of a memory allocation and means we can kill dm_rq_bio_destructor. The _rq_bio_info_cache kmem cache is unused now and needs to be deleted, but due to the way io_pool is used and overloaded this looks not quite trivial so I'm leaving it for a later patch. v6: Fix comment on struct dm_rq_clone_bio_info, per Tejun Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Alasdair Kergon <agk@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Ues bi_pool for bio_integrity_alloc()Kent Overstreet2012-09-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that bios keep track of where they were allocated from, bio_integrity_alloc_bioset() becomes redundant. Remove bio_integrity_alloc_bioset() and drop bio_set argument from the related functions and make them use bio->bi_pool. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Generalized bio pool freeingKent Overstreet2012-09-091-20/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the old code, when you allocate a bio from a bio pool you have to implement your own destructor that knows how to find the bio pool the bio was originally allocated from. This adds a new field to struct bio (bi_pool) and changes bio_alloc_bioset() to use it. This makes various bio destructors unnecessary, so they're then deleted. v6: Explain the temporary if statement in bio_put Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: Nicholas Bellinger <nab@linux-iscsi.org> CC: Lars Ellenberg <lars.ellenberg@linbit.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | dm: retain table limits when swapping to new table with no devicesMike Snitzer2012-09-261-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a safety net that will re-use the DM device's existing limits in the event that DM device has a temporary table that doesn't have any component devices. This is to reduce the chance that requests not respecting the hardware limits will reach the device. DM recalculates queue limits based only on devices which currently exist in the table. This creates a problem in the event all devices are temporarily removed such as all paths being lost in multipath. DM will reset the limits to the maximum permissible, which can then assemble requests which exceed the limits of the paths when the paths are restored. The request will fail the blk_rq_check_limits() test when sent to a path with lower limits, and will be retried without end by multipath. This became a much bigger issue after v3.6 commit fe86cdcef ("block: do not artificially constrain max_sectors for stacking drivers"). Reported-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm: handle requests beyond end of device instead of using BUG_ONMike Snitzer2012-09-261-18/+38
|/ | | | | | | | | | | | | | | | | | | | | | The access beyond the end of device BUG_ON that was introduced to dm_request_fn via commit 29e4013de7ad950280e4b2208 ("dm: implement REQ_FLUSH/FUA support for request-based dm") was an overly drastic (but simple) response to this situation. I have received a report that this BUG_ON was hit and now think it would be better to use dm_kill_unmapped_request() to fail the clone and original request with -EIO. map_request() will assign the valid target returned by dm_table_find_target to tio->ti. But when the target isn't valid tio->ti is never assigned (because map_request isn't called); so add a check for tio->ti != NULL to dm_done(). Reported-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # v2.6.37+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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