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* dm crypt: wait for endio to complete before destructionMilan Broz2009-03-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following oops has been reported when dm-crypt runs over a loop device. ... [ 70.381058] Process loop0 (pid: 4268, ti=cf3b2000 task=cf1cc1f0 task.ti=cf3b2000) ... [ 70.381058] Call Trace: [ 70.381058] [<d0d76601>] ? crypt_dec_pending+0x5e/0x62 [dm_crypt] [ 70.381058] [<d0d767b8>] ? crypt_endio+0xa2/0xaa [dm_crypt] [ 70.381058] [<d0d76716>] ? crypt_endio+0x0/0xaa [dm_crypt] [ 70.381058] [<c01a2f24>] ? bio_endio+0x2b/0x2e [ 70.381058] [<d0806530>] ? dec_pending+0x224/0x23b [dm_mod] [ 70.381058] [<d08066e4>] ? clone_endio+0x79/0xa4 [dm_mod] [ 70.381058] [<d080666b>] ? clone_endio+0x0/0xa4 [dm_mod] [ 70.381058] [<c01a2f24>] ? bio_endio+0x2b/0x2e [ 70.381058] [<c02bad86>] ? loop_thread+0x380/0x3b7 [ 70.381058] [<c02ba8a1>] ? do_lo_send_aops+0x0/0x165 [ 70.381058] [<c013754f>] ? autoremove_wake_function+0x0/0x33 [ 70.381058] [<c02baa06>] ? loop_thread+0x0/0x3b7 When a table is being replaced, it waits for I/O to complete before destroying the mempool, but the endio function doesn't call mempool_free() until after completing the bio. Fix it by swapping the order of those two operations. The same problem occurs in dm.c with md referenced after dec_pending. Again, we swap the order. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add name and uuid to sysfsMilan Broz2009-01-05
| | | | | | | | | | | | | | | | | | | | | Implement simple read-only sysfs entry for device-mapper block device. This patch adds a simple sysfs directory named "dm" under block device properties and implements - name attribute (string containing mapped device name) - uuid attribute (string containing UUID, or empty string if not set) The kobject is embedded in mapped_device struct, so no additional memory allocation is needed for initializing sysfs entry. During the processing of sysfs attribute we need to lock mapped device which is done by a new function dm_get_from_kobj, which returns the md associated with kobject and increases the usage count. Each 'show attribute' function is responsible for its own locking. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: rework reference countingMikulas Patocka2009-01-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rework table reference counting. The existing code uses a reference counter. When the last reference is dropped and the counter reaches zero, the table destructor is called. Table reference counters are acquired/released from upcalls from other kernel code (dm_any_congested, dm_merge_bvec, dm_unplug_all). If the reference counter reaches zero in one of the upcalls, the table destructor is called from almost random kernel code. This leads to various problems: * dm_any_congested being called under a spinlock, which calls the destructor, which calls some sleeping function. * the destructor attempting to take a lock that is already taken by the same process. * stale reference from some other kernel code keeps the table constructed, which keeps some devices open, even after successful return from "dmsetup remove". This can confuse lvm and prevent closing of underlying devices or reusing device minor numbers. The patch changes reference counting so that the table destructor can be called only at predetermined places. The table has always exactly one reference from either mapped_device->map or hash_cell->new_map. After this patch, this reference is not counted in table->holders. A pair of dm_create_table/dm_destroy_table functions is used for table creation/destruction. Temporary references from the other code increase table->holders. A pair of dm_table_get/dm_table_put functions is used to manipulate it. When the table is about to be destroyed, we wait for table->holders to reach 0. Then, we call the table destructor. We use active waiting with msleep(1), because the situation happens rarely (to one user in 5 years) and removing the device isn't performance-critical task: the user doesn't care if it takes one tick more or not. This way, the destructor is called only at specific points (dm_table_destroy function) and the above problems associated with lazy destruction can't happen. Finally remove the temporary protection added to dm_any_congested(). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: support barriers on simple devicesAndi Kleen2009-01-05
| | | | | | | | | | | | | | | | | Implement barrier support for single device DM devices This patch implements barrier support in DM for the common case of dm linear just remapping a single underlying device. In this case we can safely pass the barrier through because there can be no reordering between devices. NB. Any DM device might cease to support barriers if it gets reconfigured so code must continue to allow for a possible -EOPNOTSUPP on every barrier bio submitted. - agk Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm request: add cachesKiyoshi Ueda2009-01-05
| | | | | | | | This patch prepares some kmem_caches for request-based dm. 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 table: drop reference at unbindMikulas Patocka2009-01-05
| | | | | | | | | | | | | Move one dm_table_put() so that the last reference in the thread gets dropped in __unbind(). This is required for a following patch, dm-table-rework-reference-counting.patch, which will change the logic in such a way that table destructor is called only at specific points in the code. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* bio: allow individual slabs in the bio_setJens Axboe2008-12-29
| | | | | | | | | | | | | | | Instead of having a global bio slab cache, add a reference to one in each bio_set that is created. This allows for personalized slabs in each bio_set, so that they can have bios of different sizes. This means we can personalize the bios we return. File systems may want to embed the bio inside another structure, to avoid allocation more items (and stuffing them in ->bi_private) after the get a bio. Or we may want to embed a number of bio_vecs directly at the end of a bio, to avoid doing two allocations to return a bio. This is now possible. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* blktrace: port to tracepoints, updateIngo Molnar2008-11-26
| | | | | | | | | Port to the new tracepoints API: split DEFINE_TRACE() and DECLARE_TRACE() sites. Spread them out to the usage sites, as suggested by Mathieu Desnoyers. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
* blktrace: port to tracepointsArnaldo Carvalho de Melo2008-11-26
| | | | | | | | | | | This was a forward port of work done by Mathieu Desnoyers, I changed it to encode the 'what' parameter on the tracepoint name, so that one can register interest in specific events and not on classes of events to then check the 'what' parameter. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* dm: avoid destroying table in dm_any_congestedChandra Seetharaman2008-11-13
| | | | | | | | | | | | | | | | | | | | | dm_any_congested() just checks for the DMF_BLOCK_IO and has no code to make sure that suspend waits for dm_any_congested() to complete. This patch adds such a check. Without it, a race can occur with dm_table_put() attempting to destroying the table in the wrong thread, the one running dm_any_congested() which is meant to be quick and return immediately. Two examples of problems: 1. Sleeping functions called from congested code, the caller of which holds a spin lock. 2. An ABBA deadlock between pdflush and multipathd. The two locks in contention are inode lock and kernel lock. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: move pending queue wake_up end_io_acctMikulas Patocka2008-11-13
| | | | | | | | | | | | This doesn't fix any bug, just moves wake_up immediately after decrementing md->pending, for better code readability. It must be clear to anyone manipulating md->pending to wake up the queue if md->pending reaches zero, so move the wakeup as close to the decrementing as possible. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdevLinus Torvalds2008-10-23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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 ...
| * [PATCH] switch dmAl Viro2008-10-21
| | | | | | | | | | | | ioctl() doesn't need BKL here Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * [PATCH] beginning of methods conversionAl Viro2008-10-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To keep the size of changesets sane we split the switch by drivers; to keep the damn thing bisectable we do the following: 1) rename the affected methods, add ones with correct prototypes, make (few) callers handle both. That's this changeset. 2) for each driver convert to new methods. *ALL* drivers are converted in this series. 3) kill the old (renamed) methods. Note that it _is_ a flagday; all in-tree drivers are converted and by the end of this series no trace of old methods remain. The only reason why we do that this way is to keep the damn thing bisectable and allow per-driver debugging if anything goes wrong. New methods: open(bdev, mode) release(disk, mode) ioctl(bdev, mode, cmd, arg) /* Called without BKL */ compat_ioctl(bdev, mode, cmd, arg) locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * [PATCH] lose unused arguments in dm ioctl callbacksAl Viro2008-10-21
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | dm: tidy local_initKiyoshi Ueda2008-10-21
| | | | | | | | | | | | | | | | | | This patch tidies local_init() in preparation for request-based dm. No functional change. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm: remove unused flush_allKiyoshi Ueda2008-10-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the DM_WQ_FLUSH_ALL state that is unnecessary. The dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL) in dm_suspend() is never invoked because: - 'goto flush_and_out' is the same as 'goto out' because the 'goto flush_and_out' is called only when '!noflush' - If r is non-zero, then the code above will invoke 'goto out' and skip this code. 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: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm: mark split bio as clonedMartin K. Petersen2008-10-21
|/ | | | | | | When a bio gets split, mark its fragments with the BIO_CLONED flag. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* block: move stats from disk to part0Tejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: implement and use {disk|part}_to_dev()Tejun Heo2008-10-09
| | | | | | | | | | | | Implement {disk|part}_to_dev() and use them to access generic device instead of directly dereferencing {disk|part}->dev. To make sure no user is left behind, rename generic devices fields to __dev. This is in preparation of unifying partition 0 handling with other partitions. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix diskstats accessTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two variants of stat functions - ones prefixed with double underbars which don't care about preemption and ones without which disable preemption before manipulating per-cpu counters. It's unclear whether the underbarred ones assume that preemtion is disabled on entry as some callers don't do that. This patch unifies diskstats access by implementing disk_stat_lock() and disk_stat_unlock() which take care of both RCU (for partition access) and preemption (for per-cpu counter access). diskstats access should always be enclosed between the two functions. As such, there's no need for the versions which disables preemption. They're removed and double underbars ones are renamed to drop the underbars. As an extra argument is added, there's no danger of using the old version unconverted. disk_stat_lock() uses get_cpu() and returns the cpu index and all diskstat functions which access per-cpu counters now has @cpu argument to help RT. This change adds RCU or preemption operations at some places but also collapses several preemption ops into one at others. Overall, the performance difference should be negligible as all involved ops are very lightweight per-cpu ones. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: don't depend on consecutive minor spaceTejun Heo2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | * Implement disk_devt() and part_devt() and use them to directly access devt instead of computing it from ->major and ->first_minor. Note that all references to ->major and ->first_minor outside of block layer is used to determine devt of the disk (the part0) and as ->major and ->first_minor will continue to represent devt for the disk, converting these users aren't strictly necessary. However, convert them for consistency. * Implement disk_max_parts() to avoid directly deferencing genhd->minors. * Update bdget_disk() such that it doesn't assume consecutive minor space. * Move devt computation from register_disk() to add_disk() and make it the only one (all other usages use the initially determined value). These changes clean up the code and will help disk->part dereference fix and extended block device numbers. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* dm: cope with access beyond end of device in dm_merge_bvecMikulas Patocka2008-10-01
| | | | | | | | | If for any reason dm_merge_bvec() is given an offset beyond the end of the device, avoid an oops and always allow one page to be added to an empty bio. We'll reject the I/O later after the bio is submitted. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: always allow one page in dm_merge_bvecMikulas Patocka2008-10-01
| | | | | | | | | Some callers assume they can always add at least one page to an empty bio, so dm_merge_bvec should not return 0 in this case: we'll reject the I/O later after the bio is submitted. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: introduce merge_bvec_fnMilan Broz2008-07-21
| | | | | | | | | | | | Introduce a bvec merge function for device mapper devices for dynamic size restrictions. This code ensures the requested biovec lies within a single target and then calls a target-specific function to check against any constraints imposed by underlying devices. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm io: remove struct paddingRichard Kennedy2008-07-21
| | | | | | | | Rearrange struct dm_io. Shrinks size from 40 -> 32 allowing more objects/slab. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: remove md argument from specific_minorFrederik Deweerdt2008-04-25
| | | | | | | | | | | The small patch below: - Removes the unused md argument from both specific_minor() and next_free_minor() - Folds kmalloc + memset(0) into a single kzalloc call in alloc_dev() This has been compile tested on x86. Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm kcopyd: remove redundant client countingMikulas Patocka2008-04-25
| | | | | | | | | | | | Remove client counting code that is no longer needed. Initialization and destruction is made globally from dm_init and dm_exit and is not based on client counts. Initialization allocates only one empty slab cache, so there is no negative impact from performing the initialization always, regardless of whether some client uses kcopyd or not. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: move deferred bio flushing to workqueueMilan Broz2008-02-07
| | | | | | | | | Add a single-thread workqueue for each mapped device and move flushing of the lists of pushback and deferred bios to this new workqueue. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: refactor dm_suspend completion waitMilan Broz2008-02-07
| | | | | | | Move completion wait to separate function Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: split dm_suspend io_lock hold into twoMilan Broz2008-02-07
| | | | | | | | | | | | | Change io_locking to allow processing flush in separate thread. Because we have DMF_BLOCK_IO already set, any possible new ios are queued in dm_requests now. In the case of interrupting previous wait there can be more ios queued (we unlocked io_lock for a while) but this is safe. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: tidy dm_suspendMilan Broz2008-02-07
| | | | | | | | | | | Tidy dm_suspend function - change return value logic in dm_suspend - use atomic_read only once. - move DMF_BLOCK_IO clearing into one place Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: refactor deferred bio_list processingMilan Broz2008-02-07
| | | | | | | | | | | | | | Refactor deferred bio_list processing. - use separate _merge_pushback_list function - move deferred bio list pick up to flush function - use bio_list_pop instead of bio_list_get - simplify noflush flag use No real functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: tidy alloc_dev labelsMilan Broz2008-02-07
| | | | | | | | | Tidy labels in alloc_dev to make later patches more clear. No functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: convert suspend_lock semaphore to mutexDaniel Walker2008-02-07
| | | | | | | Replace semaphore with mutex. Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: mark function lists staticAlasdair G Kergon2008-02-07
| | | | | | Add a couple of statics. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add missing memory barrier to dm_suspendMilan Broz2008-02-07
| | | | | | | Add memory barrier to fix atomic_read of pending value. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Driver core: convert block from raw kobjects to core devicesKay Sievers2008-01-24
| | | | | | | | | | | | | | | | | | | | | | | | | | This moves the block devices to /sys/class/block. It will create a flat list of all block devices, with the disks and partitions in one directory. For compatibility /sys/block is created and contains symlinks to the disks. /sys/class/block |-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda |-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1 |-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10 |-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5 |-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6 |-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7 |-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8 |-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9 `-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0 /sys/block/ |-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda `-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* dm: trigger change uevent on renameAlasdair G Kergon2007-12-20
| | | | | | | Insert a missing KOBJ_CHANGE notification when a device is renamed. Cc: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: table detect io beyond deviceJun'ichi Nomura2007-12-20
| | | | | | | | | | | | | | | | | | | | | This patch fixes a panic on shrinking a DM device if there is outstanding I/O to the part of the device that is being removed. (Normally this doesn't happen - a filesystem would be resized first, for example.) The bug is that __clone_and_map() assumes dm_table_find_target() always returns a valid pointer. It may fail if a bio arrives from the block layer but its target sector is no longer included in the DM btree. This patch appends an empty entry to table->targets[] which will be returned by a lookup beyond the end of the device. After calling dm_table_find_target(), __clone_and_map() and target_message() check for this condition using dm_target_is_valid(). Sample test script to trigger oops:
* dm: uevent generate eventsMike Anderson2007-10-19
| | | | | | | | This patch adds support for the dm_path_event dm_send_event functions which create and send udev events. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add uevent to coreMike Anderson2007-10-19
| | | | | | | This patch adds a uevent skeleton to device-mapper. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: tidy bio_io_error usageMilan Broz2007-10-19
| | | | | | | | | | Use bio_io_error() in only two places and tidy the code, preparing for later patches. There is no functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: fix thaw_bdevJun'ichi Nomura2007-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a bd_mount_sem counter corruption bug in device-mapper. thaw_bdev() should be called only when freeze_bdev() was called for the device. Otherwise, thaw_bdev() will up bd_mount_sem and corrupt the semaphore counter. struct block_device with the corrupted semaphore may remain in slab cache and be reused later. Attached patch will fix it by calling unlock_fs() instead. unlock_fs() will determine whether it should call thaw_bdev() by checking the device is frozen or not. Easy reproducer is: #!/bin/sh while [ 1 ]; do dmsetup --notable create a dmsetup --nolockfs suspend a dmsetup remove a done It's not easy to see the effect of corrupted semaphore. So I have tested with putting printk below in bdev_alloc_inode(): if (atomic_read(&ei->bdev.bd_mount_sem.count) != 1) printk(KERN_DEBUG "Incorrect semaphore count = %d (%p)\n", atomic_read(&ei->bdev.bd_mount_sem.count), &ei->bdev); Without the patch, I saw something like: Incorrect semaphore count = 17 (f2ab91c0) With the patch, the message didn't appear. The bug was introduced in 2.6.16 with this bug fix: commit d9dde59ba03095e526640988c0fedd75e93bc8b7 Date: Fri Feb 24 13:04:24 2006 -0800 [PATCH] dm: missing bdput/thaw_bdev at removal Need to unfreeze and release bdev otherwise the bdev inode with inconsistent state is reused later and cause problem. and backported to 2.6.15.5. It occurs only in free_dev(), which is called only when the dm device is removed. The buggy code is executed only if md->suspended_bdev is non-NULL and that can happen only when the device was suspended without noflush. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
* block: convert blkdev_issue_flush() to use empty barriersJens Axboe2007-10-16
| | | | | | | Then we can get rid of ->issue_flush_fn() and all the driver private implementations of that. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Drop 'size' argument from bio_endio and bi_end_ioNeilBrown2007-10-10
| | | | | | | | | | | | | 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>
* Fix remap handling by blktraceAlan D. Brunelle2007-08-11
| | | | | | | | | | | | | This patch provides more information concerning REMAP operations on block IOs. The additional information provides clearer details at the user level, and supports post-processing analysis in btt. o Adds in partition remaps on the same device. o Fixed up the remap information in DM to be in the right order o Sent up mapped-from and mapped-to device information Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* [BLOCK] Get rid of request_queue_t typedefJens Axboe2007-07-24
| | | | | | | | | Some of the code has been gradually transitioned to using the proper struct request_queue, but there's lots left. So do a full sweet of the kernel and get rid of this typedef and replace its uses with the proper type. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* unregister_blkdev() delete redundant messages in callersAkinobu Mita2007-07-17
| | | | | | | | | No need to warn unregister_blkdev() failure by the callers. (The previous patch makes unregister_blkdev() print error message in error case) Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm: disable barriersStefan Bader2007-07-12
| | | | | | | | | | | | | This patch causes device-mapper to reject any barrier requests. This is done since most of the targets won't handle this correctly anyway. So until the situation improves it is better to reject these requests at the first place. Since barrier requests won't get to the targets, the checks there can be removed. Cc: stable@kernel.org Signed-off-by: Stefan Bader <shbader@de.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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