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path: root/drivers/md/md.h
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2016-07-28Merge branch 'mymd/for-next' into mymd/for-linusShaohua Li
2016-07-19md: use seconds granularity for error loggingArnd Bergmann
The md code stores the exact time of the last error in the last_read_error variable using a timespec structure. It only ever uses the seconds portion of that though, so we can use a scalar for it. There won't be an overflow in 2038 here, because it already used monotonic time and 32-bit is enough for that, but I've decided to use time64_t for consistency in the conversion. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Shaohua Li <shli@fb.com>
2016-06-13md: reduce the number of synchronize_rcu() calls when multiple devices fail.NeilBrown
Every time a device is removed with ->hot_remove_disk() a synchronize_rcu() call is made which can delay several milliseconds in some case. If lots of devices fail at once - as could happen with a large RAID10 where one set of devices are removed all at once - these delays can add up to be very inconcenient. As failure is not reversible we can check for that first, setting a separate flag if it is found, and then all synchronize_rcu() once for all the flagged devices. Then ->hot_remove_disk() function can skip the synchronize_rcu() step if the flag is set. fix build error(Shaohua) Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
2016-06-07block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie
To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07md: use bio op accessorsMike Christie
Separate the op from the rq_flag_bits and have md set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-03md-cluster: fix deadlock issue when add disk to an recoverying arrayGuoqing Jiang
Add a disk to an array which is performing recovery is a little complicated, we need to do both reap the sync thread and perform add disk for the case, then it caused deadlock as follows. linux44:~ # ps aux|grep md|grep D root 1822 0.0 0.0 0 0 ? D 16:50 0:00 [md127_resync] root 1848 0.0 0.0 19860 952 pts/0 D+ 16:50 0:00 mdadm --manage /dev/md127 --re-add /dev/vdb linux44:~ # cat /proc/1848/stack [<ffffffff8107afde>] kthread_stop+0x6e/0x120 [<ffffffffa051ddb0>] md_unregister_thread+0x40/0x80 [md_mod] [<ffffffffa0526e45>] md_reap_sync_thread+0x15/0x150 [md_mod] [<ffffffffa05271e0>] action_store+0x260/0x270 [md_mod] [<ffffffffa05206b4>] md_attr_store+0xb4/0x100 [md_mod] [<ffffffff81214a7e>] sysfs_write_file+0xbe/0x140 [<ffffffff811a6b98>] vfs_write+0xb8/0x1e0 [<ffffffff811a75b8>] SyS_write+0x48/0xa0 [<ffffffff8152a5c9>] system_call_fastpath+0x16/0x1b [<00007f068ea1ed30>] 0x7f068ea1ed30 linux44:~ # cat /proc/1822/stack [<ffffffffa05251a6>] md_do_sync+0x846/0xf40 [md_mod] [<ffffffffa052402d>] md_thread+0x16d/0x180 [md_mod] [<ffffffff8107ad94>] kthread+0xb4/0xc0 [<ffffffff8152a518>] ret_from_fork+0x58/0x90 Task1848 Task1822 md_attr_store (held reconfig_mutex by call mddev_lock()) action_store md_reap_sync_thread md_unregister_thread kthread_stop md_wakeup_thread(mddev->thread); wait_event(mddev->sb_wait, !test_bit(MD_CHANGE_PENDING)) md_check_recovery is triggered by wakeup mddev->thread, but it can't clear MD_CHANGE_PENDING flag since it can't get lock which was held by md_attr_store already. To solve the deadlock problem, we move "->resync_finish()" from md_do_sync to md_reap_sync_thread (after md_update_sb), also MD_HELD_RESYNC_LOCK is introduced since it is possible that node can't get resync lock in md_do_sync. Then we do not need to wait for MD_CHANGE_PENDING is cleared or not since metadata should be updated after md_update_sb, so just call resync_finish if MD_HELD_RESYNC_LOCK is set. We also unified the code after skip label, since set PENDING for non-clustered case should be harmless. Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
2016-01-15Merge tag 'md/4.5' of git://neil.brown.name/mdLinus Torvalds
Pull md updates from Neil Brown: "Mostly clustered-raid1 and raid5 journal updates. one Y2038 fix and other minor stuff. One patch removes me from the MAINTAINERS file and adds a record of my md maintainership to Credits" Many thanks to Neil, who has been around for a _looong_ time. * tag 'md/4.5' of git://neil.brown.name/md: (26 commits) md/raid: only permit hot-add of compatible integrity profiles Remove myself as MD Maintainer, and add to Credits. raid5-cache: handle journal hotadd in quiesce MD: add journal with array suspended md: set MD_HAS_JOURNAL in correct places md: Remove 'ready' field from mddev. md: remove unnecesary md_new_event_inintr raid5: allow r5l_io_unit allocations to fail raid5-cache: use a mempool for the metadata block raid5-cache: use a bio_set raid5-cache: add journal hot add/remove support drivers: md: use ktime_get_real_seconds() md: avoid warning for 32-bit sector_t raid5-cache: free meta_page earlier raid5-cache: simplify r5l_move_io_unit_list md: update comment for md_allow_write md-cluster: update comments for MD_CLUSTER_SEND_LOCKED_ALREADY md-cluster: Protect communication with mutexes md-cluster: Defer MD reloading to mddev->thread md-cluster: update the documentation ...
2016-01-13Merge tag 'libnvdimm-for-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has appeared in -next and independently received a build success notification from the kbuild robot. The 'for-4.5/block- dax' topic branch was rebased over the weekend to drop the "block device end-of-life" rework that Al would like to see re-implemented with a notifier, and to address bug reports against the badblocks integration. There is pending feedback against "libnvdimm: Add a poison list and export badblocks" received last week. Linda identified some localized fixups that we will handle incrementally. Summary: - Media error handling: The 'badblocks' implementation that originated in md-raid is up-levelled to a generic capability of a block device. This initial implementation is limited to being consulted in the pmem block-i/o path. Later, 'badblocks' will be consulted when creating dax mappings. - Raw block device dax: For virtualization and other cases that want large contiguous mappings of persistent memory, add the capability to dax-mmap a block device directly. - Increased /dev/mem restrictions: Add an option to treat all io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access while a driver is actively using an address range. This behavior is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be overridden by the existing "iomem=relaxed" kernel command line option. - Miscellaneous fixes include a 'pfn'-device huge page alignment fix, block device shutdown crash fix, and other small libnvdimm fixes" * tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits) block: kill disk_{check|set|clear|alloc}_badblocks libnvdimm, pmem: nvdimm_read_bytes() badblocks support pmem, dax: disable dax in the presence of bad blocks pmem: fail io-requests to known bad blocks libnvdimm: convert to statically allocated badblocks libnvdimm: don't fail init for full badblocks list block, badblocks: introduce devm_init_badblocks block: clarify badblocks lifetime badblocks: rename badblocks_free to badblocks_exit libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h libnvdimm: Add a poison list and export badblocks nfit_test: Enable DSMs for all test NFITs md: convert to use the generic badblocks code block: Add badblock management for gendisks badblocks: Add core badblock management code block: fix del_gendisk() vs blkdev_ioctl crash block: enable dax for raw block devices block: introduce bdev_file_inode() restrict /dev/mem to idle io memory ranges arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug ...
2016-01-14md/raid: only permit hot-add of compatible integrity profilesDan Williams
It is not safe for an integrity profile to be changed while i/o is in-flight in the queue. Prevent adding new disks or otherwise online spares to an array if the device has an incompatible integrity profile. The original change to the blk_integrity_unregister implementation in md, commmit c7bfced9a671 "md: suspend i/o during runtime blk_integrity_unregister" introduced an immediate hang regression. This policy of disallowing changes the integrity profile once one has been established is shared with DM. Here is an abbreviated log from a test run that: 1/ Creates a degraded raid1 with an integrity-enabled device (pmem0s) [ 59.076127] 2/ Tries to add an integrity-disabled device (pmem1m) [ 90.489209] 3/ Retries with an integrity-enabled device (pmem1s) [ 205.671277] [ 59.076127] md/raid1:md0: active with 1 out of 2 mirrors [ 59.078302] md: data integrity enabled on md0 [..] [ 90.489209] md0: incompatible integrity profile for pmem1m [..] [ 205.671277] md: super_written gets error=-5 [ 205.677386] md/raid1:md0: Disk failure on pmem1m, disabling device. [ 205.677386] md/raid1:md0: Operation continuing on 1 devices. [ 205.683037] RAID1 conf printout: [ 205.684699] --- wd:1 rd:2 [ 205.685972] disk 0, wo:0, o:1, dev:pmem0s [ 205.687562] disk 1, wo:1, o:1, dev:pmem1s [ 205.691717] md: recovery of RAID array md0 Fixes: c7bfced9a671 ("md: suspend i/o during runtime blk_integrity_unregister") Cc: <stable@vger.kernel.org> Cc: Mike Snitzer <snitzer@redhat.com> Reported-by: NeilBrown <neilb@suse.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-09md: convert to use the generic badblocks codeVishal Verma
Retain badblocks as part of rdev, but use the accessor functions from include/linux/badblocks for all manipulation. Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-07md: Remove 'ready' field from mddev.NeilBrown
This field is always set in tandem with ->pers, and when it is tested ->pers is also tested. So ->ready is not needed. It was needed once, but code rearrangement and locking changes have removed that needed. Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06drivers: md: use ktime_get_real_seconds()Deepa Dinamani
get_seconds() API is not y2038 safe on 32 bit systems and the API is deprecated. Replace it with calls to ktime_get_real_seconds() API instead. Change mddev structure types to time64_t accordingly. 32 bit signed timestamps will overflow in the year 2038. Change the user interface mdu_array_info_s structure timestamps: ctime and utime values used in ioctls GET_ARRAY_INFO and SET_ARRAY_INFO to unsigned int. This will extend the field to last until the year 2106. The long term plan is to get rid of ctime and utime values in this structure as this information can be read from the on-disk meta data directly. Clamp the tim64_t timestamps to positive values with a max of U32_MAX when returning from GET_ARRAY_INFO ioctl to accommodate above changes in the data type of timestamps to unsigned int. v0.90 on disk meta data uses u32 for maintaining time stamps. So this will also last until year 2106. Assumption is that the usage of v0.90 will be deprecated by year 2106. Timestamp fields in the on disk meta data for v1.0 version already use 64 bit data types. Remove the truncation of the bits while writing to or reading from these from the disk. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06md-cluster: Defer MD reloading to mddev->threadGuoqing Jiang
Reloading of superblock must be performed under reconfig_mutex. However, this cannot be done with md_reload_sb because it would deadlock with the message DLM lock. So, we defer it in md_check_recovery() which is executed by mddev->thread. This introduces a new flag, MD_RELOAD_SB, which if set, will reload the superblock. And good_device_nr is also added to 'struct mddev' which is used to get the num of the good device within cluster raid. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06md-cluster: remove a disk asynchronously from cluster environmentGuoqing Jiang
For cluster raid, if one disk couldn't be reach in one node, then other nodes would receive the REMOVE message for the disk. In receiving node, we can't call md_kick_rdev_from_array to remove the disk from array synchronously since the disk might still be busy in this node. So let's set a ClusterRemove flag on the disk, then let the thread to do the removal job eventually. Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-12-18MD: change journal disk role to disk 0Shaohua Li
Neil pointed out setting journal disk role to raid_disks will confuse reshape if we support reshape eventually. Switching the role to 0 (we should be fine as long as the value >=0) and skip sysfs file creation to avoid error. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01MD: add new bit to indicate raid array with journalSong Liu
If a raid array has journal feature bit set, add a new bit to indicate this. If the array is started without journal disk existing, we know there is something wrong. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01md: skip resync for raid array with journalShaohua Li
If a raid array has journal, the journal can guarantee the consistency, we can skip resync after a unclean shutdown. The exception is raid creation or user initiated resync, which we still do a raid resync. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-24md: override md superblock recovery_offset for journal deviceShaohua Li
Journal device stores data in a log structure. We need record the log start. Here we override md superblock recovery_offset for this purpose. This field of a journal device is meaningless otherwise. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-24MD: add a new disk role to present write journal deviceSong Liu
Next patches will use a disk as raid5/6 journaling. We need a new disk role to present the journal device and add MD_FEATURE_JOURNAL to feature_map for backward compability. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-12md-cluster: Improve md_reload_sb to be less error proneGoldwyn Rodrigues
md_reload_sb is too simplistic and it explicitly needs to determine the changes made by the writing node. However, there are multiple areas where a simple reload could fail. Instead, read the superblock of one of the "good" rdevs and update the necessary information: - read the superblock into a newly allocated page, by temporarily swapping out rdev->sb_page and calling ->load_super. - if that fails return - if it succeeds, call check_sb_changes 1. iterates over list of active devices and checks the matching dev_roles[] value. If that is 'faulty', the device must be marked as faulty - call md_error to mark the device as faulty. Make sure not to set CHANGE_DEVS and wakeup mddev->thread or else it would initiate a resync process, which is the responsibility of the "primary" node. - clear the Blocked bit - Call remove_and_add_spares() to hot remove the device. If the device is 'spare': - call remove_and_add_spares() to get the number of spares added in this operation. - Reduce mddev->degraded to mark the array as not degraded. 2. reset recovery_cp - read the rest of the rdevs to update recovery_offset. If recovery_offset is equal to MaxSector, call spare_active() to set it In_sync This required that recovery_offset be initialized to MaxSector, as opposed to zero so as to communicate the end of sync for a rdev. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-08-13block: kill merge_bvec_fn() completelyKent Overstreet
As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@kernel.org> Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02writeback: separate out include/linux/backing-dev-defs.hTejun Heo
With the planned cgroup writeback support, backing-dev related declarations will be more widely used across block and cgroup; unfortunately, including backing-dev.h from include/linux/blkdev.h makes cyclic include dependency quite likely. This patch separates out backing-dev-defs.h which only has the essential definitions and updates blkdev.h to include it. c files which need access to more backing-dev details now include backing-dev.h directly. This takes backing-dev.h off the common include dependency chain making it a lot easier to use it across block and cgroup. v2: fs/fat build failure fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-22md: remove 'go_faster' option from ->sync_request()NeilBrown
This option is not well justified and testing suggests that it hardly ever makes any difference. The comment suggests there might be a need to wait for non-resync activity indicated by ->nr_waiting, however raise_barrier() already waits for all of that. So just remove it to simplify reasoning about speed limiting. This allows us to remove a 'FIXME' comment from raid5.c as that never used the flag. Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22md: Export and rename find_rdev_nr_rcuGoldwyn Rodrigues
This is required by the clustering module (patches to follow) to find the device to remove or re-add. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22md: Export and rename kick_rdev_from_arrayGoldwyn Rodrigues
This export is required for clustering module in order to co-ordinate remove/readd a rdev from all nodes. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-23Add new disk to clustered arrayGoldwyn Rodrigues
Algorithm: 1. Node 1 issues mdadm --manage /dev/mdX --add /dev/sdYY which issues ioctl(ADD_NEW_DISC with disc.state set to MD_DISK_CLUSTER_ADD) 2. Node 1 sends NEWDISK with uuid and slot number 3. Other nodes issue kobject_uevent_env with uuid and slot number (Steps 4,5 could be a udev rule) 4. In userspace, the node searches for the disk, perhaps using blkid -t SUB_UUID="" 5. Other nodes issue either of the following depending on whether the disk was found: ioctl(ADD_NEW_DISK with disc.state set to MD_DISK_CANDIDATE and disc.number set to slot number) ioctl(CLUSTERED_DISK_NACK) 6. Other nodes drop lock on no-new-devs (CR) if device is found 7. Node 1 attempts EX lock on no-new-devs 8. If node 1 gets the lock, it sends METADATA_UPDATED after unmarking the disk as SpareLocal 9. If not (get no-new-dev lock), it fails the operation and sends METADATA_UPDATED 10. Other nodes understand if the device is added or not by reading the superblock again after receiving the METADATA_UPDATED message. Signed-off-by: Lidong Zhong <lzhong@suse.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Reload superblock if METADATA_UPDATED is receivedGoldwyn Rodrigues
Re-reads the devices by invalidating the cache. Since we don't write to faulty devices, this is detected using events recorded in the devices. If it is old as compared to the mddev mark it is faulty. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Add node recovery callbacksGoldwyn Rodrigues
DLM offers callbacks when a node fails and the lock remastery is performed: 1. recover_prep: called when DLM discovers a node is down 2. recover_slot: called when DLM identifies the node and recovery can start 3. recover_done: called when all nodes have completed recover_slot recover_slot() and recover_done() are also called when the node joins initially in order to inform the node with its slot number. These slot numbers start from one, so we deduct one to make it start with zero which the cluster-md code uses. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Introduce md_cluster_infoGoldwyn Rodrigues
md_cluster_info stores the cluster information in the MD device. The join() is called when mddev detects it is a clustered device. The main responsibilities are: 1. Setup a DLM lockspace 2. Setup all initial locks such as super block locks and bitmap lock (will come later) The leave() clears up the lockspace and all the locks held. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Introduce md_cluster_operations to handle cluster functionsGoldwyn Rodrigues
This allows dynamic registering of cluster hooks. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-06md: wakeup thread upon rdev_dec_pending()Hannes Reinecke
After each call to rdev_dec_pending() we should wakeup the md thread if the device is found to be faulty. Otherwise we'll incur heavy delays on failing devices. Signed-off-by: Neil Brown <nfbrown@suse.de> Signed-off-by: Hannes Reinecke <hare@suse.de>
2015-02-06md: move mddev_lock and related to md.hNeilBrown
The one which is not inline (mddev_unlock) gets EXPORTed. This makes the locking available to personality modules so that it doesn't have to be imposed upon them. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06md: use mddev->lock to protect updates to resync_{min,max}.NeilBrown
There are interdependencies between these two sysfs attributes and whether a resync is currently running. Rather than depending on reconfig_mutex to ensure no races when testing these interdependencies are met, use the spinlock. This will allow the mutex to be remove from protecting this code in a subsequent patch. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06md: move GET_BITMAP_FILE ioctl out from mddev_lock.NeilBrown
It makes more sense to report bitmap_info->file, rather than bitmap->file (the later is only available once the array is active). With that change, use mddev->lock to protect bitmap_info being set to NULL, and we can call get_bitmap_file() without taking the mutex. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06md/bitmap: protect clearing of ->bitmap by mddev->lockNeilBrown
This makes it safe to inspect the struct while holding only the spinlock. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04md: protect ->pers changes with mddev->lockNeilBrown
->pers is already protected by ->reconfig_mutex, and cannot possibly change when there are threads running or outstanding IO. However there are some places where we access ->pers not in a thread or IO context, and where ->reconfig_mutex is unnecessarily heavy-weight: level_show and md_seq_show(). So protect all changes, and those accesses, with ->lock. This is a step toward taking those accesses out from under reconfig_mutex. [Fixed missing "mddev->pers" -> "pers" conversion, thanks to Dan Carpenter <dan.carpenter@oracle.com>] Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04md: rename ->stop to ->freeNeilBrown
Now that the ->stop function only frees the private data, rename is accordingly. Also pass in the private pointer as an arg rather than using mddev->private. This flexibility will be useful in level_store(). Finally, don't clear ->private. It doesn't make sense to clear it seeing that isn't what we free, and it is no longer necessary to clear ->private (it was some time ago before ->to_remove was introduced). Setting ->to_remove in ->free() is a bit of a wart, but not a big problem at the moment. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04md: make merge_bvec_fn more robust in face of personality changes.NeilBrown
There is no locking around calls to merge_bvec_fn(), so it is possible that calls which coincide with a level (or personality) change could go wrong. So create a central dispatch point for these functions and use rcu_read_lock(). If the array is suspended, reject any merge that can be rejected. If not, we know it is safe to call the function. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04md: make ->congested robust against personality changes.NeilBrown
There is currently no locking around calls to the 'congested' bdi function. If called at an awkward time while an array is being converted from one level (or personality) to another, there is a tiny chance of running code in an unreferenced module etc. So add a 'congested' function to the md_personality operations structure, and call it with appropriate locking from a central 'mddev_congested'. When the array personality is changing the array will be 'suspended' so no IO is processed. If mddev_congested detects this, it simply reports that the array is congested, which is a safe guess. As mddev_suspend calls synchronize_rcu(), mddev_congested can avoid races by included the whole call inside an rcu_read_lock() region. This require that the congested functions for all subordinate devices can be run under rcu_lock. Fortunately this is the case. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04md: rename mddev->write_lock to mddev->lockNeilBrown
This lock is used for (slightly) more than helping with writing superblocks, and it will soon be extended further. So the name is inappropriate. Also, the _irq variant hasn't been needed since 2.6.37 as it is never taking from interrupt or bh context. So: -rename write_lock to lock -document what it protects -remove _irq ... except in md_flush_request() as there is no wait_event_lock() (with no _irq). This can be cleaned up after appropriate changes to wait.h. Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14md: remove unwanted white space from md.cNeilBrown
My editor shows much of this is RED. Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09md/bitmap: don't abuse i_writecount for bitmap files.NeilBrown
md bitmap code currently tries to use i_writecount to stop any other process from writing to out bitmap file. But that is really an abuse and has bit-rotted so locking is all wrong. So discard that - root should be allowed to shoot self in foot. Still use it in a much less intrusive way to stop the same file being used as bitmap on two different array, and apply other checks to ensure the file is at least vaguely usable for bitmap storage (is regular, is open for write. Support for ->bmap is already checked elsewhere). Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-20Merge tag 'driver-core-3.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core / sysfs patches from Greg KH: "Here's the big driver core and sysfs patch set for 3.14-rc1. There's a lot of work here moving sysfs logic out into a "kernfs" to allow other subsystems to also have a virtual filesystem with the same attributes of sysfs (handle device disconnect, dynamic creation / removal as needed / unneeded, etc) This is primarily being done for the cgroups filesystem, but the goal is to also move debugfs to it when it is ready, solving all of the known issues in that filesystem as well. The code isn't completed yet, but all should be stable now (there is a big section that was reverted due to problems found when testing) There's also some other smaller fixes, and a driver core addition that allows for a "collection" of objects, that the DRM people will be using soon (it's in this tree to make merges after -rc1 easier) All of this has been in linux-next with no reported issues" * tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (113 commits) kernfs: associate a new kernfs_node with its parent on creation kernfs: add struct dentry declaration in kernfs.h kernfs: fix get_active failure handling in kernfs_seq_*() Revert "kernfs: fix get_active failure handling in kernfs_seq_*()" Revert "kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq" Revert "kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()" Revert "kernfs: remove KERNFS_REMOVED" Revert "kernfs: restructure removal path to fix possible premature return" Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()" Revert "kernfs: remove kernfs_addrm_cxt" Revert "kernfs: make kernfs_get_active() block if the node is deactivated but not removed" Revert "kernfs: implement kernfs_{de|re}activate[_self]()" Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers" Revert "pci: use device_remove_file_self() instead of device_schedule_callback()" Revert "scsi: use device_remove_file_self() instead of device_schedule_callback()" Revert "s390: use device_remove_file_self() instead of device_schedule_callback()" Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()" Revert "kernfs: remove unnecessary NULL check in __kernfs_remove()" kernfs: remove unnecessary NULL check in __kernfs_remove() drivers/base: provide an infrastructure for componentised subsystems ...
2014-01-14md: fix problem when adding device to read-only array with bitmap.NeilBrown
If an array is started degraded, and then the missing device is found it can be re-added and a minimal bitmap-based recovery will bring it fully up-to-date. If the array is read-only a recovery would not be allowed. But also if the array is read-only and the missing device was present very recently, then there could be no need for any recovery at all, so we simply include the device in the read-only array without any recovery. However... if the missing device was removed a little longer ago it could be missing some updates, but if a bitmap is present it will be conditionally accepted pending a bitmap-based update. We don't currently detect this case properly and will include that old device into the read-only array with no recovery even though it really needs a recovery. This patch keeps track of whether a bitmap-based-recovery is really needed or not in the new Bitmap_sync rdev flag. If that is set, then the device will not be added to a read-only array. Cc: Andrei Warkentin <andreiw@vmware.com> Fixes: d70ed2e4fafdbef0800e73942482bb075c21578b Cc: stable@vger.kernel.org (3.2+) Signed-off-by: NeilBrown <neilb@suse.de>
2013-12-11kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordinglyTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Neil Brown <neilb@suse.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-14Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block IO core updates from Jens Axboe: "This is the pull request for the core changes in the block layer for 3.13. It contains: - The new blk-mq request interface. This is a new and more scalable queueing model that marries the best part of the request based interface we currently have (which is fully featured, but scales poorly) and the bio based "interface" which the new drivers for high IOPS devices end up using because it's much faster than the request based one. The bio interface has no block layer support, since it taps into the stack much earlier. This means that drivers end up having to implement a lot of functionality on their own, like tagging, timeout handling, requeue, etc. The blk-mq interface provides all these. Some drivers even provide a switch to select bio or rq and has code to handle both, since things like merging only works in the rq model and hence is faster for some workloads. This is a huge mess. Conversion of these drivers nets us a substantial code reduction. Initial results on converting SCSI to this model even shows an 8x improvement on single queue devices. So while the model was intended to work on the newer multiqueue devices, it has substantial improvements for "classic" hardware as well. This code has gone through extensive testing and development, it's now ready to go. A pull request is coming to convert virtio-blk to this model will be will be coming as well, with more drivers scheduled for 3.14 conversion. - Two blktrace fixes from Jan and Chen Gang. - A plug merge fix from Alireza Haghdoost. - Conversion of __get_cpu_var() from Christoph Lameter. - Fix for sector_div() with 64-bit divider from Geert Uytterhoeven. - A fix for a race between request completion and the timeout handling from Jeff Moyer. This is what caused the merge conflict with blk-mq/core, in case you are looking at that. - A dm stacking fix from Mike Snitzer. - A code consolidation fix and duplicated code removal from Kent Overstreet. - A handful of block bug fixes from Mikulas Patocka, fixing a loop crash and memory corruption on blk cg. - Elevator switch bug fix from Tomoki Sekiyama. A heads-up that I had to rebase this branch. Initially the immutable bio_vecs had been queued up for inclusion, but a week later, it became clear that it wasn't fully cooked yet. So the decision was made to pull this out and postpone it until 3.14. It was a straight forward rebase, just pruning out the immutable series and the later fixes of problems with it. The rest of the patches applied directly and no further changes were made" * 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits) block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO block: Do not call sector_div() with a 64-bit divisor kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup() block: Consolidate duplicated bio_trim() implementations block: Use rw_copy_check_uvector() block: Enable sysfs nomerge control for I/O requests in the plug list block: properly stack underlying max_segment_size to DM device elevator: acquire q->sysfs_lock in elevator_change() elevator: Fix a race in elevator switching and md device initialization block: Replace __get_cpu_var uses bdi: test bdi_init failure block: fix a probe argument to blk_register_region loop: fix crash if blk_alloc_queue fails blk-core: Fix memory corruption if blkcg_init_queue fails block: fix race between request completion and timeout handling blktrace: Send BLK_TN_PROCESS events to all running traces blk-mq: don't disallow request merges for req->special being set blk-mq: mq plug list breakage blk-mq: fix for flush deadlock ...
2013-11-08block: Consolidate duplicated bio_trim() implementationsKent Overstreet
Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on, we should know better than this. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-09-26sysfs: clean up sysfs_get_dirent()Tejun Heo
The pre-existing sysfs interfaces which take explicit namespace argument are weird in that they place the optional @ns in front of @name which is contrary to the established convention. For example, we end up forcing vast majority of sysfs_get_dirent() users to do sysfs_get_dirent(parent, NULL, name), which is silly and error-prone especially as @ns and @name may be interchanged without causing compilation warning. This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the positions of @name and @ns, and sysfs_get_dirent() is now a wrapper around sysfs_get_dirent_ns(). This makes confusions a lot less likely. There are other interfaces which take @ns before @name. They'll be updated by following patches. This patch doesn't introduce any functional changes. v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol error on module builds. Reported by build test robot. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27md: avoid deadlock when dirty buffers during md_stop.NeilBrown
When the last process closes /dev/mdX sync_blockdev will be called so that all buffers get flushed. So if it is then opened for the STOP_ARRAY ioctl to be sent there will be nothing to flush. However if we open /dev/mdX in order to send the STOP_ARRAY ioctl just moments before some other process which was writing closes their file descriptor, then there won't be a 'last close' and the buffers might not get flushed. So do_md_stop() calls sync_blockdev(). However at this point it is holding ->reconfig_mutex. So if the array is currently 'clean' then the writes from sync_blockdev() will not complete until the array can be marked dirty and that won't happen until some other thread can get ->reconfig_mutex. So we deadlock. We need to move the sync_blockdev() call to before we take ->reconfig_mutex. However then some other thread could open /dev/mdX and write to it after we call sync_blockdev() and before we actually stop the array. This can leave dirty data in the page cache which is awkward. So introduce new flag MD_STILL_CLOSED. Set it before calling sync_blockdev(), clear it if anyone does open the file, and abort the STOP_ARRAY attempt if it gets set before we lock against further opens. It is still possible to get problems if you open /dev/mdX, write to it, then issue the STOP_ARRAY ioctl. Just don't do that. Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27md: Don't test all of mddev->flags at once.NeilBrown
mddev->flags is mostly used to record if an update of the metadata is needed. Sometimes the whole field is tested instead of just the important bits. This makes it difficult to introduce more state bits. So replace all bare tests of mddev->flags with tests for the bits that actually need testing. Signed-off-by: NeilBrown <neilb@suse.de>