lwn.git/drivers/md/md.c, branch v3.13-rc8

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2013-12-05T23:33:27+00:00

Pull block layer fixes from Jens Axboe: "A small collection of fixes for the current series. It contains: - A fix for a use-after-free of a request in blk-mq. From Ming Lei - A fix for a blk-mq bug that could attempt to dereference a NULL rq if allocation failed - Two xen-blkfront small fixes - Cleanup of submit_bio_wait() type uses in the kernel, unifying that. From Kent - A fix for 32-bit blkg_rwstat reading. I apologize for this one looking mangled in the shortlog, it's entirely my fault for missing an empty line between the description and body of the text" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq: fix use-after-free of request blk-mq: fix dereference of rq->mq_ctx if allocation fails block: xen-blkfront: Fix possible NULL ptr dereference xen-blkfront: Silence pfn maybe-uninitialized warning block: submit_bio_wait() conversions Update of blkg_stat and blkg_rwstat may happen in bh context

md: test mddev->flags more safely in md_check_recovery.

2013-11-28T00:00:08+00:00

commit 7a0a5355cbc71efa md: Don't test all of mddev->flags at once. made most tests on mddev->flags safer, but missed one. When commit 260fa034ef7a4ff8b7306 md: avoid deadlock when dirty buffers during md_stop. added MD_STILL_CLOSED, this caused md_check_recovery to misbehave. It can think there is something to do but find nothing. This can lead to the md thread spinning during array shutdown. https://bugzilla.kernel.org/show_bug.cgi?id=65721 Reported-and-tested-by: Richard W.M. Jones Fixes: 260fa034ef7a4ff8b7306 Cc: stable@vger.kernel.org (3.12) Signed-off-by: NeilBrown

block: submit_bio_wait() conversions

2013-11-24T23:33:41+00:00

It was being open coded in a few places. Signed-off-by: Kent Overstreet Cc: Jens Axboe Cc: Joern Engel Cc: Prasad Joshi Cc: Neil Brown Cc: Chris Mason Acked-by: NeilBrown Signed-off-by: Jens Axboe

Merge tag 'md/3.13' of git://neil.brown.name/md

2013-11-20T21:05:25+00:00

Pull md update from Neil Brown: "Mostly optimisations and obscure bug fixes. - raid5 gets less lock contention - raid1 gets less contention between normal-io and resync-io during resync" * tag 'md/3.13' of git://neil.brown.name/md: md/raid5: Use conf->device_lock protect changing of multi-thread resources. md/raid5: Before freeing old multi-thread worker, it should flush them. md/raid5: For stripe with R5_ReadNoMerge, we replace REQ_FLUSH with REQ_NOMERGE. UAPI: include in linux/raid/md_p.h raid1: Rewrite the implementation of iobarrier. raid1: Add some macros to make code clearly. raid1: Replace raise_barrier/lower_barrier with freeze_array/unfreeze_array when reconfiguring the array. raid1: Add a field array_frozen to indicate whether raid in freeze state. md: Convert use of typedef ctl_table to struct ctl_table md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes. md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread. md: fix some places where mddev_lock return value is not checked. raid5: Retry R5_ReadNoMerge flag when hit a read error. raid5: relieve lock contention in get_active_stripe() raid5: relieve lock contention in get_active_stripe() wait: add wait_event_cmd() md/raid5.c: add proper locking to error path of raid5_start_reshape. md: fix calculation of stacking limits on level change. raid5: Use slow_path to release stripe when mddev->thread is null

md: Convert use of typedef ctl_table to struct ctl_table

2013-11-19T04:19:18+00:00

This typedef is unnecessary and should just be removed. Signed-off-by: Joe Perches Signed-off-by: NeilBrown

md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes.

2013-11-19T04:19:17+00:00

When raid5 recovery hits a fresh badblock, this badblock will flagged as unack badblock until md_update_sb() is called. But md_stop will take reconfig lock which means raid5d can't call md_update_sb() in md_check_recovery(), the badblock will always be unack, so raid5d thread enters an infinite loop and md_stop_write() can never stop sync_thread. This causes deadlock. To solve this, when STOP_ARRAY ioctl is issued and sync_thread is running, we need set md->recovery FROZEN and INTR flags and wait for sync_thread to stop before we (re)take reconfig lock. This requires that raid5 reshape_request notices MD_RECOVERY_INTR (which it probably should have noticed anyway) and stops waiting for a metadata update in that case. Reported-by: Jianpeng Ma Reported-by: Bian Yu Signed-off-by: NeilBrown

md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.

2013-11-19T04:19:17+00:00

We currently use kthread_should_stop() in various places in the sync/reshape code to abort early. However some places set MD_RECOVERY_INTR but don't immediately call md_reap_sync_thread() (and we will shortly get another one). When this happens we are relying on md_check_recovery() to reap the thread and that only happen when it finishes normally. So MD_RECOVERY_INTR must lead to a normal finish without the kthread_should_stop() test. So replace all relevant tests, and be more careful when the thread is interrupted not to acknowledge that latest step in a reshape as it may not be fully committed yet. Also add a test on MD_RECOVERY_INTR in the 'is_mddev_idle' loop so we don't wait have to wait for the speed to drop before we can abort. Signed-off-by: NeilBrown

md: fix some places where mddev_lock return value is not checked.

2013-11-19T04:19:17+00:00

Sometimes we need to lock and mddev and cannot cope with failure due to interrupt. In these cases we should use mutex_lock, not mutex_lock_interruptible. Signed-off-by: NeilBrown

md: fix calculation of stacking limits on level change.

2013-11-14T04:16:15+00:00

The various ->run routines of md personalities assume that the 'queue' has been initialised by the blk_set_stacking_limits() call in md_alloc(). However when the level is changed (by level_store()) the ->run routine for the new level is called for an array which has already had the stacking limits modified. This can result in incorrect final settings. So call blk_set_stacking_limits() before ->run in level_store(). A specific consequence of this bug is that it causes discard_granularity to be set incorrectly when reshaping a RAID4 to a RAID0. This is suitable for any -stable kernel since 3.3 in which blk_set_stacking_limits() was introduced. Cc: stable@vger.kernel.org (3.3+) Reported-and-tested-by: "Baldysiak, Pawel" Signed-off-by: NeilBrown

Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block

2013-11-14T03:08:14+00:00

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 ...