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2014-08-14Merge tag 'dm-3.17-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper changes from Mike Snitzer: - Allow the thin target to paired with any size external origin; also allow thin snapshots to be larger than the external origin. - Add support for quickly loading a repetitive pattern into the dm-switch target. - Use per-bio data in the dm-crypt target instead of always using a mempool for each allocation. Required switching to kmalloc alignment for the bio slab. - Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag - Fix the dm-cache and dm-thin targets' export of the minimum_io_size to match the data block size -- this fixes an issue where mkfs.xfs would improperly infer raid striping was in place on the underlying storage. - Small cleanups in dm-io, dm-mpath and dm-cache * tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm table: propagate QUEUE_FLAG_NO_SG_MERGE dm switch: efficiently support repetitive patterns dm switch: factor out switch_region_table_read dm cache: set minimum_io_size to cache's data block size dm thin: set minimum_io_size to pool's data block size dm crypt: use per-bio data block: use kmalloc alignment for bio slab dm table: make dm_table_supports_discards static dm cache metadata: use dm-space-map-metadata.h defined size limits dm cache: fail migrations in the do_worker error path dm cache: simplify deferred set reference count increments dm thin: relax external origin size constraints dm thin: switch to an atomic_t for tracking pending new block preparations dm mpath: eliminate pg_ready() wrapper dm io: simplify dec_count and sync_io
2014-08-14Merge branch 'for-3.17/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver changes from Jens Axboe: "Nothing out of the ordinary here, this pull request contains: - A big round of fixes for bcache from Kent Overstreet, Slava Pestov, and Surbhi Palande. No new features, just a lot of fixes. - The usual round of drbd updates from Andreas Gruenbacher, Lars Ellenberg, and Philipp Reisner. - virtio_blk was converted to blk-mq back in 3.13, but now Ming Lei has taken it one step further and added support for actually using more than one queue. - Addition of an explicit SG_FLAG_Q_AT_HEAD for block/bsg, to compliment the the default behavior of adding to the tail of the queue. From Douglas Gilbert" * 'for-3.17/drivers' of git://git.kernel.dk/linux-block: (86 commits) bcache: Drop unneeded blk_sync_queue() calls bcache: add mutex lock for bch_is_open bcache: Correct printing of btree_gc_max_duration_ms bcache: try to set b->parent properly bcache: fix memory corruption in init error path bcache: fix crash with incomplete cache set bcache: Fix more early shutdown bugs bcache: fix use-after-free in btree_gc_coalesce() bcache: Fix an infinite loop in journal replay bcache: fix crash in bcache_btree_node_alloc_fail tracepoint bcache: bcache_write tracepoint was crashing bcache: fix typo in bch_bkey_equal_header bcache: Allocate bounce buffers with GFP_NOWAIT bcache: Make sure to pass GFP_WAIT to mempool_alloc() bcache: fix uninterruptible sleep in writeback thread bcache: wait for buckets when allocating new btree root bcache: fix crash on shutdown in passthrough mode bcache: fix lockdep warnings on shutdown bcache allocator: send discards with correct size bcache: Fix to remove the rcu_sched stalls. ...
2014-08-11Merge tag 'md/3.17' of git://neil.brown.name/mdLinus Torvalds
Pull md updates from Neil Brown: "Most interesting is that md devices (major == 9) with minor numbers of 512 or more will no longer be created simply by opening a block device file. They can only be created by writing to /sys/module/md_mod/parameters/new_array The 'auto-create-on-open' semantic is cumbersome and we need to start moving away from it" * tag 'md/3.17' of git://neil.brown.name/md: md: don't allow bitmap file to be added to raid0/linear. md/raid0: check for bitmap compatability when changing raid levels. md: Recovery speed is wrong md: disable probing for md devices 512 and over. md/raid1,raid10: always abort recover on write error.
2014-08-10dm table: propagate QUEUE_FLAG_NO_SG_MERGEJeff Moyer
Commit 05f1dd5 ("block: add queue flag for disabling SG merging") introduced a new queue flag: QUEUE_FLAG_NO_SG_MERGE. This gets set by default in blk_mq_init_queue for mq-enabled devices. The effect of the flag is to bypass the SG segment merging. Instead, the bio->bi_vcnt is used as the number of hardware segments. With a device mapper target on top of a device with QUEUE_FLAG_NO_SG_MERGE set, we can end up sending down more segments than a driver is prepared to handle. I ran into this when backporting the virtio_blk mq support. It triggerred this BUG_ON, in virtio_queue_rq: BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); The queue's max is set here: blk_queue_max_segments(q, vblk->sg_elems-2); Basically, what happens is that a bio is built up for the dm device (which does not have the QUEUE_FLAG_NO_SG_MERGE flag set) using bio_add_page. That path will call into __blk_recalc_rq_segments, so what you end up with is bi_phys_segments being much smaller than bi_vcnt (and bi_vcnt grows beyond the maximum sg elements). Then, when the bio is submitted, it gets cloned. When the cloned bio is submitted, it will end up in blk_recount_segments, here: if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags)) bio->bi_phys_segments = bio->bi_vcnt; and now we've set bio->bi_phys_segments to a number that is beyond what was registered as queue_max_segments by the driver. The right way to fix this is to propagate the queue flag up the stack. The rules for propagating the flag are simple: - if the flag is set for any underlying device, it must be set for the upper device - consequently, if the flag is not set for any underlying device, it should not be set for the upper device. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.16+
2014-08-08md: don't allow bitmap file to be added to raid0/linear.NeilBrown
An array can only accept a bitmap if it will call bitmap_daemon_work periodically, which means it needs a thread running. If there is no thread, don't allow a bitmap to be added. Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08md/raid0: check for bitmap compatability when changing raid levels.NeilBrown
If an array has a bitmap, then it cannot be converted to raid0. Reported-by: Xiao Ni <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08md: Recovery speed is wrongXiao Ni
When we calculate the speed of recovery, the numerator that contains the recovery done sectors. It's need to subtract the sectors which don't finish recovery. Signed-off-by: Xiao Ni <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-04Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Move the nohz kick code out of the scheduler tick to a dedicated IPI, from Frederic Weisbecker. This necessiated quite some background infrastructure rework, including: * Clean up some irq-work internals * Implement remote irq-work * Implement nohz kick on top of remote irq-work * Move full dynticks timer enqueue notification to new kick * Move multi-task notification to new kick * Remove unecessary barriers on multi-task notification - Remove proliferation of wait_on_bit() action functions and allow wait_on_bit_action() functions to support a timeout. (Neil Brown) - Another round of sched/numa improvements, cleanups and fixes. (Rik van Riel) - Implement fast idling of CPUs when the system is partially loaded, for better scalability. (Tim Chen) - Restructure and fix the CPU hotplug handling code that may leave cfs_rq and rt_rq's throttled when tasks are migrated away from a dead cpu. (Kirill Tkhai) - Robustify the sched topology setup code. (Peterz Zijlstra) - Improve sched_feat() handling wrt. static_keys (Jason Baron) - Misc fixes. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) sched/fair: Fix 'make xmldocs' warning caused by missing description sched: Use macro for magic number of -1 for setparam sched: Robustify topology setup sched: Fix sched_setparam() policy == -1 logic sched: Allow wait_on_bit_action() functions to support a timeout sched: Remove proliferation of wait_on_bit() action functions sched/numa: Revert "Use effective_load() to balance NUMA loads" sched: Fix static_key race with sched_feat() sched: Remove extra static_key*() function indirection sched/rt: Fix replenish_dl_entity() comments to match the current upstream code sched: Transform resched_task() into resched_curr() sched/deadline: Kill task_struct->pi_top_task sched: Rework check_for_tasks() sched/rt: Enqueue just unthrottled rt_rq back on the stack in __disable_runtime() sched/fair: Disable runtime_enabled on dying rq sched/numa: Change scan period code to match intent sched/numa: Rework best node setting in task_numa_migrate() sched/numa: Examine a task move when examining a task swap sched/numa: Simplify task_numa_compare() sched/numa: Use effective_load() to balance NUMA loads ...
2014-08-04bcache: Drop unneeded blk_sync_queue() callsKent Overstreet
this is needed for the queue/block device we created (it's done by blk_cleanup_queue() which we do call) - but calling it for the block devices we only opened is pointless. Change-Id: I53dfded14ed15b9581d10ca8399d5e1b3abbf9f2
2014-08-04bcache: add mutex lock for bch_is_openJianjian Huo
Since bch_is_open will iterate linked list bch_cache_sets and uncached_devices, it needs bch_register_lock. Signed-off-by: Jianjian Huo <samuel.huo@gmail.com>
2014-08-04bcache: Correct printing of btree_gc_max_duration_msSurbhi Palande
time_stats::btree_gc_max_duration_mc is not bit shifted by 8 Fixes BUG #138 Change-Id: I44fc6e1d0579674016acc533f1a546b080e5371a Signed-off-by: Surbhi Palande <sap@daterainc.com>
2014-08-04bcache: try to set b->parent properlySlava Pestov
bcache_flash_dev.ktest would reliably crash with 8k and 16k bucket size before; now it passes. Change-Id: Ib542232235e39298c3a7548fe52b645cabb823d1
2014-08-04bcache: fix memory corruption in init error pathSlava Pestov
If register_cache_set() failed, we would touch ca->set after it had already been freed. Also, fix an assertion to catch this. Change-Id: I748e5f5b223e2d9b2602075dec2f997cced2394d
2014-08-04bcache: fix crash with incomplete cache setSlava Pestov
Change-Id: I6abde52afe917633480caaf4e2518f42a816d886
2014-08-04bcache: Fix more early shutdown bugsKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: fix use-after-free in btree_gc_coalesce()Slava Pestov
If we goto out_nocoalesce after we free new_nodes[0], we end up freeing new_nodes[0] again. This was generating a lockdep warning. The fix is to set new_nodes[0] to NULL, since the out_nocoalesce path safely ignores NULL entries in the new_nodes array. This regression was introduced in 2d7f9531. Change-Id: I76564d7257800583214376b4bacf236cda90c89c
2014-08-04bcache: Fix an infinite loop in journal replayKent Overstreet
When running with multiple cache devices, if one of the devices has a completely empty journal but we'd already found some journal entries on a previosu device we'd go into an infinite loop. Change-Id: I1dcdc0d738192746de28f40e8b08825b0dea5e2b Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: fix crash in bcache_btree_node_alloc_fail tracepointSlava Pestov
'b' was NULL. Change-Id: Icac0fd04afa2d23f213d96d51afd53374e6dd0c0
2014-08-04bcache: bcache_write tracepoint was crashingSlava Pestov
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: fix typo in bch_bkey_equal_headerSlava Pestov
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: Allocate bounce buffers with GFP_NOWAITKent Overstreet
There's no point in blocking on these allocations, since our fallback paths will probably go faster than blocking. Change-Id: I733ca202c25cb36bde02607a0a60552229a4241c
2014-08-04bcache: Make sure to pass GFP_WAIT to mempool_alloc()Kent Overstreet
this was very wrong - mempool_alloc() only guarantees success with GFP_WAIT. bcache uses GFP_NOWAIT in various other places where we have a fallback, circuits must've gotten crossed when writing this code or something. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: fix uninterruptible sleep in writeback threadSlava Pestov
There were two issues here: - writeback thread did not start until the device first became dirty - writeback thread used uninterruptible sleep once running Without this patch I see kernel warnings printed and a load average of 1.52 after booting my test VM. With this patch the warnings are gone and the load average is near 0.00 as expected. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: wait for buckets when allocating new btree rootSlava Pestov
Tested: - sometimes bcache_tier test would hang on startup with a failure to allocate the btree root -- no longer seeing this Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: fix crash on shutdown in passthrough modeSlava Pestov
We never started the writeback thread in this case, so don't stop it.
2014-08-04bcache: fix lockdep warnings on shutdownSlava Pestov
2014-08-04bcache allocator: send discards with correct sizeSlava Pestov
2014-08-04bcache: Fix to remove the rcu_sched stalls.Surbhi Palande
while loop was executing infinitely. This fix ends the while loop gracefully. Signed-off-by: Surbhi Palande <sap@daterainc.com> Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: Fix a journal replay bugKent Overstreet
journal replay wansn't validating pointers with bch_extent_invalid() before derefing, fixed Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: Fix a bug when detachingKent Overstreet
After detaching a backing device from a cache set, a bit wasn't getting reset meaning the second detach wouldn't work correctly. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-01dm switch: efficiently support repetitive patternsMikulas Patocka
Add support for quickly loading a repetitive pattern into the dm-switch target. In the "set_regions_mappings" message, the user may now use "Rn,m" as one of the arguments. "n" and "m" are hexadecimal numbers. The "Rn,m" argument repeats the last "n" arguments in the following "m" slots. For example: dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10 is equivalent to dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \ :1 :2 :1 :2 :1 :2 :1 :2 :1 :2 Requested-by: Jay Wang <jwang@nimblestorage.com> Tested-by: Jay Wang <jwang@nimblestorage.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm switch: factor out switch_region_table_readMikulas Patocka
Move code that reads the table to a switch_region_table_read. It will be needed for the next commit. No functional change. Tested-by: Jay Wang <jwang@nimblestorage.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm cache: set minimum_io_size to cache's data block sizeMike Snitzer
Before, if the block layer's limit stacking didn't establish an optimal_io_size that was compatible with the cache's data block size we'd set optimal_io_size to the data block size and minimum_io_size to 0 (which the block layer adjusts to be physical_block_size). Update cache_io_hints() to set both minimum_io_size and optimal_io_size to the cache's data block size. This fixes an issue where mkfs.xfs would create more XFS Allocation Groups on cache volumes than on a normal linear LV of comparable size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm thin: set minimum_io_size to pool's data block sizeMike Snitzer
Before, if the block layer's limit stacking didn't establish an optimal_io_size that was compatible with the thin-pool's data block size we'd set optimal_io_size to the data block size and minimum_io_size to 0 (which the block layer adjusts to be physical_block_size). Update pool_io_hints() to set both minimum_io_size and optimal_io_size to the thin-pool's data block size. This fixes an issue reported where mkfs.xfs would create more XFS Allocation Groups on thinp volumes than on a normal linear LV of comparable size, see: https://bugzilla.redhat.com/show_bug.cgi?id=1003227 Reported-by: Chris Murphy <lists@colorremedies.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm crypt: use per-bio dataMikulas Patocka
Change dm-crypt so that it uses auxiliary data allocated with the bio. Dm-crypt requires two allocations per request - struct dm_crypt_io and struct ablkcipher_request (with other data appended to it). It previously only used mempool allocations. Some requests may require more dm_crypt_ios and ablkcipher_requests, however most requests need just one of each of these two structures to complete. This patch changes it so that the first dm_crypt_io and ablkcipher_request are allocated with the bio (using target per_bio_data_size option). If the request needs additional values, they are allocated from the mempool. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm table: make dm_table_supports_discards staticMikulas Patocka
The function dm_table_supports_discards is only called from dm-table.c:dm_table_set_restrictions(). So move it above dm_table_set_restrictions and make it static. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm cache metadata: use dm-space-map-metadata.h defined size limitsMike Snitzer
Commit 7d48935e cleaned up the persistent-data's space-map-metadata limits by elevating them to dm-space-map-metadata.h. Update dm-cache-metadata to use these same limits. The calculation for DM_CACHE_METADATA_MAX_SECTORS didn't account for the sizeof the disk_bitmap_header. So the supported maximum metadata size is a bit smaller (reduced from 33423360 to 33292800 sectors). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
2014-08-01dm cache: fail migrations in the do_worker error pathJoe Thornber
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm cache: simplify deferred set reference count incrementsJoe Thornber
Factor out inc_and_issue and inc_ds helpers to simplify deferred set reference count increments. Also cleanup cache_map to consistently call cell_defer and inc_ds when the bio is DM_MAPIO_REMAPPED. No functional change. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm thin: relax external origin size constraintsJoe Thornber
Track the size of any external origin. Previously the external origin's size had to be a multiple of the thin-pool's block size, that is no longer a requirement. In addition, snapshots that are larger than the external origin are now supported. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm thin: switch to an atomic_t for tracking pending new block preparationsJoe Thornber
Previously we used separate boolean values to track quiescing and copying actions. By switching to an atomic_t we can support blocks that need a partial copy and partial zero. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm mpath: eliminate pg_ready() wrapperMike Snitzer
pg_ready() is not comprehensive in its logic and only serves to obfuscate code. Replace pg_ready() with the appropriate logic in multipath_map(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm io: simplify dec_count and sync_ioJoe Thornber
Remove the io struct off the stack in sync_io() and allocate it from the mempool like is done in async_io(). dec_count() now always calls a callback function and always frees the io struct back to the mempool (so sync_io and async_io share this pattern). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01dm cache: fix race affecting dirty block countAnssi Hannula
nr_dirty is updated without locking, causing it to drift so that it is non-zero (either a small positive integer, or a very large one when an underflow occurs) even when there are no actual dirty blocks. This was due to a race between the workqueue and map function accessing nr_dirty in parallel without proper protection. People were seeing under runs due to a race on increment/decrement of nr_dirty, see: https://lkml.org/lkml/2014/6/3/648 Fix this by using an atomic_t for nr_dirty. Reported-by: roma1390@gmail.com Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2014-08-01dm bufio: fully initialize shrinkerGreg Thelen
1d3d4437eae1 ("vmscan: per-node deferred work") added a flags field to struct shrinker assuming that all shrinkers were zero filled. The dm bufio shrinker is not zero filled, which leaves arbitrary kmalloc() data in flags. So far the only defined flags bit is SHRINKER_NUMA_AWARE. But there are proposed patches which add other bits to shrinker.flags (e.g. memcg awareness). Rather than simply initializing the shrinker, this patch uses kzalloc() when allocating the dm_bufio_client to ensure that the embedded shrinker and any other similar structures are zeroed. This fixes theoretical over aggressive shrinking of dm bufio objects. If the uninitialized dm_bufio_client.shrinker.flags contains SHRINKER_NUMA_AWARE then shrink_slab() would call the dm shrinker for each numa node rather than just once. This has been broken since 3.12. Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v3.12+
2014-07-31md: disable probing for md devices 512 and over.NeilBrown
The way md devices are traditionally created in the kernel is simply to open the device with the desired major/minor number. This can be problematic as some support tools, notably udev and programs run by udev, can open a device just to see what is there, and find that it has created something. It is easy for a race to cause udev to open an md device just after it was destroy, causing it to suddenly re-appear. For some time we have had an alternate way to create md devices echo md_somename > /sys/modules/md_mod/paramaters/new_array This will always use a minor number of 512 or higher, which mdadm normally avoids. Using this makes the creation-by-opening unnecessary, but does not disable it, so it is still there to cause problems. This patch disable probing for devices with a major of 9 (MD_MAJOR) and a minor of 512 and up. This devices created by writing to new_array cannot be re-created by opening the node in /dev. Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-31md/raid1,raid10: always abort recover on write error.NeilBrown
Currently we don't abort recovery on a write error if the write error to the recovering device was triggerd by normal IO (as opposed to recovery IO). This means that for one bitmap region, the recovery might write to the recovering device for a few sectors, then not bother for subsequent sectors (as it never writes to failed devices). In this case the bitmap bit will be cleared, but it really shouldn't. The result is that if the recovering device fails and is then re-added (after fixing whatever hardware problem triggerred the failure), the second recovery won't redo the region it was in the middle of, so some of the device will not be recovered properly. If we abort the recovery, the region being processes will be cancelled (bit not cleared) and the whole region will be retried. As the bug can result in data corruption the patch is suitable for -stable. For kernels prior to 3.11 there is a conflict in raid10.c which will require care. Original-from: jiao hui <jiaohui@bwstor.com.cn> Reported-and-tested-by: jiao hui <jiaohui@bwstor.com.cn> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@vger.kernel.org
2014-07-28Merge branch 'sched/urgent' into sched/core, to merge fixes before applying ↵Ingo Molnar
new changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-18Merge tag 'dm-3.16-fixes-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: "Fix the dm-thinp and dm-cache targets to disallow changing the data device's block size" * tag 'dm-3.16-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache metadata: do not allow the data block size to change dm thin metadata: do not allow the data block size to change
2014-07-16sched: Remove proliferation of wait_on_bit() action functionsNeilBrown
The current "wait_on_bit" interface requires an 'action' function to be provided which does the actual waiting. There are over 20 such functions, many of them identical. Most cases can be satisfied by one of just two functions, one which uses io_schedule() and one which just uses schedule(). So: Rename wait_on_bit and wait_on_bit_lock to wait_on_bit_action and wait_on_bit_lock_action to make it explicit that they need an action function. Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io which are *not* given an action function but implicitly use a standard one. The decision to error-out if a signal is pending is now made based on the 'mode' argument rather than being encoded in the action function. All instances of the old wait_on_bit and wait_on_bit_lock which can use the new version have been changed accordingly and their action functions have been discarded. wait_on_bit{_lock} does not return any specific error code in the event of a signal so the caller must check for non-zero and interpolate their own error code as appropriate. The wait_on_bit() call in __fscache_wait_on_invalidate() was ambiguous as it specified TASK_UNINTERRUPTIBLE but used fscache_wait_bit_interruptible as an action function. David Howells confirms this should be uniformly "uninterruptible" The main remaining user of wait_on_bit{,_lock}_action is NFS which needs to use a freezer-aware schedule() call. A comment in fs/gfs2/glock.c notes that having multiple 'action' functions is useful as they display differently in the 'wchan' field of 'ps'. (and /proc/$PID/wchan). As the new bit_wait{,_io} functions are tagged "__sched", they will not show up at all, but something higher in the stack. So the distinction will still be visible, only with different function names (gds2_glock_wait versus gfs2_glock_dq_wait in the gfs2/glock.c case). Since first version of this patch (against 3.15) two new action functions appeared, on in NFS and one in CIFS. CIFS also now uses an action function that makes the same freezer aware schedule call as NFS. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Howells <dhowells@redhat.com> (fscache, keys) Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2) Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org>