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path: root/drivers/md/bcache/super.c
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2016-08-18bcache: pr_err: more meaningful error message when nr_stripes is invalidEric Wheeler
The original error was thought to be corruption, but was actually caused by: make-bcache --data-offset N where N was in bytes and should have been in sectors. While userspace tools should be updated to check --data-offset beyond end of volume, hopefully this will help others that might not have noticed the units. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kent.overstreet@gmail.com>
2016-08-18bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.Kent Overstreet
This patch fixes a cachedev registration-time allocation deadlock. This can deadlock on boot if your initrd auto-registeres bcache devices: Allocator thread: [ 720.727614] INFO: task bcache_allocato:3833 blocked for more than 120 seconds. [ 720.732361] [<ffffffff816eeac7>] schedule+0x37/0x90 [ 720.732963] [<ffffffffa05192b8>] bch_bucket_alloc+0x188/0x360 [bcache] [ 720.733538] [<ffffffff810e6950>] ? prepare_to_wait_event+0xf0/0xf0 [ 720.734137] [<ffffffffa05302bd>] bch_prio_write+0x19d/0x340 [bcache] [ 720.734715] [<ffffffffa05190bf>] bch_allocator_thread+0x3ff/0x470 [bcache] [ 720.735311] [<ffffffff816ee41c>] ? __schedule+0x2dc/0x950 [ 720.735884] [<ffffffffa0518cc0>] ? invalidate_buckets+0x980/0x980 [bcache] Registration thread: [ 720.710403] INFO: task bash:3531 blocked for more than 120 seconds. [ 720.715226] [<ffffffff816eeac7>] schedule+0x37/0x90 [ 720.715805] [<ffffffffa05235cd>] __bch_btree_map_nodes+0x12d/0x150 [bcache] [ 720.716409] [<ffffffffa0522d30>] ? bch_btree_insert_check_key+0x1c0/0x1c0 [bcache] [ 720.717008] [<ffffffffa05236e4>] bch_btree_insert+0xf4/0x170 [bcache] [ 720.717586] [<ffffffff810e6950>] ? prepare_to_wait_event+0xf0/0xf0 [ 720.718191] [<ffffffffa0527d9a>] bch_journal_replay+0x14a/0x290 [bcache] [ 720.718766] [<ffffffff810cc90d>] ? ttwu_do_activate.constprop.94+0x5d/0x70 [ 720.719369] [<ffffffff810cf684>] ? try_to_wake_up+0x1d4/0x350 [ 720.719968] [<ffffffffa05317d0>] run_cache_set+0x580/0x8e0 [bcache] [ 720.720553] [<ffffffffa053302e>] register_bcache+0xe2e/0x13b0 [bcache] [ 720.721153] [<ffffffff81354cef>] kobj_attr_store+0xf/0x20 [ 720.721730] [<ffffffff812a2dad>] sysfs_kf_write+0x3d/0x50 [ 720.722327] [<ffffffff812a225a>] kernfs_fop_write+0x12a/0x180 [ 720.722904] [<ffffffff81225177>] __vfs_write+0x37/0x110 [ 720.723503] [<ffffffff81228048>] ? __sb_start_write+0x58/0x110 [ 720.724100] [<ffffffff812cedb3>] ? security_file_permission+0x23/0xa0 [ 720.724675] [<ffffffff812258a9>] vfs_write+0xa9/0x1b0 [ 720.725275] [<ffffffff8102479c>] ? do_audit_syscall_entry+0x6c/0x70 [ 720.725849] [<ffffffff81226755>] SyS_write+0x55/0xd0 [ 720.726451] [<ffffffff8106a390>] ? do_page_fault+0x30/0x80 [ 720.727045] [<ffffffff816f2cae>] system_call_fastpath+0x12/0x71 The fifo code in upstream bcache can't use the last element in the buffer, which was the cause of the bug: if you asked for a power of two size, it'd give you a fifo that could hold one less than what you asked for rather than allocating a buffer twice as big. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: stable@vger.kernel.org
2016-08-18bcache: register_bcache(): call blkdev_put() when cache_alloc() failsEric Wheeler
register_cache() is supposed to return an error string on error so that register_bcache() will will blkdev_put and cleanup other user counters, but it does not set 'char *err' when cache_alloc() fails (eg, due to memory pressure) and thus register_bcache() performs no cleanup. register_bcache() <----------\ <- no jump to err_close, no blkdev_put() | | +->register_cache() | <- fails to set char *err | | +->cache_alloc() ---/ <- returns error This patch sets `char *err` for this failure case so that register_cache() will cause register_bcache() to correctly jump to err_close and do cleanup. This was tested under OOM conditions that triggered the bug. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: stable@vger.kernel.org
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05bcache: Remove redundant block_size assignmentYijing Wang
We have assigned sb->block_size before the switch, so remove the redundant one. Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Acked-by: Eric Wheeler <bcache@lists.ewheeler.net> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05bcache: Remove redundant parameter for cache_alloc()Yijing Wang
Cache_sb is not used in cache_alloc, and we have copied sb info to cache->sb already, remove it. Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-11bcache: Remove deprecated create_workqueueBhaktipriya Shridhar
alloc_workqueue replaces deprecated create_workqueue(). Dedicated workqueues have been used since bcache_wq and moving_gc_wq are workqueues for writes and are being used on a memory reclaim path. WQ_MEM_RECLAIM has been set to ensure forward progress under memory pressure. Since there are only a fixed number of work items, explicit concurrency limit is unnecessary here. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07bcache: use bio op accessorsMike Christie
Separate the op from the rq_flag_bits and have bcache set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block/fs/drivers: remove rw argument from submit_bioMike Christie
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
2016-04-12bcache: switch to using blk_queue_write_cache()Jens Axboe
Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-03-08bcache: fix cache_set_flush() NULL pointer dereference on OOMEric Wheeler
When bch_cache_set_alloc() fails to kzalloc the cache_set, the asyncronous closure handling tries to dereference a cache_set that hadn't yet been allocated inside of cache_set_flush() which is called by __cache_set_unregister() during cleanup. This appears to happen only during an OOM condition on bcache_register. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: stable@vger.kernel.org
2016-03-08bcache: cleaned up error handling around register_cache()Eric Wheeler
Fix null pointer dereference by changing register_cache() to return an int instead of being void. This allows it to return -ENOMEM or -ENODEV and enables upper layers to handle the OOM case without NULL pointer issues. See this thread: http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3521 Fixes this error: gargamel:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/register bcache: register_cache() error opening sdh2: cannot allocate memory BUG: unable to handle kernel NULL pointer dereference at 00000000000009b8 IP: [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache] PGD 120dff067 PUD 1119a3067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: veth ip6table_filter ip6_tables (...) CPU: 4 PID: 3371 Comm: kworker/4:3 Not tainted 4.4.2-amd64-i915-volpreempt-20160213bc1 #3 Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013 Workqueue: events cache_set_flush [bcache] task: ffff88020d5dc280 ti: ffff88020b6f8000 task.ti: ffff88020b6f8000 RIP: 0010:[<ffffffffc05a7e8d>] [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache] Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Tested-by: Marc MERLIN <marc@merlins.org> Cc: <stable@vger.kernel.org>
2016-03-08bcache: fix race of writeback thread starting before complete initializationEric Wheeler
The bch_writeback_thread might BUG_ON in read_dirty() if dc->sb==BDEV_STATE_DIRTY and bch_sectors_dirty_init has not yet completed its related initialization. This patch downs the dc->writeback_lock until after initialization is complete, thus preventing bch_writeback_thread from proceeding prematurely. See this thread: http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3453 Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Tested-by: Marc MERLIN <marc@merlins.org> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-30bcache: allows use of register in udev to avoid "device_busy" error.Gabriel de Perthuis
Allows to use register, not register_quiet in udev to avoid "device_busy" error. The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis <g2p.code@gmail.com> does not unlock the mutex and hangs the kernel. See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion. Cc: Denis Bychkov <manover@gmail.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Gabriel de Perthuis <g2p.code@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-30bcache: unregister reboot notifier if bcache fails to unregister deviceZheng Liu
In bcache_init() function it forgot to unregister reboot notifier if bcache fails to unregister a block device. This commit fixes this. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-30bcache: fix a leak in bch_cached_dev_run()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-30bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing deviceZheng Liu
This bug can be reproduced by the following script: #!/bin/bash bcache_sysfs="/sys/fs/bcache" function clear_cache() { if [ ! -e $bcache_sysfs ]; then echo "no bcache sysfs" exit fi cset_uuid=$(ls -l $bcache_sysfs|head -n 2|tail -n 1|awk '{print $9}') sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/detach" sleep 5 sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/attach" } for ((i=0;i<10;i++)); do clear_cache done The warning messages look like below: [ 275.948611] ------------[ cut here ]------------ [ 275.963840] WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xb8/0xd0() (Tainted: P W --------------- ) [ 275.979253] Hardware name: Tecal RH2285 [ 275.994106] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:09.0/0000:08:00.0/host4/target4:2:1/4:2:1:0/block/sdb/sdb1/bcache/cache' [ 276.024105] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan] [ 276.072643] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1 [ 276.089315] Call Trace: [ 276.105801] [<ffffffff81070fe7>] ? warn_slowpath_common+0x87/0xc0 [ 276.122650] [<ffffffff810710d6>] ? warn_slowpath_fmt+0x46/0x50 [ 276.139361] [<ffffffff81205c08>] ? sysfs_add_one+0xb8/0xd0 [ 276.156012] [<ffffffff8120609b>] ? sysfs_do_create_link+0x12b/0x170 [ 276.172682] [<ffffffff81206113>] ? sysfs_create_link+0x13/0x20 [ 276.189282] [<ffffffffa03bda21>] ? bcache_device_link+0xc1/0x110 [bcache] [ 276.205993] [<ffffffffa03bfa08>] ? bch_cached_dev_attach+0x478/0x4f0 [bcache] [ 276.222794] [<ffffffffa03c4a17>] ? bch_cached_dev_store+0x627/0x780 [bcache] [ 276.239680] [<ffffffff8116783a>] ? alloc_pages_current+0xaa/0x110 [ 276.256594] [<ffffffff81203b15>] ? sysfs_write_file+0xe5/0x170 [ 276.273364] [<ffffffff811887b8>] ? vfs_write+0xb8/0x1a0 [ 276.290133] [<ffffffff811890b1>] ? sys_write+0x51/0x90 [ 276.306368] [<ffffffff8100c072>] ? system_call_fastpath+0x16/0x1b [ 276.322301] ---[ end trace 9f5d4fcdd0c3edfb ]--- [ 276.338241] ------------[ cut here ]------------ [ 276.354109] WARNING: at /home/wenqing.lz/bcache/bcache/super.c:720 bcache_device_link+0xdf/0x110 [bcache]() (Tainted: P W --------------- ) [ 276.386017] Hardware name: Tecal RH2285 [ 276.401430] Couldn't create device <-> cache set symlinks [ 276.401759] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan] [ 276.465477] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1 [ 276.482169] Call Trace: [ 276.498610] [<ffffffff81070fe7>] ? warn_slowpath_common+0x87/0xc0 [ 276.515405] [<ffffffff810710d6>] ? warn_slowpath_fmt+0x46/0x50 [ 276.532059] [<ffffffffa03bda3f>] ? bcache_device_link+0xdf/0x110 [bcache] [ 276.548808] [<ffffffffa03bfa08>] ? bch_cached_dev_attach+0x478/0x4f0 [bcache] [ 276.565569] [<ffffffffa03c4a17>] ? bch_cached_dev_store+0x627/0x780 [bcache] [ 276.582418] [<ffffffff8116783a>] ? alloc_pages_current+0xaa/0x110 [ 276.599341] [<ffffffff81203b15>] ? sysfs_write_file+0xe5/0x170 [ 276.616142] [<ffffffff811887b8>] ? vfs_write+0xb8/0x1a0 [ 276.632607] [<ffffffff811890b1>] ? sys_write+0x51/0x90 [ 276.648671] [<ffffffff8100c072>] ? system_call_fastpath+0x16/0x1b [ 276.664756] ---[ end trace 9f5d4fcdd0c3edfc ]--- We forget to clear BCACHE_DEV_UNLINK_DONE flag in bcache_device_attach() function when we attach a backing device first time. After detaching this backing device, this flag will be true and sysfs_remove_link() isn't called in bcache_device_unlink(). Then when we attach this backing device again, sysfs_create_link() will return EEXIST error in bcache_device_link(). So the fix is trival and we clear this flag in bcache_device_link(). Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-13bcache: remove driver private bio splitting codeKent Overstreet
The bcache driver has always accepted arbitrarily large bios and split them internally. Now that every driver must accept arbitrarily large bios this code isn't nessecary anymore. Cc: linux-bcache@vger.kernel.org Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: add more description in commit message] 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>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17block: have drivers use blk_queue_max_discard_sectors()Jens Axboe
Some drivers use it now, others just set the limits field manually. But in preparation for splitting this into a hard and soft limit, ensure that they all call the proper function for setting the hw limit for discards. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-30bcache: use kvfree() in various placesPekka Enberg
Use kvfree() instead of open-coding it. Signed-off-by: Pekka Enberg <penberg@kernel.org> Cc: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-04block: disable entropy contributions for nonrot devicesMike Snitzer
Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set QUEUE_FLAG_NONROT. Historically, all block devices have automatically made entropy contributions. But as previously stated in commit e2e1a148 ("block: add sysfs knob for turning off disk entropy contributions"): - On SSD disks, the completion times aren't as random as they are for rotational drives. So it's questionable whether they should contribute to the random pool in the first place. - Calling add_disk_randomness() has a lot of overhead. There are more reliable sources for randomness than non-rotational block devices. From a security perspective it is better to err on the side of caution than to allow entropy contributions from unreliable "random" sources. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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: 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 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: 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>
2014-03-18bcache: Kill bucket->gc_genKent Overstreet
gc_gen was a temporary used to recalculate last_gc, but since we only need bucket->last_gc when gc isn't running (gc_mark_valid = 1), we can just update last_gc directly. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Kill unused freelistKent Overstreet
This was originally added as at optimization that for various reasons isn't needed anymore, but it does add a lot of nasty corner cases (and it was responsible for some recently fixed bugs). Just get rid of it now. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Rework btree cache reserve handlingKent Overstreet
This changes the bucket allocation reserves to use _real_ reserves - separate freelists - instead of watermarks, which if nothing else makes the current code saner to reason about and is going to be important in the future when we add support for multiple btrees. It also adds btree_check_reserve(), which checks (and locks) the reserves for both bucket allocation and memory allocation for btree nodes; the old code just kinda sorta assumed that since (e.g. for btree node splits) it had the root locked and that meant no other threads could try to make use of the same reserve; this technically should have been ok for memory allocation (we should always have a reserve for memory allocation (the btree node cache is used as a reserve and we preallocate it)), but multiple btrees will mean that locking the root won't be sufficient anymore, and for the bucket allocation reserve it was technically possible for the old code to deadlock. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Kill btree_io_wqKent Overstreet
With the locking rework in the last patch, this shouldn't be needed anymore - btree_node_write_work() only takes b->write_lock which is never held for very long. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: btree locking reworkKent Overstreet
Add a new lock, b->write_lock, which is required to actually modify - or write - a btree node; this lock is only held for short durations. This means we can write out a btree node without taking b->lock, which _is_ held for long durations - solving a deadlock when btree_flush_write() (from the journalling code) is called with a btree node locked. Right now just occurs in bch_btree_set_root(), but with an upcoming journalling rework is going to happen a lot more. This also turns b->lock is now more of a read/intent lock instead of a read/write lock - but not completely, since it still blocks readers. May turn it into a real intent lock at some point in the future. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Fix moving_gc deadlocking with a foreground writeNicholas Swenson
Deadlock happened because a foreground write slept, waiting for a bucket to be allocated. Normally the gc would mark buckets available for invalidation. But the moving_gc was stuck waiting for outstanding writes to complete. These writes used the bcache_wq, the same queue foreground writes used. This fix gives moving_gc its own work queue, so it was still finish moving even if foreground writes are stuck waiting for allocation. It also makes work queue a parameter to the data_insert path, so moving_gc can use its workqueue for writes. Signed-off-by: Nicholas Swenson <nks@daterainc.com> Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Fix discard granularityKent Overstreet
blk_stack_limits() doesn't like a discard granularity of 0. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-17bcache: Fix a lockdep splat in an error pathKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-02-25bcache: Fix a shutdown bugKent Overstreet
Shutdown wasn't cancelling/waiting on journal_write_work() Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Convert debug code to btree_keysKent Overstreet
More work to disentangle various code from struct btree Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Abstract out stuff needed for sortingKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Rename/shuffle various code aroundKent Overstreet
More work to disentangle bset.c from the rest of the code: Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Add struct bset_sort_stateKent Overstreet
More disentangling bset.c from the rest of the bcache code - soon, the sorting routines won't have any dependencies on any outside structs. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Use a mempool for mergesort temporary spaceKent Overstreet
It was a single element mempool before, it's slightly cleaner to just use a real mempool. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Trivial error handling fixKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache/md: Use raid stripe sizeKent Overstreet
Now that we've got code for raid5/6 stripe awareness, bcache just needs to know about the stripes and when writing partial stripes is expensive - we probably don't want to enable this optimization for raid1 or 10, even though they have stripes. So add a flag to queue_limits. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Rework allocator reservesKent Overstreet
We need a reserve for allocating buckets for new btree nodes - and now that we've got multiple btrees, it really needs to be per btree. This reworks the reserves so we've got separate freelists for each reserve instead of watermarks, which seems to make things a bit cleaner, and it adds some code so that btree_split() can make sure the reserve is available before it starts. Signed-off-by: Kent Overstreet <kmo@daterainc.com>