kernel/linux.git/drivers/md/bcache, branch v3.18.62

bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.

2016-09-01T02:05:44+00:00

[ Upstream commit acc9cf8c66c66b2cbbdb4a375537edee72be64df ] 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] [] schedule+0x37/0x90 [ 720.732963] [] bch_bucket_alloc+0x188/0x360 [bcache] [ 720.733538] [] ? prepare_to_wait_event+0xf0/0xf0 [ 720.734137] [] bch_prio_write+0x19d/0x340 [bcache] [ 720.734715] [] bch_allocator_thread+0x3ff/0x470 [bcache] [ 720.735311] [] ? __schedule+0x2dc/0x950 [ 720.735884] [] ? invalidate_buckets+0x980/0x980 [bcache] Registration thread: [ 720.710403] INFO: task bash:3531 blocked for more than 120 seconds. [ 720.715226] [] schedule+0x37/0x90 [ 720.715805] [] __bch_btree_map_nodes+0x12d/0x150 [bcache] [ 720.716409] [] ? bch_btree_insert_check_key+0x1c0/0x1c0 [bcache] [ 720.717008] [] bch_btree_insert+0xf4/0x170 [bcache] [ 720.717586] [] ? prepare_to_wait_event+0xf0/0xf0 [ 720.718191] [] bch_journal_replay+0x14a/0x290 [bcache] [ 720.718766] [] ? ttwu_do_activate.constprop.94+0x5d/0x70 [ 720.719369] [] ? try_to_wake_up+0x1d4/0x350 [ 720.719968] [] run_cache_set+0x580/0x8e0 [bcache] [ 720.720553] [] register_bcache+0xe2e/0x13b0 [bcache] [ 720.721153] [] kobj_attr_store+0xf/0x20 [ 720.721730] [] sysfs_kf_write+0x3d/0x50 [ 720.722327] [] kernfs_fop_write+0x12a/0x180 [ 720.722904] [] __vfs_write+0x37/0x110 [ 720.723503] [] ? __sb_start_write+0x58/0x110 [ 720.724100] [] ? security_file_permission+0x23/0xa0 [ 720.724675] [] vfs_write+0xa9/0x1b0 [ 720.725275] [] ? do_audit_syscall_entry+0x6c/0x70 [ 720.725849] [] SyS_write+0x55/0xd0 [ 720.726451] [] ? do_page_fault+0x30/0x80 [ 720.727045] [] 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 Tested-by: Eric Wheeler Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

bcache: register_bcache(): call blkdev_put() when cache_alloc() fails

2016-09-01T02:05:44+00:00

[ Upstream commit d9dc1702b297ec4a6bb9c0326a70641b322ba886 ] 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 Cc: Kent Overstreet Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

bcache: fix cache_set_flush() NULL pointer dereference on OOM

2016-04-18T12:49:25+00:00

[ Upstream commit f8b11260a445169989d01df75d35af0f56178f95 ] 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 Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

bcache: cleaned up error handling around register_cache()

2016-04-18T12:49:25+00:00

[ Upstream commit 9b299728ed777428b3908ac72ace5f8f84b97789 ] 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: [] 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:[] [] cache_set_flush+0x102/0x15c [bcache] Signed-off-by: Eric Wheeler Tested-by: Marc MERLIN Cc: Signed-off-by: Sasha Levin

bcache: fix race of writeback thread starting before complete initialization

2016-04-18T12:49:25+00:00

[ Upstream commit 07cc6ef8edc47f8b4fc1e276d31127a0a5863d4d ] 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 Tested-by: Marc MERLIN Cc: Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: Change refill_dirty() to always scan entire disk if necessary

2016-02-10T03:56:17+00:00

[ Upstream commit 627ccd20b4ad3ba836472468208e2ac4dfadbf03 ] Previously, it would only scan the entire disk if it was starting from the very start of the disk - i.e. if the previous scan got to the end. This was broken by refill_full_stripes(), which updates last_scanned so that refill_dirty was never triggering the searched_from_start path. But if we change refill_dirty() to always scan the entire disk if necessary, regardless of what last_scanned was, the code gets cleaner and we fix that bug too. Signed-off-by: Kent Overstreet Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: prevent crash on changing writeback_running

2016-02-10T03:56:17+00:00

[ Upstream commit 8d16ce540c94c9d366eb36fc91b7154d92d6397b ] Added a safeguard in the shutdown case. At least while not being attached it is also possible to trigger a kernel bug by writing into writeback_running. This change adds the same check before trying to wake up the thread for that case. Signed-off-by: Stefan Bader Cc: Kent Overstreet Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: allows use of register in udev to avoid "device_busy" error.

2016-02-10T03:56:17+00:00

[ Upstream commit d7076f21629f8f329bca4a44dc408d94670f49e2 ] 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 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 Cc: Kent Overstreet Cc: Eric Wheeler Cc: Gabriel de Perthuis Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: unregister reboot notifier if bcache fails to unregister device

2016-02-10T03:56:16+00:00

[ Upstream commit 2ecf0cdb2b437402110ab57546e02abfa68a716b ] 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 Tested-by: Joshua Schmid Tested-by: Eric Wheeler Cc: Kent Overstreet Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: fix a leak in bch_cached_dev_run()

2016-02-10T03:56:16+00:00

[ Upstream commit 4d4d8573a8451acc9f01cbea24b7e55f04a252fe ] Signed-off-by: Al Viro Tested-by: Joshua Schmid Tested-by: Eric Wheeler Cc: Kent Overstreet Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin