kernel/linux.git/drivers/md/bcache, branch v4.4.8

bcache: fix cache_set_flush() NULL pointer dereference on OOM

2016-04-12T16:08:53+00:00

commit f8b11260a445169989d01df75d35af0f56178f95 upstream. 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 Signed-off-by: Greg Kroah-Hartman

bcache: fix race of writeback thread starting before complete initialization

2016-04-12T16:08:53+00:00

commit 07cc6ef8edc47f8b4fc1e276d31127a0a5863d4d upstream. 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: cleaned up error handling around register_cache()

2016-04-12T16:08:53+00:00

commit 9b299728ed777428b3908ac72ace5f8f84b97789 upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2016-03-03T23:07:09+00:00

commit 627ccd20b4ad3ba836472468208e2ac4dfadbf03 upstream. 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: prevent crash on changing writeback_running

2016-03-03T23:07:09+00:00

commit 8d16ce540c94c9d366eb36fc91b7154d92d6397b upstream. 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

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

2016-03-03T23:07:09+00:00

commit d7076f21629f8f329bca4a44dc408d94670f49e2 upstream. 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: unregister reboot notifier if bcache fails to unregister device

2016-03-03T23:07:09+00:00

commit 2ecf0cdb2b437402110ab57546e02abfa68a716b upstream. 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: fix a leak in bch_cached_dev_run()

2016-03-03T23:07:09+00:00

commit 4d4d8573a8451acc9f01cbea24b7e55f04a252fe upstream. Signed-off-by: Al Viro Tested-by: Joshua Schmid Tested-by: Eric Wheeler Cc: Kent Overstreet Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device

2016-03-03T23:07:09+00:00

commit fecaee6f20ee122ad75402c53d8278f9bb142ddc upstream. 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] [] ? warn_slowpath_common+0x87/0xc0 [ 276.122650] [] ? warn_slowpath_fmt+0x46/0x50 [ 276.139361] [] ? sysfs_add_one+0xb8/0xd0 [ 276.156012] [] ? sysfs_do_create_link+0x12b/0x170 [ 276.172682] [] ? sysfs_create_link+0x13/0x20 [ 276.189282] [] ? bcache_device_link+0xc1/0x110 [bcache] [ 276.205993] [] ? bch_cached_dev_attach+0x478/0x4f0 [bcache] [ 276.222794] [] ? bch_cached_dev_store+0x627/0x780 [bcache] [ 276.239680] [] ? alloc_pages_current+0xaa/0x110 [ 276.256594] [] ? sysfs_write_file+0xe5/0x170 [ 276.273364] [] ? vfs_write+0xb8/0x1a0 [ 276.290133] [] ? sys_write+0x51/0x90 [ 276.306368] [] ? 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] [] ? warn_slowpath_common+0x87/0xc0 [ 276.515405] [] ? warn_slowpath_fmt+0x46/0x50 [ 276.532059] [] ? bcache_device_link+0xdf/0x110 [bcache] [ 276.548808] [] ? bch_cached_dev_attach+0x478/0x4f0 [bcache] [ 276.565569] [] ? bch_cached_dev_store+0x627/0x780 [bcache] [ 276.582418] [] ? alloc_pages_current+0xaa/0x110 [ 276.599341] [] ? sysfs_write_file+0xe5/0x170 [ 276.616142] [] ? vfs_write+0xb8/0x1a0 [ 276.632607] [] ? sys_write+0x51/0x90 [ 276.648671] [] ? 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 Tested-by: Joshua Schmid Tested-by: Eric Wheeler Cc: Kent Overstreet Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: Add a cond_resched() call to gc

2016-03-03T23:07:09+00:00

commit c5f1e5adf956e3ba82d204c7c141a75da9fa449a upstream. Signed-off-by: Takashi Iwai Tested-by: Eric Wheeler Cc: Kent Overstreet Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman