1. 31 Dec, 2015 7 commits
    • Stefan Bader's avatar
      bcache: prevent crash on changing writeback_running · 8d16ce54
      Stefan Bader authored
      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: default avatarStefan Bader <stefan.bader@canonical.com>
      Cc: Kent Overstreet <kent.overstreet@gmail.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      8d16ce54
    • Gabriel de Perthuis's avatar
      bcache: allows use of register in udev to avoid "device_busy" error. · d7076f21
      Gabriel de Perthuis authored
      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: default avatarJens Axboe <axboe@fb.com>
      d7076f21
    • Zheng Liu's avatar
      bcache: unregister reboot notifier if bcache fails to unregister device · 2ecf0cdb
      Zheng Liu authored
      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: default avatarZheng Liu <wenqing.lz@taobao.com>
      Tested-by: default avatarJoshua Schmid <jschmid@suse.com>
      Tested-by: default avatarEric Wheeler <bcache@linux.ewheeler.net>
      Cc: Kent Overstreet <kmo@daterainc.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      2ecf0cdb
    • Al Viro's avatar
      bcache: fix a leak in bch_cached_dev_run() · 4d4d8573
      Al Viro authored
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Tested-by: default avatarJoshua Schmid <jschmid@suse.com>
      Tested-by: default avatarEric Wheeler <bcache@linux.ewheeler.net>
      Cc: Kent Overstreet <kmo@daterainc.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      4d4d8573
    • Zheng Liu's avatar
      bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device · fecaee6f
      Zheng Liu authored
      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: default avatarZheng Liu <wenqing.lz@taobao.com>
      Tested-by: default avatarJoshua Schmid <jschmid@suse.com>
      Tested-by: default avatarEric Wheeler <bcache@linux.ewheeler.net>
      Cc: Kent Overstreet <kmo@daterainc.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      fecaee6f
    • Kent Overstreet's avatar
      bcache: Add a cond_resched() call to gc · c5f1e5ad
      Kent Overstreet authored
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Tested-by: default avatarEric Wheeler <bcache@linux.ewheeler.net>
      Cc: Kent Overstreet <kmo@daterainc.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      c5f1e5ad
    • Zheng Liu's avatar
      bcache: fix a livelock when we cause a huge number of cache misses · 2ef9ccbf
      Zheng Liu authored
      Subject :	[PATCH v2] bcache: fix a livelock in btree lock
      Date :	Wed, 25 Feb 2015 20:32:09 +0800 (02/25/2015 04:32:09 AM)
      
      This commit tries to fix a livelock in bcache.  This livelock might
      happen when we causes a huge number of cache misses simultaneously.
      
      When we get a cache miss, bcache will execute the following path.
      
      ->cached_dev_make_request()
        ->cached_dev_read()
          ->cached_lookup()
            ->bch->btree_map_keys()
              ->btree_root()  <------------------------
                ->bch_btree_map_keys_recurse()        |
                  ->cache_lookup_fn()                 |
                    ->cached_dev_cache_miss()         |
                      ->bch_btree_insert_check_key() -|
                        [If btree->seq is not equal to seq + 1, we should return
                         EINTR and traverse btree again.]
      
      In bch_btree_insert_check_key() function we first need to check upgrade
      flag (op->lock == -1), and when this flag is true we need to release
      read btree->lock and try to take write btree->lock.  During taking and
      releasing this write lock, btree->seq will be monotone increased in
      order to prevent other threads modify this in cache miss (see btree.h:74).
      But if there are some cache misses caused by some requested, we could
      meet a livelock because btree->seq is always changed by others.  Thus no
      one can make progress.
      
      This commit will try to take write btree->lock if it encounters a race
      when we traverse btree.  Although it sacrifice the scalability but we
      can ensure that only one can modify the btree.
      Signed-off-by: default avatarZheng Liu <wenqing.lz@taobao.com>
      Tested-by: default avatarJoshua Schmid <jschmid@suse.com>
      Tested-by: default avatarEric Wheeler <bcache@linux.ewheeler.net>
      Cc: Joshua Schmid <jschmid@suse.com>
      Cc: Zhu Yanhai <zhu.yanhai@gmail.com>
      Cc: Kent Overstreet <kmo@daterainc.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      2ef9ccbf
  2. 23 Dec, 2015 1 commit
  3. 22 Dec, 2015 1 commit
    • Shraddha Barke's avatar
      block: sx8.c: Replace timeval with ktime_t · 8182503d
      Shraddha Barke authored
      32-bit systems using 'struct timeval' will break in the year 2038,
      in order to avoid that replace the code with more appropriate types.
      This patch replaces timeval with 64 bit ktime_t which is y2038 safe.
      Since st->timestamp is only interested in seconds, directly using
      time64_t here. Function ktime_get_seconds is used since it uses
      monotonic instead of real time and thus will not cause overflow.
      Signed-off-by: default avatarShraddha Barke <shraddha.6596@gmail.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      8182503d
  4. 25 Nov, 2015 31 commits