1. 17 Mar, 2018 1 commit
  2. 16 Mar, 2018 2 commits
    • Joseph Qi's avatar
      blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir() · 4c699480
      Joseph Qi authored
      We've triggered a WARNING in blk_throtl_bio() when throttling writeback
      io, which complains blkg->refcnt is already 0 when calling blkg_get(),
      and then kernel crashes with invalid page request.
      After investigating this issue, we've found it is caused by a race
      between blkcg_bio_issue_check() and cgroup_rmdir(), which is described
      below:
      
      writeback kworker               cgroup_rmdir
                                        cgroup_destroy_locked
                                          kill_css
                                            css_killed_ref_fn
                                              css_killed_work_fn
                                                offline_css
                                                  blkcg_css_offline
        blkcg_bio_issue_check
          rcu_read_lock
          blkg_lookup
                                                    spin_trylock(q->queue_lock)
                                                    blkg_destroy
                                                    spin_unlock(q->queue_lock)
          blk_throtl_bio
          spin_lock_irq(q->queue_lock)
          ...
          spin_unlock_irq(q->queue_lock)
        rcu_read_unlock
      
      Since rcu can only prevent blkg from releasing when it is being used,
      the blkg->refcnt can be decreased to 0 during blkg_destroy() and schedule
      blkg release.
      Then trying to blkg_get() in blk_throtl_bio() will complains the WARNING.
      And then the corresponding blkg_put() will schedule blkg release again,
      which result in double free.
      This race is introduced by commit ae118896 ("blkcg: consolidate blkg
      creation in blkcg_bio_issue_check()"). Before this commit, it will
      lookup first and then try to lookup/create again with queue_lock. Since
      revive this logic is a bit drastic, so fix it by only offlining pd during
      blkcg_css_offline(), and move the rest destruction (especially
      blkg_put()) into blkcg_css_free(), which should be the right way as
      discussed.
      
      Fixes: ae118896 ("blkcg: consolidate blkg creation in blkcg_bio_issue_check()")
      Reported-by: default avatarJiufei Xue <jiufei.xue@linux.alibaba.com>
      Signed-off-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      4c699480
    • Jonas Rabenstein's avatar
      block: sed-opal: fix u64 short atom length · 5f990d31
      Jonas Rabenstein authored
      The length must be given as bytes and not as 4 bit tuples.
      Reviewed-by: default avatarScott Bauer <scott.bauer@intel.com>
      Signed-off-by: default avatarJonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      5f990d31
  3. 13 Mar, 2018 3 commits
  4. 12 Mar, 2018 2 commits
  5. 09 Mar, 2018 5 commits
    • Ross Zwisler's avatar
      MAINTAINERS: add coverage for drivers/block · fc9de9a5
      Ross Zwisler authored
      To help folks like me that use scripts/get_maintainer.pl.
      Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      fc9de9a5
    • Bart Van Assche's avatar
      block: Suppress kernel-doc warnings triggered by blk-zoned.c · 56c4bddb
      Bart Van Assche authored
      Avoid that building with W=1 causes the kernel-doc tool to complain
      about undocumented function arguments for the blk-zoned.c source file.
      Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Damien Le Moal <damien.lemoal@wdc.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      56c4bddb
    • Maurizio Lombardi's avatar
      cdrom: do not call check_disk_change() inside cdrom_open() · 2bbea6e1
      Maurizio Lombardi authored
      when mounting an ISO filesystem sometimes (very rarely)
      the system hangs because of a race condition between two tasks.
      
      PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
       #0 [ffff880078447ae0] __schedule at ffffffff8168d605
       #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
       #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
       #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
       #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
       #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
       #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
       #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
       #8 [ffff880078447da8] mount_bdev at ffffffff81202570
       #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
      #10 [ffff880078447e28] mount_fs at ffffffff81202d09
      #11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
      #12 [ffff880078447ea8] do_mount at ffffffff81220fee
      #13 [ffff880078447f28] sys_mount at ffffffff812218d6
      #14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
          RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
          RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
          RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
          RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
          R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
          R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
          ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b
      
      This task was trying to mount the cdrom.  It allocated and configured a
      super_block struct and owned the write-lock for the super_block->s_umount
      rwsem. While exclusively owning the s_umount lock, it called
      sr_block_ioctl and waited to acquire the global sr_mutex lock.
      
      PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
       #0 [ffff880078417898] __schedule at ffffffff8168d605
       #1 [ffff880078417900] schedule at ffffffff8168dc59
       #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
       #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
       #4 [ffff8800784179d0] down_read at ffffffff8168cde0
       #5 [ffff8800784179e8] get_super at ffffffff81201cc7
       #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
       #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
       #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
       #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
      #10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
      #11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
      #12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
      #13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
      #14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
      #15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
      #16 [ffff880078417d00] do_last at ffffffff8120d53d
      #17 [ffff880078417db0] path_openat at ffffffff8120e6b2
      #18 [ffff880078417e48] do_filp_open at ffffffff8121082b
      #19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
      #20 [ffff880078417f70] sys_open at ffffffff811fde4e
      #21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
          RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
          RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
          RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
          RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
          R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
          R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
          ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b
      
      This task tried to open the cdrom device, the sr_block_open function
      acquired the global sr_mutex lock. The call to check_disk_change()
      then saw an event flag indicating a possible media change and tried
      to flush any cached data for the device.
      As part of the flush, it tried to acquire the super_block->s_umount
      lock associated with the cdrom device.
      This was the same super_block as created and locked by the previous task.
      
      The first task acquires the s_umount lock and then the sr_mutex_lock;
      the second task acquires the sr_mutex_lock and then the s_umount lock.
      
      This patch fixes the issue by moving check_disk_change() out of
      cdrom_open() and let the caller take care of it.
      Signed-off-by: default avatarMaurizio Lombardi <mlombard@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      2bbea6e1
    • Randy Dunlap's avatar
      Documentation/cdrom: fix German sharp s in LaTex · da5ff37c
      Randy Dunlap authored
      Apparently the LaTex abbreviation for the German "sharp s" (ß)
      (Unicode U+00DF) has changed from {\sz} to {\ss}.  With {\sz},
      I get this error at line 1016 (line number after another patch):
      
      ! Undefined control sequence.
      l.1016 ...nel~2.0.  Further thanks to Heiko Ei{\sz
                                                        }feldt,
      
      This is fixed by changing the {\sz} to {\ss}.
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      da5ff37c
    • Randy Dunlap's avatar
      Documentation/cdrom: update cdrom-standard.tex for kernel changes · 0a703c1f
      Randy Dunlap authored
      Documentation updates for Documentation/cdrom/cdrom-standard.tex:
      
      cdrom_device_ops:
      - add check_events() and generic_packet()
      
      cdrom_device_info:
      - add one 'const' modifier
      - correct some field descriptions
      - add some missing fields
      - drop 'kdev_t dev;' field
      
      Also drop <n_discs> sentence from documentation because it is not
      referenced anywhere in the kernel header or C files.
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      0a703c1f
  6. 08 Mar, 2018 11 commits
  7. 07 Mar, 2018 1 commit
  8. 06 Mar, 2018 1 commit
  9. 01 Mar, 2018 2 commits
    • Arnd Bergmann's avatar
      staging: rts5208: rename SG_END macro · b5d013bc
      Arnd Bergmann authored
      A change to the generic scatterlist code caused a conflict with
      the rtsx card reader driver:
      
      In file included from drivers/staging/rts5208/rtsx.h:180,
                       from drivers/staging/rts5208/rtsx.c:28:
      drivers/staging/rts5208/rtsx_chip.h:343: error: "SG_END" redefined [-Werror]
      
      This changes one instance of the driver to prefix SG_END and
      related constants.
      
      Fixes: 723fbf56 ("lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings")
      Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
      Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      b5d013bc
    • Arnd Bergmann's avatar
      misc: rtsx: rename SG_END macro · f16ee7c7
      Arnd Bergmann authored
      A change to the generic scatterlist code caused a conflict with
      the rtsx card reader driver:
      
      In file included from drivers/misc/cardreader/rtsx_pcr.c:32:
      include/linux/rtsx_pci.h:40: error: "SG_END" redefined [-Werror]
      
      This changes one instance of the driver to prefix SG_END and
      related constants.
      
      Fixes: 723fbf56 ("lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings")
      Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      f16ee7c7
  10. 28 Feb, 2018 12 commits