• Munehisa Kamata's avatar
    nbd: replace kill_bdev() with __invalidate_device() again · 2b5c8f00
    Munehisa Kamata authored
    Commit abbbdf12 ("replace kill_bdev() with __invalidate_device()")
    once did this, but 29eaadc0 ("nbd: stop using the bdev everywhere")
    resurrected kill_bdev() and it has been there since then. So buffer_head
    mappings still get killed on a server disconnection, and we can still
    hit the BUG_ON on a filesystem on the top of the nbd device.
    
      EXT4-fs (nbd0): mounted filesystem with ordered data mode. Opts: (null)
      block nbd0: Receive control failed (result -32)
      block nbd0: shutting down sockets
      print_req_error: I/O error, dev nbd0, sector 66264 flags 3000
      EXT4-fs warning (device nbd0): htree_dirblock_to_tree:979: inode #2: lblock 0: comm ls: error -5 reading directory block
      print_req_error: I/O error, dev nbd0, sector 2264 flags 3000
      EXT4-fs error (device nbd0): __ext4_get_inode_loc:4690: inode #2: block 283: comm ls: unable to read itable block
      EXT4-fs error (device nbd0) in ext4_reserve_inode_write:5894: IO failure
      ------------[ cut here ]------------
      kernel BUG at fs/buffer.c:3057!
      invalid opcode: 0000 [#1] SMP PTI
      CPU: 7 PID: 40045 Comm: jbd2/nbd0-8 Not tainted 5.1.0-rc3+ #4
      Hardware name: Amazon EC2 m5.12xlarge/, BIOS 1.0 10/16/2017
      RIP: 0010:submit_bh_wbc+0x18b/0x190
      ...
      Call Trace:
       jbd2_write_superblock+0xf1/0x230 [jbd2]
       ? account_entity_enqueue+0xc5/0xf0
       jbd2_journal_update_sb_log_tail+0x94/0xe0 [jbd2]
       jbd2_journal_commit_transaction+0x12f/0x1d20 [jbd2]
       ? __switch_to_asm+0x40/0x70
       ...
       ? lock_timer_base+0x67/0x80
       kjournald2+0x121/0x360 [jbd2]
       ? remove_wait_queue+0x60/0x60
       kthread+0xf8/0x130
       ? commit_timeout+0x10/0x10 [jbd2]
       ? kthread_bind+0x10/0x10
       ret_from_fork+0x35/0x40
    
    With __invalidate_device(), I no longer hit the BUG_ON with sync or
    unmount on the disconnected device.
    
    Fixes: 29eaadc0 ("nbd: stop using the bdev everywhere")
    Cc: linux-block@vger.kernel.org
    Cc: Ratna Manoj Bolla <manoj.br@gmail.com>
    Cc: nbd@other.debian.org
    Cc: stable@vger.kernel.org
    Cc: David Woodhouse <dwmw@amazon.com>
    Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
    Signed-off-by: default avatarMunehisa Kamata <kamatam@amazon.com>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
    2b5c8f00
nbd.c 57.4 KB