• Dan Williams's avatar
    scsi, block: fix duplicate bdi name registration crashes · 0dba1314
    Dan Williams authored
    Warnings of the following form occur because scsi reuses a devt number
    while the block layer still has it referenced as the name of the bdi
    [1]:
    
     WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80
     sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192'
     [..]
     Call Trace:
      dump_stack+0x86/0xc3
      __warn+0xcb/0xf0
      warn_slowpath_fmt+0x5f/0x80
      ? kernfs_path_from_node+0x4f/0x60
      sysfs_warn_dup+0x62/0x80
      sysfs_create_dir_ns+0x77/0x90
      kobject_add_internal+0xb2/0x350
      kobject_add+0x75/0xd0
      device_add+0x15a/0x650
      device_create_groups_vargs+0xe0/0xf0
      device_create_vargs+0x1c/0x20
      bdi_register+0x90/0x240
      ? lockdep_init_map+0x57/0x200
      bdi_register_owner+0x36/0x60
      device_add_disk+0x1bb/0x4e0
      ? __pm_runtime_use_autosuspend+0x5c/0x70
      sd_probe_async+0x10d/0x1c0
      async_run_entry_fn+0x39/0x170
    
    This is a brute-force fix to pass the devt release information from
    sd_probe() to the locations where we register the bdi,
    device_add_disk(), and unregister the bdi, blk_cleanup_queue().
    
    Thanks to Omar for the quick reproducer script [2]. This patch survives
    where an unmodified kernel fails in a few seconds.
    
    [1]: https://marc.info/?l=linux-scsi&m=147116857810716&w=4
    [2]: http://marc.info/?l=linux-block&m=148554717109098&w=2
    
    Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
    Cc: Bart Van Assche <bart.vanassche@sandisk.com>
    Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
    Cc: Jan Kara <jack@suse.cz>
    Reported-by: default avatarOmar Sandoval <osandov@osandov.com>
    Tested-by: default avatarOmar Sandoval <osandov@fb.com>
    Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Reviewed-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
    0dba1314
sd.c 91.1 KB