On Sun, Jan 29, 2017 at 11:22 PM, Omar Sandoval <osan...@osandov.com> wrote: > On Mon, Jan 30, 2017 at 08:05:52AM +0100, Hannes Reinecke wrote: >> On 01/29/2017 05:58 AM, Dan Williams wrote: >> > 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.bottom...@hansenpartnership.com> >> > Cc: Bart Van Assche <bart.vanass...@sandisk.com> >> > Cc: "Martin K. Petersen" <martin.peter...@oracle.com> >> > Cc: Christoph Hellwig <h...@lst.de> >> > Cc: Jens Axboe <ax...@kernel.dk> >> > Reported-by: Omar Sandoval <osan...@osandov.com> >> > Signed-off-by: Dan Williams <dan.j.willi...@intel.com> >> > --- >> > block/blk-core.c | 1 + >> > block/genhd.c | 7 +++++++ >> > drivers/scsi/sd.c | 41 +++++++++++++++++++++++++++++++++-------- >> > include/linux/blkdev.h | 1 + >> > include/linux/genhd.h | 17 +++++++++++++++++ >> > 5 files changed, 59 insertions(+), 8 deletions(-) >> > >> Please check the patchset from Jan Kara (cf 'BDI lifetime fix' on >> linux-block), which attempts to solve the same problem. > > Hi, Hannes, > > It's not the same problem. Jan's series fixes a bdi vs. inode lifetime > issue, this patch is for a bdi vs devt lifetime issue. Jan's series > doesn't fix the crashes caused by my reproducer script.
Correct. In fact I was running Jan's patches in my baseline kernel that fails almost immediately.
