On 02/22/2017 01:20 AM, Jan Kara wrote:=0A=

On Tue 21-02-17 19:53:29, Bart Van Assche wrote:=0A=

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This change looks suspicious to me. There are drivers that create a=0A=
block layer queue but neither call device_add_disk() nor del_gendisk(),=

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quoted

e.g. drivers/scsi/st.c. Although bdi_init() will be called for the=0A=
queues created by these drivers, this patch will cause the=0A=
bdi_unregister() call to be skipped for these drivers.=0A=

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Well, the thing is that bdi_unregister() is the counterpart to=0A=
bdi_register(). Unless you call bdi_register(), which happens only in=0A=
device_add_disk() (and some filesystems which create their private bdis),=

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there's no point in calling bdi_unregister(). Counterpart to bdi_init() i=

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bdi_exit() and that gets called always once bdi reference count drops to =

0.=0A=
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That makes sense to me. Hence:=0A=
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Reviewed-by: Bart Van Assche <redacted>=0A=
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