lkml.org 
[lkml]   [2021]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 13/53] mm: bdi: initialize bdi_min_ratio when bdi is unregistered
    Date
    From: Manjong Lee <mj0123.lee@samsung.com>

    commit 3c376dfafbf7a8ea0dea212d095ddd83e93280bb upstream.

    Initialize min_ratio if it is set during bdi unregistration. This can
    prevent problems that may occur a when bdi is removed without resetting
    min_ratio.

    For example.
    1) insert external sdcard
    2) set external sdcard's min_ratio 70
    3) remove external sdcard without setting min_ratio 0
    4) insert external sdcard
    5) set external sdcard's min_ratio 70 << error occur(can't set)

    Because when an sdcard is removed, the present bdi_min_ratio value will
    remain. Currently, the only way to reset bdi_min_ratio is to reboot.

    [akpm@linux-foundation.org: tweak comment and coding style]

    Link: https://lkml.kernel.org/r/20211021161942.5983-1-mj0123.lee@samsung.com
    Signed-off-by: Manjong Lee <mj0123.lee@samsung.com>
    Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Changheun Lee <nanich.lee@samsung.com>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: Christoph Hellwig <hch@infradead.org>
    Cc: Matthew Wilcox <willy@infradead.org>
    Cc: <seunghwan.hyun@samsung.com>
    Cc: <sookwan7.kim@samsung.com>
    Cc: <yt0928.kim@samsung.com>
    Cc: <junho89.kim@samsung.com>
    Cc: <jisoo2146.oh@samsung.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    mm/backing-dev.c | 7 +++++++
    1 file changed, 7 insertions(+)

    --- a/mm/backing-dev.c
    +++ b/mm/backing-dev.c
    @@ -942,6 +942,13 @@ void bdi_unregister(struct backing_dev_i
    wb_shutdown(&bdi->wb);
    cgwb_bdi_unregister(bdi);

    + /*
    + * If this BDI's min ratio has been set, use bdi_set_min_ratio() to
    + * update the global bdi_min_ratio.
    + */
    + if (bdi->min_ratio)
    + bdi_set_min_ratio(bdi, 0);
    +
    if (bdi->dev) {
    bdi_debug_unregister(bdi);
    device_unregister(bdi->dev);

    \
     
     \ /
      Last update: 2021-12-13 10:38    [W:2.371 / U:1.588 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site