Commit c1f6925e1091("mm: put readahead pages in cache earlier") requires fs to implement readahead callback. Otherwise there will be a performance regression. Commit 9eec1d897139("squashfs: provide backing_dev_info in order to disable read-ahead") mitigates the performance drop issue for squashfs by closing readahead for it. This series implements readahead callback for squashfs. The previous discussion are in [1] and [2]. [1] https://lore.kernel.org/all/CAJMQK-g9G6KQmH-V=BRGX0swZji9Wxe_2c7ht-MMAapdFy2pXw@xxxxxxxxxxxxxx/T/ [2] https://lore.kernel.org/linux-mm/Yn5Yij9pRPCzDozt@xxxxxxxxxxxxxxxxxxxx/t/#m4af4473b94f98a4996cb11756b633a07e5e059d1 Hsin-Yi Wang (2): Revert "squashfs: provide backing_dev_info in order to disable read-ahead" squashfs: implement readahead fs/squashfs/file.c | 77 +++++++++++++++++++++++++++++++++++++++++++++ fs/squashfs/super.c | 33 ------------------- 2 files changed, 77 insertions(+), 33 deletions(-) -- 2.36.0.550.gb090851708-goog