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Tools such as filefrag therefore cannot determine the correct swap file offset for use as resume_offset. Document the correct btrfs-progs command to use instead. Signed-off-by: Arun Rao Balappa --- Documentation/power/swsusp-and-swap-files.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/power/swsusp-and-swap-files.rst b/Documentation/power/swsusp-and-swap-files.rst index a33a2919d..44ffe02b3 100644 --- a/Documentation/power/swsusp-and-swap-files.rst +++ b/Documentation/power/swsusp-and-swap-files.rst @@ -35,6 +35,14 @@ FIBMAP ioctl and determine the location of the file's swap header, as the offset, in units, from the beginning of the partition which holds the swap file. +.. note:: + + On Btrfs, the FIBMAP ioctl does not return physical block addresses, so + tools such as ``filefrag`` cannot be used to determine the correct offset. + On Btrfs, use btrfs-progs instead:: + + btrfs inspect-internal map-swapfile -r + 3) Add the following parameters to the kernel command line:: resume= resume_offset= -- 2.53.0