The description of 'commit' mount option dates back to ext3 times. Update the description to match current meaning for ext4. Reported-by: Paul Richards <paul.richards@xxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> --- Documentation/admin-guide/ext4.rst | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index 059ddcbe769d..8d292f5aaea3 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -181,14 +181,17 @@ When mounting an ext4 filesystem, the following option are accepted: system after its metadata has been committed to the journal. commit=nrsec (*) - Ext4 can be told to sync all its data and metadata every 'nrsec' - seconds. The default value is 5 seconds. This means that if you lose - your power, you will lose as much as the latest 5 seconds of work (your - filesystem will not be damaged though, thanks to the journaling). This - default value (or any low value) will hurt performance, but it's good - for data-safety. Setting it to 0 will have the same effect as leaving - it at the default (5 seconds). Setting it to very large values will - improve performance. + This setting limits the maximum age of the running transaction to + 'nrsec' seconds. The default value is 5 seconds. This means that if + you lose your power, you will lose as much as the latest 5 seconds of + metadata changes (your filesystem will not be damaged though, thanks + to the journaling). This default value (or any low value) will hurt + performance, but it's good for data-safety. Setting it to 0 will have + the same effect as leaving it at the default (5 seconds). Setting it + to very large values will improve performance. Note that due to + delayed allocation even older data can be lost on power failure since + writeback of those data begins only after time set in + /proc/sys/vm/dirty_expire_centisecs. barrier=<0|1(*)>, barrier(*), nobarrier This enables/disables the use of write barriers in the jbd code. -- 2.16.4