From 0636c73ee7b129f77f577aaaefc8dde057be6d18 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Fri, 30 Apr 2010 11:09:34 -0500 Subject: ext3: make barrier options consistent with ext4 ext4 was updated to accept barrier/nobarrier mount options in addition to the older barrier=0/1. The barrier story is complex enough, we should help people by making the options the same at least, even if the defaults are different. This patch allows the barrier/nobarrier mount options for ext3, while keeping nobarrier the default. It also unconditionally displays barrier status in show_options, and prints a message at mount time if barriers are not enabled, just as ext4 does. Signed-off-by: Eric Sandeen Signed-off-by: Jan Kara --- Documentation/filesystems/ext3.txt | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'Documentation/filesystems/ext3.txt') diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt index 867c5b50cb4..272f80d5f96 100644 --- a/Documentation/filesystems/ext3.txt +++ b/Documentation/filesystems/ext3.txt @@ -59,8 +59,19 @@ commit=nrsec (*) Ext3 can be told to sync all its data and metadata Setting it to very large values will improve performance. -barrier=1 This enables/disables barriers. barrier=0 disables - it, barrier=1 enables it. +barrier=<0(*)|1> This enables/disables the use of write barriers in +barrier the jbd code. barrier=0 disables, barrier=1 enables. +nobarrier (*) This also requires an IO stack which can support + barriers, and if jbd gets an error on a barrier + write, it will disable again with a warning. + Write barriers enforce proper on-disk ordering + of journal commits, making volatile disk write caches + safe to use, at some performance penalty. If + your disks are battery-backed in one way or another, + disabling barriers may safely improve performance. + The mount options "barrier" and "nobarrier" can + also be used to enable or disable barriers, for + consistency with other ext3 mount options. orlov (*) This enables the new Orlov block allocator. It is enabled by default. -- cgit v1.2.3-70-g09d2