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| author | Eric Sandeen <sandeen@redhat.com> | 2010-04-30 11:09:34 -0500 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2010-05-21 19:30:41 +0200 |
| commit | 0636c73ee7b129f77f577aaaefc8dde057be6d18 (patch) | |
| tree | 6cf9dba3119f9ec6fa346572c8a5bd693828bf45 /Documentation/filesystems | |
| parent | dde9588853b1bde542eab247f8838c472806688f (diff) | |
| download | lwn-0636c73ee7b129f77f577aaaefc8dde057be6d18.tar.gz lwn-0636c73ee7b129f77f577aaaefc8dde057be6d18.zip | |
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 <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/ext3.txt | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt index 867c5b50cb42..272f80d5f966 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. |