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authorLinus Torvalds <torvalds@linux-foundation.org>2008-06-07 02:30:53 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-06-07 02:30:53 +0400
commit5f0e62c3e1db9acb35b750e02cddc1fcb8cfd52b (patch)
tree2c0b507ed89a97116cc595e090ebaeb1439df865 /Documentation
parentaab2545fdd6641b76af0ae96456c4ca9d1e50dad (diff)
parent571640cad3fda6475da45d91cf86076f1f86bd9b (diff)
downloadlinux-5f0e62c3e1db9acb35b750e02cddc1fcb8cfd52b.tar.xz
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: enable barriers by default jbd2: Fix barrier fallback code to re-lock the buffer head ext4: Display the journal_async_commit mount option in /proc/mounts jbd2: If a journal checksum error is detected, propagate the error to ext4 jbd2: Fix memory leak when verifying checksums in the journal ext4: fix online resize bug ext4: Fix uninit block group initialization with FLEX_BG ext4: Fix use of uninitialized data with debug enabled.
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/filesystems/ext4.txt12
1 files changed, 10 insertions, 2 deletions
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 560f88dc7090..0c5086db8352 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -139,8 +139,16 @@ commit=nrsec (*) Ext4 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
+ the jbd code. barrier=0 disables, barrier=1 enables.
+ 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.
orlov (*) This enables the new Orlov block allocator. It is
enabled by default.