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-rw-r--r--Documentation/filesystems/ext3.txt61
1 files changed, 32 insertions, 29 deletions
diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt
index 570f9bd9be2..7ed0d17d672 100644
--- a/Documentation/filesystems/ext3.txt
+++ b/Documentation/filesystems/ext3.txt
@@ -26,14 +26,15 @@ journal=inum When a journal already exists, this option is ignored.
Otherwise, it specifies the number of the inode which
will represent the ext3 file system's journal file.
+journal_path=path
journal_dev=devnum When the external journal device's major/minor numbers
- have changed, this option allows the user to specify
+ have changed, these options allow the user to specify
the new journal location. The journal device is
- identified through its new major/minor numbers encoded
- in devnum.
+ identified through either its new major/minor numbers
+ encoded in devnum, or via a path to the device.
-noload Don't load the journal on mounting. Note that this forces
- mount of inconsistent filesystem, which can lead to
+norecovery Don't load the journal on mounting. Note that this forces
+noload mount of inconsistent filesystem, which can lead to
various problems.
data=journal All data are committed into the journal prior to being
@@ -59,16 +60,19 @@ 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.
-
-orlov (*) This enables the new Orlov block allocator. It is
- enabled by default.
-
-oldalloc This disables the Orlov block allocator and enables
- the old block allocator. Orlov should have better
- performance - we'd like to get some feedback if it's
- the contrary for you.
+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.
user_xattr Enables Extended User Attributes. Additionally, you
need to have extended attribute support enabled in the
@@ -123,19 +127,18 @@ resuid=n The user ID which may use the reserved blocks.
sb=n Use alternate superblock at this location.
-quota
-noquota
-grpquota
-usrquota
-
-bh (*) ext3 associates buffer heads to data pages to
-nobh (a) cache disk block mapping information
- (b) link pages into transaction to provide
- ordering guarantees.
- "bh" option forces use of buffer heads.
- "nobh" option tries to avoid associating buffer
- heads (supported only for "writeback" mode).
+quota These options are ignored by the filesystem. They
+noquota are used only by quota tools to recognize volumes
+grpquota where quota should be turned on. See documentation
+usrquota in the quota-tools package for more details
+ (http://sourceforge.net/projects/linuxquota).
+jqfmt=<quota type> These options tell filesystem details about quota
+usrjquota=<file> so that quota information can be properly updated
+grpjquota=<file> during journal replay. They replace the above
+ quota options. See documentation in the quota-tools
+ package for more details
+ (http://sourceforge.net/projects/linuxquota).
Specification
=============
@@ -208,5 +211,5 @@ kernel source: <file:fs/ext3/>
programs: http://e2fsprogs.sourceforge.net/
http://ext2resize.sourceforge.net
-useful links: http://www.ibm.com/developerworks/library/l-fs7.html
- http://www.ibm.com/developerworks/library/l-fs8.html
+useful links: http://www.ibm.com/developerworks/library/l-fs7/index.html
+ http://www.ibm.com/developerworks/library/l-fs8/index.html