Re: [RFC] ext3 documentation (lack of)

From: Diego Calleja
Date: Wed Aug 18 2004 - 11:53:31 EST


El Wed, 18 Aug 2004 14:24:43 +0200 (CEST) Janusz Dziemidowicz <rraptorr@xxxxxxxxx> escribió:

> AFAIK
> user_xattr - turns on POSIX Extended attributes
> nouser_xattr - obvious
> acl - turns on ACL (Access Control Lists)
> noacl - obvious

Thanks. I've recollected those, explained it a bit (except the barrier bits,
I don't really mean what barriers are), and updated ext2 documentation with
some of them, and deleted a small comentary about ext3 not being available.

unchanged:
--- stable/Documentation/filesystems/ext2.txt-document 2004-08-18 18:17:28.000000000 +0200
+++ stable/Documentation/filesystems/ext2.txt 2004-08-18 18:15:45.000000000 +0200
@@ -17,6 +17,33 @@
bsddf (*) Makes `df' act like BSD.
minixdf Makes `df' act like Minix.

+barrier=1 This enables/disables barriers. barrier=0 disables it,
+ barrier=1 enables it.
+
+orlov (*) This enables the new Orlov block allocator. It's
+ 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.
+
+user_xattr (*) Enables POSIX Extended Attributes. It's enabled by
+ default, however you need to confifure its support
+ (CONFIG_EXT2_FS_XATTR). This is neccesary if you want
+ to use POSIX Acces Control Lists support. You can visit
+ http://acl.bestbits.at to know more about POSIX Extended
+ attributes.
+
+nouser_xattr Disables POSIX Extended Attributes.
+
+acl (*) Enables POSIX Access Control Lists support. This is
+ enabled by default, however you need to configure
+ its support (CONFIG_EXT2_FS_POSIX_ACL). If you want
+ to know more about ACLs visit http://acl.bestbits.at
+
+noacl This option disables POSIX Access Control List support.
+
check=none, nocheck (*) Don't do extra checking of bitmaps on mount
(check=normal and check=strict options removed)

@@ -336,9 +363,8 @@
the time of the crash, then there is no guarantee of consistency for
the blocks in that transaction so they are discarded (which means any
filesystem changes they represent are also lost).
-
-The ext3 code is currently (Apr 2001) available for 2.2 kernels only,
-and not yet available for 2.4 kernels.
+Check Documentation/filesystems/ext3.txt if you want to read more about
+ext3 and journaling.

References
==========
@@ -349,8 +375,6 @@
Journaling (ext3) ftp://ftp.uk.linux.org/pub/linux/sct/fs/jfs/
Hashed Directories http://kernelnewbies.org/~phillips/htree/
Filesystem Resizing http://ext2resize.sourceforge.net/
-Extended Attributes &
-Access Control Lists http://acl.bestbits.at/
Compression (*) http://www.netspace.net.au/~reiter/e2compr/

Implementations for:
only in patch2:
unchanged:
--- stable/Documentation/filesystems/ext3.txt-document 2004-08-18 01:55:48.000000000 +0200
+++ stable/Documentation/filesystems/ext3.txt 2004-08-18 18:15:15.000000000 +0200
@@ -22,6 +22,63 @@
the inode which will represent the ext3 file
system's journal file.

+noload Don't load the journal on mounting.
+
+data=journal All data are committed into the journal prior
+ to being written into the main file system.
+
+data=ordered (*) All data are forced directly out to the main file
+ system prior to its metadata being committed to
+ the journal.
+
+data=writeback Data ordering is not preserved, data may be
+ written into the main file system after its
+ metadata has been committed to the journal.
+
+commit=nrsec (*) Ext3 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, the latest 5 seconds of work (your filesystem
+ will not be damaged though, thanks to 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 than leaving the default 5 sec.
+ 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's 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.
+
+user_xattr (*) Enables POSIX Extended Attributes. It's enabled by
+ default, however you need to confifure its support
+ (CONFIG_EXT3_FS_XATTR). This is neccesary if you want
+ to use POSIX Acces Control Lists support. You can visit
+ http://acl.bestbits.at to know more about POSIX Extended
+ attributes.
+
+nouser_xattr Disables POSIX Extended Attributes.
+
+acl (*) Enables POSIX Access Control Lists support. This is
+ enabled by default, however you need to configure
+ its support (CONFIG_EXT3_FS_POSIX_ACL). If you want
+ to know more about ACLs visit http://acl.bestbits.at
+
+noacl This option disables POSIX Access Control List support.
+
+reservation
+
+noreservation
+
+resize=
+
bsddf (*) Make 'df' act like BSD.
minixdf Make 'df' act like Minix.

@@ -30,8 +87,6 @@

debug Extra debugging information is sent to syslog.

-noload Don't load the journal on mounting.
-
errors=remount-ro(*) Remount the filesystem read-only on an error.
errors=continue Keep going on a filesystem error.
errors=panic Panic and halt the machine if an error occurs.
@@ -48,17 +103,6 @@

sb=n Use alternate superblock at this location.

-data=journal All data are committed into the journal prior
- to being written into the main file system.
-
-data=ordered (*) All data are forced directly out to the main file
- system prior to its metadata being committed to
- the journal.
-
-data=writeback Data ordering is not preserved, data may be
- written into the main file system after its
- metadata has been committed to the journal.
-
quota Quota options are currently silently ignored.
noquota (see fs/ext3/super.c, line 594)
grpquota
@@ -114,7 +158,7 @@
-------------

Ext2 partitions can be easily convert to ext3, with `tune2fs -j <dev>`.
- Ext3 is fully compatible with Ext2. Ext3 partitions can easily be
+Ext3 is fully compatible with Ext2. Ext3 partitions can easily be
mounted as Ext2.

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