[PATCH] ext2 docs

[PATCH] ext2 docs

[Andries Brouwer]

Below an update of ext2.txt.
Removed barrier - it is not an ext2 option.
Corrected the distinction between kernel-selected defaults
and values read from the filesystem.
Fixed some typos. Shortened line length to 80.

Andries

diff -uprN -X /linux/dontdiff a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt
--- a/Documentation/filesystems/ext2.txt	2004-10-30 21:43:59.000000000 +0200
+++ b/Documentation/filesystems/ext2.txt	2004-11-08 14:41:22.000000000 +0100
@@ -11,57 +11,53 @@ for NetBSD, FreeBSD, the GNU HURD, Windo
 Options
 =======
 
-When mounting an ext2 filesystem, the following options are accepted.
-Defaults are marked with (*).
+Most defaults are determined by the filesystem superblock, and can be
+set using tune2fs(8). Kernel-determined defaults are indicated by (*).
 
 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				Check block and inode bitmaps at mount time
+				(requires CONFIG_EXT2_CHECK).
 check=none, nocheck	(*)	Don't do extra checking of bitmaps on mount
 				(check=normal and check=strict options removed)
 
 debug				Extra debugging information is sent to the
 				kernel syslog.  Useful for developers.
 
-errors=continue		(*)	Keep going on a filesystem error.
+errors=continue			Keep going on a filesystem error.
 errors=remount-ro		Remount the filesystem read-only on an error.
 errors=panic			Panic and halt the machine if an error occurs.
 
 grpid, bsdgroups		Give objects the same group ID as their parent.
-nogrpid, sysvgroups	(*)	New objects have the group ID of their creator.
+nogrpid, sysvgroups		New objects have the group ID of their creator.
+
+nouid32				Use 16-bit UIDs and GIDs.
+
+oldalloc			Enable the old block allocator. Orlov should
+				have better performance, we'd like to get some
+				feedback if it's the contrary for you.
+orlov			(*)	Use the Orlov block allocator.
+				(See http://lwn.net/Articles/14633/ and
+				http://lwn.net/Articles/14446/.)
 
 resuid=n			The user ID which may use the reserved blocks.
-resgid=n			The group ID which may use the reserved blocks. 
+resgid=n			The group ID which may use the reserved blocks.
 
 sb=n				Use alternate superblock at this location.
 
+user_xattr			Enable "user." POSIX Extended Attributes
+				(requires CONFIG_EXT2_FS_XATTR).
+				See also http://acl.bestbits.at
+nouser_xattr			Don't support "user." extended attributes.
+
+acl				Enable POSIX Access Control Lists support
+				(requires CONFIG_EXT2_FS_POSIX_ACL).
+				See also http://acl.bestbits.at
+noacl				Don't support POSIX ACLs.
+
+nobh				Do not attach buffer_heads to file pagecache.
+
 grpquota,noquota,quota,usrquota	Quota options are silently ignored by ext2.
 
 

Re: [PATCH] ext2 docs

[Marcelo Tosatti]

Hi Andries,

On Mon, Nov 08, 2004 at 02:55:42PM +0100, Andries Brouwer wrote:
> Below an update of ext2.txt.
> Removed barrier - it is not an ext2 option.
> Corrected the distinction between kernel-selected defaults
> and values read from the filesystem.
> Fixed some typos. Shortened line length to 80.
> 
> Andries
> 
> diff -uprN -X /linux/dontdiff a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt
> --- a/Documentation/filesystems/ext2.txt	2004-10-30 21:43:59.000000000 +0200
> +++ b/Documentation/filesystems/ext2.txt	2004-11-08 14:41:22.000000000 +0100
> @@ -11,57 +11,53 @@ for NetBSD, FreeBSD, the GNU HURD, Windo
>  Options
>  =======
>  
> -When mounting an ext2 filesystem, the following options are accepted.
> -Defaults are marked with (*).
> +Most defaults are determined by the filesystem superblock, and can be
> +set using tune2fs(8). Kernel-determined defaults are indicated by (*).
>  
>  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				Check block and inode bitmaps at mount time
> +				(requires CONFIG_EXT2_CHECK).
>  check=none, nocheck	(*)	Don't do extra checking of bitmaps on mount
>  				(check=normal and check=strict options removed)
>  
>  debug				Extra debugging information is sent to the
>  				kernel syslog.  Useful for developers.
>  
> -errors=continue		(*)	Keep going on a filesystem error.
> +errors=continue			Keep going on a filesystem error.
>  errors=remount-ro		Remount the filesystem read-only on an error.
>  errors=panic			Panic and halt the machine if an error occurs.
>  
>  grpid, bsdgroups		Give objects the same group ID as their parent.
> -nogrpid, sysvgroups	(*)	New objects have the group ID of their creator.
> +nogrpid, sysvgroups		New objects have the group ID of their creator.
> +
> +nouid32				Use 16-bit UIDs and GIDs.
> +
> +oldalloc			Enable the old block allocator. Orlov should
> +				have better performance, we'd like to get some
> +				feedback if it's the contrary for you.
> +orlov			(*)	Use the Orlov block allocator.
> +				(See http://lwn.net/Articles/14633/ and
> +				http://lwn.net/Articles/14446/.)

Did you really mean to use the second link "14446" ? 

It points to a patch from Ted fixing a memory leak into the Orlov allocator,
which is not very useful. 

You probably meant http://lwn.net/Articles/14447/, which contains the full
Orlov ext3 patch?

Re: [PATCH] ext2 docs

[Marcelo Tosatti]

On Mon, Nov 08, 2004 at 10:07:51PM +0100, Andries Brouwer wrote:
> On Mon, Nov 08, 2004 at 03:30:07PM -0200, Marcelo Tosatti wrote:
> 
> > > +oldalloc			Enable the old block allocator. Orlov should
> > > +				have better performance, we'd like to get some
> > > +				feedback if it's the contrary for you.
> > > +orlov			(*)	Use the Orlov block allocator.
> > > +				(See http://lwn.net/Articles/14633/ and
> > > +				http://lwn.net/Articles/14446/.)
> > 
> > Did you really mean to use the second link "14446" ? 
> > 
> > It points to a patch from Ted fixing a memory leak into the Orlov allocator,
> > which is not very useful. 
> > 
> > You probably meant http://lwn.net/Articles/14447/, which contains the full
> > Orlov ext3 patch?
> 
> No, not at all. I am a collector of information, and 14447 has nothing
> at all, but 14446 documents the EXT2_TOPDIR_FL flag that is undocumented
> in the kernel source. The flag can be set using chattr +T.

OK dokie.

PS: Maybe the flag should be documented? Its pretty important one.

Re: [PATCH] ext2 docs

[Andries Brouwer]

On Mon, Nov 08, 2004 at 03:30:07PM -0200, Marcelo Tosatti wrote:

> > +oldalloc			Enable the old block allocator. Orlov should
> > +				have better performance, we'd like to get some
> > +				feedback if it's the contrary for you.
> > +orlov			(*)	Use the Orlov block allocator.
> > +				(See http://lwn.net/Articles/14633/ and
> > +				http://lwn.net/Articles/14446/.)
> 
> Did you really mean to use the second link "14446" ? 
> 
> It points to a patch from Ted fixing a memory leak into the Orlov allocator,
> which is not very useful. 
> 
> You probably meant http://lwn.net/Articles/14447/, which contains the full
> Orlov ext3 patch?

No, not at all. I am a collector of information, and 14447 has nothing
at all, but 14446 documents the EXT2_TOPDIR_FL flag that is undocumented
in the kernel source. The flag can be set using chattr +T.

Andries

Re: [PATCH] ext2 docs

[Andries Brouwer]

On Mon, Nov 08, 2004 at 06:07:03PM -0200, Marcelo Tosatti wrote:

> > 14446 documents the EXT2_TOPDIR_FL flag that is undocumented
> > in the kernel source. The flag can be set using chattr +T.
> 
> PS: Maybe the flag should be documented? Its pretty important one.

Yes. Our conversation here provides for some documentation
since Google will be able to retrieve it. I added a line
in the table under "Attributes" in my old ext2 notes at
http://www.win.tue.nl/~aeb/linux/lk/lk-7.html#ss7.2
There is chattr(1). Someone searching will find something.

Andries