2004-11-08 13:56:05

by Andries E. Brouwer

[permalink] [raw]
Subject: [PATCH] ext2 docs

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.



2004-11-08 20:51:04

by Marcelo Tosatti

[permalink] [raw]
Subject: Re: [PATCH] ext2 docs


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?

2004-11-08 21:09:55

by Andries Brouwer

[permalink] [raw]
Subject: Re: [PATCH] ext2 docs

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

2004-11-08 23:27:59

by Marcelo Tosatti

[permalink] [raw]
Subject: Re: [PATCH] ext2 docs

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.

2004-11-08 23:47:29

by Andries Brouwer

[permalink] [raw]
Subject: Re: [PATCH] ext2 docs

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