[PATCH] Doc fix: ext2 can only have 32,000 subdirs, not 32,768.

[PATCH] Doc fix: ext2 can only have 32,000 subdirs, not 32,768.

[Michael Shields]

ext2.txt says that dirs can have 32,768 subdirs, but the actual value
of EXT2_LINK_MAX is 32000.
ext3 is the same, but the doc does not mention it.  One of ext4's
features is to "fix 32000 subdirectory limit".

--- linux-2.6.29.3/Documentation/filesystems/ext2.txt.orig 2009-05-08
15:47:21.000000000 -0700
+++ linux-2.6.29.3/Documentation/filesystems/ext2.txt 2009-05-18
12:03:58.000000000 -0700
@@ -322,7 +322,7 @@ an upper limit on the block size imposed
 so 8kB blocks are only allowed on Alpha systems (and other architectures
 which support larger pages).

-There is an upper limit of 32768 subdirectories in a single directory.
+There is an upper limit of 32000 subdirectories in a single directory.

 There is a "soft" upper limit of about 10-15k files in a single directory
 with the current linear linked-list directory implementation.  This limit

Re: [PATCH] Doc fix: ext2 can only have 32,000 subdirs, not 32,768.

[Andrew Morton]

On Mon, 18 May 2009 12:13:51 -0700
Michael Shields <mshields@google.com> wrote:

> ext2.txt says that dirs can have 32,768 subdirs, but the actual value
> of EXT2_LINK_MAX is 32000.
> ext3 is the same, but the doc does not mention it. __One of ext4's
> features is to "fix 32000 subdirectory limit".
> 
> --- linux-2.6.29.3/Documentation/filesystems/ext2.txt.orig 2009-05-08
> 15:47:21.000000000 -0700
> +++ linux-2.6.29.3/Documentation/filesystems/ext2.txt 2009-05-18
> 12:03:58.000000000 -0700
> @@ -322,7 +322,7 @@ an upper limit on the block size imposed
> __so 8kB blocks are only allowed on Alpha systems (and other architectures
> __which support larger pages).
> 
> -There is an upper limit of 32768 subdirectories in a single directory.
> +There is an upper limit of 32000 subdirectories in a single directory.
> 
> __There is a "soft" upper limit of about 10-15k files in a single directory
> __with the current linear linked-list directory implementation. __This limit
> --

The patch is wordwrapped and has weird non-ascii characters in the
changelog text.  I fixed all that up.  Please fix your email client for
future patches.

Please include a Signed-off-by:, as described in
Documentation/SubmittingPatches, thanks.

Re: [PATCH] Doc fix: ext2 can only have 32,000 subdirs, not 32,768.

[Pavel Machek]

On Wed 2009-05-27 17:20:45, Andrew Morton wrote:
> On Mon, 18 May 2009 12:13:51 -0700
> Michael Shields <mshields@google.com> wrote:
> 
> > ext2.txt says that dirs can have 32,768 subdirs, but the actual value
> > of EXT2_LINK_MAX is 32000.
> > ext3 is the same, but the doc does not mention it. __One of ext4's
> > features is to "fix 32000 subdirectory limit".
> > 
> > --- linux-2.6.29.3/Documentation/filesystems/ext2.txt.orig 2009-05-08
> > 15:47:21.000000000 -0700
> > +++ linux-2.6.29.3/Documentation/filesystems/ext2.txt 2009-05-18
> > 12:03:58.000000000 -0700
> > @@ -322,7 +322,7 @@ an upper limit on the block size imposed
> > __so 8kB blocks are only allowed on Alpha systems (and other architectures
> > __which support larger pages).
> > 
> > -There is an upper limit of 32768 subdirectories in a single directory.
> > +There is an upper limit of 32000 subdirectories in a single directory.
> > 
> > __There is a "soft" upper limit of about 10-15k files in a single directory
> > __with the current linear linked-list directory implementation. __This limit
> > --

Maybe it would be better to increase EXT2_LINK_MAX to fit the docs?

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH] Doc fix: ext2 can only have 32,000 subdirs, not 32,768.

[Andrew Morton]

On Sat, 30 May 2009 13:37:24 +0200 Pavel Machek <pavel@ucw.cz> wrote:

> On Wed 2009-05-27 17:20:45, Andrew Morton wrote:
> > On Mon, 18 May 2009 12:13:51 -0700
> > Michael Shields <mshields@google.com> wrote:
> > 
> > > ext2.txt says that dirs can have 32,768 subdirs, but the actual value
> > > of EXT2_LINK_MAX is 32000.
> > > ext3 is the same, but the doc does not mention it. __One of ext4's
> > > features is to "fix 32000 subdirectory limit".
> > > 
> > > --- linux-2.6.29.3/Documentation/filesystems/ext2.txt.orig 2009-05-08
> > > 15:47:21.000000000 -0700
> > > +++ linux-2.6.29.3/Documentation/filesystems/ext2.txt 2009-05-18
> > > 12:03:58.000000000 -0700
> > > @@ -322,7 +322,7 @@ an upper limit on the block size imposed
> > > __so 8kB blocks are only allowed on Alpha systems (and other architectures
> > > __which support larger pages).
> > > 
> > > -There is an upper limit of 32768 subdirectories in a single directory.
> > > +There is an upper limit of 32000 subdirectories in a single directory.
> > > 
> > > __There is a "soft" upper limit of about 10-15k files in a single directory
> > > __with the current linear linked-list directory implementation. __This limit
> > > --
> 
> Maybe it would be better to increase EXT2_LINK_MAX to fit the docs?
> 

Could be.  afacit filesystems which are created under such a driver
will still mount and work OK with older drivers.

I have this vague memory that there was a reason for the 32000 thing.