Re: [PATCH 01/60] xfs: update mount options documentation

Mark Tinguely
2013-06-20T15:35:50Z

On 06/18/13 23:50, Dave Chinner wrote:
> From: Dave Chinner<dchinner@redhat.com>
>
> Because it's horribly out of date.
>
> And mark various deprecated options as deprecated and give them a
> removal date.
>
> Signed-off-by: Dave Chinner<dchinner@redhat.com>
> ---
> Documentation/filesystems/xfs.txt | 317 ++++++++++++++++++++++++-------------
> 1 file changed, 209 insertions(+), 108 deletions(-)
>
> diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
> index 83577f0..12525b1 100644
> --- a/Documentation/filesystems/xfs.txt
> +++ b/Documentation/filesystems/xfs.txt
> @@ -18,6 +18,8 @@ Mount Options
> =============
>
> When mounting an XFS filesystem, the following options are accepted.
> +For boolean mount options, the names with the (*) suffix is the
> +default behaviour.
>
> allocsize=size
> Sets the buffered I/O end-of-file preallocation size when
> @@ -25,97 +27,128 @@ When mounting an XFS filesystem, the following options are accepted.
> Valid values for this option are page size (typically 4KiB)
> through to 1GiB, inclusive, in power-of-2 increments.
>
> - attr2/noattr2
> - The options enable/disable (default is disabled for backward
> - compatibility on-disk) an "opportunistic" improvement to be
> - made in the way inline extended attributes are stored on-disk.
> - When the new form is used for the first time (by setting or
> - removing extended attributes) the on-disk superblock feature
> - bit field will be updated to reflect this format being in use.
> + The default behaviour is for dynamic end-of-file
> + preallocation size, which uses a set of heuristics to
> + optimise the preallocation size based on the current
> + allocation patterns within the file and the access patterns
> + to the file. Specifying a fixed allocsize value turns off
> + the dynamic behaviour.
> +
> + attr2
> + noattr2
> + The options enable/disable an "opportunistic" improvement to
> + be made in the way inline extended attributes are stored
> + on-disk. When the new form is used for the first time when
> + attr2 is selected (either when setting or removing extended
> + attributes) the on-disk superblock feature bit field will be
> + updated to reflect this format being in use.
> +
> + The default behaviour is determined by the on-disk feature
> + bit indicating that attr2 behaviour is active. If either
> + mount option it set, then that becomes the new default used
> + by the filesystem.
>
> CRC enabled filesystems always use the attr2 format, and so
> will reject the noattr2 mount option if it is set.
>

Thanks for doing this.

allocsize and attr/noattr seem a bit too run-on for me, *but* we all
have our writing style; mine is terrible so you can ignore the below if
you want. The "(?)" are added if the noattr2 command is also added.

Rest looks good to me and consider it:

Reviewed-by: Mark Tinguely <tinguely@sgi.com>

allocsize=size
Sets the buffered I/O end-of-file preallocation size when
doing delayed allocation writeout. The default size is 64KiB is
and valid values for this option are page size (typically 4KiB)
through to 1GiB, inclusive, in power-of-2 increments.

The default behaviour is to use the dynamic end-of-file
preallocation size, which uses a set of heuristics to
optimise the preallocation size based on the current
allocation patterns within the file and the access patterns
to the file. Specifying a fixed allocsize value turns off
the dynamic behaviour.

attr2
noattr2
The options enable/disable the "opportunistic" improvement
in the way inline extended attributes are stored on-disk.
When the new attribute storage form is used for the first time
(that usuage may be either when setting or removing extended
attributes) after selecting (?one of ?) the attr2 (? or noattr2?)
option(?s), the on-disk superblock feature bit field will be
updated
to reflect this is the format to be used.

The default behaviour is determined by the on-disk feature
bit indicating that attr2 behaviour is active. If either
mount option it set, then that becomes the new default used
by the filesystem.

CRC enabled filesystems always use the attr2 format, and so
will reject the noattr2 mount option if it is set.

--Mark.