- use :file: and :command:
- simplify manual page references
- add more web links
- typo fixes
- more cross-references
Signed-off-by: David Sterba <dsterba@suse.com>
From the very beginning of free-space-tree feature, we allow mount
option "space_cache=v2" to convert the filesystem to the new feature.
But this is not the proper practice for new features (no matter if it's
incompat or compat_ro).
This is already making the clear_cache/space_cache mount option more
complex.
Thus this patch introduces the proper way to enable free-space-tree, and
I hope one day we can deprecate the "space_cache=" mount option.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename the options so they more accurately reflect what the command is
actually doing. The feature is enabled/disabled in the end but it's not
a simple on/off like for others, the conversion takes time.
Signed-off-by: David Sterba <dsterba@suse.com>
With previous btrfstune support to convert to block-group-tree, it has
implemented most of the infrastructure for bi-directional conversion.
This patch will implement the remaining conversion support to go back to
extent tree.
The modification includes:
- New convert_to_extent_tree() function in btrfstune.c
It's almost the same as convert_to_bg_tree(), but with small changes:
* No need to set extra features like NO_HOLES/FST.
* Need to delete the block group tree when everything finished.
- Update btrfs_delete_and_free_root() to handle non-global roots
Currently the function can only accepts global roots (extent/csum/free
space trees)
If we pass a non-global root into the function, we will screw up
global_roots_tree and crash.
Since we're going to use btrfs_delete_and_free_root() to free block
group tree which is not a global tree, this is needed.
- New handling for half converted fs in get_last_converted_bg()
There are two cases need to be handled:
* The bg tree is already empty
We need to grab the first bg in extent tree.
Or at conversion function we will fail at grabbing the first bg.
* The bg tree is not empty
Then we need to grab the last bg in extent tree.
- Extra root switching in involved functions. This involves:
* read_converting_block_groups()
* insert_block_group_item()
* update_block_group_item()
We just need to update our target root according to the current
compat_ro and super flags.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The feedback from the community on block group tree is very positive,
the only complain is, end users need to recompile btrfs-progs with
experimental features to enjoy the new feature.
So let's move it out of experimental features and let more people enjoy
faster mount speed.
Also change the option of btrfstune, from `-b` to
`--enable-block-group-tree` to avoid short option.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The option is listed among normal options but getopt does not recognize
it outside of experimental build, so make it consistent. Also mention
the correct version and need of the special build in documentation.
Signed-off-by: David Sterba <dsterba@suse.com>
RST format provides cross reference function that users can navigate
manual pages click. This patch is written by macro that replaces old
references to doc role in RST format.
Issue: #495
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The new '-b' option will be responsible for converting to block group
tree compat ro feature.
The workflow looks like this for new convert:
- Setting CHANGING_BG_TREE flag
And initialize fs_info->last_converted_bg_bytenr value to (u64)-1.
Any bg with bytenr >= last_converted_bg_bytenr will have its bg item
update go to the new root (bg tree).
- Iterate each block group by their bytenr in descending order
This involves:
* Delete the old bg item from the old tree (extent tree)
* Update last_converted_bg_bytenr to the bytenr of the bg
* Add the new bg item into the new tree (bg tree)
* If we have converted a bunch of bgs, commit current transaction
- Clear CHANGING_BG_TREE flag
And set the new BLOCK_GROUP_TREE compat ro flag and commit.
And since we're doing the convert in multiple transactions, we also need
to resume from last interrupted convert.
In that case, we just grab the last unconverted bg, and start from it.
And to co-operate with the new kernel requirement for both no-holes and
free-space-tree features, the convert tool will check for
free-space-tree feature. If not enabled, will error out with an error
message to how to continue (by mounting with "-o space_cache=v2").
For missing no-holes feature, we just need to set the flag during
convert.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba
Jonathan Liu
Qu Wenruo
Sidong Yang