Sometimes it's needed to do a check on a mounted filesystem. This should
work fine on a quiescent filesystem or a read-only mount. Changes on the
block device done by kernel might confuse the userspace checker and it
might crash when it reads some stale data.
Repair without mount checks is not supported right now.
Signed-off-by: David Sterba <dsterba@suse.cz>
Usage info of "btrfs check" shows "-Q|--qgroup-report" (and first patch
enables -Q), but the document only shows "--qgroup-report".
Therefore add -Q to the doc.
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Kernel clear_cache mount option will only rebuild free space cache if
the used space of that chunk has changed.
So it won't ensure any corrupted free space cache get cleared.
So add a new option "--clear-space-cache v1|v2" to btrfsck, to
completely wipe out free space cache.
So kernel won't complain again.
Reported-by: Ivan P <chrnosphered@gmail.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[ adjusted error messages, doc wording changes ]
Signed-off-by: David Sterba <dsterba@suse.com>
Change the single-purpose option --low-memory to a generic option that
takes the mode. Currently supported are the original mode and the
low-memory in the same way.
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce a new fsck mode: low memory mode.
Old btrfsck is working efficiently but uses some memory for each extent
item. This method will ensure extents are only iterated once at
extent/chunk tree check process.
But since it uses some memory for each extent item, for a large fs with
several TB metadata, this can easily eat up memory and cause OOM.
To handle such limitation and improve scalability, the new low-memory
mode will not use any heap memory to record which extent is checked.
Instead it will use extent backref to avoid most of uneeded checks on
shared fs/subvolume tree blocks.
And with the use forward and backward reference cross check, we can also
ensure every tree block is at least checked once.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A few minor benefits:
* editors set highliting according to the extensions
* web access to the git repository (github) renders the .asciidoc
files:
* we can link to them from the wiki
* the files are editable via browser and such editations can be
submitted for merge easily
Signed-off-by: David Sterba <dsterba@suse.cz>
David Sterba