This adds some extra documentation to the btrfs-receive manpage that
explains some of the security related aspects of btrfs-receive. The
first part covers the fact that the subvolume being received is writable
until the receive finishes, and the second covers the current lack of
sanity checking of the send stream.
Signed-off-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Suggested-by: Graham Cobb <g.btrfs@cobb.uk.net>
Signed-off-by: David Sterba <dsterba@suse.com>
The 'qgroup show' command does not synchronize filesystem.
Therefore, 'qgroup show' may not display the correct value unless
synchronized with 'filesystem sync' command etc.
So add the '--sync' option so that we can choose whether or not
to synchronize when executing the command.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A user reported on IRC that the new 32M default for target extent size
does not work. This happens because if there are no commandline options,
the v1 ioctl is used that does not do any fine grained defrag. As the v2
ioctl has been introduced 6 years ago (2010, kernel 2.6.33) we won't
keep backward compatibility anymore.
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, `btrfs device stats` returns non-zero only when there was an
error getting the counter values. This is fine for when it gets run by a
user directly, but is a serious pain when trying to use it in a script or
for monitoring since you need to parse the (not at all machine friendly)
output to check the counter values.
This patch adds an option ('-s') which causes `btrfs device stats`
to set bit 6 in the return code if any of the counters are non-zero.
This greatly simplifies checking from a script or monitoring software if
any errors have been recorded. In the event that this switch is passed
and an error occurs reading the stats, the return code will have bit
0 set (so if there are errors reading counters, and the counters which
were read were non-zero, the return value will be 65).
Signed-off-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Reword several option descriptions, add missing short option -E,
formatting adjustments.
Visual bug fix: the first line is printed in short help, the second line
is long description, thus alternative calling syntax must be printed on
one line.
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce new option, '--dump' for receive subcommand.
With this command, user can dump the metadata of a send stream.
Which is quite useful for education purpose or bug reporting.
Signed-off-by: Qu Wenruo <quwenruo@cn.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>
Quite a common sense for any RAID-like multi-device setup, just in case.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For RAID5, 2 devices setup is just RAID1 with more overhead.
For RAID6, 3 devices setup is RAID1 with 3 copies, not what most user
want.
So warn user at mkfs time for such case, and add explain in man pages.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Some tools (check, select-super, dump-super) can use the alternate
superblocks, but the options are not consistent. To make it less
confusing, change the meaning of option -s in 'dump-super' to specify
the superblock copy, instead of taking the offset.
Though this is a change in UI, the old usage is detected and the result
would be the same, no breakage in existing scripts.
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>
Currently, balance operations are run synchronously in the foreground.
This is nice for interactive management, but is kind of crappy when you
start looking at automation and similar things.
This patch adds an option to `btrfs balance start` to tell it to
daemonize prior to running the balance operation, thus allowing us to
preform balances asynchronously. The two biggest use cases I have for
this are starting a balance on a remote server without establishing a
full shell session, and being able to background the balance in a
recovery shell (which usually has no job control) so I can still get
progress information.
Because it simply daemonizes prior to calling the balance ioctl, this
doesn't actually need any kernel support.
Signed-off-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
