The member functions btrfs_size_to_num(), btrfs_size_max_delta() and
btrfs_size_to_gdouble() don't access any member variables. Therefore
they don't need the const qualifier allowing them to be called when the
btrfs object is const for read-only access to member variables, but
instead need to be static member functions with no access to member
variables.
The btrfs programs only provide approximations of file system sizes
because they display figures using binary prefix multipliers to two
decimal places of precision. E.g. 2.00GB. For partition sizes where
the contained file system size rounds upwards, GParted will fail to read
the file system usage and report a warning because the file system will
appear to be larger than the partition.
For example, create a 2047 MiB partition containing a btrfs file system
and display its size.
# btrfs filesystem show
Label: none uuid: 92535375-5e76-4a70-896a-8d796a577993
Total devices 1 FS bytes used 28.00KB
devid 1 size 2.00GB used 240.62MB path /dev/sda12
The file system size appears to be 2048 MiB, but that is larger than the
partition, hence the issue GParted has. (Actually uses the btrfs devid
size which is the size of the btrfs file system within the partition in
question).
This issue is new with the fix for Bug #499202 because it queries the
file system sizes for the first time. The same issue could
theoretically occur previously, but with the used figure (FS bytes
used). This would have been virtually impossible to trigger because
btrfs file system would have to have been greater than 99% full, but
btrfs has been notorious for early reporting of file system full.
The fix is that if a btrfs file system size appears larger than the
partition size, but the minimum possible size which could have been
rounded to the reported figure is within the partition size use the
smaller partition size instead. Apply the method to the used figure
too, in case the file system is 100% full. Also if the btrfs file
system size appears smaller than the partition size, but the maximum
possible size which could have been rounded to the reported figure is
within the partition size use the larger partition size instead to avoid
reporting, presumably false, unallocated space. Not applied to file
system used figure.
Bug 499202 - gparted does not see the difference if partition size
differs from filesystem size
Update file system specific implementations to set the size and free
space, thus allowing the unallocated space in the partition to be
calculated, for the following unmounted file systems:
btrfs, ext2, ext3, ext4, fat16, fat32, jfs, nilfs2, ntfs, reiserfs,
reiser4, xfs
Bug #499202 - gparted does not see the difference if partition size
differs from filesystem size
Add the ability to set a new random UUID on file systems that provide
the appropriate tools to perform this action.
Update the help manual to include this new functionality. Also add
reference links to "setting a partition label" and "changing a
partition UUID" in the "copying and pasting a partition" section.
This patch does not include setting the UUID on an NTFS file system.
Bug #667278 - Add support for setting UUID
Bug #608308 - fix documentation - Copying and Pasting a Partition
This adds initial handlers for Btrfs; only .create, .check and
.read_label are done for now, via external btrfs-tools.
Other methods are still only stubs.
Mike Fleetwood