Number of external symbols by categories.
This is the same plot as the previous one except this time the
file systems are grouped in categories.
The first group, which contains the disk-based file systems, is
led by
ext4 which is ahead of
xfs by 45
external symbols. Note that the number of external symbols for
both
ext4 and
ext3 is boosted by the fact the
journaling part not implemented internally but provided
by
jbd2 and
jbd respectively. At the other end
of the scale is a group of 4 file systems out of which only
two,
freevxfs and
qnx4 are truly
self-contained. The other two,
msdos and
vfat are
getting most of their functionality from the
fat module
which is more than twice of their size.
The second group contains the file systems dedicated to optical
mediums and it holds no surprises:
udf is ahead
of
isofs by a comfortable margin.
The same thing is also true for the the third group, of the
flash-based file systems, where the first place is taken
by
ubifs followed by
jffs2. The third placed is
secured by
squashfs while the bottom is shared
by
cramfs and
romfs which are separated by only
5 symbols.
The fourth group is the one dedicated to the network file
systems. Here the first two spots are taken by
nfs
and
nfsd, which provide kernel support for NFS client and
NFS server. On the next two places, at very close distance between
them, are
kafs, the Andrew File System,
and
cifs. The end is shared by
coda
and
9p.
The fifth group contains, in this order, the only two
cluster-based file systems:
ocfs2 and
gfs2. The
number of external symbols for
ocfs2 is increased due to
the use of the
jbd2 journaling library.
The sixth group, the one dedicated to memory-based file systems is
dominated authoritatively by
proc which has almost 100
more external symbols than
fuse, the file system from the
second place. As expected, at the bottom sits
ramfs.
The seventh and last group is dedicated to ancient file
systems. The first place is shared by
hfs
and
ufs. Quite surprising, this is only one of the three
ties in this group, the other two
being
hpfs/
minix and
adfs/
bfs.