Tmpfs size accounting misses memory allocations

[Topi Miettinen <toiwoton@xxxxxxxxx>]

Hi,

It seems that tmpfs does not count memory which is allocated for short 
symlinks or xattrs towards size= limit. I guess the fix would be to 
change shmem_sb_info->{used_blocks,max_blocks} to use bytes as units 
(instead of blocks) and then add accounting and checks to 
shmem_symlink() and shmem_initxattrs(). Would a patch for that be 
acceptable?

Another issue is that inodes aren't counted towards size= limit either, 
but perhaps that's intentional because there's nr_inodes= mount option 
for exactly that.

If these are not bugs but intentional features, I think the manual page 
tmpfs(5) should be clearer in this respect.

-Topi