Support for XFS

[zlind0]

Recently I did some tests without noticing that I am actually testing XFS and the pjdfstest doesn't support XFS file system.
The outcome is that, there is one failed testcase, symlink-03, which creates a symbolic link of 4095 characters length.

not ok 1 - tried 'symlink .............', expected 0, got ENAMETOOLONG

For XFS filesystem, XFS_SYMLINK_MAXLEN is limited to 1024 characters according to this patch. Since XFS performs better than EXT4 in some scenarios and is becoming increasingly popular, wouldn't it be nice if some slight changes are made thus the pjdfstest could support XFS?

[asomers]

Yes, it would be nice. Does XFS report that via pathconf(2) with the _PC_SYMLINK_MAX key? If so, pjdfstest should check for that.