an already sparse file. Drop check for FILE_SUPPORTS_SPARSE_FILES
flag. Explicitely set FILE_ATTRIBUTE_SPARSE_FILE attribute in
cached attributes.
(fhandler_base::lseek): Only set did_lseek if sparseness is supported.
* fhandler_disk_file.cc (fhandler_disk_file::ftruncate): Don't attempt
to sparsify an already sparse file. Explicitely set
FILE_ATTRIBUTE_SPARSE_FILE attribute in cached attributes.
* mount.cc (oopt): Add "sparse" flag.
(fillout_mntent): Ditto.
* path.h (enum path_types): Add PATH_SPARSE.
(path_conv::support_sparse): New method.
(path_conv::fs_flags): Constify.
(path_conv::fs_name_len): Ditto.
include/sys/mount.h: Replace unused MOUNT_MIXED flag with MOUNT_SPARSE.
05297cca5f