VFS && FS: update [part 2]

switch assorted clock drivers to debugfs_remove_recursive()
arm: don't create useless copies to pass into debugfs_create_dir()
coda_venus_readdir(): use offsetof()
minix_getattr(): don't bother with ->d_parent
don't open-code parent_ino() in assorted ->readdir()
get rid of useless dget_parent() in fs/btrfs/ioctl.c
get rid of useless dget_parent() in btrfs rename() and link()
jfs_lookup(): don't bother with . or ..
simplify gfs2_lookup()
switch d_add_ci() to d_splice_alias() in "found negative" case as well
Remove dead code in dget_parent()
fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
switch assorted clock drivers to debugfs_remove_recursive()
fat: remove i_alloc_sem abuse
fs: simplify handling of zero sized reads in __blockdev_direct_IO
fs: kill i_alloc_sem
rw_semaphore: remove up/down_read_non_owner
fs: move inode_dio_wait calls into ->setattr
fs: always maintain i_dio_count
fs: simplify the blockdev_direct_IO prototype
fs: move inode_dio_done to the end_io handler
ext3: make ext3 mount default to barrier=1
reiserfs: make reiserfs default to barrier=flush
VFS && FS: update [part 3]

AFS: Fix silly characters in a comment
isofs: Remove global fs lock
fs: add a DCACHE_NEED_LOOKUP flag for d_flags
fs: add SEEK_HOLE and SEEK_DATA flags
Ext4: handle SEEK_HOLE/SEEK_DATA generically
fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
drivers: fix up various ->llseek() implementations
fs: push i_mutex and filemap_write_and_wait down into ->fsync()