fs: import f2fs from git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git (branch dev)

Up-to-date with
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git @28cdce0459ccea71ea734d7903d39910d1c6a05d
(f2fs: recover inline xattr data in roll-forward process)

Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
f2fs: support 3.4

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Revert "tmpfs: add support for read_iter and write_iter"

This reverts commit 55a3c5928d6e5871dfd776a6aab021fb0f0178ce.
Revert "iov_iter: move into its own file (bug fix)"

This reverts commit 646454303cad74ffc578b2b225b59bd5304c7f8b.
Revert "ecrpytfs: Convert aio_read/write ops to read/write_iter"

This reverts commit 0ccce721da521a8049ed8ce3bb3fc81081f8e60d.
Revert "ext4: add support for read_iter and write_iter"

This reverts commit 11f07215bbd19a138c148dcbdc5f0cafd08a4aaa.
Revert "fs: add read_iter and write_iter to several file systems"

This reverts commit f4d077491b5588d5b169df04695d9af0130e85ca.
Revert "fs: use read_iter and write_iter rather than aio_read and aio_write"

This reverts commit f288afe9ace4d0dff7b48998324c0dacd07baed8.
Revert "fs: create file_readable() and file_writable() functions"

This reverts commit 4c94078e8ed345be2edc6e19059a2ebc95c47de1.
Revert "loop: use aio to perform io on the underlying file"

This reverts commit db127a7d7ec667ae64879a3a397f390cd5f49263.
Revert "bio: add bvec_length(), like iov_length()"

This reverts commit c4b4ca86d794fd2d9784c2c4f8ca8c9203d6f091.
Revert "aio: add aio support for iov_iter arguments"

This reverts commit 4f761bd4890648b38a2af74b63d49d80bec3ea88.
Revert "aio: add aio_kernel_() interface"

This reverts commit 37e797663f525600ee6dd048daa093119cc83074.
Revert "fs: pull iov_iter use higher up the stack"

This reverts commit cf5c8c65f51c57b8eed89b943e419f928177ad5b.
Revert "dio: add bio_vec support to __blockdev_direct_IO()"

This reverts commit 04da2362ff8b12e11412ae14ac22aa5fb9771c93.
Revert "dio: Convert direct_IO to use iov_iter"

This reverts commit 05b89e9053147f6f453912e4e73647f9a8ed4f8a.

Conflicts:
	fs/gfs2/aops.c
Clean
Revert "iov_iter: let callers extract iovecs and bio_vecs"

This reverts commit b4272f98b4d75ca5e4b37a01a5665a9941dc341d.
Revert "iov_iter: add a shorten call"

This reverts commit b19c614c6c35bb828ace89cdc08f4d2b513fcb5e.
Revert "iov_iter: add bvec support"

This reverts commit 98c281b8dd9ceeba524a5181efbdf66144524d4b.