block: cgroups, kconfig, build bits for BFQ-v5-3.0

Add a Kconfig option and do the related Makefile changes to compile
the BFQ I/O scheduler.  Also let the cgroups subsystem know about the
BFQ I/O controller.

Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: KalimochoAz <calimochoazucarado@gmail.com>
Xens_config: enable bfq i/o scheduler
Xens_config: add e210s/k support
fs: import f2fs from git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git (branch dev)
f2fs: support 3.4

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: support 3.0
f2fs: change the method of calculating the number summary blocks

npages_for_summary_flush uses (SUMMARY_SIZE + 1) as the size of a f2fs_summary
while its actual size is  SUMMARY_SIZE. So the result sometimes is bigger than
actual number by one, which causes checkpoint can't be written into disk
contiguously, and sometimes summary blocks can't be compacted like they should.
Besides, when writing summary blocks into pages, if remain space in a page
isn't big enough for one f2fs_summary, it will be left unused, current code
seems not to take it into account.

Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: check all ones or zeros bitmap with bitops for better mount performance

Previously, check_block_count check valid_map with bit data type in common
scenario that sit has all ones or zeros bitmap, it makes low mount performance.
So let's check the special bitmap with integer data type instead of the bit one.

v1-->v2:
 o use find_next_{zero_}bit_le for better performance and readable as Jaegeuk
   suggested.
 o use neat logogram in comment as Gu Zheng suggested.
 o search continuous ones or zeros for better performance when checking mixed
   bitmap.

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Shu Tan <shu.tan@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: avoid to wait all the node blocks during fsync

Previously, f2fs_sync_file() waits for all the node blocks to be written.
But, we don't need to do that, but wait only the inode-related node blocks.

This patch adds wait_on_node_pages_writeback() in which waits inode-related
node blocks that are on writeback.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: update f2fs document

This patch describes the inline_xattr support in f2fs document.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: remove unnecessary TestClearPageError when wait pages writeback

In wait_on_node_pages_writeback we will test and clear error flag for all
pages in radix tree, but not necessary.
So we only do this for pages belong to the specified inode.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: avoid to use a NULL point in destroy_segment_manager

A NULL point should avoid to be used in destroy_segment_manager after allocating
memory fail for f2fs_sm_info.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>