Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've added new features such as disk quota and statx,
  and modified internal bio management flow to merge more IOs depending
  on block types. We've also made internal threads freezeable for
  Android battery life. In addition to them, there are some patches to
  avoid lock contention as well as a couple of deadlock conditions.

  Enhancements:
   - support usrquota, grpquota, and statx
   - manage DATA/NODE typed bios separately to serialize more IOs
   - modify f2fs_lock_op/wio_mutex to avoid lock contention
   - prevent lock contention in migratepage

  Bug fixes:
   - fix missing load of written inode flag
   - fix worst case victim selection in GC
   - freezeable GC and discard threads for Android battery life
   - sanitize f2fs metadata to deal with security hole
   - clean up sysfs-related code and docs"

* tag 'for-f2fs-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (59 commits)
  f2fs: support plain user/group quota
  f2fs: avoid deadlock caused by lock order of page and lock_op
  f2fs: use spin_{,un}lock_irq{save,restore}
  f2fs: relax migratepage for atomic written page
  f2fs: don't count inode block in in-memory inode.i_blocks
  Revert "f2fs: fix to clean previous mount option when remount_fs"
  f2fs: do not set LOST_PINO for renamed dir
  f2fs: do not set LOST_PINO for newly created dir
  f2fs: skip ->writepages for {mete,node}_inode during recovery
  f2fs: introduce __check_sit_bitmap
  f2fs: stop gc/discard thread in prior during umount
  f2fs: introduce reserved_blocks in sysfs
  f2fs: avoid redundant f2fs_flush after remount
  f2fs: report # of free inodes more precisely
  f2fs: add ioctl to do gc with target block address
  f2fs: don't need to check encrypted inode for partial truncation
  f2fs: measure inode.i_blocks as generic filesystem
  f2fs: set CP_TRIMMED_FLAG correctly
  f2fs: require key for truncate(2) of encrypted file
  f2fs: move sysfs code from super.c to fs/f2fs/sysfs.c
  ...

This patch adds to support plain user/group quota.

Change Note by Jaegeuk Kim.

- Use f2fs page cache for quota files in order to consider garbage collection.
  so, quota files are not tolerable for sudden power-cuts, so user needs to do
  quotacheck.

- setattr() calls dquot_transfer which will transfer inode->i_blocks.
  We can't reclaim that during f2fs_evict_inode(). So, we need to count
  node blocks as well in order to match i_blocks with dquot's space.

  Note that, Chao wrote a patch to count inode->i_blocks without inode block.
  (f2fs: don't count inode block in in-memory inode.i_blocks)

- in f2fs_remount, we need to make RW in prior to dquot_resume.

- handle fault_injection case during f2fs_quota_off_umount

- TODO: Project quota

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

- punch_hole
 - fill_zero
  - f2fs_lock_op
  - get_new_data_page
   - lock_page

- f2fs_write_data_pages
 - lock_page
 - do_write_data_page
  - f2fs_lock_op

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In order to avoid lock contention for atomic written pages, we'd better give
EBUSY in f2fs_migrate_page when mode is asynchronous. We expect it will be
released soon as transaction commits.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Skip ->writepages in prior to ->writepage for {meta,node}_inode during
recovery, hence unneeded loop in ->writepages can be avoided.

Moreover, check SBI_POR_DOING earlier while writebacking pages.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Currently in F2FS, page faults and operations that truncate the pagecahe
or data blocks, are completely unsynchronized. This can result in page
fault faulting in a page into a range that we are changing after
truncating, and thus we can end up with a page mapped to disk blocks that
will be shortly freed. Filesystem corruption will shortly follow.

This patch fixes the problem by creating new rw semaphore i_mmap_sem in
f2fs_inode_info and grab it for functions removing blocks from extent tree
and for read over page faults. The mechanism is similar to that in ext4.

Signed-off-by: Qiuyang Sun <sunqiuyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Serialize data/node IOs by using fifo list instead of mutex lock,
it will help to enhance concurrency of f2fs, meanwhile keeping LFS
IO semantics.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Currently, if we do get_node_of_data before f2fs_lock_op, there may be dead lock
as follows, where process A would be in infinite loop, and B will NOT be awaked.

Process A(cp):            Process B:
f2fs_lock_all(sbi)
                        get_dnode_of_data <---- lock dn.node_page
flush_nodes             f2fs_lock_op

So, this patch adds f2fs_trylock_op to avoid f2fs_lock_op done by IPU.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>