zygo: cherry-picked up to linus/master --remotes=btrfs-next/* --remotes=mason/* ...

Commits included (++++) and excluded (----):

++++ b7a0365 Btrfs: ctree: reduce args where only fs_info used
++++ a585e94 Btrfs: delayed-inode: replace root args iff only fs_info used
++++ 01d5847 Btrfs: disk-io: replace root args iff only fs_info used
++++ f749303 Btrfs: switch to kvfree() helper
++++ e8c9f18 btrfs: constify structs with op functions or static definitions
++++ b9fd47c btrfs: cleanup: remove no-used alloc_chunk in btrfs_check_data_free_space()
++++ a688a04 btrfs: remove unused chunk_tree argument in several functions
++++ 08da757 btrfs: cleanup: use for() loop in btrfs_map_bio()
---- 41d6b13 btrfs: fix sizeof format specifier in btrfs_check_super_valid()
++++ 9eaed21 btrfs: remove unused fs_info arg from btrfs_close_extra_devices()
++++ 0489234 btrfs: consistently use fs_info in close_ctree()
++++ 638aa7e btrfs: factor btrfs_init_scrub() out of open_ctree()
++++ 779a65a btrfs: factor btrfs_init_balance() out of open_ctree()
---- f37938e btrfs: factor btrfs_init_btree_inode() out of open_ctree()
---- ad61836 btrfs: factor btrfs_init_dev_replace_locks() out of open_ctree()
---- f9e92e4 btrfs: factor btrfs_init_qgroup() out of open_ctree()
---- 2a45819 btrfs: factor btrfs_init_workqueues() out of open_ctree()
---- 63443bf btrfs: factor btrfs_replay_log() out of open_ctree()
---- 4bbcaa6 btrfs: factor btrfs_read_roots() out of open_ctree()
---- 6f01105 btrfs: use correct type for workqueue flags
---- a4f3d2c btrfs: cleanup, reduce temporary variables in btrfs_read_roots
++++ 853d8ec btrfs: need_resched not needed with cond_resched
++++ 351810c btrfs: use cond_resched_lock where possible
++++ f8c269d btrfs: cleanup 64bit/32bit divs, compile time constants
++++ 31e818f btrfs: cleanup, use kmalloc_array/kcalloc array helpers
++++ f64c7b1 btrfs: remove shadowing variables in __btrfs_buffered_write
++++ 3284da7 btrfs: use explicit initializer for seq_elem
++++ b8b93ad btrfs: cleanup 64bit/32bit divs, provably bounded values
++++ 47c5713 btrfs: replace remaining do_div calls with div_u64 variants
++++ 9d644a6 btrfs: cleanup, use correct type in div_u64_rem
++++ 093adbc btrfs: switch helper macros to static inlines in sysfs.h
++++ 258ece0 btrfs: remove shadowing variables in __btrfs_map_block
---- 9266ff8 Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
---- aa4661f Btrfs: prepare block group cache before writing
---- 2e0adf0 fix qgroups
---- 777414a Btrfs: fix merge delalloc logic
---- 3075d58 Btrfs: account for the correct number of extents for delalloc reservations
---- 2fdbf36 Btrfs: just free dummy extent buffers
---- 464919a Btrfs: add sanity test for outstanding_extents accounting
---- e2e40f2 fs: move struct kiocb to fs.h
++++ 4f764e5 Btrfs: remove deleted xattrs on fsync log replay
++++ 5cc2b17 Btrfs: send, add missing check for dead clone root
++++ 2f1f465 Btrfs: send, don't leave without decrementing clone root's send_progress
++++ 8996a48 Btrfs: incremental send, clear name from cache after orphanization
++++ 5f806c3 Btrfs: incremental send, remove dead code
++++ 3d850dd Btrfs: add missing inode item update in fallocate()
++++ bf69196 Btrfs: change the insertion criteria for the qgroup operations rbtree
++++ 2f2ff0e Btrfs: fix metadata inconsistencies after directory fsync
++++ dcc82f4 Btrfs: fix log tree corruption when fs mounted with -o discard
++++ 3c3b04d btrfs: don't accept bare namespace as a valid xattr
++++ 26e726a btrfs: incorrect handling for fiemap_fill_next_extent return
++++ d862095 btrfs: explicitly set control file's private_data
++++ 727b978 btrfs: cleanup orphans while looking up default subvolume
++++ e56a951 Btrfs: Remove the check for old-style mkfs
++++ dd82525 Btrfs: free and unlock our path before btrfs_free_and_pin_reserved_extent()
++++ 4a3d1ca fs: btrfs: Add missing include file
++++ 28ed134 btrfs: actively run the delayed refs while deleting large files
++++ 1262133 Btrfs: account for crcs in delayed ref processing
++++ 28f75a0 Btrfs: refill block reserves during truncate
++++ cb723e4 Btrfs: reserve space for block groups
++++ 365c531 Btrfs: don't commit the transaction in the async space flushing
++++ 3bce876 Btrfs: don't steal from the global reserve if we don't have the space
++++ 4c6d1d8 btrfs: move struct io_ctl into ctree.h and rename it
++++ c9dc4c6 Btrfs: two stage dirty block group writeout
++++ 2b10826 Btrfs: don't use highmem for free space cache pages
++++ 1bbc621 Btrfs: allow block group cache writeout outside critical section in commit
++++ cdfb080 Btrfs: fix use after free when close_ctree frees the orphan_rsv
---- 5d5d568 make new_sync_{read,write}() static
++++ 17f8c84 Remove rw from {,__,do_}blockdev_direct_IO()
---- 6f67376 direct_IO: use iov_iter_rw() instead of rw everywhere
++++ 22c6186 direct_IO: remove rw from a_ops->direct_IO()
---- 0fa6b00 generic_write_checks(): drop isblk argument
---- 3309dd0 switch generic_write_checks() to iocb and iter
---- 2ba48ce mirror O_APPEND and O_DIRECT into iocb->ki_flags
++++ df858e7 Btrfs: fix range cloning when same inode used as source and destination
++++ 113e828 Btrfs: fix inode eviction infinite loop after extent_same ioctl
++++ ccccf3d6 Btrfs: fix inode eviction infinite loop after cloning into it
++++ de249e6 Btrfs: fix uninit variable in clone ioctl
++++ 94b947b btrfs: fix condition of commit transaction
++++ f2ab761 btrfs: Fix tail space processing in find_free_dev_extent()
++++ 264ca0f btrfs: Adjust commit-transaction condition to avoid NO_SPACE more
++++ c30666d btrfs: Set relative data on clear btrfs_block_group_cache->pinned
++++ 18d018a btrfs: add WARN_ON() to check is space_info op current
++++ d7c1517 btrfs: Fix NO_SPACE bug caused by delayed-iput
++++ c99f1b0 btrfs: Support busy loop of write and delete
++++ 3eeb4d5 btrfs: qgroup: inherit limit info from srcgroup in creating snapshot.
++++ e8c8541 btrfs: qgroup: update qgroup in memory at the same time when we update it in btree.
++++ 1510e71 btrfs: qgroup: consolidate the parameter of fucntion update_qgroup_limit_item().
++++ d3001ed btrfs: qgroup: update limit info in function btrfs_run_qgroups().
++++ 03477d9 btrfs: qgroup: fix limit args override whole limit struct
++++ 4087cf2 Btrfs: qgroup: cleanup, remove an unsued parameter in btrfs_create_qgroup().
++++ 804ca12 Btrfs: qgroup: free reserved in exceeding quota.
++++ 3119321 Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.
++++ 237c0e9 Btrfs: qgroup, Account data space in more proper timings.
++++ e2d1f92 btrfs: qgroup: do a reservation in a higher level.
++++ 09870d2 btrfs: qgroup: return EINVAL if level of parent is not higher than child's.
++++ f5a6b1c btrfs: qgroup: allow to remove qgroup which has parent but no child.
++++ 8465ece btrfs: Check qgroup level in kernel qgroup assign.
++++ e09fe2d btrfs: Don't allow subvolid >= (1 << BTRFS_QGROUP_LEVEL_SHIFT) to be created
++++ 3393168 btrfs: qgroup: Fix dead judgement on qgroup_rescan_leaf() return value.
++++ 53b7cde btrfs: Update btrfs qgroup status item when rescan is done.
++++ 8ea0ec9 btrfs: qgroup: clear STATUS_FLAG_ON in disabling quota.
++++ 9c8b35b btrfs: quota: Automatically update related qgroups or mark INCONSISTENT flags when assigning/deleting a qgroup relations.
++++ e082f56 btrfs: quota: Update quota tree after qgroup relationship change.
++++ c1e31ff Btrfs: don't check for delalloc_bytes in cache_save_setup
++++ e47aabed Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
++++ e98fb71 btrfs: handle ENOMEM in btrfs_alloc_tree_block
++++ 6e8f302 btrfs: fix race on ENOMEM in alloc_extent_buffer
++++ 2f23947 btrfs: check io_ctl_prepare_pages return in __btrfs_write_out_cache
++++ f5b5132 btrfs: unlock i_mutex after attempting to delete subvolume during send
++++ c7dd5f4 Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.