zygo: cherry-picked up to e1cbbfa (extra args linus/master --remotes=btrfs-next/...

Commits included:

---- 6b6d24b3 Btrfs, scrub: uninitialized variable in scrub_extent_for_parity()
++++ df95e7f Btrfs: abort transaction if we don't find the block group
++++ c7cfb8a Btrfs: call inode_dec_link_count() on mkdir error path
++++ a1317f4 Btrfs: correctly get tree level in tree_backref_for_extent
---- 6f89605 Btrfs: don't delay inode ref updates during log replay
---- 83fe27e rcu: Make SRCU optional by using CONFIG_SRCU
---- 381cf65 btrfs: fix leak of path in btrfs_find_item
++++ 14692cc btrfs: cleanup, remove inode_item_info helper
++++ c234a24 btrfs: cleanup, remove inode_ref_info helper
++++ 9c4f61f btrfs: simplify insert_orphan_item
++++ 1d4c08e btrfs: expand btrfs_find_item if found_key is NULL
---- 98bd5c5 btrfs: sync ioctl, handle errors after transaction start
---- 379d685 Btrfs: fix incorrect freeing in scrub_stripe
---- 75c68e9 Btrfs: fix race deleting block group from space_info->ro_bgs list
++++ 6e1103a btrfs: fix state->private cast on 32 bit machines
---- b4caecd fs: introduce f_op->mmap_capabilities for nommu mmap support
---- de1414a fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
---- b83ae6d fs: remove mapping->backing_dev_info
---- df0ce26 fs: remove default_backing_dev_info
---- 6c9fe14 btrfs: Fix the bug that fs_info->pending_changes is never cleared.
---- a53f4f8 btrfs: Don't call btrfs_start_transaction() on frozen fs to avoid deadlock.
++++ e7070be Btrfs: change how we track dirty roots
---- ce93ec5 Btrfs: track dirty block groups on their own list
++++ a8df6fe Btrfs: fix setup_leaf_for_split() to avoid leaf corruption
++++ 68b663d btrfs: update message levels for errors
++++ aa8ee31 btrfs: update message levels during failed mount
++++ f0954c6 btrfs: update message levels after checksum errors
---- 5efa049 btrfs: set proper message level for skinny metadata
---- 9ee49a04 btrfs: switch extent_state state to unsigned
++++ 730a78c btrfs: remove a no-op unfreeze superbock callback
++++ 6219872 Btrfs: lookup for block group only if needed when freeing a tree block
++++ d36808e Btrfs: fix directory inconsistency after fsync log replay
++++ 2c2c452 Btrfs: fix fsync when extend references are added to an inode
++++ df8d116 Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs
---- e34c330 Btrfs: fix a out-of-bound access of raid_map
---- cc7539e Btrfs: sort raid_map before adding tgtdev stripes
---- 8e5cfb5 Btrfs: Make raid_map array be inlined in btrfs_bio structure
---- 6e9606d Btrfs: add ref_count and free function for btrfs_bio
++++ b25c94c Btrfs: Fix a jump typo of nodatasum_case to avoid wrong WARN_ON()
++++ 114ab50 Btrfs: Remove noneed force_write in scrub_write_block_to_dev_replace
++++ 09dd7a0 Btrfs: Cleanup btrfs_bio_counter_inc_blocked()
++++ 7653947 Btrfs: btrfs_rm_dev_replace_blocked(): Use wait_event()
++++ dc5f7a3 Btrfs: Break loop when reach BTRFS_MAX_MIRRORS in scrub_setup_recheck_block()
++++ 8d6738c Btrfs: Separate finding-right-mirror and writing-to-target's process in scrub_handle_errored_block()
++++ b968fed Btrfs: Combine per-page recover in dev-replace and scrub
---- be50a8d Btrfs: Simplify scrub_setup_recheck_block()'s argument
---- 10f1190 Btrfs: Include map_type in raid_bio
---- ffe2d20 Btrfs: Introduce BTRFS_BLOCK_GROUP_RAID56_MASK to check raid56 simply
---- 5701934 Rename all ref_count to refs in struct
++++ 26455d3 Btrfs: cleanup unused run_most
++++ 0ee13fe btrfs: qgroup: move WARN_ON() to the correct location.
++++ 78f55e5 Btrfs: fix unused members in struct btrfs_root
++++ 95449a1 Btrfs: insert_new_root: Fix lock type of the extent buffer.
++++ 063c54d btrfs: fix raid56 scrub failed in xfstests btrfs/072
++++ a937b97 btrfs: kill btrfs_inode_*time helpers
++++ 9cc97d6 Btrfs: Add code to support file creation time
++++ 75d6ad3 btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesize
++++ ce7fca5 btrfs: add checks for sys_chunk_array sizes
++++ 1ffb22c btrfs: cleanup, rename a few variables in btrfs_read_sys_array
++++ e3540ea btrfs: add more checks to btrfs_read_sys_array
---- d4b450c Btrfs: fix race between transaction commit and empty block group removal
++++ 001a648 Btrfs: add missing cleanup on sysfs init failure
++++ de554a4 Btrfs: fix scrub race leading to use-after-free
++++ 289454a btrfs: clear bio reference after submit_one_bio()
++++ 2f08108 btrfs: delete chunk allocation attemp when setting block group ro
++++ b76808f btrfs: cleanup init for list in free-space-cache
++++ 3da5ab5 Btrfs: add missing blk_finish_plug in btrfs_sync_log()
---- d83a08d mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub
++++ 8d38633 page_writeback: put account_page_redirty() after set_page_dirty()
++++ 575849e Btrfs: fix scheduler warning when syncing log
++++ f55985f Btrfs: scrub, fix sleep in atomic context
++++ 13212b5 btrfs: Fix out-of-space bug
++++ 3e05bde Btrfs: only adjust outstanding_extents when we do a short write
++++ 3266789 Btrfs: don't set and clear delalloc for O_DIRECT writes
++++ dcab6a3 Btrfs: account for large extents with enospc
++++ 3d84be7 Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group
---- 1a4bcf4 Btrfs: fix fsync data loss after adding hard link to inode
++++ a742994 Btrfs: don't remove extents and xattrs when logging new names
++++ 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
---- e57cf21 Btrfs: fix allocation size calculations in alloc_btrfs_bio
---- e36cb0b VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
---- 4d884fc Btrfs: fix fsync race leading to ordered extent memory leaks
++++ 0c0ef4b Btrfs: abort the transaction if we fail to update the free space cache inode
++++ e8c1c76 Btrfs: add missing inode update when punching hole
++++ 5dfe2be Btrfs: fix off-by-one logic error in btrfs_realloc_node
---- 5cdf83e Btrfs: do not ignore errors from btrfs_lookup_xattr in do_setxattr
---- 1932b7b btrfs: fix lost return value due to variable shadowing
++++ 84471e2 Btrfs: incremental send, don't rename a directory too soon
++++ 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
---- f5c0a12 Btrfs: remove extra run_delayed_refs in update_cowonly_root
---- 3a8b36f Btrfs: fix data loss in the fast fsync path
---- dd9ef13 Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.
++++ 9266ff8 Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
++++ aa4661f Btrfs: prepare block group cache before writing
---- 2e0adf0 fix qgroups
---- d220712 btrfs: fix sizeof format specifier in btrfs_check_super_valid()
++++ b4924a0 Btrfs: catch transaction abortion after waiting for it
++++ 48da5f0 Btrfs: fix comp_oper to get right order
++++ 8461a3d Btrfs: fix merge delalloc logic
++++ 6a41dd0 Btrfs: account for the correct number of extents for delalloc reservations
---- ea526d1 Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
---- 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
---- dcdf7f6 Btrfs: prepare block group cache before writing
++++ ba11721 Btrfs: account merges/splits properly
---- bcb7e44 Btrfs: just free dummy extent buffers
---- 6a3891c Btrfs: add sanity test for outstanding_extents accounting
++++ e1cbbfa Btrfs: fix outstanding_extents accounting in DIO