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 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2007 Oracle.  All rights reserved.
  */
 
 #ifndef BTRFS_CTREE_H
 #define BTRFS_CTREE_H
 
 #include <linux/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/highmem.h>
 #include <linux/fs.h>
 #include <linux/rwsem.h>
 #include <linux/semaphore.h>
 #include <linux/completion.h>
 #include <linux/backing-dev.h>
 #include <linux/wait.h>
 #include <linux/slab.h>
 #include <trace/events/btrfs.h>
 #include <asm/unaligned.h>
 #include <linux/pagemap.h>
 #include <linux/btrfs.h>
 #include <linux/btrfs_tree.h>
 #include <linux/workqueue.h>
 #include <linux/security.h>
 #include <linux/sizes.h>
 #include <linux/dynamic_debug.h>
 #include <linux/refcount.h>
 #include <linux/crc32c.h>
 #include <linux/iomap.h>
 #include "extent-io-tree.h"
 #include "extent_io.h"
 #include "extent_map.h"
 #include "async-thread.h"
 #include "block-rsv.h"
 #include "locking.h"
 
 struct btrfs_trans_handle;
 struct btrfs_transaction;
 struct btrfs_pending_snapshot;
 struct btrfs_delayed_ref_root;
 struct btrfs_space_info;
 struct btrfs_block_group;
 extern struct kmem_cache *btrfs_trans_handle_cachep;
 extern struct kmem_cache *btrfs_bit_radix_cachep;
 extern struct kmem_cache *btrfs_path_cachep;
 extern struct kmem_cache *btrfs_free_space_cachep;
 extern struct kmem_cache *btrfs_free_space_bitmap_cachep;
 struct btrfs_ordered_sum;
 struct btrfs_ref;
 struct btrfs_bio;
 struct btrfs_ioctl_encoded_io_args;
 
 #define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
 
 /*
  * Maximum number of mirrors that can be available for all profiles counting
  * the target device of dev-replace as one. During an active device replace
  * procedure, the target device of the copy operation is a mirror for the
  * filesystem data as well that can be used to read data in order to repair
  * read errors on other disks.
  *
  * Current value is derived from RAID1C4 with 4 copies.
  */
 #define BTRFS_MAX_MIRRORS (4 + 1)
 
 #define BTRFS_MAX_LEVEL 8
 
 #define BTRFS_OLDEST_GENERATION 0ULL
 
 /*
  * we can actually store much bigger names, but lets not confuse the rest
  * of linux
  */
 #define BTRFS_NAME_LEN 255
 
 /*
  * Theoretical limit is larger, but we keep this down to a sane
  * value. That should limit greatly the possibility of collisions on
  * inode ref items.
  */
 #define BTRFS_LINK_MAX 65535U
 
 #define BTRFS_EMPTY_DIR_SIZE 0
 
 /* ioprio of readahead is set to idle */
 #define BTRFS_IOPRIO_READA (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0))
 
 #define BTRFS_DIRTY_METADATA_THRESH SZ_32M
 
 /*
  * Use large batch size to reduce overhead of metadata updates.  On the reader
  * side, we only read it when we are close to ENOSPC and the read overhead is
  * mostly related to the number of CPUs, so it is OK to use arbitrary large
  * value here.
  */
 #define BTRFS_TOTAL_BYTES_PINNED_BATCH  SZ_128M
 
 #define BTRFS_MAX_EXTENT_SIZE SZ_128M
 
 /*
  * Deltas are an effective way to populate global statistics.  Give macro names
  * to make it clear what we're doing.  An example is discard_extents in
  * btrfs_free_space_ctl.
  */
 #define BTRFS_STAT_NR_ENTRIES   2
 #define BTRFS_STAT_CURR     0
 #define BTRFS_STAT_PREV     1
 
 static inline unsigned long btrfs_chunk_item_size(int num_stripes)
 {
     BUG_ON(num_stripes == 0);
     return sizeof(struct btrfs_chunk) +
         sizeof(struct btrfs_stripe) * (num_stripes - 1);
 }
 
 /*
  * Runtime (in-memory) states of filesystem
  */
 enum {
     /* Global indicator of serious filesystem errors */
     BTRFS_FS_STATE_ERROR,
     /*
      * Filesystem is being remounted, allow to skip some operations, like
      * defrag
      */
     BTRFS_FS_STATE_REMOUNTING,
     /* Filesystem in RO mode */
     BTRFS_FS_STATE_RO,
     /* Track if a transaction abort has been reported on this filesystem */
     BTRFS_FS_STATE_TRANS_ABORTED,
     /*
      * Bio operations should be blocked on this filesystem because a source
      * or target device is being destroyed as part of a device replace
      */
     BTRFS_FS_STATE_DEV_REPLACING,
     /* The btrfs_fs_info created for self-tests */
     BTRFS_FS_STATE_DUMMY_FS_INFO,
 
     BTRFS_FS_STATE_NO_CSUMS,
 
     /* Indicates there was an error cleaning up a log tree. */
     BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
 
     BTRFS_FS_STATE_COUNT
 };
 
 #define BTRFS_BACKREF_REV_MAX       256
 #define BTRFS_BACKREF_REV_SHIFT     56
 #define BTRFS_BACKREF_REV_MASK      (((u64)BTRFS_BACKREF_REV_MAX - 1) << \
                      BTRFS_BACKREF_REV_SHIFT)
 
 #define BTRFS_OLD_BACKREF_REV       0
 #define BTRFS_MIXED_BACKREF_REV     1
 
 /*
  * every tree block (leaf or node) starts with this header.
  */
 struct btrfs_header {
     /* these first four must match the super block */
     u8 csum[BTRFS_CSUM_SIZE];
     u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
     __le64 bytenr; /* which block this node is supposed to live in */
     __le64 flags;
 
     /* allowed to be different from the super from here on down */
     u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
     __le64 generation;
     __le64 owner;
     __le32 nritems;
     u8 level;
 } __attribute__ ((__packed__));
 
 /*
  * this is a very generous portion of the super block, giving us
  * room to translate 14 chunks with 3 stripes each.
  */
 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
 
 /*
  * just in case we somehow lose the roots and are not able to mount,
  * we store an array of the roots from previous transactions
  * in the super.
  */
 #define BTRFS_NUM_BACKUP_ROOTS 4
 struct btrfs_root_backup {
     __le64 tree_root;
     __le64 tree_root_gen;
 
     __le64 chunk_root;
     __le64 chunk_root_gen;
 
     __le64 extent_root;
     __le64 extent_root_gen;
 
     __le64 fs_root;
     __le64 fs_root_gen;
 
     __le64 dev_root;
     __le64 dev_root_gen;
 
     __le64 csum_root;
     __le64 csum_root_gen;
 
     __le64 total_bytes;
     __le64 bytes_used;
     __le64 num_devices;
     /* future */
     __le64 unused_64[4];
 
     u8 tree_root_level;
     u8 chunk_root_level;
     u8 extent_root_level;
     u8 fs_root_level;
     u8 dev_root_level;
     u8 csum_root_level;
     /* future and to align */
     u8 unused_8[10];
 } __attribute__ ((__packed__));
 
 #define BTRFS_SUPER_INFO_OFFSET         SZ_64K
 #define BTRFS_SUPER_INFO_SIZE           4096
 
 /*
  * The reserved space at the beginning of each device.
  * It covers the primary super block and leaves space for potential use by other
  * tools like bootloaders or to lower potential damage of accidental overwrite.
  */
 #define BTRFS_DEVICE_RANGE_RESERVED         (SZ_1M)
 
 /*
  * the super block basically lists the main trees of the FS
  * it currently lacks any block count etc etc
  */
 struct btrfs_super_block {
     /* the first 4 fields must match struct btrfs_header */
     u8 csum[BTRFS_CSUM_SIZE];
     /* FS specific UUID, visible to user */
     u8 fsid[BTRFS_FSID_SIZE];
     __le64 bytenr; /* this block number */
     __le64 flags;
 
     /* allowed to be different from the btrfs_header from here own down */
     __le64 magic;
     __le64 generation;
     __le64 root;
     __le64 chunk_root;
     __le64 log_root;
 
     /*
      * This member has never been utilized since the very beginning, thus
      * it's always 0 regardless of kernel version.  We always use
      * generation + 1 to read log tree root.  So here we mark it deprecated.
      */
     __le64 __unused_log_root_transid;
     __le64 total_bytes;
     __le64 bytes_used;
     __le64 root_dir_objectid;
     __le64 num_devices;
     __le32 sectorsize;
     __le32 nodesize;
     __le32 __unused_leafsize;
     __le32 stripesize;
     __le32 sys_chunk_array_size;
     __le64 chunk_root_generation;
     __le64 compat_flags;
     __le64 compat_ro_flags;
     __le64 incompat_flags;
     __le16 csum_type;
     u8 root_level;
     u8 chunk_root_level;
     u8 log_root_level;
     struct btrfs_dev_item dev_item;
 
     char label[BTRFS_LABEL_SIZE];
 
     __le64 cache_generation;
     __le64 uuid_tree_generation;
 
     /* the UUID written into btree blocks */
     u8 metadata_uuid[BTRFS_FSID_SIZE];
 
     /* Extent tree v2 */
     __le64 block_group_root;
     __le64 block_group_root_generation;
     u8 block_group_root_level;
 
     /* future expansion */
     u8 reserved8[7];
     __le64 reserved[25];
     u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
     struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
 
     /* Padded to 4096 bytes */
     u8 padding[565];
 } __attribute__ ((__packed__));
 static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE);
 
 /*
  * Compat flags that we support.  If any incompat flags are set other than the
  * ones specified below then we will fail to mount
  */
 #define BTRFS_FEATURE_COMPAT_SUPP       0ULL
 #define BTRFS_FEATURE_COMPAT_SAFE_SET       0ULL
 #define BTRFS_FEATURE_COMPAT_SAFE_CLEAR     0ULL
 
 #define BTRFS_FEATURE_COMPAT_RO_SUPP            \
     (BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |  \
      BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID | \
      BTRFS_FEATURE_COMPAT_RO_VERITY)
 
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_SET    0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR  0ULL
 
 #ifdef CONFIG_BTRFS_DEBUG
 /*
  * Extent tree v2 supported only with CONFIG_BTRFS_DEBUG
  */
 #define BTRFS_FEATURE_INCOMPAT_SUPP         \
     (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |     \
      BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |    \
      BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |      \
      BTRFS_FEATURE_INCOMPAT_BIG_METADATA |      \
      BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |      \
      BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD |     \
      BTRFS_FEATURE_INCOMPAT_RAID56 |        \
      BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |     \
      BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |   \
      BTRFS_FEATURE_INCOMPAT_NO_HOLES    |   \
      BTRFS_FEATURE_INCOMPAT_METADATA_UUID   |   \
      BTRFS_FEATURE_INCOMPAT_RAID1C34    |   \
      BTRFS_FEATURE_INCOMPAT_ZONED       |   \
      BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
 #else
 #define BTRFS_FEATURE_INCOMPAT_SUPP         \
     (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |     \
      BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |    \
      BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |      \
      BTRFS_FEATURE_INCOMPAT_BIG_METADATA |      \
      BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |      \
      BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD |     \
      BTRFS_FEATURE_INCOMPAT_RAID56 |        \
      BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |     \
      BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |   \
      BTRFS_FEATURE_INCOMPAT_NO_HOLES    |   \
      BTRFS_FEATURE_INCOMPAT_METADATA_UUID   |   \
      BTRFS_FEATURE_INCOMPAT_RAID1C34    |   \
      BTRFS_FEATURE_INCOMPAT_ZONED)
 #endif
 
 #define BTRFS_FEATURE_INCOMPAT_SAFE_SET         \
     (BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
 #define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR       0ULL
 
 /*
  * A leaf is full of items. offset and size tell us where to find
  * the item in the leaf (relative to the start of the data area)
  */
 struct btrfs_item {
     struct btrfs_disk_key key;
     __le32 offset;
     __le32 size;
 } __attribute__ ((__packed__));
 
 /*
  * leaves have an item area and a data area:
  * [item0, item1....itemN] [free space] [dataN...data1, data0]
  *
  * The data is separate from the items to get the keys closer together
  * during searches.
  */
 struct btrfs_leaf {
     struct btrfs_header header;
     struct btrfs_item items[];
 } __attribute__ ((__packed__));
 
 /*
  * all non-leaf blocks are nodes, they hold only keys and pointers to
  * other blocks
  */
 struct btrfs_key_ptr {
     struct btrfs_disk_key key;
     __le64 blockptr;
     __le64 generation;
 } __attribute__ ((__packed__));
 
 struct btrfs_node {
     struct btrfs_header header;
     struct btrfs_key_ptr ptrs[];
 } __attribute__ ((__packed__));
 
 /* Read ahead values for struct btrfs_path.reada */
 enum {
     READA_NONE,
     READA_BACK,
     READA_FORWARD,
     /*
      * Similar to READA_FORWARD but unlike it:
      *
      * 1) It will trigger readahead even for leaves that are not close to
      *    each other on disk;
      * 2) It also triggers readahead for nodes;
      * 3) During a search, even when a node or leaf is already in memory, it
      *    will still trigger readahead for other nodes and leaves that follow
      *    it.
      *
      * This is meant to be used only when we know we are iterating over the
      * entire tree or a very large part of it.
      */
     READA_FORWARD_ALWAYS,
 };
 
 /*
  * btrfs_paths remember the path taken from the root down to the leaf.
  * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
  * to any other levels that are present.
  *
  * The slots array records the index of the item or block pointer
  * used while walking the tree.
  */
 struct btrfs_path {
     struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
     int slots[BTRFS_MAX_LEVEL];
     /* if there is real range locking, this locks field will change */
     u8 locks[BTRFS_MAX_LEVEL];
     u8 reada;
     /* keep some upper locks as we walk down */
     u8 lowest_level;
 
     /*
      * set by btrfs_split_item, tells search_slot to keep all locks
      * and to force calls to keep space in the nodes
      */
     unsigned int search_for_split:1;
     unsigned int keep_locks:1;
     unsigned int skip_locking:1;
     unsigned int search_commit_root:1;
     unsigned int need_commit_sem:1;
     unsigned int skip_release_on_error:1;
     /*
      * Indicate that new item (btrfs_search_slot) is extending already
      * existing item and ins_len contains only the data size and not item
      * header (ie. sizeof(struct btrfs_item) is not included).
      */
     unsigned int search_for_extension:1;
 };
 #define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
                     sizeof(struct btrfs_item))
 struct btrfs_dev_replace {
     u64 replace_state;  /* see #define above */
     time64_t time_started;  /* seconds since 1-Jan-1970 */
     time64_t time_stopped;  /* seconds since 1-Jan-1970 */
     atomic64_t num_write_errors;
     atomic64_t num_uncorrectable_read_errors;
 
     u64 cursor_left;
     u64 committed_cursor_left;
     u64 cursor_left_last_write_of_item;
     u64 cursor_right;
 
     u64 cont_reading_from_srcdev_mode;  /* see #define above */
 
     int is_valid;
     int item_needs_writeback;
     struct btrfs_device *srcdev;
     struct btrfs_device *tgtdev;
 
     struct mutex lock_finishing_cancel_unmount;
     struct rw_semaphore rwsem;
 
     struct btrfs_scrub_progress scrub_progress;
 
     struct percpu_counter bio_counter;
     wait_queue_head_t replace_wait;
 };
 
 /*
  * free clusters are used to claim free space in relatively large chunks,
  * allowing us to do less seeky writes. They are used for all metadata
  * allocations. In ssd_spread mode they are also used for data allocations.
  */
 struct btrfs_free_cluster {
     spinlock_t lock;
     spinlock_t refill_lock;
     struct rb_root root;
 
     /* largest extent in this cluster */
     u64 max_size;
 
     /* first extent starting offset */
     u64 window_start;
 
     /* We did a full search and couldn't create a cluster */
     bool fragmented;
 
     struct btrfs_block_group *block_group;
     /*
      * when a cluster is allocated from a block group, we put the
      * cluster onto a list in the block group so that it can
      * be freed before the block group is freed.
      */
     struct list_head block_group_list;
 };
 
 enum btrfs_caching_type {
     BTRFS_CACHE_NO,
     BTRFS_CACHE_STARTED,
     BTRFS_CACHE_FINISHED,
     BTRFS_CACHE_ERROR,
 };
 
 /*
  * Tree to record all locked full stripes of a RAID5/6 block group
  */
 struct btrfs_full_stripe_locks_tree {
     struct rb_root root;
     struct mutex lock;
 };
 
 /* Discard control. */
 /*
  * Async discard uses multiple lists to differentiate the discard filter
  * parameters.  Index 0 is for completely free block groups where we need to
  * ensure the entire block group is trimmed without being lossy.  Indices
  * afterwards represent monotonically decreasing discard filter sizes to
  * prioritize what should be discarded next.
  */
 #define BTRFS_NR_DISCARD_LISTS      3
 #define BTRFS_DISCARD_INDEX_UNUSED  0
 #define BTRFS_DISCARD_INDEX_START   1
 
 struct btrfs_discard_ctl {
     struct workqueue_struct *discard_workers;
     struct delayed_work work;
     spinlock_t lock;
     struct btrfs_block_group *block_group;
     struct list_head discard_list[BTRFS_NR_DISCARD_LISTS];
     u64 prev_discard;
     u64 prev_discard_time;
     atomic_t discardable_extents;
     atomic64_t discardable_bytes;
     u64 max_discard_size;
     u64 delay_ms;
     u32 iops_limit;
     u32 kbps_limit;
     u64 discard_extent_bytes;
     u64 discard_bitmap_bytes;
     atomic64_t discard_bytes_saved;
 };
 
 void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info);
 
 /* fs_info */
 struct reloc_control;
 struct btrfs_device;
 struct btrfs_fs_devices;
 struct btrfs_balance_control;
 struct btrfs_delayed_root;
 
 /*
  * Block group or device which contains an active swapfile. Used for preventing
  * unsafe operations while a swapfile is active.
  *
  * These are sorted on (ptr, inode) (note that a block group or device can
  * contain more than one swapfile). We compare the pointer values because we
  * don't actually care what the object is, we just need a quick check whether
  * the object exists in the rbtree.
  */
 struct btrfs_swapfile_pin {
     struct rb_node node;
     void *ptr;
     struct inode *inode;
     /*
      * If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
      * points to a struct btrfs_device.
      */
     bool is_block_group;
     /*
      * Only used when 'is_block_group' is true and it is the number of
      * extents used by a swapfile for this block group ('ptr' field).
      */
     int bg_extent_count;
 };
 
 bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
 
 enum {
     BTRFS_FS_CLOSING_START,
     BTRFS_FS_CLOSING_DONE,
     BTRFS_FS_LOG_RECOVERING,
     BTRFS_FS_OPEN,
     BTRFS_FS_QUOTA_ENABLED,
     BTRFS_FS_UPDATE_UUID_TREE_GEN,
     BTRFS_FS_CREATING_FREE_SPACE_TREE,
     BTRFS_FS_BTREE_ERR,
     BTRFS_FS_LOG1_ERR,
     BTRFS_FS_LOG2_ERR,
     BTRFS_FS_QUOTA_OVERRIDE,
     /* Used to record internally whether fs has been frozen */
     BTRFS_FS_FROZEN,
     /*
      * Indicate that balance has been set up from the ioctl and is in the
      * main phase. The fs_info::balance_ctl is initialized.
      */
     BTRFS_FS_BALANCE_RUNNING,
 
     /*
      * Indicate that relocation of a chunk has started, it's set per chunk
      * and is toggled between chunks.
      */
     BTRFS_FS_RELOC_RUNNING,
 
     /* Indicate that the cleaner thread is awake and doing something. */
     BTRFS_FS_CLEANER_RUNNING,
 
     /*
      * The checksumming has an optimized version and is considered fast,
      * so we don't need to offload checksums to workqueues.
      */
     BTRFS_FS_CSUM_IMPL_FAST,
 
     /* Indicate that the discard workqueue can service discards. */
     BTRFS_FS_DISCARD_RUNNING,
 
     /* Indicate that we need to cleanup space cache v1 */
     BTRFS_FS_CLEANUP_SPACE_CACHE_V1,
 
     /* Indicate that we can't trust the free space tree for caching yet */
     BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED,
 
     /* Indicate whether there are any tree modification log users */
     BTRFS_FS_TREE_MOD_LOG_USERS,
 
     /* Indicate that we want the transaction kthread to commit right now. */
     BTRFS_FS_COMMIT_TRANS,
 
     /* Indicate we have half completed snapshot deletions pending. */
     BTRFS_FS_UNFINISHED_DROPS,
 
     /* Indicate we have to finish a zone to do next allocation. */
     BTRFS_FS_NEED_ZONE_FINISH,
 
 #if BITS_PER_LONG == 32
     /* Indicate if we have error/warn message printed on 32bit systems */
     BTRFS_FS_32BIT_ERROR,
     BTRFS_FS_32BIT_WARN,
 #endif
 };
 
 /*
  * Exclusive operations (device replace, resize, device add/remove, balance)
  */
 enum btrfs_exclusive_operation {
     BTRFS_EXCLOP_NONE,
     BTRFS_EXCLOP_BALANCE_PAUSED,
     BTRFS_EXCLOP_BALANCE,
     BTRFS_EXCLOP_DEV_ADD,
     BTRFS_EXCLOP_DEV_REMOVE,
     BTRFS_EXCLOP_DEV_REPLACE,
     BTRFS_EXCLOP_RESIZE,
     BTRFS_EXCLOP_SWAP_ACTIVATE,
 };
 
 /* Store data about transaction commits, exported via sysfs. */
 struct btrfs_commit_stats {
     /* Total number of commits */
     u64 commit_count;
     /* The maximum commit duration so far in ns */
     u64 max_commit_dur;
     /* The last commit duration in ns */
     u64 last_commit_dur;
     /* The total commit duration in ns */
     u64 total_commit_dur;
 };
 
 struct btrfs_fs_info {
     u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
     unsigned long flags;
     struct btrfs_root *tree_root;
     struct btrfs_root *chunk_root;
     struct btrfs_root *dev_root;
     struct btrfs_root *fs_root;
     struct btrfs_root *quota_root;
     struct btrfs_root *uuid_root;
     struct btrfs_root *data_reloc_root;
     struct btrfs_root *block_group_root;
 
     /* the log root tree is a directory of all the other log roots */
     struct btrfs_root *log_root_tree;
 
     /* The tree that holds the global roots (csum, extent, etc) */
     rwlock_t global_root_lock;
     struct rb_root global_root_tree;
 
     spinlock_t fs_roots_radix_lock;
     struct radix_tree_root fs_roots_radix;
 
     /* block group cache stuff */
     rwlock_t block_group_cache_lock;
     struct rb_root_cached block_group_cache_tree;
 
     /* keep track of unallocated space */
     atomic64_t free_chunk_space;
 
     /* Track ranges which are used by log trees blocks/logged data extents */
     struct extent_io_tree excluded_extents;
 
     /* logical->physical extent mapping */
     struct extent_map_tree mapping_tree;
 
     /*
      * block reservation for extent, checksum, root tree and
      * delayed dir index item
      */
     struct btrfs_block_rsv global_block_rsv;
     /* block reservation for metadata operations */
     struct btrfs_block_rsv trans_block_rsv;
     /* block reservation for chunk tree */
     struct btrfs_block_rsv chunk_block_rsv;
     /* block reservation for delayed operations */
     struct btrfs_block_rsv delayed_block_rsv;
     /* block reservation for delayed refs */
     struct btrfs_block_rsv delayed_refs_rsv;
 
     struct btrfs_block_rsv empty_block_rsv;
 
     u64 generation;
     u64 last_trans_committed;
     /*
      * Generation of the last transaction used for block group relocation
      * since the filesystem was last mounted (or 0 if none happened yet).
      * Must be written and read while holding btrfs_fs_info::commit_root_sem.
      */
     u64 last_reloc_trans;
     u64 avg_delayed_ref_runtime;
 
     /*
      * this is updated to the current trans every time a full commit
      * is required instead of the faster short fsync log commits
      */
     u64 last_trans_log_full_commit;
     unsigned long mount_opt;
     /*
      * Track requests for actions that need to be done during transaction
      * commit (like for some mount options).
      */
     unsigned long pending_changes;
     unsigned long compress_type:4;
     unsigned int compress_level;
     u32 commit_interval;
     /*
      * It is a suggestive number, the read side is safe even it gets a
      * wrong number because we will write out the data into a regular
      * extent. The write side(mount/remount) is under ->s_umount lock,
      * so it is also safe.
      */
     u64 max_inline;
 
     struct btrfs_transaction *running_transaction;
     wait_queue_head_t transaction_throttle;
     wait_queue_head_t transaction_wait;
     wait_queue_head_t transaction_blocked_wait;
     wait_queue_head_t async_submit_wait;
 
     /*
      * Used to protect the incompat_flags, compat_flags, compat_ro_flags
      * when they are updated.
      *
      * Because we do not clear the flags for ever, so we needn't use
      * the lock on the read side.
      *
      * We also needn't use the lock when we mount the fs, because
      * there is no other task which will update the flag.
      */
     spinlock_t super_lock;
     struct btrfs_super_block *super_copy;
     struct btrfs_super_block *super_for_commit;
     struct super_block *sb;
     struct inode *btree_inode;
     struct mutex tree_log_mutex;
     struct mutex transaction_kthread_mutex;
     struct mutex cleaner_mutex;
     struct mutex chunk_mutex;
 
     /*
      * this is taken to make sure we don't set block groups ro after
      * the free space cache has been allocated on them
      */
     struct mutex ro_block_group_mutex;
 
     /* this is used during read/modify/write to make sure
      * no two ios are trying to mod the same stripe at the same
      * time
      */
     struct btrfs_stripe_hash_table *stripe_hash_table;
 
     /*
      * this protects the ordered operations list only while we are
      * processing all of the entries on it.  This way we make
      * sure the commit code doesn't find the list temporarily empty
      * because another function happens to be doing non-waiting preflush
      * before jumping into the main commit.
      */
     struct mutex ordered_operations_mutex;
 
     struct rw_semaphore commit_root_sem;
 
     struct rw_semaphore cleanup_work_sem;
 
     struct rw_semaphore subvol_sem;
 
     spinlock_t trans_lock;
     /*
      * the reloc mutex goes with the trans lock, it is taken
      * during commit to protect us from the relocation code
      */
     struct mutex reloc_mutex;
 
     struct list_head trans_list;
     struct list_head dead_roots;
     struct list_head caching_block_groups;
 
     spinlock_t delayed_iput_lock;
     struct list_head delayed_iputs;
     atomic_t nr_delayed_iputs;
     wait_queue_head_t delayed_iputs_wait;
 
     atomic64_t tree_mod_seq;
 
     /* this protects tree_mod_log and tree_mod_seq_list */
     rwlock_t tree_mod_log_lock;
     struct rb_root tree_mod_log;
     struct list_head tree_mod_seq_list;
 
     atomic_t async_delalloc_pages;
 
     /*
      * this is used to protect the following list -- ordered_roots.
      */
     spinlock_t ordered_root_lock;
 
     /*
      * all fs/file tree roots in which there are data=ordered extents
      * pending writeback are added into this list.
      *
      * these can span multiple transactions and basically include
      * every dirty data page that isn't from nodatacow
      */
     struct list_head ordered_roots;
 
     struct mutex delalloc_root_mutex;
     spinlock_t delalloc_root_lock;
     /* all fs/file tree roots that have delalloc inodes. */
     struct list_head delalloc_roots;
 
     /*
      * there is a pool of worker threads for checksumming during writes
      * and a pool for checksumming after reads.  This is because readers
      * can run with FS locks held, and the writers may be waiting for
      * those locks.  We don't want ordering in the pending list to cause
      * deadlocks, and so the two are serviced separately.
      *
      * A third pool does submit_bio to avoid deadlocking with the other
      * two
      */
     struct btrfs_workqueue *workers;
     struct btrfs_workqueue *hipri_workers;
     struct btrfs_workqueue *delalloc_workers;
     struct btrfs_workqueue *flush_workers;
     struct workqueue_struct *endio_workers;
     struct workqueue_struct *endio_meta_workers;
     struct workqueue_struct *endio_raid56_workers;
     struct workqueue_struct *rmw_workers;
     struct workqueue_struct *compressed_write_workers;
     struct btrfs_workqueue *endio_write_workers;
     struct btrfs_workqueue *endio_freespace_worker;
     struct btrfs_workqueue *caching_workers;
 
     /*
      * fixup workers take dirty pages that didn't properly go through
      * the cow mechanism and make them safe to write.  It happens
      * for the sys_munmap function call path
      */
     struct btrfs_workqueue *fixup_workers;
     struct btrfs_workqueue *delayed_workers;
 
     struct task_struct *transaction_kthread;
     struct task_struct *cleaner_kthread;
     u32 thread_pool_size;
 
     struct kobject *space_info_kobj;
     struct kobject *qgroups_kobj;
 
     /* used to keep from writing metadata until there is a nice batch */
     struct percpu_counter dirty_metadata_bytes;
     struct percpu_counter delalloc_bytes;
     struct percpu_counter ordered_bytes;
     s32 dirty_metadata_batch;
     s32 delalloc_batch;
 
     struct list_head dirty_cowonly_roots;
 
     struct btrfs_fs_devices *fs_devices;
 
     /*
      * The space_info list is effectively read only after initial
      * setup.  It is populated at mount time and cleaned up after
      * all block groups are removed.  RCU is used to protect it.
      */
     struct list_head space_info;
 
     struct btrfs_space_info *data_sinfo;
 
     struct reloc_control *reloc_ctl;
 
     /* data_alloc_cluster is only used in ssd_spread mode */
     struct btrfs_free_cluster data_alloc_cluster;
 
     /* all metadata allocations go through this cluster */
     struct btrfs_free_cluster meta_alloc_cluster;
 
     /* auto defrag inodes go here */
     spinlock_t defrag_inodes_lock;
     struct rb_root defrag_inodes;
     atomic_t defrag_running;
 
     /* Used to protect avail_{data, metadata, system}_alloc_bits */
     seqlock_t profiles_lock;
     /*
      * these three are in extended format (availability of single
      * chunks is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other
      * types are denoted by corresponding BTRFS_BLOCK_GROUP_* bits)
      */
     u64 avail_data_alloc_bits;
     u64 avail_metadata_alloc_bits;
     u64 avail_system_alloc_bits;
 
     /* restriper state */
     spinlock_t balance_lock;
     struct mutex balance_mutex;
     atomic_t balance_pause_req;
     atomic_t balance_cancel_req;
     struct btrfs_balance_control *balance_ctl;
     wait_queue_head_t balance_wait_q;
 
     /* Cancellation requests for chunk relocation */
     atomic_t reloc_cancel_req;
 
     u32 data_chunk_allocations;
     u32 metadata_ratio;
 
     void *bdev_holder;
 
     /* private scrub information */
     struct mutex scrub_lock;
     atomic_t scrubs_running;
     atomic_t scrub_pause_req;
     atomic_t scrubs_paused;
     atomic_t scrub_cancel_req;
     wait_queue_head_t scrub_pause_wait;
     /*
      * The worker pointers are NULL iff the refcount is 0, ie. scrub is not
      * running.
      */
     refcount_t scrub_workers_refcnt;
     struct workqueue_struct *scrub_workers;
     struct workqueue_struct *scrub_wr_completion_workers;
     struct workqueue_struct *scrub_parity_workers;
     struct btrfs_subpage_info *subpage_info;
 
     struct btrfs_discard_ctl discard_ctl;
 
 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
     u32 check_integrity_print_mask;
 #endif
     /* is qgroup tracking in a consistent state? */
     u64 qgroup_flags;
 
     /* holds configuration and tracking. Protected by qgroup_lock */
     struct rb_root qgroup_tree;
     spinlock_t qgroup_lock;
 
     /*
      * used to avoid frequently calling ulist_alloc()/ulist_free()
      * when doing qgroup accounting, it must be protected by qgroup_lock.
      */
     struct ulist *qgroup_ulist;
 
     /*
      * Protect user change for quota operations. If a transaction is needed,
      * it must be started before locking this lock.
      */
     struct mutex qgroup_ioctl_lock;
 
     /* list of dirty qgroups to be written at next commit */
     struct list_head dirty_qgroups;
 
     /* used by qgroup for an efficient tree traversal */
     u64 qgroup_seq;
 
     /* qgroup rescan items */
     struct mutex qgroup_rescan_lock; /* protects the progress item */
     struct btrfs_key qgroup_rescan_progress;
     struct btrfs_workqueue *qgroup_rescan_workers;
     struct completion qgroup_rescan_completion;
     struct btrfs_work qgroup_rescan_work;
     bool qgroup_rescan_running; /* protected by qgroup_rescan_lock */
 
     /* filesystem state */
     unsigned long fs_state;
 
     struct btrfs_delayed_root *delayed_root;
 
     /* Extent buffer radix tree */
     spinlock_t buffer_lock;
     /* Entries are eb->start / sectorsize */
     struct radix_tree_root buffer_radix;
 
     /* next backup root to be overwritten */
     int backup_root_index;
 
     /* device replace state */
     struct btrfs_dev_replace dev_replace;
 
     struct semaphore uuid_tree_rescan_sem;
 
     /* Used to reclaim the metadata space in the background. */
     struct work_struct async_reclaim_work;
     struct work_struct async_data_reclaim_work;
     struct work_struct preempt_reclaim_work;
 
     /* Reclaim partially filled block groups in the background */
     struct work_struct reclaim_bgs_work;
     struct list_head reclaim_bgs;
     int bg_reclaim_threshold;
 
     spinlock_t unused_bgs_lock;
     struct list_head unused_bgs;
     struct mutex unused_bg_unpin_mutex;
     /* Protect block groups that are going to be deleted */
     struct mutex reclaim_bgs_lock;
 
     /* Cached block sizes */
     u32 nodesize;
     u32 sectorsize;
     /* ilog2 of sectorsize, use to avoid 64bit division */
     u32 sectorsize_bits;
     u32 csum_size;
     u32 csums_per_leaf;
     u32 stripesize;
 
     /*
      * Maximum size of an extent. BTRFS_MAX_EXTENT_SIZE on regular
      * filesystem, on zoned it depends on the device constraints.
      */
     u64 max_extent_size;
 
     /* Block groups and devices containing active swapfiles. */
     spinlock_t swapfile_pins_lock;
     struct rb_root swapfile_pins;
 
     struct crypto_shash *csum_shash;
 
     /* Type of exclusive operation running, protected by super_lock */
     enum btrfs_exclusive_operation exclusive_operation;
 
     /*
      * Zone size > 0 when in ZONED mode, otherwise it's used for a check
      * if the mode is enabled
      */
     u64 zone_size;
 
     /* Max size to emit ZONE_APPEND write command */
     u64 max_zone_append_size;
     struct mutex zoned_meta_io_lock;
     spinlock_t treelog_bg_lock;
     u64 treelog_bg;
 
     /*
      * Start of the dedicated data relocation block group, protected by
      * relocation_bg_lock.
      */
     spinlock_t relocation_bg_lock;
     u64 data_reloc_bg;
     struct mutex zoned_data_reloc_io_lock;
 
     u64 nr_global_roots;
 
     spinlock_t zone_active_bgs_lock;
     struct list_head zone_active_bgs;
 
     /* Updates are not protected by any lock */
     struct btrfs_commit_stats commit_stats;
 
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
     spinlock_t ref_verify_lock;
     struct rb_root block_tree;
 #endif
 
 #ifdef CONFIG_BTRFS_DEBUG
     struct kobject *debug_kobj;
     struct kobject *discard_debug_kobj;
     struct list_head allocated_roots;
 
     spinlock_t eb_leak_lock;
     struct list_head allocated_ebs;
 #endif
 };
 
 static inline struct btrfs_fs_info *btrfs_sb(struct super_block *sb)
 {
     return sb->s_fs_info;
 }
 
 /*
  * The state of btrfs root
  */
 enum {
     /*
      * btrfs_record_root_in_trans is a multi-step process, and it can race
      * with the balancing code.   But the race is very small, and only the
      * first time the root is added to each transaction.  So IN_TRANS_SETUP
      * is used to tell us when more checks are required
      */
     BTRFS_ROOT_IN_TRANS_SETUP,
 
     /*
      * Set if tree blocks of this root can be shared by other roots.
      * Only subvolume trees and their reloc trees have this bit set.
      * Conflicts with TRACK_DIRTY bit.
      *
      * This affects two things:
      *
      * - How balance works
      *   For shareable roots, we need to use reloc tree and do path
      *   replacement for balance, and need various pre/post hooks for
      *   snapshot creation to handle them.
      *
      *   While for non-shareable trees, we just simply do a tree search
      *   with COW.
      *
      * - How dirty roots are tracked
      *   For shareable roots, btrfs_record_root_in_trans() is needed to
      *   track them, while non-subvolume roots have TRACK_DIRTY bit, they
      *   don't need to set this manually.
      */
     BTRFS_ROOT_SHAREABLE,
     BTRFS_ROOT_TRACK_DIRTY,
     BTRFS_ROOT_IN_RADIX,
     BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
     BTRFS_ROOT_DEFRAG_RUNNING,
     BTRFS_ROOT_FORCE_COW,
     BTRFS_ROOT_MULTI_LOG_TASKS,
     BTRFS_ROOT_DIRTY,
     BTRFS_ROOT_DELETING,
 
     /*
      * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
      *
      * Set for the subvolume tree owning the reloc tree.
      */
     BTRFS_ROOT_DEAD_RELOC_TREE,
     /* Mark dead root stored on device whose cleanup needs to be resumed */
     BTRFS_ROOT_DEAD_TREE,
     /* The root has a log tree. Used for subvolume roots and the tree root. */
     BTRFS_ROOT_HAS_LOG_TREE,
     /* Qgroup flushing is in progress */
     BTRFS_ROOT_QGROUP_FLUSHING,
     /* We started the orphan cleanup for this root. */
     BTRFS_ROOT_ORPHAN_CLEANUP,
     /* This root has a drop operation that was started previously. */
     BTRFS_ROOT_UNFINISHED_DROP,
     /* This reloc root needs to have its buffers lockdep class reset. */
     BTRFS_ROOT_RESET_LOCKDEP_CLASS,
 };
 
 static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info)
 {
     clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);
 }
 
 /*
  * Record swapped tree blocks of a subvolume tree for delayed subtree trace
  * code. For detail check comment in fs/btrfs/qgroup.c.
  */
 struct btrfs_qgroup_swapped_blocks {
     spinlock_t lock;
     /* RM_EMPTY_ROOT() of above blocks[] */
     bool swapped;
     struct rb_root blocks[BTRFS_MAX_LEVEL];
 };
 
 /*
  * in ram representation of the tree.  extent_root is used for all allocations
  * and for the extent tree extent_root root.
  */
 struct btrfs_root {
     struct rb_node rb_node;
 
     struct extent_buffer *node;
 
     struct extent_buffer *commit_root;
     struct btrfs_root *log_root;
     struct btrfs_root *reloc_root;
 
     unsigned long state;
     struct btrfs_root_item root_item;
     struct btrfs_key root_key;
     struct btrfs_fs_info *fs_info;
     struct extent_io_tree dirty_log_pages;
 
     struct mutex objectid_mutex;
 
     spinlock_t accounting_lock;
     struct btrfs_block_rsv *block_rsv;
 
     struct mutex log_mutex;
     wait_queue_head_t log_writer_wait;
     wait_queue_head_t log_commit_wait[2];
     struct list_head log_ctxs[2];
     /* Used only for log trees of subvolumes, not for the log root tree */
     atomic_t log_writers;
     atomic_t log_commit[2];
     /* Used only for log trees of subvolumes, not for the log root tree */
     atomic_t log_batch;
     int log_transid;
     /* No matter the commit succeeds or not*/
     int log_transid_committed;
     /* Just be updated when the commit succeeds. */
     int last_log_commit;
     pid_t log_start_pid;
 
     u64 last_trans;
 
     u32 type;
 
     u64 free_objectid;
 
     struct btrfs_key defrag_progress;
     struct btrfs_key defrag_max;
 
     /* The dirty list is only used by non-shareable roots */
     struct list_head dirty_list;
 
     struct list_head root_list;
 
     spinlock_t log_extents_lock[2];
     struct list_head logged_list[2];
 
     spinlock_t inode_lock;
     /* red-black tree that keeps track of in-memory inodes */
     struct rb_root inode_tree;
 
     /*
      * radix tree that keeps track of delayed nodes of every inode,
      * protected by inode_lock
      */
     struct radix_tree_root delayed_nodes_tree;
     /*
      * right now this just gets used so that a root has its own devid
      * for stat.  It may be used for more later
      */
     dev_t anon_dev;
 
     spinlock_t root_item_lock;
     refcount_t refs;
 
     struct mutex delalloc_mutex;
     spinlock_t delalloc_lock;
     /*
      * all of the inodes that have delalloc bytes.  It is possible for
      * this list to be empty even when there is still dirty data=ordered
      * extents waiting to finish IO.
      */
     struct list_head delalloc_inodes;
     struct list_head delalloc_root;
     u64 nr_delalloc_inodes;
 
     struct mutex ordered_extent_mutex;
     /*
      * this is used by the balancing code to wait for all the pending
      * ordered extents
      */
     spinlock_t ordered_extent_lock;
 
     /*
      * all of the data=ordered extents pending writeback
      * these can span multiple transactions and basically include
      * every dirty data page that isn't from nodatacow
      */
     struct list_head ordered_extents;
     struct list_head ordered_root;
     u64 nr_ordered_extents;
 
     /*
      * Not empty if this subvolume root has gone through tree block swap
      * (relocation)
      *
      * Will be used by reloc_control::dirty_subvol_roots.
      */
     struct list_head reloc_dirty_list;
 
     /*
      * Number of currently running SEND ioctls to prevent
      * manipulation with the read-only status via SUBVOL_SETFLAGS
      */
     int send_in_progress;
     /*
      * Number of currently running deduplication operations that have a
      * destination inode belonging to this root. Protected by the lock
      * root_item_lock.
      */
     int dedupe_in_progress;
     /* For exclusion of snapshot creation and nocow writes */
     struct btrfs_drew_lock snapshot_lock;
 
     atomic_t snapshot_force_cow;
 
     /* For qgroup metadata reserved space */
     spinlock_t qgroup_meta_rsv_lock;
     u64 qgroup_meta_rsv_pertrans;
     u64 qgroup_meta_rsv_prealloc;
     wait_queue_head_t qgroup_flush_wait;
 
     /* Number of active swapfiles */
     atomic_t nr_swapfiles;
 
     /* Record pairs of swapped blocks for qgroup */
     struct btrfs_qgroup_swapped_blocks swapped_blocks;
 
     /* Used only by log trees, when logging csum items */
     struct extent_io_tree log_csum_range;
 
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
     u64 alloc_bytenr;
 #endif
 
 #ifdef CONFIG_BTRFS_DEBUG
     struct list_head leak_list;
 #endif
 };
 
 /*
  * Structure that conveys information about an extent that is going to replace
  * all the extents in a file range.
  */
 struct btrfs_replace_extent_info {
     u64 disk_offset;
     u64 disk_len;
     u64 data_offset;
     u64 data_len;
     u64 file_offset;
     /* Pointer to a file extent item of type regular or prealloc. */
     char *extent_buf;
     /*
      * Set to true when attempting to replace a file range with a new extent
      * described by this structure, set to false when attempting to clone an
      * existing extent into a file range.
      */
     bool is_new_extent;
     /* Indicate if we should update the inode's mtime and ctime. */
     bool update_times;
     /* Meaningful only if is_new_extent is true. */
     int qgroup_reserved;
     /*
      * Meaningful only if is_new_extent is true.
      * Used to track how many extent items we have already inserted in a
      * subvolume tree that refer to the extent described by this structure,
      * so that we know when to create a new delayed ref or update an existing
      * one.
      */
     int insertions;
 };
 
 /* Arguments for btrfs_drop_extents() */
 struct btrfs_drop_extents_args {
     /* Input parameters */
 
     /*
      * If NULL, btrfs_drop_extents() will allocate and free its own path.
      * If 'replace_extent' is true, this must not be NULL. Also the path
      * is always released except if 'replace_extent' is true and
      * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
      * the path is kept locked.
      */
     struct btrfs_path *path;
     /* Start offset of the range to drop extents from */
     u64 start;
     /* End (exclusive, last byte + 1) of the range to drop extents from */
     u64 end;
     /* If true drop all the extent maps in the range */
     bool drop_cache;
     /*
      * If true it means we want to insert a new extent after dropping all
      * the extents in the range. If this is true, the 'extent_item_size'
      * parameter must be set as well and the 'extent_inserted' field will
      * be set to true by btrfs_drop_extents() if it could insert the new
      * extent.
      * Note: when this is set to true the path must not be NULL.
      */
     bool replace_extent;
     /*
      * Used if 'replace_extent' is true. Size of the file extent item to
      * insert after dropping all existing extents in the range
      */
     u32 extent_item_size;
 
     /* Output parameters */
 
     /*
      * Set to the minimum between the input parameter 'end' and the end
      * (exclusive, last byte + 1) of the last dropped extent. This is always
      * set even if btrfs_drop_extents() returns an error.
      */
     u64 drop_end;
     /*
      * The number of allocated bytes found in the range. This can be smaller
      * than the range's length when there are holes in the range.
      */
     u64 bytes_found;
     /*
      * Only set if 'replace_extent' is true. Set to true if we were able
      * to insert a replacement extent after dropping all extents in the
      * range, otherwise set to false by btrfs_drop_extents().
      * Also, if btrfs_drop_extents() has set this to true it means it
      * returned with the path locked, otherwise if it has set this to
      * false it has returned with the path released.
      */
     bool extent_inserted;
 };
 
 struct btrfs_file_private {
     void *filldir_buf;
 };
 
 
 static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
 {
 
     return info->nodesize - sizeof(struct btrfs_header);
 }
 
 #define BTRFS_LEAF_DATA_OFFSET      offsetof(struct btrfs_leaf, items)
 
 static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
 {
     return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
 }
 
 static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
 {
     return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
 }
 
 #define BTRFS_FILE_EXTENT_INLINE_DATA_START     \
         (offsetof(struct btrfs_file_extent_item, disk_bytenr))
 static inline u32 BTRFS_MAX_INLINE_DATA_SIZE(const struct btrfs_fs_info *info)
 {
     return BTRFS_MAX_ITEM_SIZE(info) -
            BTRFS_FILE_EXTENT_INLINE_DATA_START;
 }
 
 static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
 {
     return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
 }
 
 /*
  * Flags for mount options.
  *
  * Note: don't forget to add new options to btrfs_show_options()
  */
 enum {
     BTRFS_MOUNT_NODATASUM           = (1UL << 0),
     BTRFS_MOUNT_NODATACOW           = (1UL << 1),
     BTRFS_MOUNT_NOBARRIER           = (1UL << 2),
     BTRFS_MOUNT_SSD             = (1UL << 3),
     BTRFS_MOUNT_DEGRADED            = (1UL << 4),
     BTRFS_MOUNT_COMPRESS            = (1UL << 5),
     BTRFS_MOUNT_NOTREELOG           = (1UL << 6),
     BTRFS_MOUNT_FLUSHONCOMMIT       = (1UL << 7),
     BTRFS_MOUNT_SSD_SPREAD          = (1UL << 8),
     BTRFS_MOUNT_NOSSD           = (1UL << 9),
     BTRFS_MOUNT_DISCARD_SYNC        = (1UL << 10),
     BTRFS_MOUNT_FORCE_COMPRESS          = (1UL << 11),
     BTRFS_MOUNT_SPACE_CACHE         = (1UL << 12),
     BTRFS_MOUNT_CLEAR_CACHE         = (1UL << 13),
     BTRFS_MOUNT_USER_SUBVOL_RM_ALLOWED  = (1UL << 14),
     BTRFS_MOUNT_ENOSPC_DEBUG        = (1UL << 15),
     BTRFS_MOUNT_AUTO_DEFRAG         = (1UL << 16),
     BTRFS_MOUNT_USEBACKUPROOT       = (1UL << 17),
     BTRFS_MOUNT_SKIP_BALANCE        = (1UL << 18),
     BTRFS_MOUNT_CHECK_INTEGRITY     = (1UL << 19),
     BTRFS_MOUNT_CHECK_INTEGRITY_DATA    = (1UL << 20),
     BTRFS_MOUNT_PANIC_ON_FATAL_ERROR    = (1UL << 21),
     BTRFS_MOUNT_RESCAN_UUID_TREE        = (1UL << 22),
     BTRFS_MOUNT_FRAGMENT_DATA       = (1UL << 23),
     BTRFS_MOUNT_FRAGMENT_METADATA       = (1UL << 24),
     BTRFS_MOUNT_FREE_SPACE_TREE     = (1UL << 25),
     BTRFS_MOUNT_NOLOGREPLAY         = (1UL << 26),
     BTRFS_MOUNT_REF_VERIFY          = (1UL << 27),
     BTRFS_MOUNT_DISCARD_ASYNC       = (1UL << 28),
     BTRFS_MOUNT_IGNOREBADROOTS      = (1UL << 29),
     BTRFS_MOUNT_IGNOREDATACSUMS     = (1UL << 30),
 };
 
 #define BTRFS_DEFAULT_COMMIT_INTERVAL   (30)
 #define BTRFS_DEFAULT_MAX_INLINE    (2048)
 
 #define btrfs_clear_opt(o, opt)     ((o) &= ~BTRFS_MOUNT_##opt)
 #define btrfs_set_opt(o, opt)       ((o) |= BTRFS_MOUNT_##opt)
 #define btrfs_raw_test_opt(o, opt)  ((o) & BTRFS_MOUNT_##opt)
 #define btrfs_test_opt(fs_info, opt)    ((fs_info)->mount_opt & \
                      BTRFS_MOUNT_##opt)
 
 #define btrfs_set_and_info(fs_info, opt, fmt, args...)          \
 do {                                    \
     if (!btrfs_test_opt(fs_info, opt))              \
         btrfs_info(fs_info, fmt, ##args);           \
     btrfs_set_opt(fs_info->mount_opt, opt);             \
 } while (0)
 
 #define btrfs_clear_and_info(fs_info, opt, fmt, args...)        \
 do {                                    \
     if (btrfs_test_opt(fs_info, opt))               \
         btrfs_info(fs_info, fmt, ##args);           \
     btrfs_clear_opt(fs_info->mount_opt, opt);           \
 } while (0)
 
 /*
  * Requests for changes that need to be done during transaction commit.
  *
  * Internal mount options that are used for special handling of the real
  * mount options (eg. cannot be set during remount and have to be set during
  * transaction commit)
  */
 
 #define BTRFS_PENDING_COMMIT            (0)
 
 #define btrfs_test_pending(info, opt)   \
     test_bit(BTRFS_PENDING_##opt, &(info)->pending_changes)
 #define btrfs_set_pending(info, opt)    \
     set_bit(BTRFS_PENDING_##opt, &(info)->pending_changes)
 #define btrfs_clear_pending(info, opt)  \
     clear_bit(BTRFS_PENDING_##opt, &(info)->pending_changes)
 
 /*
  * Helpers for setting pending mount option changes.
  *
  * Expects corresponding macros
  * BTRFS_PENDING_SET_ and CLEAR_ + short mount option name
  */
 #define btrfs_set_pending_and_info(info, opt, fmt, args...)            \
 do {                                                                   \
        if (!btrfs_raw_test_opt((info)->mount_opt, opt)) {              \
                btrfs_info((info), fmt, ##args);                        \
                btrfs_set_pending((info), SET_##opt);                   \
                btrfs_clear_pending((info), CLEAR_##opt);               \
        }                                                               \
 } while(0)
 
 #define btrfs_clear_pending_and_info(info, opt, fmt, args...)          \
 do {                                                                   \
        if (btrfs_raw_test_opt((info)->mount_opt, opt)) {               \
                btrfs_info((info), fmt, ##args);                        \
                btrfs_set_pending((info), CLEAR_##opt);                 \
                btrfs_clear_pending((info), SET_##opt);                 \
        }                                                               \
 } while(0)
 
 /*
  * Inode flags
  */
 #define BTRFS_INODE_NODATASUM       (1U << 0)
 #define BTRFS_INODE_NODATACOW       (1U << 1)
 #define BTRFS_INODE_READONLY        (1U << 2)
 #define BTRFS_INODE_NOCOMPRESS      (1U << 3)
 #define BTRFS_INODE_PREALLOC        (1U << 4)
 #define BTRFS_INODE_SYNC        (1U << 5)
 #define BTRFS_INODE_IMMUTABLE       (1U << 6)
 #define BTRFS_INODE_APPEND      (1U << 7)
 #define BTRFS_INODE_NODUMP      (1U << 8)
 #define BTRFS_INODE_NOATIME     (1U << 9)
 #define BTRFS_INODE_DIRSYNC     (1U << 10)
 #define BTRFS_INODE_COMPRESS        (1U << 11)
 
 #define BTRFS_INODE_ROOT_ITEM_INIT  (1U << 31)
 
 #define BTRFS_INODE_FLAG_MASK                       \
     (BTRFS_INODE_NODATASUM |                    \
      BTRFS_INODE_NODATACOW |                    \
      BTRFS_INODE_READONLY |                     \
      BTRFS_INODE_NOCOMPRESS |                   \
      BTRFS_INODE_PREALLOC |                     \
      BTRFS_INODE_SYNC |                     \
      BTRFS_INODE_IMMUTABLE |                    \
      BTRFS_INODE_APPEND |                       \
      BTRFS_INODE_NODUMP |                       \
      BTRFS_INODE_NOATIME |                      \
      BTRFS_INODE_DIRSYNC |                      \
      BTRFS_INODE_COMPRESS |                     \
      BTRFS_INODE_ROOT_ITEM_INIT)
 
 #define BTRFS_INODE_RO_VERITY       (1U << 0)
 
 #define BTRFS_INODE_RO_FLAG_MASK    (BTRFS_INODE_RO_VERITY)
 
 struct btrfs_map_token {
     struct extent_buffer *eb;
     char *kaddr;
     unsigned long offset;
 };
 
 #define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
                 ((bytes) >> (fs_info)->sectorsize_bits)
 
 static inline void btrfs_init_map_token(struct btrfs_map_token *token,
                     struct extent_buffer *eb)
 {
     token->eb = eb;
     token->kaddr = page_address(eb->pages[0]);
     token->offset = 0;
 }
 
 /* some macros to generate set/get functions for the struct fields.  This
  * assumes there is a lefoo_to_cpu for every type, so lets make a simple
  * one for u8:
  */
 #define le8_to_cpu(v) (v)
 #define cpu_to_le8(v) (v)
 #define __le8 u8
 
 static inline u8 get_unaligned_le8(const void *p)
 {
        return *(u8 *)p;
 }
 
 static inline void put_unaligned_le8(u8 val, void *p)
 {
        *(u8 *)p = val;
 }
 
 #define read_eb_member(eb, ptr, type, member, result) (\
     read_extent_buffer(eb, (char *)(result),            \
                ((unsigned long)(ptr)) +         \
                 offsetof(type, member),         \
                sizeof(((type *)0)->member)))
 
 #define write_eb_member(eb, ptr, type, member, result) (\
     write_extent_buffer(eb, (char *)(result),           \
                ((unsigned long)(ptr)) +         \
                 offsetof(type, member),         \
                sizeof(((type *)0)->member)))
 
 #define DECLARE_BTRFS_SETGET_BITS(bits)                 \
 u##bits btrfs_get_token_##bits(struct btrfs_map_token *token,       \
                    const void *ptr, unsigned long off); \
 void btrfs_set_token_##bits(struct btrfs_map_token *token,      \
                 const void *ptr, unsigned long off,     \
                 u##bits val);               \
 u##bits btrfs_get_##bits(const struct extent_buffer *eb,        \
              const void *ptr, unsigned long off);       \
 void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr,    \
               unsigned long off, u##bits val);
 
 DECLARE_BTRFS_SETGET_BITS(8)
 DECLARE_BTRFS_SETGET_BITS(16)
 DECLARE_BTRFS_SETGET_BITS(32)
 DECLARE_BTRFS_SETGET_BITS(64)
 
 #define BTRFS_SETGET_FUNCS(name, type, member, bits)            \
 static inline u##bits btrfs_##name(const struct extent_buffer *eb,  \
                    const type *s)           \
 {                                   \
     static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);  \
     return btrfs_get_##bits(eb, s, offsetof(type, member));     \
 }                                   \
 static inline void btrfs_set_##name(const struct extent_buffer *eb, type *s, \
                     u##bits val)            \
 {                                   \
     static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);  \
     btrfs_set_##bits(eb, s, offsetof(type, member), val);       \
 }                                   \
 static inline u##bits btrfs_token_##name(struct btrfs_map_token *token, \
                      const type *s)         \
 {                                   \
     static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);  \
     return btrfs_get_token_##bits(token, s, offsetof(type, member));\
 }                                   \
 static inline void btrfs_set_token_##name(struct btrfs_map_token *token,\
                       type *s, u##bits val)     \
 {                                   \
     static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);  \
     btrfs_set_token_##bits(token, s, offsetof(type, member), val);  \
 }
 
 #define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)     \
 static inline u##bits btrfs_##name(const struct extent_buffer *eb)  \
 {                                   \
     const type *p = page_address(eb->pages[0]) +            \
             offset_in_page(eb->start);          \
     return get_unaligned_le##bits(&p->member);          \
 }                                   \
 static inline void btrfs_set_##name(const struct extent_buffer *eb, \
                     u##bits val)            \
 {                                   \
     type *p = page_address(eb->pages[0]) + offset_in_page(eb->start); \
     put_unaligned_le##bits(val, &p->member);            \
 }
 
 #define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)      \
 static inline u##bits btrfs_##name(const type *s)           \
 {                                   \
     return get_unaligned_le##bits(&s->member);          \
 }                                   \
 static inline void btrfs_set_##name(type *s, u##bits val)       \
 {                                   \
     put_unaligned_le##bits(val, &s->member);            \
 }
 
 static inline u64 btrfs_device_total_bytes(const struct extent_buffer *eb,
                        struct btrfs_dev_item *s)
 {
     static_assert(sizeof(u64) ==
               sizeof(((struct btrfs_dev_item *)0))->total_bytes);
     return btrfs_get_64(eb, s, offsetof(struct btrfs_dev_item,
                         total_bytes));
 }
 static inline void btrfs_set_device_total_bytes(const struct extent_buffer *eb,
                         struct btrfs_dev_item *s,
                         u64 val)
 {
     static_assert(sizeof(u64) ==
               sizeof(((struct btrfs_dev_item *)0))->total_bytes);
     WARN_ON(!IS_ALIGNED(val, eb->fs_info->sectorsize));
     btrfs_set_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes), val);
 }
 
 
 BTRFS_SETGET_FUNCS(device_type, struct btrfs_dev_item, type, 64);
 BTRFS_SETGET_FUNCS(device_bytes_used, struct btrfs_dev_item, bytes_used, 64);
 BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32);
 BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
 BTRFS_SETGET_FUNCS(device_start_offset, struct btrfs_dev_item,
            start_offset, 64);
 BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
 BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
 BTRFS_SETGET_FUNCS(device_group, struct btrfs_dev_item, dev_group, 32);
 BTRFS_SETGET_FUNCS(device_seek_speed, struct btrfs_dev_item, seek_speed, 8);
 BTRFS_SETGET_FUNCS(device_bandwidth, struct btrfs_dev_item, bandwidth, 8);
 BTRFS_SETGET_FUNCS(device_generation, struct btrfs_dev_item, generation, 64);
 
 BTRFS_SETGET_STACK_FUNCS(stack_device_type, struct btrfs_dev_item, type, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_device_total_bytes, struct btrfs_dev_item,
              total_bytes, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_device_bytes_used, struct btrfs_dev_item,
              bytes_used, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_device_io_align, struct btrfs_dev_item,
              io_align, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_device_io_width, struct btrfs_dev_item,
              io_width, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_device_sector_size, struct btrfs_dev_item,
              sector_size, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_device_id, struct btrfs_dev_item, devid, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_device_group, struct btrfs_dev_item,
              dev_group, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_device_seek_speed, struct btrfs_dev_item,
              seek_speed, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_device_bandwidth, struct btrfs_dev_item,
              bandwidth, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_device_generation, struct btrfs_dev_item,
              generation, 64);
 
 static inline unsigned long btrfs_device_uuid(struct btrfs_dev_item *d)
 {
     return (unsigned long)d + offsetof(struct btrfs_dev_item, uuid);
 }
 
 static inline unsigned long btrfs_device_fsid(struct btrfs_dev_item *d)
 {
     return (unsigned long)d + offsetof(struct btrfs_dev_item, fsid);
 }
 
 BTRFS_SETGET_FUNCS(chunk_length, struct btrfs_chunk, length, 64);
 BTRFS_SETGET_FUNCS(chunk_owner, struct btrfs_chunk, owner, 64);
 BTRFS_SETGET_FUNCS(chunk_stripe_len, struct btrfs_chunk, stripe_len, 64);
 BTRFS_SETGET_FUNCS(chunk_io_align, struct btrfs_chunk, io_align, 32);
 BTRFS_SETGET_FUNCS(chunk_io_width, struct btrfs_chunk, io_width, 32);
 BTRFS_SETGET_FUNCS(chunk_sector_size, struct btrfs_chunk, sector_size, 32);
 BTRFS_SETGET_FUNCS(chunk_type, struct btrfs_chunk, type, 64);
 BTRFS_SETGET_FUNCS(chunk_num_stripes, struct btrfs_chunk, num_stripes, 16);
 BTRFS_SETGET_FUNCS(chunk_sub_stripes, struct btrfs_chunk, sub_stripes, 16);
 BTRFS_SETGET_FUNCS(stripe_devid, struct btrfs_stripe, devid, 64);
 BTRFS_SETGET_FUNCS(stripe_offset, struct btrfs_stripe, offset, 64);
 
 static inline char *btrfs_stripe_dev_uuid(struct btrfs_stripe *s)
 {
     return (char *)s + offsetof(struct btrfs_stripe, dev_uuid);
 }
 
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_length, struct btrfs_chunk, length, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_owner, struct btrfs_chunk, owner, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_stripe_len, struct btrfs_chunk,
              stripe_len, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_align, struct btrfs_chunk,
              io_align, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_width, struct btrfs_chunk,
              io_width, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_sector_size, struct btrfs_chunk,
              sector_size, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_type, struct btrfs_chunk, type, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_num_stripes, struct btrfs_chunk,
              num_stripes, 16);
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_sub_stripes, struct btrfs_chunk,
              sub_stripes, 16);
 BTRFS_SETGET_STACK_FUNCS(stack_stripe_devid, struct btrfs_stripe, devid, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_stripe_offset, struct btrfs_stripe, offset, 64);
 
 static inline struct btrfs_stripe *btrfs_stripe_nr(struct btrfs_chunk *c,
                            int nr)
 {
     unsigned long offset = (unsigned long)c;
     offset += offsetof(struct btrfs_chunk, stripe);
     offset += nr * sizeof(struct btrfs_stripe);
     return (struct btrfs_stripe *)offset;
 }
 
 static inline char *btrfs_stripe_dev_uuid_nr(struct btrfs_chunk *c, int nr)
 {
     return btrfs_stripe_dev_uuid(btrfs_stripe_nr(c, nr));
 }
 
 static inline u64 btrfs_stripe_offset_nr(const struct extent_buffer *eb,
                      struct btrfs_chunk *c, int nr)
 {
     return btrfs_stripe_offset(eb, btrfs_stripe_nr(c, nr));
 }
 
 static inline u64 btrfs_stripe_devid_nr(const struct extent_buffer *eb,
                      struct btrfs_chunk *c, int nr)
 {
     return btrfs_stripe_devid(eb, btrfs_stripe_nr(c, nr));
 }
 
 /* struct btrfs_block_group_item */
 BTRFS_SETGET_STACK_FUNCS(stack_block_group_used, struct btrfs_block_group_item,
              used, 64);
 BTRFS_SETGET_FUNCS(block_group_used, struct btrfs_block_group_item,
              used, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_block_group_chunk_objectid,
             struct btrfs_block_group_item, chunk_objectid, 64);
 
 BTRFS_SETGET_FUNCS(block_group_chunk_objectid,
            struct btrfs_block_group_item, chunk_objectid, 64);
 BTRFS_SETGET_FUNCS(block_group_flags,
            struct btrfs_block_group_item, flags, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_block_group_flags,
             struct btrfs_block_group_item, flags, 64);
 
 /* struct btrfs_free_space_info */
 BTRFS_SETGET_FUNCS(free_space_extent_count, struct btrfs_free_space_info,
            extent_count, 32);
 BTRFS_SETGET_FUNCS(free_space_flags, struct btrfs_free_space_info, flags, 32);
 
 /* struct btrfs_inode_ref */
 BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
 BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64);
 
 /* struct btrfs_inode_extref */
 BTRFS_SETGET_FUNCS(inode_extref_parent, struct btrfs_inode_extref,
            parent_objectid, 64);
 BTRFS_SETGET_FUNCS(inode_extref_name_len, struct btrfs_inode_extref,
            name_len, 16);
 BTRFS_SETGET_FUNCS(inode_extref_index, struct btrfs_inode_extref, index, 64);
 
 /* struct btrfs_inode_item */
 BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
 BTRFS_SETGET_FUNCS(inode_sequence, struct btrfs_inode_item, sequence, 64);
 BTRFS_SETGET_FUNCS(inode_transid, struct btrfs_inode_item, transid, 64);
 BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
 BTRFS_SETGET_FUNCS(inode_nbytes, struct btrfs_inode_item, nbytes, 64);
 BTRFS_SETGET_FUNCS(inode_block_group, struct btrfs_inode_item, block_group, 64);
 BTRFS_SETGET_FUNCS(inode_nlink, struct btrfs_inode_item, nlink, 32);
 BTRFS_SETGET_FUNCS(inode_uid, struct btrfs_inode_item, uid, 32);
 BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32);
 BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32);
 BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64);
 BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
              generation, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
              sequence, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
              transid, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
              nbytes, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
              block_group, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
 BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64);
 BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
 
 /* struct btrfs_dev_extent */
 BTRFS_SETGET_FUNCS(dev_extent_chunk_tree, struct btrfs_dev_extent,
            chunk_tree, 64);
 BTRFS_SETGET_FUNCS(dev_extent_chunk_objectid, struct btrfs_dev_extent,
            chunk_objectid, 64);
 BTRFS_SETGET_FUNCS(dev_extent_chunk_offset, struct btrfs_dev_extent,
            chunk_offset, 64);
 BTRFS_SETGET_FUNCS(dev_extent_length, struct btrfs_dev_extent, length, 64);
 BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 64);
 BTRFS_SETGET_FUNCS(extent_generation, struct btrfs_extent_item,
            generation, 64);
 BTRFS_SETGET_FUNCS(extent_flags, struct btrfs_extent_item, flags, 64);
 
 BTRFS_SETGET_FUNCS(tree_block_level, struct btrfs_tree_block_info, level, 8);
 
 static inline void btrfs_tree_block_key(const struct extent_buffer *eb,
                     struct btrfs_tree_block_info *item,
                     struct btrfs_disk_key *key)
 {
     read_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
 }
 
 static inline void btrfs_set_tree_block_key(const struct extent_buffer *eb,
                         struct btrfs_tree_block_info *item,
                         struct btrfs_disk_key *key)
 {
     write_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
 }
 
 BTRFS_SETGET_FUNCS(extent_data_ref_root, struct btrfs_extent_data_ref,
            root, 64);
 BTRFS_SETGET_FUNCS(extent_data_ref_objectid, struct btrfs_extent_data_ref,
            objectid, 64);
 BTRFS_SETGET_FUNCS(extent_data_ref_offset, struct btrfs_extent_data_ref,
            offset, 64);
 BTRFS_SETGET_FUNCS(extent_data_ref_count, struct btrfs_extent_data_ref,
            count, 32);
 
 BTRFS_SETGET_FUNCS(shared_data_ref_count, struct btrfs_shared_data_ref,
            count, 32);
 
 BTRFS_SETGET_FUNCS(extent_inline_ref_type, struct btrfs_extent_inline_ref,
            type, 8);
 BTRFS_SETGET_FUNCS(extent_inline_ref_offset, struct btrfs_extent_inline_ref,
            offset, 64);
 
 static inline u32 btrfs_extent_inline_ref_size(int type)
 {
     if (type == BTRFS_TREE_BLOCK_REF_KEY ||
         type == BTRFS_SHARED_BLOCK_REF_KEY)
         return sizeof(struct btrfs_extent_inline_ref);
     if (type == BTRFS_SHARED_DATA_REF_KEY)
         return sizeof(struct btrfs_shared_data_ref) +
                sizeof(struct btrfs_extent_inline_ref);
     if (type == BTRFS_EXTENT_DATA_REF_KEY)
         return sizeof(struct btrfs_extent_data_ref) +
                offsetof(struct btrfs_extent_inline_ref, offset);
     return 0;
 }
 
 /* struct btrfs_node */
 BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);
 BTRFS_SETGET_FUNCS(key_generation, struct btrfs_key_ptr, generation, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_key_blockptr, struct btrfs_key_ptr,
              blockptr, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_key_generation, struct btrfs_key_ptr,
              generation, 64);
 
 static inline u64 btrfs_node_blockptr(const struct extent_buffer *eb, int nr)
 {
     unsigned long ptr;
     ptr = offsetof(struct btrfs_node, ptrs) +
         sizeof(struct btrfs_key_ptr) * nr;
     return btrfs_key_blockptr(eb, (struct btrfs_key_ptr *)ptr);
 }
 
 static inline void btrfs_set_node_blockptr(const struct extent_buffer *eb,
                        int nr, u64 val)
 {
     unsigned long ptr;
     ptr = offsetof(struct btrfs_node, ptrs) +
         sizeof(struct btrfs_key_ptr) * nr;
     btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);
 }
 
 static inline u64 btrfs_node_ptr_generation(const struct extent_buffer *eb, int nr)
 {
     unsigned long ptr;
     ptr = offsetof(struct btrfs_node, ptrs) +
         sizeof(struct btrfs_key_ptr) * nr;
     return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);
 }
 
 static inline void btrfs_set_node_ptr_generation(const struct extent_buffer *eb,
                          int nr, u64 val)
 {
     unsigned long ptr;
     ptr = offsetof(struct btrfs_node, ptrs) +
         sizeof(struct btrfs_key_ptr) * nr;
     btrfs_set_key_generation(eb, (struct btrfs_key_ptr *)ptr, val);
 }
 
 static inline unsigned long btrfs_node_key_ptr_offset(int nr)
 {
     return offsetof(struct btrfs_node, ptrs) +
         sizeof(struct btrfs_key_ptr) * nr;
 }
 
 void btrfs_node_key(const struct extent_buffer *eb,
             struct btrfs_disk_key *disk_key, int nr);
 
 static inline void btrfs_set_node_key(const struct extent_buffer *eb,
                       struct btrfs_disk_key *disk_key, int nr)
 {
     unsigned long ptr;
     ptr = btrfs_node_key_ptr_offset(nr);
     write_eb_member(eb, (struct btrfs_key_ptr *)ptr,
                struct btrfs_key_ptr, key, disk_key);
 }
 
 /* struct btrfs_item */
 BTRFS_SETGET_FUNCS(raw_item_offset, struct btrfs_item, offset, 32);
 BTRFS_SETGET_FUNCS(raw_item_size, struct btrfs_item, size, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_item_offset, struct btrfs_item, offset, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_item_size, struct btrfs_item, size, 32);
 
 static inline unsigned long btrfs_item_nr_offset(int nr)
 {
     return offsetof(struct btrfs_leaf, items) +
         sizeof(struct btrfs_item) * nr;
 }
 
 static inline struct btrfs_item *btrfs_item_nr(int nr)
 {
     return (struct btrfs_item *)btrfs_item_nr_offset(nr);
 }
 
 #define BTRFS_ITEM_SETGET_FUNCS(member)                     \
 static inline u32 btrfs_item_##member(const struct extent_buffer *eb,       \
                       int slot)                 \
 {                                       \
     return btrfs_raw_item_##member(eb, btrfs_item_nr(slot));        \
 }                                       \
 static inline void btrfs_set_item_##member(const struct extent_buffer *eb,  \
                        int slot, u32 val)           \
 {                                       \
     btrfs_set_raw_item_##member(eb, btrfs_item_nr(slot), val);      \
 }                                       \
 static inline u32 btrfs_token_item_##member(struct btrfs_map_token *token,  \
                         int slot)               \
 {                                       \
     struct btrfs_item *item = btrfs_item_nr(slot);              \
     return btrfs_token_raw_item_##member(token, item);          \
 }                                       \
 static inline void btrfs_set_token_item_##member(struct btrfs_map_token *token, \
                          int slot, u32 val)     \
 {                                       \
     struct btrfs_item *item = btrfs_item_nr(slot);              \
     btrfs_set_token_raw_item_##member(token, item, val);            \
 }
 
 BTRFS_ITEM_SETGET_FUNCS(offset)
 BTRFS_ITEM_SETGET_FUNCS(size);
 
 static inline u32 btrfs_item_data_end(const struct extent_buffer *eb, int nr)
 {
     return btrfs_item_offset(eb, nr) + btrfs_item_size(eb, nr);
 }
 
 static inline void btrfs_item_key(const struct extent_buffer *eb,
                struct btrfs_disk_key *disk_key, int nr)
 {
     struct btrfs_item *item = btrfs_item_nr(nr);
     read_eb_member(eb, item, struct btrfs_item, key, disk_key);
 }
 
 static inline void btrfs_set_item_key(struct extent_buffer *eb,
                    struct btrfs_disk_key *disk_key, int nr)
 {
     struct btrfs_item *item = btrfs_item_nr(nr);
     write_eb_member(eb, item, struct btrfs_item, key, disk_key);
 }
 
 BTRFS_SETGET_FUNCS(dir_log_end, struct btrfs_dir_log_item, end, 64);
 
 /*
  * struct btrfs_root_ref
  */
 BTRFS_SETGET_FUNCS(root_ref_dirid, struct btrfs_root_ref, dirid, 64);
 BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64);
 BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16);
 
 /* struct btrfs_dir_item */
 BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
 BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
 BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);
 BTRFS_SETGET_FUNCS(dir_transid, struct btrfs_dir_item, transid, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_type, struct btrfs_dir_item, type, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_data_len, struct btrfs_dir_item,
              data_len, 16);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_name_len, struct btrfs_dir_item,
              name_len, 16);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_transid, struct btrfs_dir_item,
              transid, 64);
 
 static inline void btrfs_dir_item_key(const struct extent_buffer *eb,
                       const struct btrfs_dir_item *item,
                       struct btrfs_disk_key *key)
 {
     read_eb_member(eb, item, struct btrfs_dir_item, location, key);
 }
 
 static inline void btrfs_set_dir_item_key(struct extent_buffer *eb,
                       struct btrfs_dir_item *item,
                       const struct btrfs_disk_key *key)
 {
     write_eb_member(eb, item, struct btrfs_dir_item, location, key);
 }
 
 BTRFS_SETGET_FUNCS(free_space_entries, struct btrfs_free_space_header,
            num_entries, 64);
 BTRFS_SETGET_FUNCS(free_space_bitmaps, struct btrfs_free_space_header,
            num_bitmaps, 64);
 BTRFS_SETGET_FUNCS(free_space_generation, struct btrfs_free_space_header,
            generation, 64);
 
 static inline void btrfs_free_space_key(const struct extent_buffer *eb,
                     const struct btrfs_free_space_header *h,
                     struct btrfs_disk_key *key)
 {
     read_eb_member(eb, h, struct btrfs_free_space_header, location, key);
 }
 
 static inline void btrfs_set_free_space_key(struct extent_buffer *eb,
                         struct btrfs_free_space_header *h,
                         const struct btrfs_disk_key *key)
 {
     write_eb_member(eb, h, struct btrfs_free_space_header, location, key);
 }
 
 /* struct btrfs_disk_key */
 BTRFS_SETGET_STACK_FUNCS(disk_key_objectid, struct btrfs_disk_key,
              objectid, 64);
 BTRFS_SETGET_STACK_FUNCS(disk_key_offset, struct btrfs_disk_key, offset, 64);
 BTRFS_SETGET_STACK_FUNCS(disk_key_type, struct btrfs_disk_key, type, 8);
 
 #ifdef __LITTLE_ENDIAN
 
 /*
  * Optimized helpers for little-endian architectures where CPU and on-disk
  * structures have the same endianness and we can skip conversions.
  */
 
 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu_key,
                      const struct btrfs_disk_key *disk_key)
 {
     memcpy(cpu_key, disk_key, sizeof(struct btrfs_key));
 }
 
 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk_key,
                      const struct btrfs_key *cpu_key)
 {
     memcpy(disk_key, cpu_key, sizeof(struct btrfs_key));
 }
 
 static inline void btrfs_node_key_to_cpu(const struct extent_buffer *eb,
                      struct btrfs_key *cpu_key, int nr)
 {
     struct btrfs_disk_key *disk_key = (struct btrfs_disk_key *)cpu_key;
 
     btrfs_node_key(eb, disk_key, nr);
 }
 
 static inline void btrfs_item_key_to_cpu(const struct extent_buffer *eb,
                      struct btrfs_key *cpu_key, int nr)
 {
     struct btrfs_disk_key *disk_key = (struct btrfs_disk_key *)cpu_key;
 
     btrfs_item_key(eb, disk_key, nr);
 }
 
 static inline void btrfs_dir_item_key_to_cpu(const struct extent_buffer *eb,
                          const struct btrfs_dir_item *item,
                          struct btrfs_key *cpu_key)
 {
     struct btrfs_disk_key *disk_key = (struct btrfs_disk_key *)cpu_key;
 
     btrfs_dir_item_key(eb, item, disk_key);
 }
 
 #else
 
 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
                      const struct btrfs_disk_key *disk)
 {
     cpu->offset = le64_to_cpu(disk->offset);
     cpu->type = disk->type;
     cpu->objectid = le64_to_cpu(disk->objectid);
 }
 
 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
                      const struct btrfs_key *cpu)
 {
     disk->offset = cpu_to_le64(cpu->offset);
     disk->type = cpu->type;
     disk->objectid = cpu_to_le64(cpu->objectid);
 }
 
 static inline void btrfs_node_key_to_cpu(const struct extent_buffer *eb,
                      struct btrfs_key *key, int nr)
 {
     struct btrfs_disk_key disk_key;
     btrfs_node_key(eb, &disk_key, nr);
     btrfs_disk_key_to_cpu(key, &disk_key);
 }
 
 static inline void btrfs_item_key_to_cpu(const struct extent_buffer *eb,
                      struct btrfs_key *key, int nr)
 {
     struct btrfs_disk_key disk_key;
     btrfs_item_key(eb, &disk_key, nr);
     btrfs_disk_key_to_cpu(key, &disk_key);
 }
 
 static inline void btrfs_dir_item_key_to_cpu(const struct extent_buffer *eb,
                          const struct btrfs_dir_item *item,
                          struct btrfs_key *key)
 {
     struct btrfs_disk_key disk_key;
     btrfs_dir_item_key(eb, item, &disk_key);
     btrfs_disk_key_to_cpu(key, &disk_key);
 }
 
 #endif
 
 /* struct btrfs_header */
 BTRFS_SETGET_HEADER_FUNCS(header_bytenr, struct btrfs_header, bytenr, 64);
 BTRFS_SETGET_HEADER_FUNCS(header_generation, struct btrfs_header,
               generation, 64);
 BTRFS_SETGET_HEADER_FUNCS(header_owner, struct btrfs_header, owner, 64);
 BTRFS_SETGET_HEADER_FUNCS(header_nritems, struct btrfs_header, nritems, 32);
 BTRFS_SETGET_HEADER_FUNCS(header_flags, struct btrfs_header, flags, 64);
 BTRFS_SETGET_HEADER_FUNCS(header_level, struct btrfs_header, level, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_header_generation, struct btrfs_header,
              generation, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_header_owner, struct btrfs_header, owner, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_header_nritems, struct btrfs_header,
              nritems, 32);
 BTRFS_SETGET_STACK_FUNCS(stack_header_bytenr, struct btrfs_header, bytenr, 64);
 
 static inline int btrfs_header_flag(const struct extent_buffer *eb, u64 flag)
 {
     return (btrfs_header_flags(eb) & flag) == flag;
 }
 
 static inline void btrfs_set_header_flag(struct extent_buffer *eb, u64 flag)
 {
     u64 flags = btrfs_header_flags(eb);
     btrfs_set_header_flags(eb, flags | flag);
 }
 
 static inline void btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
 {
     u64 flags = btrfs_header_flags(eb);
     btrfs_set_header_flags(eb, flags & ~flag);
 }
 
 static inline int btrfs_header_backref_rev(const struct extent_buffer *eb)
 {
     u64 flags = btrfs_header_flags(eb);
     return flags >> BTRFS_BACKREF_REV_SHIFT;
 }
 
 static inline void btrfs_set_header_backref_rev(struct extent_buffer *eb,
                         int rev)
 {
     u64 flags = btrfs_header_flags(eb);
     flags &= ~BTRFS_BACKREF_REV_MASK;
     flags |= (u64)rev << BTRFS_BACKREF_REV_SHIFT;
     btrfs_set_header_flags(eb, flags);
 }
 
 static inline int btrfs_is_leaf(const struct extent_buffer *eb)
 {
     return btrfs_header_level(eb) == 0;
 }
 
 /* struct btrfs_root_item */
 BTRFS_SETGET_FUNCS(disk_root_generation, struct btrfs_root_item,
            generation, 64);
 BTRFS_SETGET_FUNCS(disk_root_refs, struct btrfs_root_item, refs, 32);
 BTRFS_SETGET_FUNCS(disk_root_bytenr, struct btrfs_root_item, bytenr, 64);
 BTRFS_SETGET_FUNCS(disk_root_level, struct btrfs_root_item, level, 8);
 
 BTRFS_SETGET_STACK_FUNCS(root_generation, struct btrfs_root_item,
              generation, 64);
 BTRFS_SETGET_STACK_FUNCS(root_bytenr, struct btrfs_root_item, bytenr, 64);
 BTRFS_SETGET_STACK_FUNCS(root_drop_level, struct btrfs_root_item, drop_level, 8);
 BTRFS_SETGET_STACK_FUNCS(root_level, struct btrfs_root_item, level, 8);
 BTRFS_SETGET_STACK_FUNCS(root_dirid, struct btrfs_root_item, root_dirid, 64);
 BTRFS_SETGET_STACK_FUNCS(root_refs, struct btrfs_root_item, refs, 32);
 BTRFS_SETGET_STACK_FUNCS(root_flags, struct btrfs_root_item, flags, 64);
 BTRFS_SETGET_STACK_FUNCS(root_used, struct btrfs_root_item, bytes_used, 64);
 BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);
 BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
              last_snapshot, 64);
 BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item,
              generation_v2, 64);
 BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item,
              ctransid, 64);
 BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item,
              otransid, 64);
 BTRFS_SETGET_STACK_FUNCS(root_stransid, struct btrfs_root_item,
              stransid, 64);
 BTRFS_SETGET_STACK_FUNCS(root_rtransid, struct btrfs_root_item,
              rtransid, 64);
 
 static inline bool btrfs_root_readonly(const struct btrfs_root *root)
 {
     /* Byte-swap the constant at compile time, root_item::flags is LE */
     return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
 }
 
 static inline bool btrfs_root_dead(const struct btrfs_root *root)
 {
     /* Byte-swap the constant at compile time, root_item::flags is LE */
     return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
 }
 
 static inline u64 btrfs_root_id(const struct btrfs_root *root)
 {
     return root->root_key.objectid;
 }
 
 /* struct btrfs_root_backup */
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
            tree_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root_gen, struct btrfs_root_backup,
            tree_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root_level, struct btrfs_root_backup,
            tree_root_level, 8);
 
 BTRFS_SETGET_STACK_FUNCS(backup_chunk_root, struct btrfs_root_backup,
            chunk_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_gen, struct btrfs_root_backup,
            chunk_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_level, struct btrfs_root_backup,
            chunk_root_level, 8);
 
 BTRFS_SETGET_STACK_FUNCS(backup_extent_root, struct btrfs_root_backup,
            extent_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_extent_root_gen, struct btrfs_root_backup,
            extent_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_extent_root_level, struct btrfs_root_backup,
            extent_root_level, 8);
 
 BTRFS_SETGET_STACK_FUNCS(backup_fs_root, struct btrfs_root_backup,
            fs_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_fs_root_gen, struct btrfs_root_backup,
            fs_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_fs_root_level, struct btrfs_root_backup,
            fs_root_level, 8);
 
 BTRFS_SETGET_STACK_FUNCS(backup_dev_root, struct btrfs_root_backup,
            dev_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_dev_root_gen, struct btrfs_root_backup,
            dev_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_dev_root_level, struct btrfs_root_backup,
            dev_root_level, 8);
 
 BTRFS_SETGET_STACK_FUNCS(backup_csum_root, struct btrfs_root_backup,
            csum_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_csum_root_gen, struct btrfs_root_backup,
            csum_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_csum_root_level, struct btrfs_root_backup,
            csum_root_level, 8);
 BTRFS_SETGET_STACK_FUNCS(backup_total_bytes, struct btrfs_root_backup,
            total_bytes, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
            bytes_used, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
            num_devices, 64);
 
 /*
  * For extent tree v2 we overload the extent root with the block group root, as
  * we will have multiple extent roots.
  */
 BTRFS_SETGET_STACK_FUNCS(backup_block_group_root, struct btrfs_root_backup,
              extent_root, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_gen, struct btrfs_root_backup,
              extent_root_gen, 64);
 BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_level,
              struct btrfs_root_backup, extent_root_level, 8);
 
 /* struct btrfs_balance_item */
 BTRFS_SETGET_FUNCS(balance_flags, struct btrfs_balance_item, flags, 64);
 
 static inline void btrfs_balance_data(const struct extent_buffer *eb,
                       const struct btrfs_balance_item *bi,
                       struct btrfs_disk_balance_args *ba)
 {
     read_eb_member(eb, bi, struct btrfs_balance_item, data, ba);
 }
 
 static inline void btrfs_set_balance_data(struct extent_buffer *eb,
                   struct btrfs_balance_item *bi,
                   const struct btrfs_disk_balance_args *ba)
 {
     write_eb_member(eb, bi, struct btrfs_balance_item, data, ba);
 }
 
 static inline void btrfs_balance_meta(const struct extent_buffer *eb,
                       const struct btrfs_balance_item *bi,
                       struct btrfs_disk_balance_args *ba)
 {
     read_eb_member(eb, bi, struct btrfs_balance_item, meta, ba);
 }
 
 static inline void btrfs_set_balance_meta(struct extent_buffer *eb,
                   struct btrfs_balance_item *bi,
                   const struct btrfs_disk_balance_args *ba)
 {
     write_eb_member(eb, bi, struct btrfs_balance_item, meta, ba);
 }
 
 static inline void btrfs_balance_sys(const struct extent_buffer *eb,
                      const struct btrfs_balance_item *bi,
                      struct btrfs_disk_balance_args *ba)
 {
     read_eb_member(eb, bi, struct btrfs_balance_item, sys, ba);
 }
 
 static inline void btrfs_set_balance_sys(struct extent_buffer *eb,
                  struct btrfs_balance_item *bi,
                  const struct btrfs_disk_balance_args *ba)
 {
     write_eb_member(eb, bi, struct btrfs_balance_item, sys, ba);
 }
 
 static inline void
 btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu,
                    const struct btrfs_disk_balance_args *disk)
 {
     memset(cpu, 0, sizeof(*cpu));
 
     cpu->profiles = le64_to_cpu(disk->profiles);
     cpu->usage = le64_to_cpu(disk->usage);
     cpu->devid = le64_to_cpu(disk->devid);
     cpu->pstart = le64_to_cpu(disk->pstart);
     cpu->pend = le64_to_cpu(disk->pend);
     cpu->vstart = le64_to_cpu(disk->vstart);
     cpu->vend = le64_to_cpu(disk->vend);
     cpu->target = le64_to_cpu(disk->target);
     cpu->flags = le64_to_cpu(disk->flags);
     cpu->limit = le64_to_cpu(disk->limit);
     cpu->stripes_min = le32_to_cpu(disk->stripes_min);
     cpu->stripes_max = le32_to_cpu(disk->stripes_max);
 }
 
 static inline void
 btrfs_cpu_balance_args_to_disk(struct btrfs_disk_balance_args *disk,
                    const struct btrfs_balance_args *cpu)
 {
     memset(disk, 0, sizeof(*disk));
 
     disk->profiles = cpu_to_le64(cpu->profiles);
     disk->usage = cpu_to_le64(cpu->usage);
     disk->devid = cpu_to_le64(cpu->devid);
     disk->pstart = cpu_to_le64(cpu->pstart);
     disk->pend = cpu_to_le64(cpu->pend);
     disk->vstart = cpu_to_le64(cpu->vstart);
     disk->vend = cpu_to_le64(cpu->vend);
     disk->target = cpu_to_le64(cpu->target);
     disk->flags = cpu_to_le64(cpu->flags);
     disk->limit = cpu_to_le64(cpu->limit);
     disk->stripes_min = cpu_to_le32(cpu->stripes_min);
     disk->stripes_max = cpu_to_le32(cpu->stripes_max);
 }
 
 /* struct btrfs_super_block */
 BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
 BTRFS_SETGET_STACK_FUNCS(super_flags, struct btrfs_super_block, flags, 64);
 BTRFS_SETGET_STACK_FUNCS(super_generation, struct btrfs_super_block,
              generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_root, struct btrfs_super_block, root, 64);
 BTRFS_SETGET_STACK_FUNCS(super_sys_array_size,
              struct btrfs_super_block, sys_chunk_array_size, 32);
 BTRFS_SETGET_STACK_FUNCS(super_chunk_root_generation,
              struct btrfs_super_block, chunk_root_generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_root_level, struct btrfs_super_block,
              root_level, 8);
 BTRFS_SETGET_STACK_FUNCS(super_chunk_root, struct btrfs_super_block,
              chunk_root, 64);
 BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
              chunk_root_level, 8);
 BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
              log_root, 64);
 BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
              log_root_level, 8);
 BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
              total_bytes, 64);
 BTRFS_SETGET_STACK_FUNCS(super_bytes_used, struct btrfs_super_block,
              bytes_used, 64);
 BTRFS_SETGET_STACK_FUNCS(super_sectorsize, struct btrfs_super_block,
              sectorsize, 32);
 BTRFS_SETGET_STACK_FUNCS(super_nodesize, struct btrfs_super_block,
              nodesize, 32);
 BTRFS_SETGET_STACK_FUNCS(super_stripesize, struct btrfs_super_block,
              stripesize, 32);
 BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block,
              root_dir_objectid, 64);
 BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
              num_devices, 64);
 BTRFS_SETGET_STACK_FUNCS(super_compat_flags, struct btrfs_super_block,
              compat_flags, 64);
 BTRFS_SETGET_STACK_FUNCS(super_compat_ro_flags, struct btrfs_super_block,
              compat_ro_flags, 64);
 BTRFS_SETGET_STACK_FUNCS(super_incompat_flags, struct btrfs_super_block,
              incompat_flags, 64);
 BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct btrfs_super_block,
              csum_type, 16);
 BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
              cache_generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
 BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
              uuid_tree_generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_block_group_root, struct btrfs_super_block,
              block_group_root, 64);
 BTRFS_SETGET_STACK_FUNCS(super_block_group_root_generation,
              struct btrfs_super_block,
              block_group_root_generation, 64);
 BTRFS_SETGET_STACK_FUNCS(super_block_group_root_level, struct btrfs_super_block,
              block_group_root_level, 8);
 
 int btrfs_super_csum_size(const struct btrfs_super_block *s);
 const char *btrfs_super_csum_name(u16 csum_type);
 const char *btrfs_super_csum_driver(u16 csum_type);
 size_t __attribute_const__ btrfs_get_num_csums(void);
 
 
 /*
  * The leaf data grows from end-to-front in the node.
  * this returns the address of the start of the last item,
  * which is the stop of the leaf data stack
  */
 static inline unsigned int leaf_data_end(const struct extent_buffer *leaf)
 {
     u32 nr = btrfs_header_nritems(leaf);
 
     if (nr == 0)
         return BTRFS_LEAF_DATA_SIZE(leaf->fs_info);
     return btrfs_item_offset(leaf, nr - 1);
 }
 
 /* struct btrfs_file_extent_item */
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_type, struct btrfs_file_extent_item,
              type, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr,
              struct btrfs_file_extent_item, disk_bytenr, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_offset,
              struct btrfs_file_extent_item, offset, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_generation,
              struct btrfs_file_extent_item, generation, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_num_bytes,
              struct btrfs_file_extent_item, num_bytes, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_ram_bytes,
              struct btrfs_file_extent_item, ram_bytes, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_num_bytes,
              struct btrfs_file_extent_item, disk_num_bytes, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_compression,
              struct btrfs_file_extent_item, compression, 8);
 
 static inline unsigned long
 btrfs_file_extent_inline_start(const struct btrfs_file_extent_item *e)
 {
     return (unsigned long)e + BTRFS_FILE_EXTENT_INLINE_DATA_START;
 }
 
 static inline u32 btrfs_file_extent_calc_inline_size(u32 datasize)
 {
     return BTRFS_FILE_EXTENT_INLINE_DATA_START + datasize;
 }
 
 BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8);
 BTRFS_SETGET_FUNCS(file_extent_disk_bytenr, struct btrfs_file_extent_item,
            disk_bytenr, 64);
 BTRFS_SETGET_FUNCS(file_extent_generation, struct btrfs_file_extent_item,
            generation, 64);
 BTRFS_SETGET_FUNCS(file_extent_disk_num_bytes, struct btrfs_file_extent_item,
            disk_num_bytes, 64);
 BTRFS_SETGET_FUNCS(file_extent_offset, struct btrfs_file_extent_item,
           offset, 64);
 BTRFS_SETGET_FUNCS(file_extent_num_bytes, struct btrfs_file_extent_item,
            num_bytes, 64);
 BTRFS_SETGET_FUNCS(file_extent_ram_bytes, struct btrfs_file_extent_item,
            ram_bytes, 64);
 BTRFS_SETGET_FUNCS(file_extent_compression, struct btrfs_file_extent_item,
            compression, 8);
 BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item,
            encryption, 8);
 BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item,
            other_encoding, 16);
 
 /*
  * this returns the number of bytes used by the item on disk, minus the
  * size of any extent headers.  If a file is compressed on disk, this is
  * the compressed size
  */
 static inline u32 btrfs_file_extent_inline_item_len(
                         const struct extent_buffer *eb,
                         int nr)
 {
     return btrfs_item_size(eb, nr) - BTRFS_FILE_EXTENT_INLINE_DATA_START;
 }
 
 /* btrfs_qgroup_status_item */
 BTRFS_SETGET_FUNCS(qgroup_status_generation, struct btrfs_qgroup_status_item,
            generation, 64);
 BTRFS_SETGET_FUNCS(qgroup_status_version, struct btrfs_qgroup_status_item,
            version, 64);
 BTRFS_SETGET_FUNCS(qgroup_status_flags, struct btrfs_qgroup_status_item,
            flags, 64);
 BTRFS_SETGET_FUNCS(qgroup_status_rescan, struct btrfs_qgroup_status_item,
            rescan, 64);
 
 /* btrfs_qgroup_info_item */
 BTRFS_SETGET_FUNCS(qgroup_info_generation, struct btrfs_qgroup_info_item,
            generation, 64);
 BTRFS_SETGET_FUNCS(qgroup_info_rfer, struct btrfs_qgroup_info_item, rfer, 64);
 BTRFS_SETGET_FUNCS(qgroup_info_rfer_cmpr, struct btrfs_qgroup_info_item,
            rfer_cmpr, 64);
 BTRFS_SETGET_FUNCS(qgroup_info_excl, struct btrfs_qgroup_info_item, excl, 64);
 BTRFS_SETGET_FUNCS(qgroup_info_excl_cmpr, struct btrfs_qgroup_info_item,
            excl_cmpr, 64);
 
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_generation,
              struct btrfs_qgroup_info_item, generation, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_rfer, struct btrfs_qgroup_info_item,
              rfer, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_rfer_cmpr,
              struct btrfs_qgroup_info_item, rfer_cmpr, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_excl, struct btrfs_qgroup_info_item,
              excl, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_excl_cmpr,
              struct btrfs_qgroup_info_item, excl_cmpr, 64);
 
 /* btrfs_qgroup_limit_item */
 BTRFS_SETGET_FUNCS(qgroup_limit_flags, struct btrfs_qgroup_limit_item,
            flags, 64);
 BTRFS_SETGET_FUNCS(qgroup_limit_max_rfer, struct btrfs_qgroup_limit_item,
            max_rfer, 64);
 BTRFS_SETGET_FUNCS(qgroup_limit_max_excl, struct btrfs_qgroup_limit_item,
            max_excl, 64);
 BTRFS_SETGET_FUNCS(qgroup_limit_rsv_rfer, struct btrfs_qgroup_limit_item,
            rsv_rfer, 64);
 BTRFS_SETGET_FUNCS(qgroup_limit_rsv_excl, struct btrfs_qgroup_limit_item,
            rsv_excl, 64);
 
 /* btrfs_dev_replace_item */
 BTRFS_SETGET_FUNCS(dev_replace_src_devid,
            struct btrfs_dev_replace_item, src_devid, 64);
 BTRFS_SETGET_FUNCS(dev_replace_cont_reading_from_srcdev_mode,
            struct btrfs_dev_replace_item, cont_reading_from_srcdev_mode,
            64);
 BTRFS_SETGET_FUNCS(dev_replace_replace_state, struct btrfs_dev_replace_item,
            replace_state, 64);
 BTRFS_SETGET_FUNCS(dev_replace_time_started, struct btrfs_dev_replace_item,
            time_started, 64);
 BTRFS_SETGET_FUNCS(dev_replace_time_stopped, struct btrfs_dev_replace_item,
            time_stopped, 64);
 BTRFS_SETGET_FUNCS(dev_replace_num_write_errors, struct btrfs_dev_replace_item,
            num_write_errors, 64);
 BTRFS_SETGET_FUNCS(dev_replace_num_uncorrectable_read_errors,
            struct btrfs_dev_replace_item, num_uncorrectable_read_errors,
            64);
 BTRFS_SETGET_FUNCS(dev_replace_cursor_left, struct btrfs_dev_replace_item,
            cursor_left, 64);
 BTRFS_SETGET_FUNCS(dev_replace_cursor_right, struct btrfs_dev_replace_item,
            cursor_right, 64);
 
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_src_devid,
              struct btrfs_dev_replace_item, src_devid, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_cont_reading_from_srcdev_mode,
              struct btrfs_dev_replace_item,
              cont_reading_from_srcdev_mode, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_replace_state,
              struct btrfs_dev_replace_item, replace_state, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_time_started,
              struct btrfs_dev_replace_item, time_started, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_time_stopped,
              struct btrfs_dev_replace_item, time_stopped, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_num_write_errors,
              struct btrfs_dev_replace_item, num_write_errors, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_num_uncorrectable_read_errors,
              struct btrfs_dev_replace_item,
              num_uncorrectable_read_errors, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_cursor_left,
              struct btrfs_dev_replace_item, cursor_left, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_cursor_right,
              struct btrfs_dev_replace_item, cursor_right, 64);
 
 /* helper function to cast into the data area of the leaf. */
 #define btrfs_item_ptr(leaf, slot, type) \
     ((type *)(BTRFS_LEAF_DATA_OFFSET + \
     btrfs_item_offset(leaf, slot)))
 
 #define btrfs_item_ptr_offset(leaf, slot) \
     ((unsigned long)(BTRFS_LEAF_DATA_OFFSET + \
     btrfs_item_offset(leaf, slot)))
 
 static inline u32 btrfs_crc32c(u32 crc, const void *address, unsigned length)
 {
     return crc32c(crc, address, length);
 }
 
 static inline void btrfs_crc32c_final(u32 crc, u8 *result)
 {
     put_unaligned_le32(~crc, result);
 }
 
 static inline u64 btrfs_name_hash(const char *name, int len)
 {
        return crc32c((u32)~1, name, len);
 }
 
 /*
  * Figure the key offset of an extended inode ref
  */
 static inline u64 btrfs_extref_hash(u64 parent_objectid, const char *name,
                                    int len)
 {
        return (u64) crc32c(parent_objectid, name, len);
 }
 
 static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
 {
     return mapping_gfp_constraint(mapping, ~__GFP_FS);
 }
 
 /* extent-tree.c */
 
 enum btrfs_inline_ref_type {
     BTRFS_REF_TYPE_INVALID,
     BTRFS_REF_TYPE_BLOCK,
     BTRFS_REF_TYPE_DATA,
     BTRFS_REF_TYPE_ANY,
 };
 
 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
                      struct btrfs_extent_inline_ref *iref,
                      enum btrfs_inline_ref_type is_data);
 u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset);
 
 static inline u8 *btrfs_csum_ptr(const struct btrfs_fs_info *fs_info, u8 *csums,
                  u64 offset)
 {
     u64 offset_in_sectors = offset >> fs_info->sectorsize_bits;
 
     return csums + offset_in_sectors * fs_info->csum_size;
 }
 
 /*
  * Take the number of bytes to be checksummed and figure out how many leaves
  * it would require to store the csums for that many bytes.
  */
 static inline u64 btrfs_csum_bytes_to_leaves(
             const struct btrfs_fs_info *fs_info, u64 csum_bytes)
 {
     const u64 num_csums = csum_bytes >> fs_info->sectorsize_bits;
 
     return DIV_ROUND_UP_ULL(num_csums, fs_info->csums_per_leaf);
 }
 
 /*
  * Use this if we would be adding new items, as we could split nodes as we cow
  * down the tree.
  */
 static inline u64 btrfs_calc_insert_metadata_size(struct btrfs_fs_info *fs_info,
                           unsigned num_items)
 {
     return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
 }
 
 /*
  * Doing a truncate or a modification won't result in new nodes or leaves, just
  * what we need for COW.
  */
 static inline u64 btrfs_calc_metadata_size(struct btrfs_fs_info *fs_info,
                          unsigned num_items)
 {
     return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
 }
 
 int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
                   u64 start, u64 num_bytes);
 void btrfs_free_excluded_extents(struct btrfs_block_group *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
                unsigned long count);
 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
                   struct btrfs_delayed_ref_root *delayed_refs,
                   struct btrfs_delayed_ref_head *head);
 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len);
 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
                  struct btrfs_fs_info *fs_info, u64 bytenr,
                  u64 offset, int metadata, u64 *refs, u64 *flags);
 int btrfs_pin_extent(struct btrfs_trans_handle *trans, u64 bytenr, u64 num,
              int reserved);
 int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
                     u64 bytenr, u64 num_bytes);
 int btrfs_exclude_logged_extents(struct extent_buffer *eb);
 int btrfs_cross_ref_exist(struct btrfs_root *root,
               u64 objectid, u64 offset, u64 bytenr, bool strict,
               struct btrfs_path *path);
 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          u64 parent, u64 root_objectid,
                          const struct btrfs_disk_key *key,
                          int level, u64 hint,
                          u64 empty_size,
                          enum btrfs_lock_nesting nest);
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                u64 root_id,
                struct extent_buffer *buf,
                u64 parent, int last_ref);
 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root, u64 owner,
                      u64 offset, u64 ram_bytes,
                      struct btrfs_key *ins);
 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
                    u64 root_objectid, u64 owner, u64 offset,
                    struct btrfs_key *ins);
 int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes, u64 num_bytes,
              u64 min_alloc_size, u64 empty_size, u64 hint_byte,
              struct btrfs_key *ins, int is_data, int delalloc);
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
           struct extent_buffer *buf, int full_backref);
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
           struct extent_buffer *buf, int full_backref);
 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
                 struct extent_buffer *eb, u64 flags, int level);
 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref);
 
 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
                    u64 start, u64 len, int delalloc);
 int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans, u64 start,
                   u64 len);
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans);
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
              struct btrfs_ref *generic_ref);
 
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
 
 /*
  * Different levels for to flush space when doing space reservations.
  *
  * The higher the level, the more methods we try to reclaim space.
  */
 enum btrfs_reserve_flush_enum {
     /* If we are in the transaction, we can't flush anything.*/
     BTRFS_RESERVE_NO_FLUSH,
 
     /*
      * Flush space by:
      * - Running delayed inode items
      * - Allocating a new chunk
      */
     BTRFS_RESERVE_FLUSH_LIMIT,
 
     /*
      * Flush space by:
      * - Running delayed inode items
      * - Running delayed refs
      * - Running delalloc and waiting for ordered extents
      * - Allocating a new chunk
      */
     BTRFS_RESERVE_FLUSH_EVICT,
 
     /*
      * Flush space by above mentioned methods and by:
      * - Running delayed iputs
      * - Committing transaction
      *
      * Can be interrupted by a fatal signal.
      */
     BTRFS_RESERVE_FLUSH_DATA,
     BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE,
     BTRFS_RESERVE_FLUSH_ALL,
 
     /*
      * Pretty much the same as FLUSH_ALL, but can also steal space from
      * global rsv.
      *
      * Can be interrupted by a fatal signal.
      */
     BTRFS_RESERVE_FLUSH_ALL_STEAL,
 };
 
 enum btrfs_flush_state {
     FLUSH_DELAYED_ITEMS_NR  =   1,
     FLUSH_DELAYED_ITEMS =   2,
     FLUSH_DELAYED_REFS_NR   =   3,
     FLUSH_DELAYED_REFS  =   4,
     FLUSH_DELALLOC      =   5,
     FLUSH_DELALLOC_WAIT =   6,
     FLUSH_DELALLOC_FULL =   7,
     ALLOC_CHUNK     =   8,
     ALLOC_CHUNK_FORCE   =   9,
     RUN_DELAYED_IPUTS   =   10,
     COMMIT_TRANS        =   11,
 };
 
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
                      struct btrfs_block_rsv *rsv,
                      int nitems, bool use_global_rsv);
 void btrfs_subvolume_release_metadata(struct btrfs_root *root,
                       struct btrfs_block_rsv *rsv);
 void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
 
 int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
                     u64 disk_num_bytes, bool noflush);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
                    u64 start, u64 end);
 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
              u64 num_bytes, u64 *actual_bytes);
 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
 
 int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
 int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
                      struct btrfs_fs_info *fs_info);
 int btrfs_start_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_end_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
 
 /* ctree.c */
 int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
              int *slot);
 int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
 int btrfs_previous_item(struct btrfs_root *root,
             struct btrfs_path *path, u64 min_objectid,
             int type);
 int btrfs_previous_extent_item(struct btrfs_root *root,
             struct btrfs_path *path, u64 min_objectid);
 void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info,
                  struct btrfs_path *path,
                  const struct btrfs_key *new_key);
 struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
             struct btrfs_key *key, int lowest_level,
             u64 min_trans);
 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
              struct btrfs_path *path,
              u64 min_trans);
 struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
                        int slot);
 
 int btrfs_cow_block(struct btrfs_trans_handle *trans,
             struct btrfs_root *root, struct extent_buffer *buf,
             struct extent_buffer *parent, int parent_slot,
             struct extent_buffer **cow_ret,
             enum btrfs_lock_nesting nest);
 int btrfs_copy_root(struct btrfs_trans_handle *trans,
               struct btrfs_root *root,
               struct extent_buffer *buf,
               struct extent_buffer **cow_ret, u64 new_root_objectid);
 int btrfs_block_can_be_shared(struct btrfs_root *root,
                   struct extent_buffer *buf);
 void btrfs_extend_item(struct btrfs_path *path, u32 data_size);
 void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end);
 int btrfs_split_item(struct btrfs_trans_handle *trans,
              struct btrfs_root *root,
              struct btrfs_path *path,
              const struct btrfs_key *new_key,
              unsigned long split_offset);
 int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
              struct btrfs_root *root,
              struct btrfs_path *path,
              const struct btrfs_key *new_key);
 int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
         u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
               const struct btrfs_key *key, struct btrfs_path *p,
               int ins_len, int cow);
 int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
               struct btrfs_path *p, u64 time_seq);
 int btrfs_search_slot_for_read(struct btrfs_root *root,
                    const struct btrfs_key *key,
                    struct btrfs_path *p, int find_higher,
                    int return_any);
 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                struct btrfs_root *root, struct extent_buffer *parent,
                int start_slot, u64 *last_ret,
                struct btrfs_key *progress);
 void btrfs_release_path(struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
            struct btrfs_path *path, int slot, int nr);
 static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
                  struct btrfs_root *root,
                  struct btrfs_path *path)
 {
     return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }
 
 /*
  * Describes a batch of items to insert in a btree. This is used by
  * btrfs_insert_empty_items().
  */
 struct btrfs_item_batch {
     /*
      * Pointer to an array containing the keys of the items to insert (in
      * sorted order).
      */
     const struct btrfs_key *keys;
     /* Pointer to an array containing the data size for each item to insert. */
     const u32 *data_sizes;
     /*
      * The sum of data sizes for all items. The caller can compute this while
      * setting up the data_sizes array, so it ends up being more efficient
      * than having btrfs_insert_empty_items() or setup_item_for_insert()
      * doing it, as it would avoid an extra loop over a potentially large
      * array, and in the case of setup_item_for_insert(), we would be doing
      * it while holding a write lock on a leaf and often on upper level nodes
      * too, unnecessarily increasing the size of a critical section.
      */
     u32 total_data_size;
     /* Size of the keys and data_sizes arrays (number of items in the batch). */
     int nr;
 };
 
 void btrfs_setup_item_for_insert(struct btrfs_root *root,
                  struct btrfs_path *path,
                  const struct btrfs_key *key,
                  u32 data_size);
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
               const struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                  struct btrfs_root *root,
                  struct btrfs_path *path,
                  const struct btrfs_item_batch *batch);
 
 static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root,
                       struct btrfs_path *path,
                       const struct btrfs_key *key,
                       u32 data_size)
 {
     struct btrfs_item_batch batch;
 
     batch.keys = key;
     batch.data_sizes = &data_size;
     batch.total_data_size = data_size;
     batch.nr = 1;
 
     return btrfs_insert_empty_items(trans, root, path, &batch);
 }
 
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
             u64 time_seq);
 
 int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
                struct btrfs_path *path);
 
 int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
                   struct btrfs_path *path);
 
 /*
  * Search in @root for a given @key, and store the slot found in @found_key.
  *
  * @root:   The root node of the tree.
  * @key:    The key we are looking for.
  * @found_key:  Will hold the found item.
  * @path:   Holds the current slot/leaf.
  * @iter_ret:   Contains the value returned from btrfs_search_slot or
  *      btrfs_get_next_valid_item, whichever was executed last.
  *
  * The @iter_ret is an output variable that will contain the return value of
  * btrfs_search_slot, if it encountered an error, or the value returned from
  * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
  * slot was found, 1 if there were no more leaves, and <0 if there was an error.
  *
  * It's recommended to use a separate variable for iter_ret and then use it to
  * set the function return value so there's no confusion of the 0/1/errno
  * values stemming from btrfs_search_slot.
  */
 #define btrfs_for_each_slot(root, key, found_key, path, iter_ret)       \
     for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0);   \
         (iter_ret) >= 0 &&                      \
         (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
         (path)->slots[0]++                      \
     )
 
 static inline int btrfs_next_old_item(struct btrfs_root *root,
                       struct btrfs_path *p, u64 time_seq)
 {
     ++p->slots[0];
     if (p->slots[0] >= btrfs_header_nritems(p->nodes[0]))
         return btrfs_next_old_leaf(root, p, time_seq);
     return 0;
 }
 
 /*
  * Search the tree again to find a leaf with greater keys.
  *
  * Returns 0 if it found something or 1 if there are no greater leaves.
  * Returns < 0 on error.
  */
 static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 {
     return btrfs_next_old_leaf(root, path, 0);
 }
 
 static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
 {
     return btrfs_next_old_item(root, p, 0);
 }
 int btrfs_leaf_free_space(struct extent_buffer *leaf);
 int __must_check btrfs_drop_snapshot(struct btrfs_root *root, int update_ref,
                      int for_reloc);
 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
             struct btrfs_root *root,
             struct extent_buffer *node,
             struct extent_buffer *parent);
 static inline int btrfs_fs_closing(struct btrfs_fs_info *fs_info)
 {
     /*
      * Do it this way so we only ever do one test_bit in the normal case.
      */
     if (test_bit(BTRFS_FS_CLOSING_START, &fs_info->flags)) {
         if (test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags))
             return 2;
         return 1;
     }
     return 0;
 }
 
 /*
  * If we remount the fs to be R/O or umount the fs, the cleaner needn't do
  * anything except sleeping. This function is used to check the status of
  * the fs.
  * We check for BTRFS_FS_STATE_RO to avoid races with a concurrent remount,
  * since setting and checking for SB_RDONLY in the superblock's flags is not
  * atomic.
  */
 static inline int btrfs_need_cleaner_sleep(struct btrfs_fs_info *fs_info)
 {
     return test_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state) ||
         btrfs_fs_closing(fs_info);
 }
 
 static inline void btrfs_set_sb_rdonly(struct super_block *sb)
 {
     sb->s_flags |= SB_RDONLY;
     set_bit(BTRFS_FS_STATE_RO, &btrfs_sb(sb)->fs_state);
 }
 
 static inline void btrfs_clear_sb_rdonly(struct super_block *sb)
 {
     sb->s_flags &= ~SB_RDONLY;
     clear_bit(BTRFS_FS_STATE_RO, &btrfs_sb(sb)->fs_state);
 }
 
 /* root-item.c */
 int btrfs_add_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
                u64 ref_id, u64 dirid, u64 sequence, const char *name,
                int name_len);
 int btrfs_del_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
                u64 ref_id, u64 dirid, u64 *sequence, const char *name,
                int name_len);
 int btrfs_del_root(struct btrfs_trans_handle *trans,
            const struct btrfs_key *key);
 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
               const struct btrfs_key *key,
               struct btrfs_root_item *item);
 int __must_check btrfs_update_root(struct btrfs_trans_handle *trans,
                    struct btrfs_root *root,
                    struct btrfs_key *key,
                    struct btrfs_root_item *item);
 int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,
             struct btrfs_path *path, struct btrfs_root_item *root_item,
             struct btrfs_key *root_key);
 int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info);
 void btrfs_set_root_node(struct btrfs_root_item *item,
              struct extent_buffer *node);
 void btrfs_check_and_init_root_item(struct btrfs_root_item *item);
 void btrfs_update_root_times(struct btrfs_trans_handle *trans,
                  struct btrfs_root *root);
 
 /* uuid-tree.c */
 int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, u8 *uuid, u8 type,
             u64 subid);
 int btrfs_uuid_tree_remove(struct btrfs_trans_handle *trans, u8 *uuid, u8 type,
             u64 subid);
 int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info);
 
 /* dir-item.c */
 int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
               const char *name, int name_len);
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
               int name_len, struct btrfs_inode *dir,
               struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          struct btrfs_path *path, u64 dir,
                          const char *name, int name_len,
                          int mod);
 struct btrfs_dir_item *
 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
                 struct btrfs_root *root,
                 struct btrfs_path *path, u64 dir,
                 u64 index, const char *name, int name_len,
                 int mod);
 struct btrfs_dir_item *
 btrfs_search_dir_index_item(struct btrfs_root *root,
                 struct btrfs_path *path, u64 dirid,
                 const char *name, int name_len);
 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
                   struct btrfs_root *root,
                   struct btrfs_path *path,
                   struct btrfs_dir_item *di);
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
                 struct btrfs_root *root,
                 struct btrfs_path *path, u64 objectid,
                 const char *name, u16 name_len,
                 const void *data, u16 data_len);
 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root,
                       struct btrfs_path *path, u64 dir,
                       const char *name, u16 name_len,
                       int mod);
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
                          struct btrfs_path *path,
                          const char *name,
                          int name_len);
 
 /* orphan.c */
 int btrfs_insert_orphan_item(struct btrfs_trans_handle *trans,
                  struct btrfs_root *root, u64 offset);
 int btrfs_del_orphan_item(struct btrfs_trans_handle *trans,
               struct btrfs_root *root, u64 offset);
 int btrfs_find_orphan_item(struct btrfs_root *root, u64 offset);
 
 /* file-item.c */
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
             struct btrfs_root *root, u64 bytenr, u64 len);
 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst);
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                  struct btrfs_root *root,
                  u64 objectid, u64 pos,
                  u64 disk_offset, u64 disk_num_bytes,
                  u64 num_bytes, u64 offset, u64 ram_bytes,
                  u8 compression, u8 encryption, u16 other_encoding);
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
                  struct btrfs_root *root,
                  struct btrfs_path *path, u64 objectid,
                  u64 bytenr, int mod);
 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
                struct btrfs_root *root,
                struct btrfs_ordered_sum *sums);
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
                 u64 offset, bool one_ordered);
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
                  struct list_head *list, int search_commit);
 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
                      const struct btrfs_path *path,
                      struct btrfs_file_extent_item *fi,
                      const bool new_inline,
                      struct extent_map *em);
 int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
                     u64 len);
 int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
                       u64 len);
 void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size);
 u64 btrfs_file_extent_end(const struct btrfs_path *path);
 
 /* inode.c */
 void btrfs_submit_data_write_bio(struct inode *inode, struct bio *bio, int mirror_num);
 void btrfs_submit_data_read_bio(struct inode *inode, struct bio *bio,
             int mirror_num, enum btrfs_compression_type compress_type);
 int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
                 u32 pgoff, u8 *csum, const u8 * const csum_expected);
 int btrfs_check_data_csum(struct inode *inode, struct btrfs_bio *bbio,
               u32 bio_offset, struct page *page, u32 pgoff);
 unsigned int btrfs_verify_data_csum(struct btrfs_bio *bbio,
                     u32 bio_offset, struct page *page,
                     u64 start, u64 end);
 int btrfs_check_data_csum(struct inode *inode, struct btrfs_bio *bbio,
               u32 bio_offset, struct page *page, u32 pgoff);
 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
                        u64 start, u64 len);
 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
                   u64 *orig_start, u64 *orig_block_len,
                   u64 *ram_bytes, bool strict);
 
 void __btrfs_del_delalloc_inode(struct btrfs_root *root,
                 struct btrfs_inode *inode);
 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index);
 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
                struct btrfs_inode *dir, struct btrfs_inode *inode,
                const char *name, int name_len);
 int btrfs_add_link(struct btrfs_trans_handle *trans,
            struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
            const char *name, int name_len, int add_backref, u64 index);
 int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry);
 int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
              int front);
 
 int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context);
 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
                    bool in_reclaim_context);
 int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
                   unsigned int extra_bits,
                   struct extent_state **cached_state);
 struct btrfs_new_inode_args {
     /* Input */
     struct inode *dir;
     struct dentry *dentry;
     struct inode *inode;
     bool orphan;
     bool subvol;
 
     /*
      * Output from btrfs_new_inode_prepare(), input to
      * btrfs_create_new_inode().
      */
     struct posix_acl *default_acl;
     struct posix_acl *acl;
 };
 int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
                 unsigned int *trans_num_items);
 int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
                struct btrfs_new_inode_args *args);
 void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args);
 struct inode *btrfs_new_subvol_inode(struct user_namespace *mnt_userns,
                      struct inode *dir);
  void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
                     u32 bits);
 void btrfs_clear_delalloc_extent(struct inode *inode,
                  struct extent_state *state, u32 bits);
 void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
                  struct extent_state *other);
 void btrfs_split_delalloc_extent(struct inode *inode,
                  struct extent_state *orig, u64 split);
 void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end);
 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
 void btrfs_evict_inode(struct inode *inode);
 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc);
 struct inode *btrfs_alloc_inode(struct super_block *sb);
 void btrfs_destroy_inode(struct inode *inode);
 void btrfs_free_inode(struct inode *inode);
 int btrfs_drop_inode(struct inode *inode);
 int __init btrfs_init_cachep(void);
 void __cold btrfs_destroy_cachep(void);
 struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
                   struct btrfs_root *root, struct btrfs_path *path);
 struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root);
 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
                     struct page *page, size_t pg_offset,
                     u64 start, u64 end);
 int btrfs_update_inode(struct btrfs_trans_handle *trans,
                struct btrfs_root *root, struct btrfs_inode *inode);
 int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
                 struct btrfs_root *root, struct btrfs_inode *inode);
 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
         struct btrfs_inode *inode);
 int btrfs_orphan_cleanup(struct btrfs_root *root);
 int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size);
 void btrfs_add_delayed_iput(struct inode *inode);
 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info);
 int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info);
 int btrfs_prealloc_file_range(struct inode *inode, int mode,
                   u64 start, u64 num_bytes, u64 min_size,
                   loff_t actual_len, u64 *alloc_hint);
 int btrfs_prealloc_file_range_trans(struct inode *inode,
                     struct btrfs_trans_handle *trans, int mode,
                     u64 start, u64 num_bytes, u64 min_size,
                     loff_t actual_len, u64 *alloc_hint);
 int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
         u64 start, u64 end, int *page_started, unsigned long *nr_written,
         struct writeback_control *wbc);
 int btrfs_writepage_cow_fixup(struct page *page);
 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
                       struct page *page, u64 start,
                       u64 end, bool uptodate);
 int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
                          int compress_type);
 int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
                       u64 file_offset, u64 disk_bytenr,
                       u64 disk_io_size,
                       struct page **pages);
 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
                struct btrfs_ioctl_encoded_io_args *encoded);
 ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
                  const struct btrfs_ioctl_encoded_io_args *encoded);
 
 ssize_t btrfs_dio_rw(struct kiocb *iocb, struct iov_iter *iter, size_t done_before);
 
 extern const struct dentry_operations btrfs_dentry_operations;
 
 /* Inode locking type flags, by default the exclusive lock is taken */
 #define BTRFS_ILOCK_SHARED  (1U << 0)
 #define BTRFS_ILOCK_TRY     (1U << 1)
 #define BTRFS_ILOCK_MMAP    (1U << 2)
 
 int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags);
 void btrfs_inode_unlock(struct inode *inode, unsigned int ilock_flags);
 void btrfs_update_inode_bytes(struct btrfs_inode *inode,
                   const u64 add_bytes,
                   const u64 del_bytes);
 void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end);
 
 /* ioctl.c */
 long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
 int btrfs_fileattr_set(struct user_namespace *mnt_userns,
                struct dentry *dentry, struct fileattr *fa);
 int btrfs_ioctl_get_supported_features(void __user *arg);
 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode);
 int __pure btrfs_is_empty_uuid(u8 *uuid);
 int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra,
               struct btrfs_ioctl_defrag_range_args *range,
               u64 newer_than, unsigned long max_to_defrag);
 void btrfs_get_block_group_info(struct list_head *groups_list,
                 struct btrfs_ioctl_space_info *space);
 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
                    struct btrfs_ioctl_balance_args *bargs);
 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
             enum btrfs_exclusive_operation type);
 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
                  enum btrfs_exclusive_operation type);
 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info);
 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info);
 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
               enum btrfs_exclusive_operation op);
 
 
 /* file.c */
 int __init btrfs_auto_defrag_init(void);
 void __cold btrfs_auto_defrag_exit(void);
 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
                struct btrfs_inode *inode, u32 extent_thresh);
 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info);
 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info);
 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync);
 void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
                  int skip_pinned);
 extern const struct file_operations btrfs_file_operations;
 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
                struct btrfs_root *root, struct btrfs_inode *inode,
                struct btrfs_drop_extents_args *args);
 int btrfs_replace_file_extents(struct btrfs_inode *inode,
                struct btrfs_path *path, const u64 start,
                const u64 end,
                struct btrfs_replace_extent_info *extent_info,
                struct btrfs_trans_handle **trans_out);
 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
                   struct btrfs_inode *inode, u64 start, u64 end);
 ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from,
                 const struct btrfs_ioctl_encoded_io_args *encoded);
 int btrfs_release_file(struct inode *inode, struct file *file);
 int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
               size_t num_pages, loff_t pos, size_t write_bytes,
               struct extent_state **cached, bool noreserve);
 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);
 int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
                size_t *write_bytes);
 void btrfs_check_nocow_unlock(struct btrfs_inode *inode);
 
 /* tree-defrag.c */
 int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
             struct btrfs_root *root);
 
 /* super.c */
 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
             unsigned long new_flags);
 int btrfs_sync_fs(struct super_block *sb, int wait);
 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
                       u64 subvol_objectid);
 
 static inline __printf(2, 3) __cold
 void btrfs_no_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 {
 }
 
 #ifdef CONFIG_PRINTK_INDEX
 
 #define btrfs_printk(fs_info, fmt, args...)                 \
 do {                                        \
     printk_index_subsys_emit("%sBTRFS %s (device %s): ", NULL, fmt);    \
     _btrfs_printk(fs_info, fmt, ##args);                    \
 } while (0)
 
 __printf(2, 3)
 __cold
 void _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...);
 
 #elif defined(CONFIG_PRINTK)
 
 #define btrfs_printk(fs_info, fmt, args...)             \
     _btrfs_printk(fs_info, fmt, ##args)
 
 __printf(2, 3)
 __cold
 void _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...);
 
 #else
 
 #define btrfs_printk(fs_info, fmt, args...) \
     btrfs_no_printk(fs_info, fmt, ##args)
 #endif
 
 #define btrfs_emerg(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_EMERG fmt, ##args)
 #define btrfs_alert(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_ALERT fmt, ##args)
 #define btrfs_crit(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_CRIT fmt, ##args)
 #define btrfs_err(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_ERR fmt, ##args)
 #define btrfs_warn(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_WARNING fmt, ##args)
 #define btrfs_notice(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_NOTICE fmt, ##args)
 #define btrfs_info(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_INFO fmt, ##args)
 
 /*
  * Wrappers that use printk_in_rcu
  */
 #define btrfs_emerg_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_EMERG fmt, ##args)
 #define btrfs_alert_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_ALERT fmt, ##args)
 #define btrfs_crit_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_CRIT fmt, ##args)
 #define btrfs_err_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_ERR fmt, ##args)
 #define btrfs_warn_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_WARNING fmt, ##args)
 #define btrfs_notice_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_NOTICE fmt, ##args)
 #define btrfs_info_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_INFO fmt, ##args)
 
 /*
  * Wrappers that use a ratelimited printk_in_rcu
  */
 #define btrfs_emerg_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_EMERG fmt, ##args)
 #define btrfs_alert_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_ALERT fmt, ##args)
 #define btrfs_crit_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_CRIT fmt, ##args)
 #define btrfs_err_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_ERR fmt, ##args)
 #define btrfs_warn_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_WARNING fmt, ##args)
 #define btrfs_notice_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_NOTICE fmt, ##args)
 #define btrfs_info_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_INFO fmt, ##args)
 
 /*
  * Wrappers that use a ratelimited printk
  */
 #define btrfs_emerg_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_EMERG fmt, ##args)
 #define btrfs_alert_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_ALERT fmt, ##args)
 #define btrfs_crit_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_CRIT fmt, ##args)
 #define btrfs_err_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_ERR fmt, ##args)
 #define btrfs_warn_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_WARNING fmt, ##args)
 #define btrfs_notice_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_NOTICE fmt, ##args)
 #define btrfs_info_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_INFO fmt, ##args)
 
 #if defined(CONFIG_DYNAMIC_DEBUG)
 #define btrfs_debug(fs_info, fmt, args...)              \
     _dynamic_func_call_no_desc(fmt, btrfs_printk,           \
                    fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_in_rcu(fs_info, fmt, args...)           \
     _dynamic_func_call_no_desc(fmt, btrfs_printk_in_rcu,        \
                    fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl_in_rcu(fs_info, fmt, args...)            \
     _dynamic_func_call_no_desc(fmt, btrfs_printk_rl_in_rcu,     \
                    fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl(fs_info, fmt, args...)               \
     _dynamic_func_call_no_desc(fmt, btrfs_printk_ratelimited,   \
                    fs_info, KERN_DEBUG fmt, ##args)
 #elif defined(DEBUG)
 #define btrfs_debug(fs_info, fmt, args...) \
     btrfs_printk(fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_in_rcu(fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_printk_rl_in_rcu(fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl(fs_info, fmt, args...) \
     btrfs_printk_ratelimited(fs_info, KERN_DEBUG fmt, ##args)
 #else
 #define btrfs_debug(fs_info, fmt, args...) \
     btrfs_no_printk(fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_in_rcu(fs_info, fmt, args...) \
     btrfs_no_printk_in_rcu(fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl_in_rcu(fs_info, fmt, args...) \
     btrfs_no_printk_in_rcu(fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl(fs_info, fmt, args...) \
     btrfs_no_printk(fs_info, KERN_DEBUG fmt, ##args)
 #endif
 
 #define btrfs_printk_in_rcu(fs_info, fmt, args...)  \
 do {                            \
     rcu_read_lock();                \
     btrfs_printk(fs_info, fmt, ##args);     \
     rcu_read_unlock();              \
 } while (0)
 
 #define btrfs_no_printk_in_rcu(fs_info, fmt, args...)   \
 do {                            \
     rcu_read_lock();                \
     btrfs_no_printk(fs_info, fmt, ##args);      \
     rcu_read_unlock();              \
 } while (0)
 
 #define btrfs_printk_ratelimited(fs_info, fmt, args...)     \
 do {                                \
     static DEFINE_RATELIMIT_STATE(_rs,          \
         DEFAULT_RATELIMIT_INTERVAL,         \
         DEFAULT_RATELIMIT_BURST);               \
     if (__ratelimit(&_rs))                  \
         btrfs_printk(fs_info, fmt, ##args);     \
 } while (0)
 
 #define btrfs_printk_rl_in_rcu(fs_info, fmt, args...)       \
 do {                                \
     rcu_read_lock();                    \
     btrfs_printk_ratelimited(fs_info, fmt, ##args);     \
     rcu_read_unlock();                  \
 } while (0)
 
 #ifdef CONFIG_BTRFS_ASSERT
 __cold __noreturn
 static inline void assertfail(const char *expr, const char *file, int line)
 {
     pr_err("assertion failed: %s, in %s:%d\n", expr, file, line);
     BUG();
 }
 
 #define ASSERT(expr)                        \
     (likely(expr) ? (void)0 : assertfail(#expr, __FILE__, __LINE__))
 
 #else
 static inline void assertfail(const char *expr, const char* file, int line) { }
 #define ASSERT(expr)    (void)(expr)
 #endif
 
 #if BITS_PER_LONG == 32
 #define BTRFS_32BIT_MAX_FILE_SIZE (((u64)ULONG_MAX + 1) << PAGE_SHIFT)
 /*
  * The warning threshold is 5/8th of the MAX_LFS_FILESIZE that limits the logical
  * addresses of extents.
  *
  * For 4K page size it's about 10T, for 64K it's 160T.
  */
 #define BTRFS_32BIT_EARLY_WARN_THRESHOLD (BTRFS_32BIT_MAX_FILE_SIZE * 5 / 8)
 void btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info);
 void btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info);
 #endif
 
 /*
  * Get the correct offset inside the page of extent buffer.
  *
  * @eb:     target extent buffer
  * @start:  offset inside the extent buffer
  *
  * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
  */
 static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb,
                        unsigned long offset)
 {
     /*
      * For sectorsize == PAGE_SIZE case, eb->start will always be aligned
      * to PAGE_SIZE, thus adding it won't cause any difference.
      *
      * For sectorsize < PAGE_SIZE, we must only read the data that belongs
      * to the eb, thus we have to take the eb->start into consideration.
      */
     return offset_in_page(offset + eb->start);
 }
 
 static inline unsigned long get_eb_page_index(unsigned long offset)
 {
     /*
      * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough.
      *
      * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE,
      * and have ensured that all tree blocks are contained in one page,
      * thus we always get index == 0.
      */
     return offset >> PAGE_SHIFT;
 }
 
 /*
  * Use that for functions that are conditionally exported for sanity tests but
  * otherwise static
  */
 #ifndef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 #define EXPORT_FOR_TESTS static
 #else
 #define EXPORT_FOR_TESTS
 #endif
 
 __cold
 static inline void btrfs_print_v0_err(struct btrfs_fs_info *fs_info)
 {
     btrfs_err(fs_info,
 "Unsupported V0 extent filesystem detected. Aborting. Please re-create your filesystem with a newer kernel");
 }
 
 __printf(5, 6)
 __cold
 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
              unsigned int line, int errno, const char *fmt, ...);
 
 const char * __attribute_const__ btrfs_decode_error(int errno);
 
 __cold
 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
                    const char *function,
                    unsigned int line, int errno);
 
 /*
  * Call btrfs_abort_transaction as early as possible when an error condition is
  * detected, that way the exact line number is reported.
  */
 #define btrfs_abort_transaction(trans, errno)       \
 do {                                \
     /* Report first abort since mount */            \
     if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \
             &((trans)->fs_info->fs_state))) {   \
         if ((errno) != -EIO && (errno) != -EROFS) {     \
             WARN(1, KERN_DEBUG              \
             "BTRFS: Transaction aborted (error %d)\n",  \
             (errno));                   \
         } else {                        \
             btrfs_debug((trans)->fs_info,           \
                     "Transaction aborted (error %d)", \
                   (errno));         \
         }                       \
     }                           \
     __btrfs_abort_transaction((trans), __func__,        \
                   __LINE__, (errno));       \
 } while (0)
 
 #ifdef CONFIG_PRINTK_INDEX
 
 #define btrfs_handle_fs_error(fs_info, errno, fmt, args...)     \
 do {                                    \
     printk_index_subsys_emit(                   \
         "BTRFS: error (device %s%s) in %s:%d: errno=%d %s", \
         KERN_CRIT, fmt);                    \
     __btrfs_handle_fs_error((fs_info), __func__, __LINE__,      \
                 (errno), fmt, ##args);          \
 } while (0)
 
 #else
 
 #define btrfs_handle_fs_error(fs_info, errno, fmt, args...)     \
     __btrfs_handle_fs_error((fs_info), __func__, __LINE__,      \
                 (errno), fmt, ##args)
 
 #endif
 
 #define BTRFS_FS_ERROR(fs_info) (unlikely(test_bit(BTRFS_FS_STATE_ERROR, \
                            &(fs_info)->fs_state)))
 #define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info)             \
     (unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,        \
                &(fs_info)->fs_state)))
 
 __printf(5, 6)
 __cold
 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
            unsigned int line, int errno, const char *fmt, ...);
 /*
  * If BTRFS_MOUNT_PANIC_ON_FATAL_ERROR is in mount_opt, __btrfs_panic
  * will panic().  Otherwise we BUG() here.
  */
 #define btrfs_panic(fs_info, errno, fmt, args...)           \
 do {                                    \
     __btrfs_panic(fs_info, __func__, __LINE__, errno, fmt, ##args); \
     BUG();                              \
 } while (0)
 
 
 /* compatibility and incompatibility defines */
 
 #define btrfs_set_fs_incompat(__fs_info, opt) \
     __btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, \
                 #opt)
 
 static inline void __btrfs_set_fs_incompat(struct btrfs_fs_info *fs_info,
                        u64 flag, const char* name)
 {
     struct btrfs_super_block *disk_super;
     u64 features;
 
     disk_super = fs_info->super_copy;
     features = btrfs_super_incompat_flags(disk_super);
     if (!(features & flag)) {
         spin_lock(&fs_info->super_lock);
         features = btrfs_super_incompat_flags(disk_super);
         if (!(features & flag)) {
             features |= flag;
             btrfs_set_super_incompat_flags(disk_super, features);
             btrfs_info(fs_info,
                 "setting incompat feature flag for %s (0x%llx)",
                 name, flag);
         }
         spin_unlock(&fs_info->super_lock);
     }
 }
 
 #define btrfs_clear_fs_incompat(__fs_info, opt) \
     __btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, \
                   #opt)
 
 static inline void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info,
                          u64 flag, const char* name)
 {
     struct btrfs_super_block *disk_super;
     u64 features;
 
     disk_super = fs_info->super_copy;
     features = btrfs_super_incompat_flags(disk_super);
     if (features & flag) {
         spin_lock(&fs_info->super_lock);
         features = btrfs_super_incompat_flags(disk_super);
         if (features & flag) {
             features &= ~flag;
             btrfs_set_super_incompat_flags(disk_super, features);
             btrfs_info(fs_info,
                 "clearing incompat feature flag for %s (0x%llx)",
                 name, flag);
         }
         spin_unlock(&fs_info->super_lock);
     }
 }
 
 #define btrfs_fs_incompat(fs_info, opt) \
     __btrfs_fs_incompat((fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
 
 static inline bool __btrfs_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag)
 {
     struct btrfs_super_block *disk_super;
     disk_super = fs_info->super_copy;
     return !!(btrfs_super_incompat_flags(disk_super) & flag);
 }
 
 #define btrfs_set_fs_compat_ro(__fs_info, opt) \
     __btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, \
                  #opt)
 
 static inline void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info,
                         u64 flag, const char *name)
 {
     struct btrfs_super_block *disk_super;
     u64 features;
 
     disk_super = fs_info->super_copy;
     features = btrfs_super_compat_ro_flags(disk_super);
     if (!(features & flag)) {
         spin_lock(&fs_info->super_lock);
         features = btrfs_super_compat_ro_flags(disk_super);
         if (!(features & flag)) {
             features |= flag;
             btrfs_set_super_compat_ro_flags(disk_super, features);
             btrfs_info(fs_info,
                 "setting compat-ro feature flag for %s (0x%llx)",
                 name, flag);
         }
         spin_unlock(&fs_info->super_lock);
     }
 }
 
 #define btrfs_clear_fs_compat_ro(__fs_info, opt) \
     __btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, \
                    #opt)
 
 static inline void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info,
                           u64 flag, const char *name)
 {
     struct btrfs_super_block *disk_super;
     u64 features;
 
     disk_super = fs_info->super_copy;
     features = btrfs_super_compat_ro_flags(disk_super);
     if (features & flag) {
         spin_lock(&fs_info->super_lock);
         features = btrfs_super_compat_ro_flags(disk_super);
         if (features & flag) {
             features &= ~flag;
             btrfs_set_super_compat_ro_flags(disk_super, features);
             btrfs_info(fs_info,
                 "clearing compat-ro feature flag for %s (0x%llx)",
                 name, flag);
         }
         spin_unlock(&fs_info->super_lock);
     }
 }
 
 #define btrfs_fs_compat_ro(fs_info, opt) \
     __btrfs_fs_compat_ro((fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
 
 static inline int __btrfs_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag)
 {
     struct btrfs_super_block *disk_super;
     disk_super = fs_info->super_copy;
     return !!(btrfs_super_compat_ro_flags(disk_super) & flag);
 }
 
 /* acl.c */
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu);
 int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
           struct posix_acl *acl, int type);
 int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
             struct posix_acl *acl, int type);
 #else
 #define btrfs_get_acl NULL
 #define btrfs_set_acl NULL
 static inline int __btrfs_set_acl(struct btrfs_trans_handle *trans,
                   struct inode *inode, struct posix_acl *acl,
                   int type)
 {
     return -EOPNOTSUPP;
 }
 #endif
 
 /* relocation.c */
 int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start);
 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
               struct btrfs_root *root);
 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
                 struct btrfs_root *root);
 int btrfs_recover_relocation(struct btrfs_fs_info *fs_info);
 int btrfs_reloc_clone_csums(struct btrfs_inode *inode, u64 file_pos, u64 len);
 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
               struct btrfs_root *root, struct extent_buffer *buf,
               struct extent_buffer *cow);
 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
                   u64 *bytes_to_reserve);
 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
                   struct btrfs_pending_snapshot *pending);
 int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info);
 struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info,
                    u64 bytenr);
 int btrfs_should_ignore_reloc_root(struct btrfs_root *root);
 
 /* scrub.c */
 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
             u64 end, struct btrfs_scrub_progress *progress,
             int readonly, int is_dev_replace);
 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info);
 void btrfs_scrub_continue(struct btrfs_fs_info *fs_info);
 int btrfs_scrub_cancel(struct btrfs_fs_info *info);
 int btrfs_scrub_cancel_dev(struct btrfs_device *dev);
 int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
              struct btrfs_scrub_progress *progress);
 static inline void btrfs_init_full_stripe_locks_tree(
             struct btrfs_full_stripe_locks_tree *locks_root)
 {
     locks_root->root = RB_ROOT;
     mutex_init(&locks_root->lock);
 }
 
 /* dev-replace.c */
 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info);
 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info);
 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount);
 
 static inline void btrfs_bio_counter_dec(struct btrfs_fs_info *fs_info)
 {
     btrfs_bio_counter_sub(fs_info, 1);
 }
 
 static inline int is_fstree(u64 rootid)
 {
     if (rootid == BTRFS_FS_TREE_OBJECTID ||
         ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID &&
           !btrfs_qgroup_level(rootid)))
         return 1;
     return 0;
 }
 
 static inline int btrfs_defrag_cancelled(struct btrfs_fs_info *fs_info)
 {
     return signal_pending(current);
 }
 
 /* verity.c */
 #ifdef CONFIG_FS_VERITY
 
 extern const struct fsverity_operations btrfs_verityops;
 int btrfs_drop_verity_items(struct btrfs_inode *inode);
 
 BTRFS_SETGET_FUNCS(verity_descriptor_encryption, struct btrfs_verity_descriptor_item,
            encryption, 8);
 BTRFS_SETGET_FUNCS(verity_descriptor_size, struct btrfs_verity_descriptor_item,
            size, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_verity_descriptor_encryption,
              struct btrfs_verity_descriptor_item, encryption, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_verity_descriptor_size,
              struct btrfs_verity_descriptor_item, size, 64);
 
 #else
 
 static inline int btrfs_drop_verity_items(struct btrfs_inode *inode)
 {
     return 0;
 }
 
 #endif
 
 /* Sanity test specific functions */
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 void btrfs_test_destroy_inode(struct inode *inode);
 static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
 {
     return test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
 }
 #else
 static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
 {
     return 0;
 }
 #endif
 
 static inline bool btrfs_is_zoned(const struct btrfs_fs_info *fs_info)
 {
     return fs_info->zone_size > 0;
 }
 
 /*
  * Count how many fs_info->max_extent_size cover the @size
  */
 static inline u32 count_max_extents(struct btrfs_fs_info *fs_info, u64 size)
 {
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
     if (!fs_info)
         return div_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE);
 #endif
 
     return div_u64(size + fs_info->max_extent_size - 1, fs_info->max_extent_size);
 }
 
 static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
 {
     return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
 }
 
 /*
  * We use page status Private2 to indicate there is an ordered extent with
  * unfinished IO.
  *
  * Rename the Private2 accessors to Ordered, to improve readability.
  */
 #define PageOrdered(page)       PagePrivate2(page)
 #define SetPageOrdered(page)        SetPagePrivate2(page)
 #define ClearPageOrdered(page)      ClearPagePrivate2(page)
 #define folio_test_ordered(folio)   folio_test_private_2(folio)
 #define folio_set_ordered(folio)    folio_set_private_2(folio)
 #define folio_clear_ordered(folio)  folio_clear_private_2(folio)
 
 #endif