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+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_FS_H
+#define BTRFS_FS_H
+
+#include <linux/blkdev.h>
+#include <linux/fs.h>
+#include <linux/btrfs_tree.h>
+#include <linux/sizes.h>
+#include "extent-io-tree.h"
+#include "extent_map.h"
+#include "async-thread.h"
+#include "block-rsv.h"
+
+#define BTRFS_MAX_EXTENT_SIZE SZ_128M
+
+#define BTRFS_OLDEST_GENERATION 0ULL
+
+#define BTRFS_EMPTY_DIR_SIZE 0
+
+#define BTRFS_DIRTY_METADATA_THRESH SZ_32M
+
+#define BTRFS_SUPER_INFO_OFFSET SZ_64K
+#define BTRFS_SUPER_INFO_SIZE 4096
+static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE);
+
+/*
+ * Number of metadata items necessary for an unlink operation:
+ *
+ * 1 for the possible orphan item
+ * 1 for the dir item
+ * 1 for the dir index
+ * 1 for the inode ref
+ * 1 for the inode
+ * 1 for the parent inode
+ */
+#define BTRFS_UNLINK_METADATA_UNITS 6
+
+/*
+ * 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)
+/*
+ * Runtime (in-memory) states of filesystem
+ */
+enum {
+ /*
+ * 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
+};
+
+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,
+
+ /* Indicate that we want to commit the transaction. */
+ BTRFS_FS_NEED_TRANS_COMMIT,
+
+ /* This is set when active zone tracking is needed. */
+ BTRFS_FS_ACTIVE_ZONE_TRACKING,
+
+ /*
+ * Indicate if we have some features changed, this is mostly for
+ * cleaner thread to update the sysfs interface.
+ */
+ BTRFS_FS_FEATURE_CHANGED,
+
+#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
+};
+
+/*
+ * 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),
+ BTRFS_MOUNT_NODISCARD = (1UL << 31),
+};
+
+/*
+ * 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 | \
+ BTRFS_FEATURE_COMPAT_RO_BLOCK_GROUP_TREE)
+
+#define BTRFS_FEATURE_COMPAT_RO_SAFE_SET 0ULL
+#define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR 0ULL
+
+#define BTRFS_FEATURE_INCOMPAT_SUPP_STABLE \
+ (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)
+
+#ifdef CONFIG_BTRFS_DEBUG
+ /*
+ * Features under developmen like Extent tree v2 support is enabled
+ * only under CONFIG_BTRFS_DEBUG.
+ */
+#define BTRFS_FEATURE_INCOMPAT_SUPP \
+ (BTRFS_FEATURE_INCOMPAT_SUPP_STABLE | \
+ BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
+
+#else
+
+#define BTRFS_FEATURE_INCOMPAT_SUPP \
+ (BTRFS_FEATURE_INCOMPAT_SUPP_STABLE)
+
+#endif
+
+#define BTRFS_FEATURE_INCOMPAT_SAFE_SET \
+ (BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
+#define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR 0ULL
+
+#define BTRFS_DEFAULT_COMMIT_INTERVAL (30)
+#define BTRFS_DEFAULT_MAX_INLINE (2048)
+
+struct btrfs_dev_replace {
+ /* See #define above */
+ u64 replace_state;
+ /* Seconds since 1-Jan-1970 */
+ time64_t time_started;
+ /* Seconds since 1-Jan-1970 */
+ time64_t time_stopped;
+ 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;
+
+ /* See #define above */
+ u64 cont_reading_from_srcdev_mode;
+
+ 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;
+};
+
+/* 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;
+};
+
+/*
+ * 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;
+
+ /*
+ * 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;
+
+ 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 *delalloc_workers;
+ struct btrfs_workqueue *flush_workers;
+ struct workqueue_struct *endio_workers;
+ struct workqueue_struct *endio_meta_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;
+ struct kobject *discard_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;
+
+ /* Protected by 'trans_lock'. */
+ 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;
+
+ /* Balance 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 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. */
+ /* Protects the progress item */
+ struct mutex qgroup_rescan_lock;
+ struct btrfs_key qgroup_rescan_progress;
+ struct btrfs_workqueue *qgroup_rescan_workers;
+ struct completion qgroup_rescan_completion;
+ struct btrfs_work qgroup_rescan_work;
+ /* Protected by qgroup_rescan_lock */
+ bool qgroup_rescan_running;
+ u8 qgroup_drop_subtree_thres;
+
+ /*
+ * If this is not 0, then it indicates a serious filesystem error has
+ * happened and it contains that error (negative errno value).
+ */
+ int fs_error;
+
+ /* 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;
+
+ /* Constraints for ZONE_APPEND commands: */
+ struct queue_limits limits;
+ 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;
+
+ struct btrfs_block_group *active_meta_bg;
+ struct btrfs_block_group *active_system_bg;
+
+ 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;
+
+ /*
+ * Last generation where we dropped a non-relocation root.
+ * Use btrfs_set_last_root_drop_gen() and btrfs_get_last_root_drop_gen()
+ * to change it and to read it, respectively.
+ */
+ u64 last_root_drop_gen;
+
+ /*
+ * Annotations for transaction events (structures are empty when
+ * compiled without lockdep).
+ */
+ struct lockdep_map btrfs_trans_num_writers_map;
+ struct lockdep_map btrfs_trans_num_extwriters_map;
+ struct lockdep_map btrfs_state_change_map[4];
+ struct lockdep_map btrfs_trans_pending_ordered_map;
+ struct lockdep_map btrfs_ordered_extent_map;
+
+#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 list_head allocated_roots;
+
+ spinlock_t eb_leak_lock;
+ struct list_head allocated_ebs;
+#endif
+};
+
+static inline void btrfs_set_last_root_drop_gen(struct btrfs_fs_info *fs_info,
+ u64 gen)
+{
+ WRITE_ONCE(fs_info->last_root_drop_gen, gen);
+}
+
+static inline u64 btrfs_get_last_root_drop_gen(const struct btrfs_fs_info *fs_info)
+{
+ return READ_ONCE(fs_info->last_root_drop_gen);
+}
+
+/*
+ * 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(const 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(const struct btrfs_fs_info *fs_info,
+ unsigned num_items)
+{
+ return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
+}
+
+#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
+ sizeof(struct btrfs_item))
+
+static inline bool btrfs_is_zoned(const struct btrfs_fs_info *fs_info)
+{
+ return IS_ENABLED(CONFIG_BLK_DEV_ZONED) && 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);
+}
+
+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);
+
+/* Compatibility and incompatibility defines */
+void __btrfs_set_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
+ const char *name);
+void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
+ const char *name);
+void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
+ const char *name);
+void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
+ const char *name);
+
+#define __btrfs_fs_incompat(fs_info, flags) \
+ (!!(btrfs_super_incompat_flags((fs_info)->super_copy) & (flags)))
+
+#define __btrfs_fs_compat_ro(fs_info, flags) \
+ (!!(btrfs_super_compat_ro_flags((fs_info)->super_copy) & (flags)))
+
+#define btrfs_set_fs_incompat(__fs_info, opt) \
+ __btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
+
+#define btrfs_clear_fs_incompat(__fs_info, opt) \
+ __btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
+
+#define btrfs_fs_incompat(fs_info, opt) \
+ __btrfs_fs_incompat((fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
+
+#define btrfs_set_fs_compat_ro(__fs_info, opt) \
+ __btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
+
+#define btrfs_clear_fs_compat_ro(__fs_info, opt) \
+ __btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
+
+#define btrfs_fs_compat_ro(fs_info, opt) \
+ __btrfs_fs_compat_ro((fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
+
+#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)
+
+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_wake_unfinished_drop(struct btrfs_fs_info *fs_info)
+{
+ clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);
+}
+
+#define BTRFS_FS_ERROR(fs_info) (READ_ONCE((fs_info)->fs_error))
+
+#define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info) \
+ (unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR, \
+ &(fs_info)->fs_state)))
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+
+#define EXPORT_FOR_TESTS
+
+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);
+}
+
+void btrfs_test_destroy_inode(struct inode *inode);
+
+#else
+
+#define EXPORT_FOR_TESTS static
+
+static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
+{
+ return 0;
+}
+#endif
+
+#endif