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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 
 #include "misc.h"
 #include "ctree.h"
 #include "block-rsv.h"
 #include "space-info.h"
 #include "transaction.h"
 #include "block-group.h"
 #include "disk-io.h"
 
 /*
  * HOW DO BLOCK RESERVES WORK
  *
  *   Think of block_rsv's as buckets for logically grouped metadata
  *   reservations.  Each block_rsv has a ->size and a ->reserved.  ->size is
  *   how large we want our block rsv to be, ->reserved is how much space is
  *   currently reserved for this block reserve.
  *
  *   ->failfast exists for the truncate case, and is described below.
  *
  * NORMAL OPERATION
  *
  *   -> Reserve
  *     Entrance: btrfs_block_rsv_add, btrfs_block_rsv_refill
  *
  *     We call into btrfs_reserve_metadata_bytes() with our bytes, which is
  *     accounted for in space_info->bytes_may_use, and then add the bytes to
  *     ->reserved, and ->size in the case of btrfs_block_rsv_add.
  *
  *     ->size is an over-estimation of how much we may use for a particular
  *     operation.
  *
  *   -> Use
  *     Entrance: btrfs_use_block_rsv
  *
  *     When we do a btrfs_alloc_tree_block() we call into btrfs_use_block_rsv()
  *     to determine the appropriate block_rsv to use, and then verify that
  *     ->reserved has enough space for our tree block allocation.  Once
  *     successful we subtract fs_info->nodesize from ->reserved.
  *
  *   -> Finish
  *     Entrance: btrfs_block_rsv_release
  *
  *     We are finished with our operation, subtract our individual reservation
  *     from ->size, and then subtract ->size from ->reserved and free up the
  *     excess if there is any.
  *
  *     There is some logic here to refill the delayed refs rsv or the global rsv
  *     as needed, otherwise the excess is subtracted from
  *     space_info->bytes_may_use.
  *
  * TYPES OF BLOCK RESERVES
  *
  * BLOCK_RSV_TRANS, BLOCK_RSV_DELOPS, BLOCK_RSV_CHUNK
  *   These behave normally, as described above, just within the confines of the
  *   lifetime of their particular operation (transaction for the whole trans
  *   handle lifetime, for example).
  *
  * BLOCK_RSV_GLOBAL
  *   It is impossible to properly account for all the space that may be required
  *   to make our extent tree updates.  This block reserve acts as an overflow
  *   buffer in case our delayed refs reserve does not reserve enough space to
  *   update the extent tree.
  *
  *   We can steal from this in some cases as well, notably on evict() or
  *   truncate() in order to help users recover from ENOSPC conditions.
  *
  * BLOCK_RSV_DELALLOC
  *   The individual item sizes are determined by the per-inode size
  *   calculations, which are described with the delalloc code.  This is pretty
  *   straightforward, it's just the calculation of ->size encodes a lot of
  *   different items, and thus it gets used when updating inodes, inserting file
  *   extents, and inserting checksums.
  *
  * BLOCK_RSV_DELREFS
  *   We keep a running tally of how many delayed refs we have on the system.
  *   We assume each one of these delayed refs are going to use a full
  *   reservation.  We use the transaction items and pre-reserve space for every
  *   operation, and use this reservation to refill any gap between ->size and
  *   ->reserved that may exist.
  *
  *   From there it's straightforward, removing a delayed ref means we remove its
  *   count from ->size and free up reservations as necessary.  Since this is
  *   the most dynamic block reserve in the system, we will try to refill this
  *   block reserve first with any excess returned by any other block reserve.
  *
  * BLOCK_RSV_EMPTY
  *   This is the fallback block reserve to make us try to reserve space if we
  *   don't have a specific bucket for this allocation.  It is mostly used for
  *   updating the device tree and such, since that is a separate pool we're
  *   content to just reserve space from the space_info on demand.
  *
  * BLOCK_RSV_TEMP
  *   This is used by things like truncate and iput.  We will temporarily
  *   allocate a block reserve, set it to some size, and then truncate bytes
  *   until we have no space left.  With ->failfast set we'll simply return
  *   ENOSPC from btrfs_use_block_rsv() to signal that we need to unwind and try
  *   to make a new reservation.  This is because these operations are
  *   unbounded, so we want to do as much work as we can, and then back off and
  *   re-reserve.
  */
 
 static u64 block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
                     struct btrfs_block_rsv *block_rsv,
                     struct btrfs_block_rsv *dest, u64 num_bytes,
                     u64 *qgroup_to_release_ret)
 {
     struct btrfs_space_info *space_info = block_rsv->space_info;
     u64 qgroup_to_release = 0;
     u64 ret;
 
     spin_lock(&block_rsv->lock);
     if (num_bytes == (u64)-1) {
         num_bytes = block_rsv->size;
         qgroup_to_release = block_rsv->qgroup_rsv_size;
     }
     block_rsv->size -= num_bytes;
     if (block_rsv->reserved >= block_rsv->size) {
         num_bytes = block_rsv->reserved - block_rsv->size;
         block_rsv->reserved = block_rsv->size;
         block_rsv->full = true;
     } else {
         num_bytes = 0;
     }
     if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) {
         qgroup_to_release = block_rsv->qgroup_rsv_reserved -
                     block_rsv->qgroup_rsv_size;
         block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size;
     } else {
         qgroup_to_release = 0;
     }
     spin_unlock(&block_rsv->lock);
 
     ret = num_bytes;
     if (num_bytes > 0) {
         if (dest) {
             spin_lock(&dest->lock);
             if (!dest->full) {
                 u64 bytes_to_add;
 
                 bytes_to_add = dest->size - dest->reserved;
                 bytes_to_add = min(num_bytes, bytes_to_add);
                 dest->reserved += bytes_to_add;
                 if (dest->reserved >= dest->size)
                     dest->full = true;
                 num_bytes -= bytes_to_add;
             }
             spin_unlock(&dest->lock);
         }
         if (num_bytes)
             btrfs_space_info_free_bytes_may_use(fs_info,
                                 space_info,
                                 num_bytes);
     }
     if (qgroup_to_release_ret)
         *qgroup_to_release_ret = qgroup_to_release;
     return ret;
 }
 
 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src,
                 struct btrfs_block_rsv *dst, u64 num_bytes,
                 bool update_size)
 {
     int ret;
 
     ret = btrfs_block_rsv_use_bytes(src, num_bytes);
     if (ret)
         return ret;
 
     btrfs_block_rsv_add_bytes(dst, num_bytes, update_size);
     return 0;
 }
 
 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type)
 {
     memset(rsv, 0, sizeof(*rsv));
     spin_lock_init(&rsv->lock);
     rsv->type = type;
 }
 
 void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
                    struct btrfs_block_rsv *rsv,
                    enum btrfs_rsv_type type)
 {
     btrfs_init_block_rsv(rsv, type);
     rsv->space_info = btrfs_find_space_info(fs_info,
                         BTRFS_BLOCK_GROUP_METADATA);
 }
 
 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
                           enum btrfs_rsv_type type)
 {
     struct btrfs_block_rsv *block_rsv;
 
     block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
     if (!block_rsv)
         return NULL;
 
     btrfs_init_metadata_block_rsv(fs_info, block_rsv, type);
     return block_rsv;
 }
 
 void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
               struct btrfs_block_rsv *rsv)
 {
     if (!rsv)
         return;
     btrfs_block_rsv_release(fs_info, rsv, (u64)-1, NULL);
     kfree(rsv);
 }
 
 int btrfs_block_rsv_add(struct btrfs_fs_info *fs_info,
             struct btrfs_block_rsv *block_rsv, u64 num_bytes,
             enum btrfs_reserve_flush_enum flush)
 {
     int ret;
 
     if (num_bytes == 0)
         return 0;
 
     ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, num_bytes, flush);
     if (!ret)
         btrfs_block_rsv_add_bytes(block_rsv, num_bytes, true);
 
     return ret;
 }
 
 int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor)
 {
     u64 num_bytes = 0;
     int ret = -ENOSPC;
 
     if (!block_rsv)
         return 0;
 
     spin_lock(&block_rsv->lock);
     num_bytes = div_factor(block_rsv->size, min_factor);
     if (block_rsv->reserved >= num_bytes)
         ret = 0;
     spin_unlock(&block_rsv->lock);
 
     return ret;
 }
 
 int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info,
                struct btrfs_block_rsv *block_rsv, u64 min_reserved,
                enum btrfs_reserve_flush_enum flush)
 {
     u64 num_bytes = 0;
     int ret = -ENOSPC;
 
     if (!block_rsv)
         return 0;
 
     spin_lock(&block_rsv->lock);
     num_bytes = min_reserved;
     if (block_rsv->reserved >= num_bytes)
         ret = 0;
     else
         num_bytes -= block_rsv->reserved;
     spin_unlock(&block_rsv->lock);
 
     if (!ret)
         return 0;
 
     ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, num_bytes, flush);
     if (!ret) {
         btrfs_block_rsv_add_bytes(block_rsv, num_bytes, false);
         return 0;
     }
 
     return ret;
 }
 
 u64 btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
                 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
                 u64 *qgroup_to_release)
 {
     struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
     struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
     struct btrfs_block_rsv *target = NULL;
 
     /*
      * If we are the delayed_rsv then push to the global rsv, otherwise dump
      * into the delayed rsv if it is not full.
      */
     if (block_rsv == delayed_rsv)
         target = global_rsv;
     else if (block_rsv != global_rsv && !delayed_rsv->full)
         target = delayed_rsv;
 
     if (target && block_rsv->space_info != target->space_info)
         target = NULL;
 
     return block_rsv_release_bytes(fs_info, block_rsv, target, num_bytes,
                        qgroup_to_release);
 }
 
 int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes)
 {
     int ret = -ENOSPC;
 
     spin_lock(&block_rsv->lock);
     if (block_rsv->reserved >= num_bytes) {
         block_rsv->reserved -= num_bytes;
         if (block_rsv->reserved < block_rsv->size)
             block_rsv->full = false;
         ret = 0;
     }
     spin_unlock(&block_rsv->lock);
     return ret;
 }
 
 void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
                    u64 num_bytes, bool update_size)
 {
     spin_lock(&block_rsv->lock);
     block_rsv->reserved += num_bytes;
     if (update_size)
         block_rsv->size += num_bytes;
     else if (block_rsv->reserved >= block_rsv->size)
         block_rsv->full = true;
     spin_unlock(&block_rsv->lock);
 }
 
 int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
                  struct btrfs_block_rsv *dest, u64 num_bytes,
                  int min_factor)
 {
     struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
     u64 min_bytes;
 
     if (global_rsv->space_info != dest->space_info)
         return -ENOSPC;
 
     spin_lock(&global_rsv->lock);
     min_bytes = div_factor(global_rsv->size, min_factor);
     if (global_rsv->reserved < min_bytes + num_bytes) {
         spin_unlock(&global_rsv->lock);
         return -ENOSPC;
     }
     global_rsv->reserved -= num_bytes;
     if (global_rsv->reserved < global_rsv->size)
         global_rsv->full = false;
     spin_unlock(&global_rsv->lock);
 
     btrfs_block_rsv_add_bytes(dest, num_bytes, true);
     return 0;
 }
 
 void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
 {
     struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
     struct btrfs_space_info *sinfo = block_rsv->space_info;
     struct btrfs_root *root, *tmp;
     u64 num_bytes = btrfs_root_used(&fs_info->tree_root->root_item);
     unsigned int min_items = 1;
 
     /*
      * The global block rsv is based on the size of the extent tree, the
      * checksum tree and the root tree.  If the fs is empty we want to set
      * it to a minimal amount for safety.
      *
      * We also are going to need to modify the minimum of the tree root and
      * any global roots we could touch.
      */
     read_lock(&fs_info->global_root_lock);
     rbtree_postorder_for_each_entry_safe(root, tmp, &fs_info->global_root_tree,
                          rb_node) {
         if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID ||
             root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID ||
             root->root_key.objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) {
             num_bytes += btrfs_root_used(&root->root_item);
             min_items++;
         }
     }
     read_unlock(&fs_info->global_root_lock);
 
     /*
      * But we also want to reserve enough space so we can do the fallback
      * global reserve for an unlink, which is an additional 5 items (see the
      * comment in __unlink_start_trans for what we're modifying.)
      *
      * But we also need space for the delayed ref updates from the unlink,
      * so its 10, 5 for the actual operation, and 5 for the delayed ref
      * updates.
      */
     min_items += 10;
 
     num_bytes = max_t(u64, num_bytes,
               btrfs_calc_insert_metadata_size(fs_info, min_items));
 
     spin_lock(&sinfo->lock);
     spin_lock(&block_rsv->lock);
 
     block_rsv->size = min_t(u64, num_bytes, SZ_512M);
 
     if (block_rsv->reserved < block_rsv->size) {
         num_bytes = block_rsv->size - block_rsv->reserved;
         btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
                               num_bytes);
         block_rsv->reserved = block_rsv->size;
     } else if (block_rsv->reserved > block_rsv->size) {
         num_bytes = block_rsv->reserved - block_rsv->size;
         btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
                               -num_bytes);
         block_rsv->reserved = block_rsv->size;
         btrfs_try_granting_tickets(fs_info, sinfo);
     }
 
     block_rsv->full = (block_rsv->reserved == block_rsv->size);
 
     if (block_rsv->size >= sinfo->total_bytes)
         sinfo->force_alloc = CHUNK_ALLOC_FORCE;
     spin_unlock(&block_rsv->lock);
     spin_unlock(&sinfo->lock);
 }
 
 void btrfs_init_root_block_rsv(struct btrfs_root *root)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
 
     switch (root->root_key.objectid) {
     case BTRFS_CSUM_TREE_OBJECTID:
     case BTRFS_EXTENT_TREE_OBJECTID:
     case BTRFS_FREE_SPACE_TREE_OBJECTID:
         root->block_rsv = &fs_info->delayed_refs_rsv;
         break;
     case BTRFS_ROOT_TREE_OBJECTID:
     case BTRFS_DEV_TREE_OBJECTID:
     case BTRFS_QUOTA_TREE_OBJECTID:
         root->block_rsv = &fs_info->global_block_rsv;
         break;
     case BTRFS_CHUNK_TREE_OBJECTID:
         root->block_rsv = &fs_info->chunk_block_rsv;
         break;
     default:
         root->block_rsv = NULL;
         break;
     }
 }
 
 void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info)
 {
     struct btrfs_space_info *space_info;
 
     space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
     fs_info->chunk_block_rsv.space_info = space_info;
 
     space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
     fs_info->global_block_rsv.space_info = space_info;
     fs_info->trans_block_rsv.space_info = space_info;
     fs_info->empty_block_rsv.space_info = space_info;
     fs_info->delayed_block_rsv.space_info = space_info;
     fs_info->delayed_refs_rsv.space_info = space_info;
 
     btrfs_update_global_block_rsv(fs_info);
 }
 
 void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info)
 {
     btrfs_block_rsv_release(fs_info, &fs_info->global_block_rsv, (u64)-1,
                 NULL);
     WARN_ON(fs_info->trans_block_rsv.size > 0);
     WARN_ON(fs_info->trans_block_rsv.reserved > 0);
     WARN_ON(fs_info->chunk_block_rsv.size > 0);
     WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
     WARN_ON(fs_info->delayed_block_rsv.size > 0);
     WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
     WARN_ON(fs_info->delayed_refs_rsv.reserved > 0);
     WARN_ON(fs_info->delayed_refs_rsv.size > 0);
 }
 
 static struct btrfs_block_rsv *get_block_rsv(
                     const struct btrfs_trans_handle *trans,
                     const struct btrfs_root *root)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_block_rsv *block_rsv = NULL;
 
     if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
         (root == fs_info->uuid_root) ||
         (trans->adding_csums &&
          root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID))
         block_rsv = trans->block_rsv;
 
     if (!block_rsv)
         block_rsv = root->block_rsv;
 
     if (!block_rsv)
         block_rsv = &fs_info->empty_block_rsv;
 
     return block_rsv;
 }
 
 struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root,
                         u32 blocksize)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_block_rsv *block_rsv;
     struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
     int ret;
     bool global_updated = false;
 
     block_rsv = get_block_rsv(trans, root);
 
     if (unlikely(block_rsv->size == 0))
         goto try_reserve;
 again:
     ret = btrfs_block_rsv_use_bytes(block_rsv, blocksize);
     if (!ret)
         return block_rsv;
 
     if (block_rsv->failfast)
         return ERR_PTR(ret);
 
     if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
         global_updated = true;
         btrfs_update_global_block_rsv(fs_info);
         goto again;
     }
 
     /*
      * The global reserve still exists to save us from ourselves, so don't
      * warn_on if we are short on our delayed refs reserve.
      */
     if (block_rsv->type != BTRFS_BLOCK_RSV_DELREFS &&
         btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
         static DEFINE_RATELIMIT_STATE(_rs,
                 DEFAULT_RATELIMIT_INTERVAL * 10,
                 /*DEFAULT_RATELIMIT_BURST*/ 1);
         if (__ratelimit(&_rs))
             WARN(1, KERN_DEBUG
                 "BTRFS: block rsv %d returned %d\n",
                 block_rsv->type, ret);
     }
 try_reserve:
     ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, blocksize,
                        BTRFS_RESERVE_NO_FLUSH);
     if (!ret)
         return block_rsv;
     /*
      * If we couldn't reserve metadata bytes try and use some from
      * the global reserve if its space type is the same as the global
      * reservation.
      */
     if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
         block_rsv->space_info == global_rsv->space_info) {
         ret = btrfs_block_rsv_use_bytes(global_rsv, blocksize);
         if (!ret)
             return global_rsv;
     }
     return ERR_PTR(ret);
 }

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