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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
 /*
  * Copyright (C) 2007 Oracle.  All rights reserved.
  */
 
 #include <linux/slab.h>
 #include <linux/blkdev.h>
 #include <linux/writeback.h>
 #include <linux/sched/mm.h>
 #include "misc.h"
 #include "ctree.h"
 #include "transaction.h"
 #include "btrfs_inode.h"
 #include "extent_io.h"
 #include "disk-io.h"
 #include "compression.h"
 #include "delalloc-space.h"
 #include "qgroup.h"
 #include "subpage.h"
 
 static struct kmem_cache *btrfs_ordered_extent_cache;
 
 static u64 entry_end(struct btrfs_ordered_extent *entry)
 {
     if (entry->file_offset + entry->num_bytes < entry->file_offset)
         return (u64)-1;
     return entry->file_offset + entry->num_bytes;
 }
 
 /* returns NULL if the insertion worked, or it returns the node it did find
  * in the tree
  */
 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
                    struct rb_node *node)
 {
     struct rb_node **p = &root->rb_node;
     struct rb_node *parent = NULL;
     struct btrfs_ordered_extent *entry;
 
     while (*p) {
         parent = *p;
         entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
 
         if (file_offset < entry->file_offset)
             p = &(*p)->rb_left;
         else if (file_offset >= entry_end(entry))
             p = &(*p)->rb_right;
         else
             return parent;
     }
 
     rb_link_node(node, parent, p);
     rb_insert_color(node, root);
     return NULL;
 }
 
 /*
  * look for a given offset in the tree, and if it can't be found return the
  * first lesser offset
  */
 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
                      struct rb_node **prev_ret)
 {
     struct rb_node *n = root->rb_node;
     struct rb_node *prev = NULL;
     struct rb_node *test;
     struct btrfs_ordered_extent *entry;
     struct btrfs_ordered_extent *prev_entry = NULL;
 
     while (n) {
         entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
         prev = n;
         prev_entry = entry;
 
         if (file_offset < entry->file_offset)
             n = n->rb_left;
         else if (file_offset >= entry_end(entry))
             n = n->rb_right;
         else
             return n;
     }
     if (!prev_ret)
         return NULL;
 
     while (prev && file_offset >= entry_end(prev_entry)) {
         test = rb_next(prev);
         if (!test)
             break;
         prev_entry = rb_entry(test, struct btrfs_ordered_extent,
                       rb_node);
         if (file_offset < entry_end(prev_entry))
             break;
 
         prev = test;
     }
     if (prev)
         prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
                       rb_node);
     while (prev && file_offset < entry_end(prev_entry)) {
         test = rb_prev(prev);
         if (!test)
             break;
         prev_entry = rb_entry(test, struct btrfs_ordered_extent,
                       rb_node);
         prev = test;
     }
     *prev_ret = prev;
     return NULL;
 }
 
 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
               u64 len)
 {
     if (file_offset + len <= entry->file_offset ||
         entry->file_offset + entry->num_bytes <= file_offset)
         return 0;
     return 1;
 }
 
 /*
  * look find the first ordered struct that has this offset, otherwise
  * the first one less than this offset
  */
 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
                       u64 file_offset)
 {
     struct rb_root *root = &tree->tree;
     struct rb_node *prev = NULL;
     struct rb_node *ret;
     struct btrfs_ordered_extent *entry;
 
     if (tree->last) {
         entry = rb_entry(tree->last, struct btrfs_ordered_extent,
                  rb_node);
         if (in_range(file_offset, entry->file_offset, entry->num_bytes))
             return tree->last;
     }
     ret = __tree_search(root, file_offset, &prev);
     if (!ret)
         ret = prev;
     if (ret)
         tree->last = ret;
     return ret;
 }
 
 /**
  * Add an ordered extent to the per-inode tree.
  *
  * @inode:           Inode that this extent is for.
  * @file_offset:     Logical offset in file where the extent starts.
  * @num_bytes:       Logical length of extent in file.
  * @ram_bytes:       Full length of unencoded data.
  * @disk_bytenr:     Offset of extent on disk.
  * @disk_num_bytes:  Size of extent on disk.
  * @offset:          Offset into unencoded data where file data starts.
  * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
  * @compress_type:   Compression algorithm used for data.
  *
  * Most of these parameters correspond to &struct btrfs_file_extent_item. The
  * tree is given a single reference on the ordered extent that was inserted.
  *
  * Return: 0 or -ENOMEM.
  */
 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
                  u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
                  u64 disk_num_bytes, u64 offset, unsigned flags,
                  int compress_type)
 {
     struct btrfs_root *root = inode->root;
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
     struct rb_node *node;
     struct btrfs_ordered_extent *entry;
     int ret;
 
     if (flags &
         ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
         /* For nocow write, we can release the qgroup rsv right now */
         ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
         if (ret < 0)
             return ret;
         ret = 0;
     } else {
         /*
          * The ordered extent has reserved qgroup space, release now
          * and pass the reserved number for qgroup_record to free.
          */
         ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
         if (ret < 0)
             return ret;
     }
     entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
     if (!entry)
         return -ENOMEM;
 
     entry->file_offset = file_offset;
     entry->num_bytes = num_bytes;
     entry->ram_bytes = ram_bytes;
     entry->disk_bytenr = disk_bytenr;
     entry->disk_num_bytes = disk_num_bytes;
     entry->offset = offset;
     entry->bytes_left = num_bytes;
     entry->inode = igrab(&inode->vfs_inode);
     entry->compress_type = compress_type;
     entry->truncated_len = (u64)-1;
     entry->qgroup_rsv = ret;
     entry->physical = (u64)-1;
 
     ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
     entry->flags = flags;
 
     percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
                  fs_info->delalloc_batch);
 
     /* one ref for the tree */
     refcount_set(&entry->refs, 1);
     init_waitqueue_head(&entry->wait);
     INIT_LIST_HEAD(&entry->list);
     INIT_LIST_HEAD(&entry->log_list);
     INIT_LIST_HEAD(&entry->root_extent_list);
     INIT_LIST_HEAD(&entry->work_list);
     init_completion(&entry->completion);
 
     trace_btrfs_ordered_extent_add(inode, entry);
 
     spin_lock_irq(&tree->lock);
     node = tree_insert(&tree->tree, file_offset,
                &entry->rb_node);
     if (node)
         btrfs_panic(fs_info, -EEXIST,
                 "inconsistency in ordered tree at offset %llu",
                 file_offset);
     spin_unlock_irq(&tree->lock);
 
     spin_lock(&root->ordered_extent_lock);
     list_add_tail(&entry->root_extent_list,
               &root->ordered_extents);
     root->nr_ordered_extents++;
     if (root->nr_ordered_extents == 1) {
         spin_lock(&fs_info->ordered_root_lock);
         BUG_ON(!list_empty(&root->ordered_root));
         list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
         spin_unlock(&fs_info->ordered_root_lock);
     }
     spin_unlock(&root->ordered_extent_lock);
 
     /*
      * We don't need the count_max_extents here, we can assume that all of
      * that work has been done at higher layers, so this is truly the
      * smallest the extent is going to get.
      */
     spin_lock(&inode->lock);
     btrfs_mod_outstanding_extents(inode, 1);
     spin_unlock(&inode->lock);
 
     return 0;
 }
 
 /*
  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
  * when an ordered extent is finished.  If the list covers more than one
  * ordered extent, it is split across multiples.
  */
 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
                struct btrfs_ordered_sum *sum)
 {
     struct btrfs_ordered_inode_tree *tree;
 
     tree = &BTRFS_I(entry->inode)->ordered_tree;
     spin_lock_irq(&tree->lock);
     list_add_tail(&sum->list, &entry->list);
     spin_unlock_irq(&tree->lock);
 }
 
 static void finish_ordered_fn(struct btrfs_work *work)
 {
     struct btrfs_ordered_extent *ordered_extent;
 
     ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
     btrfs_finish_ordered_io(ordered_extent);
 }
 
 /*
  * Mark all ordered extents io inside the specified range finished.
  *
  * @page:    The involved page for the operation.
  *       For uncompressed buffered IO, the page status also needs to be
  *       updated to indicate whether the pending ordered io is finished.
  *       Can be NULL for direct IO and compressed write.
  *       For these cases, callers are ensured they won't execute the
  *       endio function twice.
  *
  * This function is called for endio, thus the range must have ordered
  * extent(s) covering it.
  */
 void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
                     struct page *page, u64 file_offset,
                     u64 num_bytes, bool uptodate)
 {
     struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
     struct btrfs_fs_info *fs_info = inode->root->fs_info;
     struct btrfs_workqueue *wq;
     struct rb_node *node;
     struct btrfs_ordered_extent *entry = NULL;
     unsigned long flags;
     u64 cur = file_offset;
 
     if (btrfs_is_free_space_inode(inode))
         wq = fs_info->endio_freespace_worker;
     else
         wq = fs_info->endio_write_workers;
 
     if (page)
         ASSERT(page->mapping && page_offset(page) <= file_offset &&
                file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
 
     spin_lock_irqsave(&tree->lock, flags);
     while (cur < file_offset + num_bytes) {
         u64 entry_end;
         u64 end;
         u32 len;
 
         node = tree_search(tree, cur);
         /* No ordered extents at all */
         if (!node)
             break;
 
         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
         entry_end = entry->file_offset + entry->num_bytes;
         /*
          * |<-- OE --->|  |
          *        cur
          * Go to next OE.
          */
         if (cur >= entry_end) {
             node = rb_next(node);
             /* No more ordered extents, exit */
             if (!node)
                 break;
             entry = rb_entry(node, struct btrfs_ordered_extent,
                      rb_node);
 
             /* Go to next ordered extent and continue */
             cur = entry->file_offset;
             continue;
         }
         /*
          * |    |<--- OE --->|
          * cur
          * Go to the start of OE.
          */
         if (cur < entry->file_offset) {
             cur = entry->file_offset;
             continue;
         }
 
         /*
          * Now we are definitely inside one ordered extent.
          *
          * |<--- OE --->|
          *  |
          *  cur
          */
         end = min(entry->file_offset + entry->num_bytes,
               file_offset + num_bytes) - 1;
         ASSERT(end + 1 - cur < U32_MAX);
         len = end + 1 - cur;
 
         if (page) {
             /*
              * Ordered (Private2) bit indicates whether we still
              * have pending io unfinished for the ordered extent.
              *
              * If there's no such bit, we need to skip to next range.
              */
             if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
                 cur += len;
                 continue;
             }
             btrfs_page_clear_ordered(fs_info, page, cur, len);
         }
 
         /* Now we're fine to update the accounting */
         if (unlikely(len > entry->bytes_left)) {
             WARN_ON(1);
             btrfs_crit(fs_info,
 "bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
                    inode->root->root_key.objectid,
                    btrfs_ino(inode),
                    entry->file_offset,
                    entry->num_bytes,
                    len, entry->bytes_left);
             entry->bytes_left = 0;
         } else {
             entry->bytes_left -= len;
         }
 
         if (!uptodate)
             set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 
         /*
          * All the IO of the ordered extent is finished, we need to queue
          * the finish_func to be executed.
          */
         if (entry->bytes_left == 0) {
             set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
             cond_wake_up(&entry->wait);
             refcount_inc(&entry->refs);
             trace_btrfs_ordered_extent_mark_finished(inode, entry);
             spin_unlock_irqrestore(&tree->lock, flags);
             btrfs_init_work(&entry->work, finish_ordered_fn, NULL, NULL);
             btrfs_queue_work(wq, &entry->work);
             spin_lock_irqsave(&tree->lock, flags);
         }
         cur += len;
     }
     spin_unlock_irqrestore(&tree->lock, flags);
 }
 
 /*
  * Finish IO for one ordered extent across a given range.  The range can only
  * contain one ordered extent.
  *
  * @cached:  The cached ordered extent. If not NULL, we can skip the tree
  *               search and use the ordered extent directly.
  *       Will be also used to store the finished ordered extent.
  * @file_offset: File offset for the finished IO
  * @io_size:     Length of the finish IO range
  *
  * Return true if the ordered extent is finished in the range, and update
  * @cached.
  * Return false otherwise.
  *
  * NOTE: The range can NOT cross multiple ordered extents.
  * Thus caller should ensure the range doesn't cross ordered extents.
  */
 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
                     struct btrfs_ordered_extent **cached,
                     u64 file_offset, u64 io_size)
 {
     struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
     struct rb_node *node;
     struct btrfs_ordered_extent *entry = NULL;
     unsigned long flags;
     bool finished = false;
 
     spin_lock_irqsave(&tree->lock, flags);
     if (cached && *cached) {
         entry = *cached;
         goto have_entry;
     }
 
     node = tree_search(tree, file_offset);
     if (!node)
         goto out;
 
     entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 have_entry:
     if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
         goto out;
 
     if (io_size > entry->bytes_left)
         btrfs_crit(inode->root->fs_info,
                "bad ordered accounting left %llu size %llu",
                entry->bytes_left, io_size);
 
     entry->bytes_left -= io_size;
 
     if (entry->bytes_left == 0) {
         /*
          * Ensure only one caller can set the flag and finished_ret
          * accordingly
          */
         finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
         /* test_and_set_bit implies a barrier */
         cond_wake_up_nomb(&entry->wait);
     }
 out:
     if (finished && cached && entry) {
         *cached = entry;
         refcount_inc(&entry->refs);
         trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
     }
     spin_unlock_irqrestore(&tree->lock, flags);
     return finished;
 }
 
 /*
  * used to drop a reference on an ordered extent.  This will free
  * the extent if the last reference is dropped
  */
 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 {
     struct list_head *cur;
     struct btrfs_ordered_sum *sum;
 
     trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 
     if (refcount_dec_and_test(&entry->refs)) {
         ASSERT(list_empty(&entry->root_extent_list));
         ASSERT(list_empty(&entry->log_list));
         ASSERT(RB_EMPTY_NODE(&entry->rb_node));
         if (entry->inode)
             btrfs_add_delayed_iput(entry->inode);
         while (!list_empty(&entry->list)) {
             cur = entry->list.next;
             sum = list_entry(cur, struct btrfs_ordered_sum, list);
             list_del(&sum->list);
             kvfree(sum);
         }
         kmem_cache_free(btrfs_ordered_extent_cache, entry);
     }
 }
 
 /*
  * remove an ordered extent from the tree.  No references are dropped
  * and waiters are woken up.
  */
 void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
                  struct btrfs_ordered_extent *entry)
 {
     struct btrfs_ordered_inode_tree *tree;
     struct btrfs_root *root = btrfs_inode->root;
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct rb_node *node;
     bool pending;
 
     /* This is paired with btrfs_add_ordered_extent. */
     spin_lock(&btrfs_inode->lock);
     btrfs_mod_outstanding_extents(btrfs_inode, -1);
     spin_unlock(&btrfs_inode->lock);
     if (root != fs_info->tree_root) {
         u64 release;
 
         if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
             release = entry->disk_num_bytes;
         else
             release = entry->num_bytes;
         btrfs_delalloc_release_metadata(btrfs_inode, release, false);
     }
 
     percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
                  fs_info->delalloc_batch);
 
     tree = &btrfs_inode->ordered_tree;
     spin_lock_irq(&tree->lock);
     node = &entry->rb_node;
     rb_erase(node, &tree->tree);
     RB_CLEAR_NODE(node);
     if (tree->last == node)
         tree->last = NULL;
     set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
     pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
     spin_unlock_irq(&tree->lock);
 
     /*
      * The current running transaction is waiting on us, we need to let it
      * know that we're complete and wake it up.
      */
     if (pending) {
         struct btrfs_transaction *trans;
 
         /*
          * The checks for trans are just a formality, it should be set,
          * but if it isn't we don't want to deref/assert under the spin
          * lock, so be nice and check if trans is set, but ASSERT() so
          * if it isn't set a developer will notice.
          */
         spin_lock(&fs_info->trans_lock);
         trans = fs_info->running_transaction;
         if (trans)
             refcount_inc(&trans->use_count);
         spin_unlock(&fs_info->trans_lock);
 
         ASSERT(trans);
         if (trans) {
             if (atomic_dec_and_test(&trans->pending_ordered))
                 wake_up(&trans->pending_wait);
             btrfs_put_transaction(trans);
         }
     }
 
     spin_lock(&root->ordered_extent_lock);
     list_del_init(&entry->root_extent_list);
     root->nr_ordered_extents--;
 
     trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 
     if (!root->nr_ordered_extents) {
         spin_lock(&fs_info->ordered_root_lock);
         BUG_ON(list_empty(&root->ordered_root));
         list_del_init(&root->ordered_root);
         spin_unlock(&fs_info->ordered_root_lock);
     }
     spin_unlock(&root->ordered_extent_lock);
     wake_up(&entry->wait);
 }
 
 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 {
     struct btrfs_ordered_extent *ordered;
 
     ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
     btrfs_start_ordered_extent(ordered, 1);
     complete(&ordered->completion);
 }
 
 /*
  * wait for all the ordered extents in a root.  This is done when balancing
  * space between drives.
  */
 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
                    const u64 range_start, const u64 range_len)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     LIST_HEAD(splice);
     LIST_HEAD(skipped);
     LIST_HEAD(works);
     struct btrfs_ordered_extent *ordered, *next;
     u64 count = 0;
     const u64 range_end = range_start + range_len;
 
     mutex_lock(&root->ordered_extent_mutex);
     spin_lock(&root->ordered_extent_lock);
     list_splice_init(&root->ordered_extents, &splice);
     while (!list_empty(&splice) && nr) {
         ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
                        root_extent_list);
 
         if (range_end <= ordered->disk_bytenr ||
             ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
             list_move_tail(&ordered->root_extent_list, &skipped);
             cond_resched_lock(&root->ordered_extent_lock);
             continue;
         }
 
         list_move_tail(&ordered->root_extent_list,
                    &root->ordered_extents);
         refcount_inc(&ordered->refs);
         spin_unlock(&root->ordered_extent_lock);
 
         btrfs_init_work(&ordered->flush_work,
                 btrfs_run_ordered_extent_work, NULL, NULL);
         list_add_tail(&ordered->work_list, &works);
         btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 
         cond_resched();
         spin_lock(&root->ordered_extent_lock);
         if (nr != U64_MAX)
             nr--;
         count++;
     }
     list_splice_tail(&skipped, &root->ordered_extents);
     list_splice_tail(&splice, &root->ordered_extents);
     spin_unlock(&root->ordered_extent_lock);
 
     list_for_each_entry_safe(ordered, next, &works, work_list) {
         list_del_init(&ordered->work_list);
         wait_for_completion(&ordered->completion);
         btrfs_put_ordered_extent(ordered);
         cond_resched();
     }
     mutex_unlock(&root->ordered_extent_mutex);
 
     return count;
 }
 
 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
                  const u64 range_start, const u64 range_len)
 {
     struct btrfs_root *root;
     struct list_head splice;
     u64 done;
 
     INIT_LIST_HEAD(&splice);
 
     mutex_lock(&fs_info->ordered_operations_mutex);
     spin_lock(&fs_info->ordered_root_lock);
     list_splice_init(&fs_info->ordered_roots, &splice);
     while (!list_empty(&splice) && nr) {
         root = list_first_entry(&splice, struct btrfs_root,
                     ordered_root);
         root = btrfs_grab_root(root);
         BUG_ON(!root);
         list_move_tail(&root->ordered_root,
                    &fs_info->ordered_roots);
         spin_unlock(&fs_info->ordered_root_lock);
 
         done = btrfs_wait_ordered_extents(root, nr,
                           range_start, range_len);
         btrfs_put_root(root);
 
         spin_lock(&fs_info->ordered_root_lock);
         if (nr != U64_MAX) {
             nr -= done;
         }
     }
     list_splice_tail(&splice, &fs_info->ordered_roots);
     spin_unlock(&fs_info->ordered_root_lock);
     mutex_unlock(&fs_info->ordered_operations_mutex);
 }
 
 /*
  * Used to start IO or wait for a given ordered extent to finish.
  *
  * If wait is one, this effectively waits on page writeback for all the pages
  * in the extent, and it waits on the io completion code to insert
  * metadata into the btree corresponding to the extent
  */
 void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
 {
     u64 start = entry->file_offset;
     u64 end = start + entry->num_bytes - 1;
     struct btrfs_inode *inode = BTRFS_I(entry->inode);
 
     trace_btrfs_ordered_extent_start(inode, entry);
 
     /*
      * pages in the range can be dirty, clean or writeback.  We
      * start IO on any dirty ones so the wait doesn't stall waiting
      * for the flusher thread to find them
      */
     if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
         filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
     if (wait) {
         wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
                          &entry->flags));
     }
 }
 
 /*
  * Used to wait on ordered extents across a large range of bytes.
  */
 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 {
     int ret = 0;
     int ret_wb = 0;
     u64 end;
     u64 orig_end;
     struct btrfs_ordered_extent *ordered;
 
     if (start + len < start) {
         orig_end = INT_LIMIT(loff_t);
     } else {
         orig_end = start + len - 1;
         if (orig_end > INT_LIMIT(loff_t))
             orig_end = INT_LIMIT(loff_t);
     }
 
     /* start IO across the range first to instantiate any delalloc
      * extents
      */
     ret = btrfs_fdatawrite_range(inode, start, orig_end);
     if (ret)
         return ret;
 
     /*
      * If we have a writeback error don't return immediately. Wait first
      * for any ordered extents that haven't completed yet. This is to make
      * sure no one can dirty the same page ranges and call writepages()
      * before the ordered extents complete - to avoid failures (-EEXIST)
      * when adding the new ordered extents to the ordered tree.
      */
     ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 
     end = orig_end;
     while (1) {
         ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
         if (!ordered)
             break;
         if (ordered->file_offset > orig_end) {
             btrfs_put_ordered_extent(ordered);
             break;
         }
         if (ordered->file_offset + ordered->num_bytes <= start) {
             btrfs_put_ordered_extent(ordered);
             break;
         }
         btrfs_start_ordered_extent(ordered, 1);
         end = ordered->file_offset;
         /*
          * If the ordered extent had an error save the error but don't
          * exit without waiting first for all other ordered extents in
          * the range to complete.
          */
         if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
             ret = -EIO;
         btrfs_put_ordered_extent(ordered);
         if (end == 0 || end == start)
             break;
         end--;
     }
     return ret_wb ? ret_wb : ret;
 }
 
 /*
  * find an ordered extent corresponding to file_offset.  return NULL if
  * nothing is found, otherwise take a reference on the extent and return it
  */
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
                              u64 file_offset)
 {
     struct btrfs_ordered_inode_tree *tree;
     struct rb_node *node;
     struct btrfs_ordered_extent *entry = NULL;
     unsigned long flags;
 
     tree = &inode->ordered_tree;
     spin_lock_irqsave(&tree->lock, flags);
     node = tree_search(tree, file_offset);
     if (!node)
         goto out;
 
     entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
     if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
         entry = NULL;
     if (entry) {
         refcount_inc(&entry->refs);
         trace_btrfs_ordered_extent_lookup(inode, entry);
     }
 out:
     spin_unlock_irqrestore(&tree->lock, flags);
     return entry;
 }
 
 /* Since the DIO code tries to lock a wide area we need to look for any ordered
  * extents that exist in the range, rather than just the start of the range.
  */
 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
         struct btrfs_inode *inode, u64 file_offset, u64 len)
 {
     struct btrfs_ordered_inode_tree *tree;
     struct rb_node *node;
     struct btrfs_ordered_extent *entry = NULL;
 
     tree = &inode->ordered_tree;
     spin_lock_irq(&tree->lock);
     node = tree_search(tree, file_offset);
     if (!node) {
         node = tree_search(tree, file_offset + len);
         if (!node)
             goto out;
     }
 
     while (1) {
         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
         if (range_overlaps(entry, file_offset, len))
             break;
 
         if (entry->file_offset >= file_offset + len) {
             entry = NULL;
             break;
         }
         entry = NULL;
         node = rb_next(node);
         if (!node)
             break;
     }
 out:
     if (entry) {
         refcount_inc(&entry->refs);
         trace_btrfs_ordered_extent_lookup_range(inode, entry);
     }
     spin_unlock_irq(&tree->lock);
     return entry;
 }
 
 /*
  * Adds all ordered extents to the given list. The list ends up sorted by the
  * file_offset of the ordered extents.
  */
 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
                        struct list_head *list)
 {
     struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
     struct rb_node *n;
 
     ASSERT(inode_is_locked(&inode->vfs_inode));
 
     spin_lock_irq(&tree->lock);
     for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
         struct btrfs_ordered_extent *ordered;
 
         ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 
         if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
             continue;
 
         ASSERT(list_empty(&ordered->log_list));
         list_add_tail(&ordered->log_list, list);
         refcount_inc(&ordered->refs);
         trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
     }
     spin_unlock_irq(&tree->lock);
 }
 
 /*
  * lookup and return any extent before 'file_offset'.  NULL is returned
  * if none is found
  */
 struct btrfs_ordered_extent *
 btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 {
     struct btrfs_ordered_inode_tree *tree;
     struct rb_node *node;
     struct btrfs_ordered_extent *entry = NULL;
 
     tree = &inode->ordered_tree;
     spin_lock_irq(&tree->lock);
     node = tree_search(tree, file_offset);
     if (!node)
         goto out;
 
     entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
     refcount_inc(&entry->refs);
     trace_btrfs_ordered_extent_lookup_first(inode, entry);
 out:
     spin_unlock_irq(&tree->lock);
     return entry;
 }
 
 /*
  * Lookup the first ordered extent that overlaps the range
  * [@file_offset, @file_offset + @len).
  *
  * The difference between this and btrfs_lookup_first_ordered_extent() is
  * that this one won't return any ordered extent that does not overlap the range.
  * And the difference against btrfs_lookup_ordered_extent() is, this function
  * ensures the first ordered extent gets returned.
  */
 struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
             struct btrfs_inode *inode, u64 file_offset, u64 len)
 {
     struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
     struct rb_node *node;
     struct rb_node *cur;
     struct rb_node *prev;
     struct rb_node *next;
     struct btrfs_ordered_extent *entry = NULL;
 
     spin_lock_irq(&tree->lock);
     node = tree->tree.rb_node;
     /*
      * Here we don't want to use tree_search() which will use tree->last
      * and screw up the search order.
      * And __tree_search() can't return the adjacent ordered extents
      * either, thus here we do our own search.
      */
     while (node) {
         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 
         if (file_offset < entry->file_offset) {
             node = node->rb_left;
         } else if (file_offset >= entry_end(entry)) {
             node = node->rb_right;
         } else {
             /*
              * Direct hit, got an ordered extent that starts at
              * @file_offset
              */
             goto out;
         }
     }
     if (!entry) {
         /* Empty tree */
         goto out;
     }
 
     cur = &entry->rb_node;
     /* We got an entry around @file_offset, check adjacent entries */
     if (entry->file_offset < file_offset) {
         prev = cur;
         next = rb_next(cur);
     } else {
         prev = rb_prev(cur);
         next = cur;
     }
     if (prev) {
         entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
         if (range_overlaps(entry, file_offset, len))
             goto out;
     }
     if (next) {
         entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
         if (range_overlaps(entry, file_offset, len))
             goto out;
     }
     /* No ordered extent in the range */
     entry = NULL;
 out:
     if (entry) {
         refcount_inc(&entry->refs);
         trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
     }
 
     spin_unlock_irq(&tree->lock);
     return entry;
 }
 
 /*
  * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
  * ordered extents in it are run to completion.
  *
  * @inode:        Inode whose ordered tree is to be searched
  * @start:        Beginning of range to flush
  * @end:          Last byte of range to lock
  * @cached_state: If passed, will return the extent state responsible for the
  * locked range. It's the caller's responsibility to free the cached state.
  *
  * This function always returns with the given range locked, ensuring after it's
  * called no order extent can be pending.
  */
 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
                     u64 end,
                     struct extent_state **cached_state)
 {
     struct btrfs_ordered_extent *ordered;
     struct extent_state *cache = NULL;
     struct extent_state **cachedp = &cache;
 
     if (cached_state)
         cachedp = cached_state;
 
     while (1) {
         lock_extent_bits(&inode->io_tree, start, end, cachedp);
         ordered = btrfs_lookup_ordered_range(inode, start,
                              end - start + 1);
         if (!ordered) {
             /*
              * If no external cached_state has been passed then
              * decrement the extra ref taken for cachedp since we
              * aren't exposing it outside of this function
              */
             if (!cached_state)
                 refcount_dec(&cache->refs);
             break;
         }
         unlock_extent_cached(&inode->io_tree, start, end, cachedp);
         btrfs_start_ordered_extent(ordered, 1);
         btrfs_put_ordered_extent(ordered);
     }
 }
 
 static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
                 u64 len)
 {
     struct inode *inode = ordered->inode;
     struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
     u64 file_offset = ordered->file_offset + pos;
     u64 disk_bytenr = ordered->disk_bytenr + pos;
     unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
 
     /*
      * The splitting extent is already counted and will be added again in
      * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
      */
     percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
                  fs_info->delalloc_batch);
     WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
     return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
                     disk_bytenr, len, 0, flags,
                     ordered->compress_type);
 }
 
 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
                 u64 post)
 {
     struct inode *inode = ordered->inode;
     struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
     struct rb_node *node;
     struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
     int ret = 0;
 
     trace_btrfs_ordered_extent_split(BTRFS_I(inode), ordered);
 
     spin_lock_irq(&tree->lock);
     /* Remove from tree once */
     node = &ordered->rb_node;
     rb_erase(node, &tree->tree);
     RB_CLEAR_NODE(node);
     if (tree->last == node)
         tree->last = NULL;
 
     ordered->file_offset += pre;
     ordered->disk_bytenr += pre;
     ordered->num_bytes -= (pre + post);
     ordered->disk_num_bytes -= (pre + post);
     ordered->bytes_left -= (pre + post);
 
     /* Re-insert the node */
     node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
     if (node)
         btrfs_panic(fs_info, -EEXIST,
             "zoned: inconsistency in ordered tree at offset %llu",
                 ordered->file_offset);
 
     spin_unlock_irq(&tree->lock);
 
     if (pre)
         ret = clone_ordered_extent(ordered, 0, pre);
     if (ret == 0 && post)
         ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
                        post);
 
     return ret;
 }
 
 int __init ordered_data_init(void)
 {
     btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
                      sizeof(struct btrfs_ordered_extent), 0,
                      SLAB_MEM_SPREAD,
                      NULL);
     if (!btrfs_ordered_extent_cache)
         return -ENOMEM;
 
     return 0;
 }
 
 void __cold ordered_data_exit(void)
 {
     kmem_cache_destroy(btrfs_ordered_extent_cache);
 }

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