2 files changed, 43 insertions, 41 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1818dd90c27e..51e1151a0a02 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4748,7 +4748,8 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
         spin_lock(&BTRFS_I(inode)->lock);
         dropped = drop_outstanding_extent(inode);
 
-        to_free = calc_csum_metadata_size(inode, num_bytes, 0);
+        if (num_bytes)
+                to_free = calc_csum_metadata_size(inode, num_bytes, 0);
         spin_unlock(&BTRFS_I(inode)->lock);
         if (dropped > 0)
                 to_free += btrfs_calc_trans_metadata_size(root, dropped);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 16925807a9ed..d11f38d8696c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6059,16 +6059,15 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
         u64 len = bh_result->b_size;
         struct btrfs_trans_handle *trans;
         int unlock_bits = EXTENT_LOCKED;
-        int ret;
+        int ret = 0;
 
         if (create) {
-                ret = btrfs_delalloc_reserve_space(inode, len);
-                if (ret)
-                        return ret;
+                spin_lock(&BTRFS_I(inode)->lock);
+                BTRFS_I(inode)->outstanding_extents++;
+                spin_unlock(&BTRFS_I(inode)->lock);
                 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
-        } else {
+        } else
                 len = min_t(u64, len, root->sectorsize);
-        }
 
         lockstart = start;
         lockend = start + len - 1;
@@ -6080,14 +6079,6 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
         if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
                 return -ENOTBLK;
 
-        if (create) {
-                ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
-                                     lockend, EXTENT_DELALLOC, NULL,
-                                     &cached_state, GFP_NOFS);
-                if (ret)
-                        goto unlock_err;
-        }
-
         em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
         if (IS_ERR(em)) {
                 ret = PTR_ERR(em);
@@ -6119,7 +6110,6 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
         if (!create && (em->block_start == EXTENT_MAP_HOLE ||
                         test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
                 free_extent_map(em);
-                ret = 0;
                 goto unlock_err;
         }
 
@@ -6217,6 +6207,11 @@ unlock:
                  */
                 if (start + len > i_size_read(inode))
                         i_size_write(inode, start + len);
+
+                ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                     lockstart + len - 1, EXTENT_DELALLOC, NULL,
+                                     &cached_state, GFP_NOFS);
+                BUG_ON(ret);
         }
 
         /*
@@ -6225,24 +6220,9 @@ unlock:
          * aren't using if there is any left over space.
          */
         if (lockstart < lockend) {
-                if (create && len < lockend - lockstart) {
-                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
-                                         lockstart + len - 1,
-                                         unlock_bits | EXTENT_DEFRAG, 1, 0,
-                                         &cached_state, GFP_NOFS);
-                        /*
-                         * Beside unlock, we also need to cleanup reserved space
-                         * for the left range by attaching EXTENT_DO_ACCOUNTING.
-                         */
-                        clear_extent_bit(&BTRFS_I(inode)->io_tree,
-                                         lockstart + len, lockend,
-                                         unlock_bits | EXTENT_DO_ACCOUNTING |
-                                         EXTENT_DEFRAG, 1, 0, NULL, GFP_NOFS);
-                } else {
-                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
-                                         lockend, unlock_bits, 1, 0,
-                                         &cached_state, GFP_NOFS);
-                }
+                clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                 lockend, unlock_bits, 1, 0,
+                                 &cached_state, GFP_NOFS);
         } else {
                 free_extent_state(cached_state);
         }
@@ -6252,9 +6232,6 @@ unlock:
         return 0;
 
 unlock_err:
-        if (create)
-                unlock_bits |= EXTENT_DO_ACCOUNTING;
-
         clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
                          unlock_bits, 1, 0, &cached_state, GFP_NOFS);
         return ret;
@@ -6692,15 +6669,39 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
+        size_t count = 0;
+        ssize_t ret;
 
         if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
                             offset, nr_segs))
                 return 0;
 
-        return __blockdev_direct_IO(rw, iocb, inode,
-                   BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
-                   iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
-                   btrfs_submit_direct, 0);
+        if (rw & WRITE) {
+                count = iov_length(iov, nr_segs);
+                ret = btrfs_delalloc_reserve_space(inode, count);
+                if (ret)
+                        return ret;
+        }
+
+        ret = __blockdev_direct_IO(rw, iocb, inode,
+                        BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
+                        iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
+                        btrfs_submit_direct, 0);
+
+        if (rw & WRITE) {
+                if (ret < 0 && ret != -EIOCBQUEUED)
+                        btrfs_delalloc_release_space(inode, count);
+                else if (ret > 0 && (size_t)ret < count) {
+                        spin_lock(&BTRFS_I(inode)->lock);
+                        BTRFS_I(inode)->outstanding_extents++;
+                        spin_unlock(&BTRFS_I(inode)->lock);
+                        btrfs_delalloc_release_space(inode,
+                                                     count - (size_t)ret);
+                }
+                btrfs_delalloc_release_metadata(inode, 0);
+        }
+
+        return ret;
 }
 
 #define BTRFS_FIEMAP_FLAGS      (FIEMAP_FLAG_SYNC)