1 files changed, 23 insertions, 12 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 100e409e9053..f1db57d4a016 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3343,15 +3343,16 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
         u64 max_reclaim;
         u64 reclaimed = 0;
         long time_left;
-        int pause = 1;
         int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
         int loops = 0;
+        unsigned long progress;
 
         block_rsv = &root->fs_info->delalloc_block_rsv;
         space_info = block_rsv->space_info;
 
         smp_mb();
         reserved = space_info->bytes_reserved;
+        progress = space_info->reservation_progress;
 
         if (reserved == 0)
                 return 0;
@@ -3366,31 +3367,36 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
                 writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
 
                 spin_lock(&space_info->lock);
-                if (reserved > space_info->bytes_reserved) {
-                        loops = 0;
+                if (reserved > space_info->bytes_reserved)
                         reclaimed += reserved - space_info->bytes_reserved;
-                } else {
-                        loops++;
-                }
                 reserved = space_info->bytes_reserved;
                 spin_unlock(&space_info->lock);
 
+                loops++;
+
                 if (reserved == 0 || reclaimed >= max_reclaim)
                         break;
 
                 if (trans && trans->transaction->blocked)
                         return -EAGAIN;
 
-                __set_current_state(TASK_INTERRUPTIBLE);
-                time_left = schedule_timeout(pause);
+                time_left = schedule_timeout_interruptible(1);
 
                 /* We were interrupted, exit */
                 if (time_left)
                         break;
 
-                pause <<= 1;
-                if (pause > HZ / 10)
-                        pause = HZ / 10;
+                /* we've kicked the IO a few times, if anything has been freed,
+                 * exit.  There is no sense in looping here for a long time
+                 * when we really need to commit the transaction, or there are
+                 * just too many writers without enough free space
+                 */
+
+                if (loops > 3) {
+                        smp_mb();
+                        if (progress != space_info->reservation_progress)
+                                break;
+                }
 
         }
         return reclaimed >= to_reclaim;
@@ -3613,6 +3619,7 @@ void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
                 if (num_bytes) {
                         spin_lock(&space_info->lock);
                         space_info->bytes_reserved -= num_bytes;
+                        space_info->reservation_progress++;
                         spin_unlock(&space_info->lock);
                 }
         }
@@ -3845,6 +3852,7 @@ static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
         if (block_rsv->reserved >= block_rsv->size) {
                 num_bytes = block_rsv->reserved - block_rsv->size;
                 sinfo->bytes_reserved -= num_bytes;
+                sinfo->reservation_progress++;
                 block_rsv->reserved = block_rsv->size;
                 block_rsv->full = 1;
         }
@@ -4006,7 +4014,6 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
                 to_reserve = 0;
         }
         spin_unlock(&BTRFS_I(inode)->accounting_lock);
-
         to_reserve += calc_csum_metadata_size(inode, num_bytes);
         ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1);
         if (ret)
@@ -4134,6 +4141,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                         btrfs_set_block_group_used(&cache->item, old_val);
                         cache->reserved -= num_bytes;
                         cache->space_info->bytes_reserved -= num_bytes;
+                        cache->space_info->reservation_progress++;
                         cache->space_info->bytes_used += num_bytes;
                         cache->space_info->disk_used += num_bytes * factor;
                         spin_unlock(&cache->lock);
@@ -4185,6 +4193,7 @@ static int pin_down_extent(struct btrfs_root *root,
         if (reserved) {
                 cache->reserved -= num_bytes;
                 cache->space_info->bytes_reserved -= num_bytes;
+                cache->space_info->reservation_progress++;
         }
         spin_unlock(&cache->lock);
         spin_unlock(&cache->space_info->lock);
@@ -4235,6 +4244,7 @@ static int update_reserved_bytes(struct btrfs_block_group_cache *cache,
                                 space_info->bytes_readonly += num_bytes;
                         cache->reserved -= num_bytes;
                         space_info->bytes_reserved -= num_bytes;
+                        space_info->reservation_progress++;
                 }
                 spin_unlock(&cache->lock);
                 spin_unlock(&space_info->lock);
@@ -4713,6 +4723,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                 if (ret) {
                         spin_lock(&cache->space_info->lock);
                         cache->space_info->bytes_reserved -= buf->len;
+                        cache->space_info->reservation_progress++;
                         spin_unlock(&cache->space_info->lock);
                 }
                 goto out;