1 files changed, 9 insertions, 7 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 92e14dd9bddb..bbba14b629d2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -429,7 +429,7 @@ int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
         return 0;
 }
 
-static unsigned long async_submit_limit(struct btrfs_fs_info *info)
+unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 {
         unsigned long limit = min_t(unsigned long,
                                     info->workers.max_workers,
@@ -439,7 +439,8 @@ static unsigned long async_submit_limit(struct btrfs_fs_info *info)
 
 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
 {
-        return atomic_read(&info->nr_async_bios) > async_submit_limit(info);
+        return atomic_read(&info->nr_async_bios) >
+                btrfs_async_submit_limit(info);
 }
 
 static void run_one_async_submit(struct btrfs_work *work)
@@ -451,12 +452,13 @@ static void run_one_async_submit(struct btrfs_work *work)
         async = container_of(work, struct  async_submit_bio, work);
         fs_info = BTRFS_I(async->inode)->root->fs_info;
 
-        limit = async_submit_limit(fs_info);
+        limit = btrfs_async_submit_limit(fs_info);
         limit = limit * 2 / 3;
 
         atomic_dec(&fs_info->nr_async_submits);
 
-        if (atomic_read(&fs_info->nr_async_submits) < limit)
+        if (atomic_read(&fs_info->nr_async_submits) < limit &&
+            waitqueue_active(&fs_info->async_submit_wait))
                 wake_up(&fs_info->async_submit_wait);
 
         async->submit_bio_hook(async->inode, async->rw, async->bio,
@@ -469,7 +471,7 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                         extent_submit_bio_hook_t *submit_bio_hook)
 {
         struct async_submit_bio *async;
-        int limit = async_submit_limit(fs_info);
+        int limit = btrfs_async_submit_limit(fs_info);
 
         async = kmalloc(sizeof(*async), GFP_NOFS);
         if (!async)
@@ -1863,10 +1865,10 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
         struct extent_io_tree *tree;
         u64 num_dirty;
         u64 start = 0;
-        unsigned long thresh = 12 * 1024 * 1024;
+        unsigned long thresh = 96 * 1024 * 1024;
         tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 
-        if (current_is_pdflush())
+        if (current_is_pdflush() || current->flags & PF_MEMALLOC)
                 return;
 
         num_dirty = count_range_bits(tree, &start, (u64)-1,