4 files changed, 27 insertions, 10 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,
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index e904a69347a4..2562a273ae18 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -73,4 +73,5 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                         int rw, struct bio *bio, int mirror_num,
                         extent_submit_bio_hook_t *submit_bio_hook);
 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone);
+unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
 #endif
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 6bcb0876f9bb..eff3ad72991b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -322,8 +322,6 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
                 if (ret)
                         break;
                 while(start <= end) {
-                        if (btrfs_congested_async(root->fs_info, 0))
-                                congestion_wait(WRITE, HZ/10);
                         cond_resched();
 
                         index = start >> PAGE_CACHE_SHIFT;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 23a5b0aba00a..2652660e6079 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -138,12 +138,18 @@ int run_scheduled_bios(struct btrfs_device *device)
 {
         struct bio *pending;
         struct backing_dev_info *bdi;
+        struct btrfs_fs_info *fs_info;
         struct bio *tail;
         struct bio *cur;
         int again = 0;
         unsigned long num_run = 0;
+        unsigned long limit;
 
         bdi = device->bdev->bd_inode->i_mapping->backing_dev_info;
+        fs_info = device->dev_root->fs_info;
+        limit = btrfs_async_submit_limit(fs_info);
+        limit = limit * 2 / 3;
+
 loop:
         spin_lock(&device->io_lock);
 
@@ -179,7 +185,11 @@ loop:
                 cur = pending;
                 pending = pending->bi_next;
                 cur->bi_next = NULL;
-                atomic_dec(&device->dev_root->fs_info->nr_async_bios);
+                atomic_dec(&fs_info->nr_async_bios);
+
+                if (atomic_read(&fs_info->nr_async_bios) < limit &&
+                    waitqueue_active(&fs_info->async_submit_wait))
+                        wake_up(&fs_info->async_submit_wait);
 
                 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
                 bio_get(cur);
@@ -2135,6 +2145,7 @@ int schedule_bio(struct btrfs_root *root, struct btrfs_device *device,
                  int rw, struct bio *bio)
 {
         int should_queue = 1;
+        unsigned long limit;
 
         /* don't bother with additional async steps for reads, right now */
         if (!(rw & (1 << BIO_RW))) {
@@ -2171,6 +2182,11 @@ int schedule_bio(struct btrfs_root *root, struct btrfs_device *device,
         if (should_queue)
                 btrfs_queue_worker(&root->fs_info->submit_workers,
                                    &device->work);
+
+        limit = btrfs_async_submit_limit(root->fs_info);
+        wait_event_timeout(root->fs_info->async_submit_wait,
+                           (atomic_read(&root->fs_info->nr_async_bios) < limit),
+                           HZ/10);
         return 0;
 }