btrfs: dev-replace: remove custom read/write blocking scheme

After the rw semaphore has been added, the custom blocking using
::blocking_readers and ::read_lock_wq is redundant.

The blocking logic in __btrfs_map_block is replaced by extending the
time the semaphore is held, that has the same blocking effect on writes
as the previous custom scheme that waited until ::blocking_readers was
zero.

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 0 insertions, 16 deletions

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 316a29278306..a71661f43dec 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -1012,14 +1012,7 @@ void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace)
 
 void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace)
 {
-again:
-        wait_event(dev_replace->read_lock_wq,
-                   atomic_read(&dev_replace->blocking_readers) == 0);
         down_write(&dev_replace->rwsem);
-        if (atomic_read(&dev_replace->blocking_readers)) {
-                up_write(&dev_replace->rwsem);
-                goto again;
-        }
 }
 
 void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace)
@@ -1027,15 +1020,6 @@ void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace)
         up_write(&dev_replace->rwsem);
 }
 
-/* inc blocking cnt and release read lock */
-void btrfs_dev_replace_set_lock_blocking(
-                                        struct btrfs_dev_replace *dev_replace)
-{
-        /* only set blocking for read lock */
-        atomic_inc(&dev_replace->blocking_readers);
-        up_read(&dev_replace->rwsem);
-}
-
 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
 {
         percpu_counter_inc(&fs_info->dev_replace.bio_counter);