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authorDavid Sterba <dsterba@suse.com>2018-04-04 01:52:31 +0200
committerDavid Sterba <dsterba@suse.com>2019-02-25 14:13:27 +0100
commitaa12c02778a9719283fc3c32cfe5cffb902a7685 (patch)
tree3e16f94482bf883da2f9ed4f0bac7bb4ea17d0d8 /fs/btrfs/locking.c
parentb95be2d9fb2a6120958b777e13d2328f9770bc2d (diff)
btrfs: split btrfs_clear_lock_blocking_rw to read and write helpers
There are many callers that hardcode the desired lock type so we can avoid the switch and call them directly. Split the current function to two. There are no remaining users of btrfs_clear_lock_blocking_rw so it's removed. The call sites will be converted in followup patches. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/locking.c')
-rw-r--r--fs/btrfs/locking.c47
1 files changed, 25 insertions, 22 deletions
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 7201d000f61d..7f89ca6f1fbc 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -48,11 +48,24 @@ void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
}
}
-/*
- * if we currently have a blocking lock, take the spinlock
- * and drop our blocking count
- */
-void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
+void btrfs_clear_lock_blocking_read(struct extent_buffer *eb)
+{
+ /*
+ * No lock is required. The lock owner may change if we have a read
+ * lock, but it won't change to or away from us. If we have the write
+ * lock, we are the owner and it'll never change.
+ */
+ if (eb->lock_nested && current->pid == eb->lock_owner)
+ return;
+ BUG_ON(atomic_read(&eb->blocking_readers) == 0);
+ read_lock(&eb->lock);
+ atomic_inc(&eb->spinning_readers);
+ /* atomic_dec_and_test implies a barrier */
+ if (atomic_dec_and_test(&eb->blocking_readers))
+ cond_wake_up_nomb(&eb->read_lock_wq);
+}
+
+void btrfs_clear_lock_blocking_write(struct extent_buffer *eb)
{
/*
* no lock is required. The lock owner may change if
@@ -62,23 +75,13 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
*/
if (eb->lock_nested && current->pid == eb->lock_owner)
return;
-
- if (rw == BTRFS_WRITE_LOCK_BLOCKING) {
- BUG_ON(atomic_read(&eb->blocking_writers) != 1);
- write_lock(&eb->lock);
- WARN_ON(atomic_read(&eb->spinning_writers));
- atomic_inc(&eb->spinning_writers);
- /* atomic_dec_and_test implies a barrier */
- if (atomic_dec_and_test(&eb->blocking_writers))
- cond_wake_up_nomb(&eb->write_lock_wq);
- } else if (rw == BTRFS_READ_LOCK_BLOCKING) {
- BUG_ON(atomic_read(&eb->blocking_readers) == 0);
- read_lock(&eb->lock);
- atomic_inc(&eb->spinning_readers);
- /* atomic_dec_and_test implies a barrier */
- if (atomic_dec_and_test(&eb->blocking_readers))
- cond_wake_up_nomb(&eb->read_lock_wq);
- }
+ BUG_ON(atomic_read(&eb->blocking_writers) != 1);
+ write_lock(&eb->lock);
+ WARN_ON(atomic_read(&eb->spinning_writers));
+ atomic_inc(&eb->spinning_writers);
+ /* atomic_dec_and_test implies a barrier */
+ if (atomic_dec_and_test(&eb->blocking_writers))
+ cond_wake_up_nomb(&eb->write_lock_wq);
}
/*