[XFS] Fix up sparse warnings.

These are mostly locking annotations, marking things static, casts where
needed and declaring stuff in header files.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30002a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/fs/xfs/xfs_mru_cache.c b/fs/xfs/xfs_mru_cache.c
index 012209eda35d..a0b2c0a2589a 100644
--- a/fs/xfs/xfs_mru_cache.c
+++ b/fs/xfs/xfs_mru_cache.c
@@ -225,10 +225,14 @@ _xfs_mru_cache_list_insert(
  * list need to be deleted.  For each element this involves removing it from the
  * data store, removing it from the reap list, calling the client's free
  * function and deleting the element from the element zone.
+ *
+ * We get called holding the mru->lock, which we drop and then reacquire.
+ * Sparse need special help with this to tell it we know what we are doing.
  */
 STATIC void
 _xfs_mru_cache_clear_reap_list(
-        xfs_mru_cache_t         *mru)
+        xfs_mru_cache_t         *mru) __releases(mru->lock) __acquires(mru->lock)
+
 {
         xfs_mru_cache_elem_t    *elem, *next;
         struct list_head        tmp;
@@ -528,6 +532,10 @@ xfs_mru_cache_delete(
  *
  * If the element isn't found, this function returns NULL and the spinlock is
  * released.  xfs_mru_cache_done() should NOT be called when this occurs.
+ *
+ * Because sparse isn't smart enough to know about conditional lock return
+ * status, we need to help it get it right by annotating the path that does
+ * not release the lock.
  */
 void *
 xfs_mru_cache_lookup(
@@ -545,8 +553,8 @@ xfs_mru_cache_lookup(
         if (elem) {
                 list_del(&elem->list_node);
                 _xfs_mru_cache_list_insert(mru, elem);
-        }
-        else
+                __release(mru_lock); /* help sparse not be stupid */
+        } else
                 spin_unlock(&mru->lock);
 
         return elem ? elem->value : NULL;
@@ -575,6 +583,8 @@ xfs_mru_cache_peek(
         elem = radix_tree_lookup(&mru->store, key);
         if (!elem)
                 spin_unlock(&mru->lock);
+        else
+                __release(mru_lock); /* help sparse not be stupid */
 
         return elem ? elem->value : NULL;
 }
@@ -586,7 +596,7 @@ xfs_mru_cache_peek(
  */
 void
 xfs_mru_cache_done(
-        xfs_mru_cache_t *mru)
+        xfs_mru_cache_t *mru) __releases(mru->lock)
 {
         spin_unlock(&mru->lock);
 }