2 files changed, 28 insertions, 15 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 62fa39276a24..07b77b73b024 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -97,12 +97,16 @@ static inline void
 xfs_buf_ioacct_inc(
         struct xfs_buf  *bp)
 {
-        if (bp->b_flags & (XBF_NO_IOACCT|_XBF_IN_FLIGHT))
+        if (bp->b_flags & XBF_NO_IOACCT)
                 return;
 
         ASSERT(bp->b_flags & XBF_ASYNC);
-        bp->b_flags |= _XBF_IN_FLIGHT;
-        percpu_counter_inc(&bp->b_target->bt_io_count);
+        spin_lock(&bp->b_lock);
+        if (!(bp->b_state & XFS_BSTATE_IN_FLIGHT)) {
+                bp->b_state |= XFS_BSTATE_IN_FLIGHT;
+                percpu_counter_inc(&bp->b_target->bt_io_count);
+        }
+        spin_unlock(&bp->b_lock);
 }
 
 /*
@@ -110,14 +114,24 @@ xfs_buf_ioacct_inc(
  * freed and unaccount from the buftarg.
  */
 static inline void
-xfs_buf_ioacct_dec(
+__xfs_buf_ioacct_dec(
         struct xfs_buf  *bp)
 {
-        if (!(bp->b_flags & _XBF_IN_FLIGHT))
-                return;
+        ASSERT(spin_is_locked(&bp->b_lock));
 
-        bp->b_flags &= ~_XBF_IN_FLIGHT;
-        percpu_counter_dec(&bp->b_target->bt_io_count);
+        if (bp->b_state & XFS_BSTATE_IN_FLIGHT) {
+                bp->b_state &= ~XFS_BSTATE_IN_FLIGHT;
+                percpu_counter_dec(&bp->b_target->bt_io_count);
+        }
+}
+
+static inline void
+xfs_buf_ioacct_dec(
+        struct xfs_buf  *bp)
+{
+        spin_lock(&bp->b_lock);
+        __xfs_buf_ioacct_dec(bp);
+        spin_unlock(&bp->b_lock);
 }
 
 /*
@@ -149,9 +163,9 @@ xfs_buf_stale(
          * unaccounted (released to LRU) before that occurs. Drop in-flight
          * status now to preserve accounting consistency.
          */
-        xfs_buf_ioacct_dec(bp);
-
         spin_lock(&bp->b_lock);
+        __xfs_buf_ioacct_dec(bp);
+
         atomic_set(&bp->b_lru_ref, 0);
         if (!(bp->b_state & XFS_BSTATE_DISPOSE) &&
             (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru)))
@@ -979,12 +993,12 @@ xfs_buf_rele(
                  * ensures the decrement occurs only once per-buf.
                  */
                 if ((atomic_read(&bp->b_hold) == 1) && !list_empty(&bp->b_lru))
-                        xfs_buf_ioacct_dec(bp);
+                        __xfs_buf_ioacct_dec(bp);
                 goto out_unlock;
         }
 
         /* the last reference has been dropped ... */
-        xfs_buf_ioacct_dec(bp);
+        __xfs_buf_ioacct_dec(bp);
         if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) {
                 /*
                  * If the buffer is added to the LRU take a new reference to the
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 8d1d44f87ce9..1508121f29f2 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -63,7 +63,6 @@ typedef enum {
 #define _XBF_KMEM        (1 << 21)/* backed by heap memory */
 #define _XBF_DELWRI_Q    (1 << 22)/* buffer on a delwri queue */
 #define _XBF_COMPOUND    (1 << 23)/* compound buffer */
-#define _XBF_IN_FLIGHT   (1 << 25) /* I/O in flight, for accounting purposes */
 
 typedef unsigned int xfs_buf_flags_t;
 
@@ -84,14 +83,14 @@ typedef unsigned int xfs_buf_flags_t;
         { _XBF_PAGES,           "PAGES" }, \
         { _XBF_KMEM,            "KMEM" }, \
         { _XBF_DELWRI_Q,        "DELWRI_Q" }, \
-        { _XBF_COMPOUND,        "COMPOUND" }, \
-        { _XBF_IN_FLIGHT,       "IN_FLIGHT" }
+        { _XBF_COMPOUND,        "COMPOUND" }
 
 
 /*
  * Internal state flags.
  */
 #define XFS_BSTATE_DISPOSE       (1 << 0)       /* buffer being discarded */
+#define XFS_BSTATE_IN_FLIGHT     (1 << 1)       /* I/O in flight */
 
 /*
  * The xfs_buftarg contains 2 notions of "sector size" -