[XFS] Current usage of buftarg flags is incorrect.

The {test,set,clear}_bit() operations take a bit index for the bit to
operate on. The XBT_* flags are defined as bit fields which is incorrect,
not to mention the way the bit fields are enumerated is broken too. This
was only working by chance.

Fix the definitions of the flags and make the code using them use the
{test,set,clear}_bit() operations correctly.

SGI-PV: 958639
SGI-Modid: xfs-linux-melb:xfs-kern:27565a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

2 files changed, 9 insertions, 10 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 946b00bf3841..168eecd8127e 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1687,14 +1687,15 @@ STATIC int
 xfs_buf_delwri_split(
         xfs_buftarg_t   *target,
         struct list_head *list,
-        unsigned long   age,
-        int             flags)
+        unsigned long   age)
 {
         xfs_buf_t       *bp, *n;
         struct list_head *dwq = &target->bt_delwrite_queue;
         spinlock_t      *dwlk = &target->bt_delwrite_lock;
         int             skipped = 0;
+        int             force;
 
+        force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags);
         INIT_LIST_HEAD(list);
         spin_lock(dwlk);
         list_for_each_entry_safe(bp, n, dwq, b_list) {
@@ -1702,7 +1703,7 @@ xfs_buf_delwri_split(
                 ASSERT(bp->b_flags & XBF_DELWRI);
 
                 if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) {
-                        if (!(flags & XBT_FORCE_FLUSH) &&
+                        if (!force &&
                             time_before(jiffies, bp->b_queuetime + age)) {
                                 xfs_buf_unlock(bp);
                                 break;
@@ -1744,9 +1745,7 @@ xfsbufd(
                         xfs_buf_timer_centisecs * msecs_to_jiffies(10));
 
                 xfs_buf_delwri_split(target, &tmp,
-                                xfs_buf_age_centisecs * msecs_to_jiffies(10),
-                                test_bit(XBT_FORCE_FLUSH, &target->bt_flags)
-                                                ? XBT_FORCE_FLUSH : 0);
+                                xfs_buf_age_centisecs * msecs_to_jiffies(10));
 
                 count = 0;
                 while (!list_empty(&tmp)) {
@@ -1763,7 +1762,6 @@ xfsbufd(
                 if (count)
                         blk_run_address_space(target->bt_mapping);
 
-                clear_bit(XBT_FORCE_FLUSH, &target->bt_flags);
         } while (!kthread_should_stop());
 
         return 0;
@@ -1786,7 +1784,8 @@ xfs_flush_buftarg(
         xfs_buf_runall_queues(xfsdatad_workqueue);
         xfs_buf_runall_queues(xfslogd_workqueue);
 
-        pincount = xfs_buf_delwri_split(target, &tmp, 0, XBT_FORCE_FLUSH);
+        set_bit(XBT_FORCE_FLUSH, &target->bt_flags);
+        pincount = xfs_buf_delwri_split(target, &tmp, 0);
 
         /*
          * Dropped the delayed write list lock, now walk the temporary list
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 9dd235cb0107..9e8ef8fef39f 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -69,8 +69,8 @@ typedef enum {
 } xfs_buf_flags_t;
 
 typedef enum {
-        XBT_FORCE_SLEEP = (0 << 1),
-        XBT_FORCE_FLUSH = (1 << 1),
+        XBT_FORCE_SLEEP = 0,
+        XBT_FORCE_FLUSH = 1,
 } xfs_buftarg_flags_t;
 
 typedef struct xfs_bufhash {