[XFS] replace the XFS buf iodone semaphore with a completion

The xfs_buf_t b_iodonesema is really just a semaphore that wants to be a
completion. Change it to a completion and remove the last user of the
sema_t from XFS.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31815a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

4 files changed, 7 insertions, 7 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index a01daa7b5922..a0072d9315a9 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -253,7 +253,7 @@ _xfs_buf_initialize(
 
         memset(bp, 0, sizeof(xfs_buf_t));
         atomic_set(&bp->b_hold, 1);
-        init_MUTEX_LOCKED(&bp->b_iodonesema);
+        init_completion(&bp->b_iowait);
         INIT_LIST_HEAD(&bp->b_list);
         INIT_LIST_HEAD(&bp->b_hash_list);
         init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */
@@ -1033,7 +1033,7 @@ xfs_buf_ioend(
                         xfs_buf_iodone_work(&bp->b_iodone_work);
                 }
         } else {
-                up(&bp->b_iodonesema);
+                complete(&bp->b_iowait);
         }
 }
 
@@ -1271,7 +1271,7 @@ xfs_buf_iowait(
         XB_TRACE(bp, "iowait", 0);
         if (atomic_read(&bp->b_io_remaining))
                 blk_run_address_space(bp->b_target->bt_mapping);
-        down(&bp->b_iodonesema);
+        wait_for_completion(&bp->b_iowait);
         XB_TRACE(bp, "iowaited", (long)bp->b_error);
         return bp->b_error;
 }
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 29d1d4adc078..fe0109956656 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -157,7 +157,7 @@ typedef struct xfs_buf {
         xfs_buf_iodone_t        b_iodone;       /* I/O completion function */
         xfs_buf_relse_t         b_relse;        /* releasing function */
         xfs_buf_bdstrat_t       b_strat;        /* pre-write function */
-        struct semaphore        b_iodonesema;   /* Semaphore for I/O waiters */
+        struct completion       b_iowait;       /* queue for I/O waiters */
         void                    *b_fspriv;
         void                    *b_fspriv2;
         void                    *b_fspriv3;
@@ -352,7 +352,7 @@ extern void xfs_buf_trace(xfs_buf_t *, char *, void *, void *);
 #define XFS_BUF_CPSEMA(bp)      (xfs_buf_cond_lock(bp) == 0)
 #define XFS_BUF_VSEMA(bp)       xfs_buf_unlock(bp)
 #define XFS_BUF_PSEMA(bp,x)     xfs_buf_lock(bp)
-#define XFS_BUF_V_IODONESEMA(bp) up(&bp->b_iodonesema);
+#define XFS_BUF_FINISH_IOWAIT(bp)       complete(&bp->b_iowait);
 
 #define XFS_BUF_SET_TARGET(bp, target)  ((bp)->b_target = (target))
 #define XFS_BUF_TARGET(bp)              ((bp)->b_target)
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index d86ca2c03a70..215c36dee324 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -1056,7 +1056,7 @@ xfs_buf_iodone_callbacks(
                            anyway. */
                         XFS_BUF_SET_BRELSE_FUNC(bp,xfs_buf_error_relse);
                         XFS_BUF_DONE(bp);
-                        XFS_BUF_V_IODONESEMA(bp);
+                        XFS_BUF_FINISH_IOWAIT(bp);
                 }
                 return;
         }
diff --git a/fs/xfs/xfs_rw.c b/fs/xfs/xfs_rw.c
index b0f31c09a76d..3a82576dde9a 100644
--- a/fs/xfs/xfs_rw.c
+++ b/fs/xfs/xfs_rw.c
@@ -314,7 +314,7 @@ xfs_bioerror_relse(
                  * ASYNC buffers.
                  */
                 XFS_BUF_ERROR(bp, EIO);
-                XFS_BUF_V_IODONESEMA(bp);
+                XFS_BUF_FINISH_IOWAIT(bp);
         } else {
                 xfs_buf_relse(bp);
         }