[PATCH 4/6] Replace the XFS buf iodone semaphore with a completion

Dave Chinner
2008-06-26T04:40:58Z

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.

Signed-off-by: Dave Chinner <david@fromorbit.com>
---
fs/xfs/linux-2.6/xfs_buf.c | 6 +++---
fs/xfs/linux-2.6/xfs_buf.h | 4 ++--
fs/xfs/xfs_buf_item.c | 2 +-
fs/xfs/xfs_rw.c | 2 +-
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 9cc8f02..9438c90 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 */
@@ -1037,7 +1037,7 @@ xfs_buf_ioend(
xfs_buf_iodone_work(&bp->b_iodone_work);
}
} else {
- up(&bp->b_iodonesema);
+ complete(&bp->b_iowait);
}
}

@@ -1275,7 +1275,7 @@ 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 29d1d4a..fe01099 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 d86ca2c..215c36d 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 b0f31c0..3a82576 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);
}
--
1.5.5.4